Release 0.3.0

to the left side of the screen. So by adding a constant offset,
we can avoid having possible links that are partly out of the view
just after starting the program

.gitignore

@@ -1,2 +1,3 @@
+/.flatpak-builder
 /.vscode
 /target

Cargo.lock

@@ -1,10 +1,12 @@
 # This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
+version = 3
+
 [[package]]
 name = "aho-corasick"
-version = "0.7.18"
+version = "0.7.15"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1e37cfd5e7657ada45f742d6e99ca5788580b5c529dc78faf11ece6dc702656f"
+checksum = "7404febffaa47dac81aa44dba71523c9d069b1bdc50a77db41195149e17f68e5"
 dependencies = [
  "memchr",
 ]
@@ -20,9 +22,9 @@ dependencies = [
 
 [[package]]
 name = "anyhow"
-version = "1.0.40"
+version = "1.0.42"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "28b2cd92db5cbd74e8e5028f7e27dd7aa3090e89e4f2a197cc7c8dfb69c7063b"
+checksum = "595d3cfa7a60d4555cb5067b99f07142a08ea778de5cf993f7b75c7d8fabc486"
 
 [[package]]
 name = "arrayvec"
@@ -49,15 +51,15 @@ checksum = "cdb031dd78e28731d87d56cc8ffef4a8f36ca26c38fe2de700543e627f8a464a"
 
 [[package]]
 name = "bindgen"
-version = "0.58.1"
+version = "0.59.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0f8523b410d7187a43085e7e064416ea32ded16bd0a4e6fc025e21616d01258f"
+checksum = "453c49e5950bb0eb63bb3df640e31618846c89d5b7faa54040d76e98e0134375"
 dependencies = [
  "bitflags",
  "cexpr",
  "clang-sys",
  "clap",
- "env_logger",
+ "env_logger 0.8.4",
  "lazy_static",
  "lazycell",
  "log",
@@ -90,8 +92,9 @@ dependencies = [
 
 [[package]]
 name = "cairo-rs"
-version = "0.13.0"
+version = "0.14.1"
-source = "git+https://github.com/gtk-rs/gtk-rs#74a02cdd2855a387ebbe700eb509029c8e338d19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a408c13bbc04c3337b94194c1a4d04067097439b79dbc1dcbceba299d828b9ea"
 dependencies = [
  "bitflags",
  "cairo-sys-rs",
@@ -102,8 +105,9 @@ dependencies = [
 
 [[package]]
 name = "cairo-sys-rs"
-version = "0.13.0"
+version = "0.14.0"
-source = "git+https://github.com/gtk-rs/gtk-rs#74a02cdd2855a387ebbe700eb509029c8e338d19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d7c9c3928781e8a017ece15eace05230f04b647457d170d2d9641c94a444ff80"
 dependencies = [
  "glib-sys",
  "libc",
@@ -112,24 +116,24 @@ dependencies = [
 
 [[package]]
 name = "cc"
-version = "1.0.67"
+version = "1.0.69"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e3c69b077ad434294d3ce9f1f6143a2a4b89a8a2d54ef813d85003a4fd1137fd"
+checksum = "e70cc2f62c6ce1868963827bd677764c62d07c3d9a3e1fb1177ee1a9ab199eb2"
 
 [[package]]
 name = "cexpr"
-version = "0.4.0"
+version = "0.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f4aedb84272dbe89af497cf81375129abda4fc0a9e7c5d317498c15cc30c0d27"
+checksum = "db507a7679252d2276ed0dd8113c6875ec56d3089f9225b2b42c30cc1f8e5c89"
 dependencies = [
- "nom 5.1.2",
+ "nom",
 ]
 
 [[package]]
 name = "cfg-expr"
-version = "0.7.4"
+version = "0.8.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "30aa9e2ffbb838c6b451db14f3cd8e63ed622bf859f9956bc93845a10fafc26a"
+checksum = "b412e83326147c2bb881f8b40edfbf9905b9b8abaebd0e47ca190ba62fda8f0e"
 dependencies = [
  "smallvec",
 ]
@@ -186,9 +190,22 @@ checksum = "e78d4f1cc4ae33bbfc157ed5d5a5ef3bc29227303d595861deb238fcec4e9457"
 
 [[package]]
 name = "env_logger"
-version = "0.8.3"
+version = "0.8.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "17392a012ea30ef05a610aa97dfb49496e71c9f676b27879922ea5bdf60d9d3f"
+checksum = "a19187fea3ac7e84da7dacf48de0c45d63c6a76f9490dae389aead16c243fce3"
+dependencies = [
+ "atty",
+ "humantime",
+ "log",
+ "regex",
+ "termcolor",
+]
+
+[[package]]
+name = "env_logger"
+version = "0.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0b2cf0344971ee6c64c31be0d530793fba457d322dfec2810c453d0ef228f9c3"
 dependencies = [
  "atty",
  "humantime",
@@ -220,9 +237,9 @@ dependencies = [
 
 [[package]]
 name = "field-offset"
-version = "0.3.3"
+version = "0.3.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cf539fba70056b50f40a22e0da30639518a12ee18c35807858a63b158cb6dde7"
+checksum = "1e1c54951450cbd39f3dbcf1005ac413b49487dabf18a720ad2383eccfeffb92"
 dependencies = [
  "memoffset",
  "rustc_version",
@@ -236,24 +253,24 @@ checksum = "fed34cd105917e91daa4da6b3728c47b068749d6a62c59811f06ed2ac71d9da7"
 
 [[package]]
 name = "futures-channel"
-version = "0.3.14"
+version = "0.3.16"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ce79c6a52a299137a6013061e0cf0e688fce5d7f1bc60125f520912fdb29ec25"
+checksum = "74ed2411805f6e4e3d9bc904c95d5d423b89b3b25dc0250aa74729de20629ff9"
 dependencies = [
  "futures-core",
 ]
 
 [[package]]
 name = "futures-core"
-version = "0.3.14"
+version = "0.3.16"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "098cd1c6dda6ca01650f1a37a794245eb73181d0d4d4e955e2f3c37db7af1815"
+checksum = "af51b1b4a7fdff033703db39de8802c673eb91855f2e0d47dcf3bf2c0ef01f99"
 
 [[package]]
 name = "futures-executor"
-version = "0.3.14"
+version = "0.3.16"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "10f6cb7042eda00f0049b1d2080aa4b93442997ee507eb3828e8bd7577f94c9d"
+checksum = "4d0d535a57b87e1ae31437b892713aee90cd2d7b0ee48727cd11fc72ef54761c"
 dependencies = [
  "futures-core",
  "futures-task",
@@ -262,22 +279,23 @@ dependencies = [
 
 [[package]]
 name = "futures-io"
-version = "0.3.14"
+version = "0.3.16"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "365a1a1fb30ea1c03a830fdb2158f5236833ac81fa0ad12fe35b29cddc35cb04"
+checksum = "0b0e06c393068f3a6ef246c75cdca793d6a46347e75286933e5e75fd2fd11582"
 
 [[package]]
 name = "futures-task"
-version = "0.3.14"
+version = "0.3.16"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ba7aa51095076f3ba6d9a1f702f74bd05ec65f555d70d2033d55ba8d69f581bc"
+checksum = "bbe54a98670017f3be909561f6ad13e810d9a51f3f061b902062ca3da80799f2"
 
 [[package]]
 name = "futures-util"
-version = "0.3.14"
+version = "0.3.16"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3c144ad54d60f23927f0a6b6d816e4271278b64f005ad65e4e35291d2de9c025"
+checksum = "67eb846bfd58e44a8481a00049e82c43e0ccb5d61f8dc071057cb19249dd4d78"
 dependencies = [
+ "autocfg",
  "futures-core",
  "futures-task",
  "pin-project-lite",
@@ -293,8 +311,9 @@ checksum = "8f5f3913fa0bfe7ee1fd8248b6b9f42a5af4b9d65ec2dd2c3c26132b950ecfc2"
 
 [[package]]
 name = "gdk-pixbuf"
-version = "0.13.0"
+version = "0.14.0"
-source = "git+https://github.com/gtk-rs/gtk-rs#74a02cdd2855a387ebbe700eb509029c8e338d19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "534192cb8f01daeb8fab2c8d4baa8f9aae5b7a39130525779f5c2608e235b10f"
 dependencies = [
  "gdk-pixbuf-sys",
  "gio",
@@ -304,8 +323,9 @@ dependencies = [
 
 [[package]]
 name = "gdk-pixbuf-sys"
-version = "0.13.0"
+version = "0.14.0"
-source = "git+https://github.com/gtk-rs/gtk-rs#74a02cdd2855a387ebbe700eb509029c8e338d19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f097c0704201fbc8f69c1762dc58c6947c8bb188b8ed0bc7e65259f1894fe590"
 dependencies = [
  "gio-sys",
  "glib-sys",
@@ -316,8 +336,9 @@ dependencies = [
 
 [[package]]
 name = "gdk4"
-version = "0.1.0"
+version = "0.2.0"
-source = "git+https://github.com/gtk-rs/gtk4-rs/#e90c5752ba5229f874e912e84bc83739003434ed"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8ce41092cc569129a0afa34926e6dd1cf8411e25652d87febdea36859f7ff7ba"
 dependencies = [
  "bitflags",
  "cairo-rs",
@@ -331,8 +352,9 @@ dependencies = [
 
 [[package]]
 name = "gdk4-sys"
-version = "0.1.0"
+version = "0.2.0"
-source = "git+https://github.com/gtk-rs/gtk4-rs/#e90c5752ba5229f874e912e84bc83739003434ed"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ce39c71861b5bcde319fd4711a74e1bd6f4f474911170d51096597fef0b56011"
 dependencies = [
  "cairo-sys-rs",
  "gdk-pixbuf-sys",
@@ -347,8 +369,9 @@ dependencies = [
 
 [[package]]
 name = "gio"
-version = "0.13.0"
+version = "0.14.0"
-source = "git+https://github.com/gtk-rs/gtk-rs#74a02cdd2855a387ebbe700eb509029c8e338d19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "86c6823b39d46d22cac2466de261f28d7f049ebc18f7b35296a42c7ed8a88325"
 dependencies = [
  "bitflags",
  "futures-channel",
@@ -363,8 +386,9 @@ dependencies = [
 
 [[package]]
 name = "gio-sys"
-version = "0.13.0"
+version = "0.14.0"
-source = "git+https://github.com/gtk-rs/gtk-rs#74a02cdd2855a387ebbe700eb509029c8e338d19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c0a41df66e57fcc287c4bcf74fc26b884f31901ea9792ec75607289b456f48fa"
 dependencies = [
  "glib-sys",
  "gobject-sys",
@@ -375,8 +399,9 @@ dependencies = [
 
 [[package]]
 name = "glib"
-version = "0.13.0"
+version = "0.14.2"
-source = "git+https://github.com/gtk-rs/gtk-rs#74a02cdd2855a387ebbe700eb509029c8e338d19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dbecad7a3a898ee749d491ce2ae0decb0bce9e736f9747bc49159b1cea5d37f4"
 dependencies = [
  "bitflags",
  "futures-channel",
@@ -393,8 +418,9 @@ dependencies = [
 
 [[package]]
 name = "glib-macros"
-version = "0.13.0"
+version = "0.14.1"
-source = "git+https://github.com/gtk-rs/gtk-rs#74a02cdd2855a387ebbe700eb509029c8e338d19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2aad66361f66796bfc73f530c51ef123970eb895ffba991a234fcf7bea89e518"
 dependencies = [
  "anyhow",
  "heck",
@@ -407,8 +433,9 @@ dependencies = [
 
 [[package]]
 name = "glib-sys"
-version = "0.13.0"
+version = "0.14.0"
-source = "git+https://github.com/gtk-rs/gtk-rs#74a02cdd2855a387ebbe700eb509029c8e338d19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1c1d60554a212445e2a858e42a0e48cece1bd57b311a19a9468f70376cf554ae"
 dependencies = [
  "libc",
  "system-deps",
@@ -422,8 +449,9 @@ checksum = "9b919933a397b79c37e33b77bb2aa3dc8eb6e165ad809e58ff75bc7db2e34574"
 
 [[package]]
 name = "gobject-sys"
-version = "0.13.0"
+version = "0.14.0"
-source = "git+https://github.com/gtk-rs/gtk-rs#74a02cdd2855a387ebbe700eb509029c8e338d19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "aa92cae29759dae34ab5921d73fff5ad54b3d794ab842c117e36cafc7994c3f5"
 dependencies = [
  "glib-sys",
  "libc",
@@ -432,8 +460,9 @@ dependencies = [
 
 [[package]]
 name = "graphene-rs"
-version = "0.13.0"
+version = "0.14.0"
-source = "git+https://github.com/gtk-rs/gtk-rs#74a02cdd2855a387ebbe700eb509029c8e338d19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f1460a39f06e491e6112f27e71e51435c833ba370723224dd1743dfd1f201f19"
 dependencies = [
  "glib",
  "graphene-sys",
@@ -442,8 +471,9 @@ dependencies = [
 
 [[package]]
 name = "graphene-sys"
-version = "0.13.0"
+version = "0.14.0"
-source = "git+https://github.com/gtk-rs/gtk-rs#74a02cdd2855a387ebbe700eb509029c8e338d19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e7d23fb7a9547e5f072a7e0cd49cd648fedeb786d122b106217511980cbb8962"
 dependencies = [
  "glib-sys",
  "libc",
@@ -453,8 +483,9 @@ dependencies = [
 
 [[package]]
 name = "gsk4"
-version = "0.1.0"
+version = "0.2.0"
-source = "git+https://github.com/gtk-rs/gtk4-rs/#e90c5752ba5229f874e912e84bc83739003434ed"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "64932b730eaad3340378a03d633616eeed6d6705b59b81c9f579c88be8932475"
 dependencies = [
  "bitflags",
  "cairo-rs",
@@ -468,8 +499,9 @@ dependencies = [
 
 [[package]]
 name = "gsk4-sys"
-version = "0.1.0"
+version = "0.2.0"
-source = "git+https://github.com/gtk-rs/gtk4-rs/#e90c5752ba5229f874e912e84bc83739003434ed"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "685ffc776bedd91d68f47b41239525778b669432889721d7050d045270549b9a"
 dependencies = [
  "cairo-sys-rs",
  "gdk4-sys",
@@ -483,8 +515,9 @@ dependencies = [
 
 [[package]]
 name = "gtk4"
-version = "0.1.0"
+version = "0.2.0"
-source = "git+https://github.com/gtk-rs/gtk4-rs/#e90c5752ba5229f874e912e84bc83739003434ed"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c49e0311dac847a8ebc05e31f5c44c596314ee3b16c5f638ccfe24086d24bf1b"
 dependencies = [
  "bitflags",
  "cairo-rs",
@@ -505,8 +538,9 @@ dependencies = [
 
 [[package]]
 name = "gtk4-macros"
-version = "0.1.0"
+version = "0.2.0"
-source = "git+https://github.com/gtk-rs/gtk4-rs/#e90c5752ba5229f874e912e84bc83739003434ed"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bbe4b77996bcf1ef20208c00043edda854ca2091b4be5e6a7c367f0f3846fa67"
 dependencies = [
  "anyhow",
  "heck",
@@ -520,8 +554,9 @@ dependencies = [
 
 [[package]]
 name = "gtk4-sys"
-version = "0.1.0"
+version = "0.2.0"
-source = "git+https://github.com/gtk-rs/gtk4-rs/#e90c5752ba5229f874e912e84bc83739003434ed"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3737e91619cf4257d8a07834f7a2c035d4daeaf9ad8e3958e56b2c411dbdca18"
 dependencies = [
  "cairo-sys-rs",
  "gdk-pixbuf-sys",
@@ -538,18 +573,18 @@ dependencies = [
 
 [[package]]
 name = "heck"
-version = "0.3.2"
+version = "0.3.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "87cbf45460356b7deeb5e3415b5563308c0a9b057c85e12b06ad551f98d0a6ac"
+checksum = "6d621efb26863f0e9924c6ac577e8275e5e6b77455db64ffa6c65c904e9e132c"
 dependencies = [
  "unicode-segmentation",
 ]
 
 [[package]]
 name = "helvum"
-version = "0.2.0"
+version = "0.3.0"
 dependencies = [
- "env_logger",
+ "env_logger 0.9.0",
  "gtk4",
  "log",
  "once_cell",
@@ -558,9 +593,9 @@ dependencies = [
 
 [[package]]
 name = "hermit-abi"
-version = "0.1.18"
+version = "0.1.19"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "322f4de77956e22ed0e5032c359a0f1273f1f7f0d79bfa3b8ffbc730d7fbcc5c"
+checksum = "62b467343b94ba476dcb2500d242dadbb39557df889310ac77c5d99100aaac33"
 dependencies = [
  "libc",
 ]
@@ -573,9 +608,9 @@ checksum = "9a3a5bfb195931eeb336b2a7b4d761daec841b97f947d34394601737a7bba5e4"
 
 [[package]]
 name = "itertools"
-version = "0.10.0"
+version = "0.10.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "37d572918e350e82412fe766d24b15e6682fb2ed2bbe018280caa810397cb319"
+checksum = "69ddb889f9d0d08a67338271fa9b62996bc788c7796a5c18cf057420aaed5eaf"
 dependencies = [
  "either",
 ]
@@ -607,9 +642,9 @@ dependencies = [
 
 [[package]]
 name = "libc"
-version = "0.2.94"
+version = "0.2.98"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "18794a8ad5b29321f790b55d93dfba91e125cb1a9edbd4f8e3150acc771c1a5e"
+checksum = "320cfe77175da3a483efed4bc0adc1968ca050b098ce4f2f1c13a56626128790"
 
 [[package]]
 name = "libloading"
@@ -623,8 +658,9 @@ dependencies = [
 
 [[package]]
 name = "libspa"
-version = "0.3.0"
+version = "0.4.1"
-source = "git+https://gitlab.freedesktop.org/pipewire/pipewire-rs?branch=main#f8dc21b0f85f391201e7c6346b121fbd21c02836"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "aeb373e8b03740369c5fe48a557c6408b6898982d57e17940de144375d472743"
 dependencies = [
  "bitflags",
  "cc",
@@ -632,14 +668,15 @@ dependencies = [
  "errno",
  "libc",
  "libspa-sys",
- "nom 6.1.2",
+ "nom",
  "system-deps",
 ]
 
 [[package]]
 name = "libspa-sys"
-version = "0.3.0"
+version = "0.4.1"
-source = "git+https://gitlab.freedesktop.org/pipewire/pipewire-rs?branch=main#f8dc21b0f85f391201e7c6346b121fbd21c02836"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d301a2fc2fed0a97c13836408a4d98f419af0c2695ecf74e634a214c17beefa6"
 dependencies = [
  "bindgen",
  "system-deps",
@@ -656,15 +693,15 @@ dependencies = [
 
 [[package]]
 name = "memchr"
-version = "2.4.0"
+version = "2.3.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b16bd47d9e329435e309c58469fe0791c2d0d1ba96ec0954152a5ae2b04387dc"
+checksum = "0ee1c47aaa256ecabcaea351eae4a9b01ef39ed810004e298d2511ed284b1525"
 
 [[package]]
 name = "memoffset"
-version = "0.6.3"
+version = "0.6.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f83fb6581e8ed1f85fd45c116db8405483899489e38406156c25eb743554361d"
+checksum = "59accc507f1338036a0477ef61afdae33cde60840f4dfe481319ce3ad116ddf9"
 dependencies = [
  "autocfg",
 ]
@@ -684,19 +721,9 @@ dependencies = [
 
 [[package]]
 name = "nom"
-version = "5.1.2"
+version = "6.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ffb4262d26ed83a1c0a33a38fe2bb15797329c85770da05e6b828ddb782627af"
+checksum = "9c5c51b9083a3c620fa67a2a635d1ce7d95b897e957d6b28ff9a5da960a103a6"
-dependencies = [
- "memchr",
- "version_check",
-]
-
-[[package]]
-name = "nom"
-version = "6.1.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e7413f999671bd4745a7b624bd370a569fb6bc574b23c83a3c5ed2e453f3d5e2"
 dependencies = [
  "bitvec",
  "funty",
@@ -707,14 +734,15 @@ dependencies = [
 
 [[package]]
 name = "once_cell"
-version = "1.7.2"
+version = "1.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "af8b08b04175473088b46763e51ee54da5f9a164bc162f615b91bc179dbf15a3"
+checksum = "692fcb63b64b1758029e0a96ee63e049ce8c5948587f2f7208df04625e5f6b56"
 
 [[package]]
 name = "pango"
-version = "0.13.0"
+version = "0.14.0"
-source = "git+https://github.com/gtk-rs/gtk-rs#74a02cdd2855a387ebbe700eb509029c8e338d19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "415823a4fb9f1789785cd6e2d2413816f2ecff92380382969aaca9c400e13a19"
 dependencies = [
  "bitflags",
  "glib",
@@ -725,8 +753,9 @@ dependencies = [
 
 [[package]]
 name = "pango-sys"
-version = "0.13.0"
+version = "0.14.0"
-source = "git+https://github.com/gtk-rs/gtk-rs#74a02cdd2855a387ebbe700eb509029c8e338d19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2367099ca5e761546ba1d501955079f097caa186bb53ce0f718dca99ac1942fe"
 dependencies = [
  "glib-sys",
  "gobject-sys",
@@ -751,9 +780,9 @@ dependencies = [
 
 [[package]]
 name = "pin-project-lite"
-version = "0.2.6"
+version = "0.2.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dc0e1f259c92177c30a4c9d177246edd0a3568b25756a977d0632cf8fa37e905"
+checksum = "8d31d11c69a6b52a174b42bdc0c30e5e11670f90788b2c471c31c1d17d449443"
 
 [[package]]
 name = "pin-utils"
@@ -763,8 +792,9 @@ checksum = "8b870d8c151b6f2fb93e84a13146138f05d02ed11c7e7c54f8826aaaf7c9f184"
 
 [[package]]
 name = "pipewire"
-version = "0.3.0"
+version = "0.4.1"
-source = "git+https://gitlab.freedesktop.org/pipewire/pipewire-rs?branch=main#f8dc21b0f85f391201e7c6346b121fbd21c02836"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5de050d879e7b8d9313429ec314b88b26fe48ba29a6ecc3bc8289d3673fee6c8"
 dependencies = [
  "anyhow",
  "bitflags",
@@ -780,8 +810,9 @@ dependencies = [
 
 [[package]]
 name = "pipewire-sys"
-version = "0.3.0"
+version = "0.4.1"
-source = "git+https://gitlab.freedesktop.org/pipewire/pipewire-rs?branch=main#f8dc21b0f85f391201e7c6346b121fbd21c02836"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9b4aa5ef9f3afef7dbb335106f69bd6bb541259e8796c693810cde20db1eb949"
 dependencies = [
  "bindgen",
  "libspa-sys",
@@ -830,9 +861,9 @@ dependencies = [
 
 [[package]]
 name = "proc-macro2"
-version = "1.0.26"
+version = "1.0.28"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a152013215dca273577e18d2bf00fa862b89b24169fb78c4c95aeb07992c9cec"
+checksum = "5c7ed8b8c7b886ea3ed7dde405212185f423ab44682667c8c6dd14aa1d9f6612"
 dependencies = [
  "unicode-xid",
 ]
@@ -854,9 +885,9 @@ checksum = "941ba9d78d8e2f7ce474c015eea4d9c6d25b6a3327f9832ee29a4de27f91bbb8"
 
 [[package]]
 name = "regex"
-version = "1.5.4"
+version = "1.4.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d07a8629359eb56f1e2fb1652bb04212c072a87ba68546a04065d525673ac461"
+checksum = "2a26af418b574bd56588335b3a3659a65725d4e636eb1016c2f9e3b38c7cc759"
 dependencies = [
  "aho-corasick",
  "memchr",
@@ -910,9 +941,9 @@ dependencies = [
 
 [[package]]
 name = "serde"
-version = "1.0.125"
+version = "1.0.127"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "558dc50e1a5a5fa7112ca2ce4effcb321b0300c0d4ccf0776a9f60cd89031171"
+checksum = "f03b9878abf6d14e6779d3f24f07b2cfa90352cfec4acc5aab8f1ac7f146fae8"
 
 [[package]]
 name = "shlex"
@@ -932,9 +963,9 @@ dependencies = [
 
 [[package]]
 name = "slab"
-version = "0.4.3"
+version = "0.4.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f173ac3d1a7e3b28003f40de0b5ce7fe2710f9b9dc3fc38664cebee46b3b6527"
+checksum = "c307a32c1c5c437f38c7fd45d753050587732ba8628319fbdf12a7e289ccc590"
 
 [[package]]
 name = "smallvec"
@@ -956,15 +987,15 @@ checksum = "8ea5119cdb4c55b55d432abb513a0429384878c15dde60cc77b1c99de1a95a6a"
 
 [[package]]
 name = "strum"
-version = "0.20.0"
+version = "0.21.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7318c509b5ba57f18533982607f24070a55d353e90d4cae30c467cdb2ad5ac5c"
+checksum = "aaf86bbcfd1fa9670b7a129f64fc0c9fcbbfe4f1bc4210e9e98fe71ffc12cde2"
 
 [[package]]
 name = "strum_macros"
-version = "0.20.1"
+version = "0.21.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ee8bc6b87a5112aeeab1f4a9f7ab634fe6cbefc4850006df31267f4cfb9e3149"
+checksum = "d06aaeeee809dbc59eb4556183dd927df67db1540de5be8d3ec0b6636358a5ec"
 dependencies = [
  "heck",
  "proc-macro2",
@@ -974,9 +1005,9 @@ dependencies = [
 
 [[package]]
 name = "syn"
-version = "1.0.72"
+version = "1.0.74"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a1e8cdbefb79a9a5a65e0db8b47b723ee907b7c7f8496c76a1770b5c310bab82"
+checksum = "1873d832550d4588c3dbc20f01361ab00bfe741048f71e3fecf145a7cc18b29c"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -985,9 +1016,9 @@ dependencies = [
 
 [[package]]
 name = "system-deps"
-version = "3.1.1"
+version = "3.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c248107ad7bc1ac07066a4d003cae9e9a7bc2e27d3418f7a9cdcdc8699dbea70"
+checksum = "480c269f870722b3b08d2f13053ce0c2ab722839f472863c3e2d61ff3a1c2fa6"
 dependencies = [
  "anyhow",
  "cfg-expr",
@@ -1027,18 +1058,18 @@ dependencies = [
 
 [[package]]
 name = "thiserror"
-version = "1.0.24"
+version = "1.0.26"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e0f4a65597094d4483ddaed134f409b2cb7c1beccf25201a9f73c719254fa98e"
+checksum = "93119e4feac1cbe6c798c34d3a53ea0026b0b1de6a120deef895137c0529bfe2"
 dependencies = [
  "thiserror-impl",
 ]
 
 [[package]]
 name = "thiserror-impl"
-version = "1.0.24"
+version = "1.0.26"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7765189610d8241a44529806d6fd1f2e0a08734313a35d5b3a556f92b381f3c0"
+checksum = "060d69a0afe7796bf42e9e2ff91f5ee691fb15c53d38b4b62a9a53eb23164745"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -1062,9 +1093,9 @@ checksum = "56dee185309b50d1f11bfedef0fe6d036842e3fb77413abef29f8f8d1c5d4c1c"
 
 [[package]]
 name = "unicode-segmentation"
-version = "1.7.1"
+version = "1.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bb0d2e7be6ae3a5fa87eed5fb451aff96f2573d2694942e40543ae0bbe19c796"
+checksum = "8895849a949e7845e06bd6dc1aa51731a103c42707010a5b591c0038fb73385b"
 
 [[package]]
 name = "unicode-width"

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "helvum"
-version = "0.2.0"
+version = "0.3.0"
 authors = ["Tom A. Wagner <tom.a.wagner@protonmail.com>"]
 edition = "2018"
 license = "GPL-3.0-only"
@@ -13,10 +13,10 @@ categories = ["gui", "multimedia"]
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-gtk = { git = "https://github.com/gtk-rs/gtk4-rs/", package = "gtk4" }
+pipewire = "0.4"
-pipewire = { git = "https://gitlab.freedesktop.org/pipewire/pipewire-rs", branch = "main" }
+gtk = { version = "0.2", package = "gtk4" }
 
 log = "0.4.11"
-env_logger = "0.8.2"
+env_logger = "0.9.0"
 
 once_cell = "1.7.2"

README.md

@@ -2,6 +2,9 @@ Helvum is a GTK-based patchbay for pipewire, inspired by the JACK tool [catia](h
 
 ![Screenshot](screenshot.png)
 
+[![Packaging status](https://repology.org/badge/vertical-allrepos/helvum.svg)](https://repology.org/project/helvum/versions)
+
+
 # Features planned
 
 - Volume control
@@ -9,11 +12,27 @@ Helvum is a GTK-based patchbay for pipewire, inspired by the JACK tool [catia](h
 
 More suggestions are welcome!
 
-# Distribution packages
-
-- ArchLinux: [aur/helvum-git](https://aur.archlinux.org/packages/helvum-git)
-
 # Building
+
+## Via flatpak (recommended)
+The recommended way to build is using flatpak, which will take care of all dependencies and avoid any problems that may come from different system configurations.
+
+First, install the required flatpak platform and SDK, if you dont have them already:
+```shell
+$ flatpak install org.gnome.{Platform,Sdk}//40 org.freedesktop.Sdk.Extension.rust-stable//20.08
+```
+
+To compile and install as a flatpak, run
+```shell
+$ flatpak-builder --install flatpak-build/ org.freedesktop.ryuukyu.Helvum.json
+```
+
+You can then run the app via
+```shell
+flatpak run org.freedesktop.ryuukyu.Helvum
+```
+
+## Manually
 For compilation, you will need:
 
 - An up-to-date rust toolchain
@@ -26,3 +45,7 @@ To compile, run
 
 in the repository root.
 The resulting binary will be at `target/release/helvum`.
+
+# License
+Helvum is distributed under the terms of the GPL3 license.
+See LICENSE for more information.

docs/architecture.md

@@ -14,41 +14,37 @@ Helvum uses an architecture with the components laid out like this:
 │ View │
 └────┬─┘
  Λ   ┆
- │<───── updates view
+ │<───── updates view                               ┌───────┐
- │   ┆
+ │   ┆                                              │ State │
- │   ┆<─ notifies of user input
+ │   ┆<─ notifies of user input                     └───────┘
- │   ┆    (using signals)
+ │   ┆      (using signals)                             Λ
- │   ┆
+ │   ┆                                                  │
- │   ┆
+ │   ┆                                                  │<─── updates/reads state
- │   V           notifies of remote changes
+ │   V           notifies of remote changes             │
-┌┴────────────┐         via messages          ┌───────────────────┐
+┌┴────────────┐         via messages          ┌─────────┴─────────┐
 │ Application │<╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┤     Seperate      │
 │   Object    ├╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌>│  Pipewire Thread  │
-└┬────────────┘   request changes to remote   └───────────────────┘
+└─────────────┘   request changes to remote   └───────────────────┘
- │                      via messages                    Λ
+                        via messages                    Λ
- │                                                      ║
+                                                        ║
- │<─── updates/reads state                              ║
+                                                        ║
- │                                                      ║
+                                                        V
- V                                                      ║
+                                            [ Remote Pipewire Server ]
-┌───────┐                                               V
-│ State │                                   [ Remote Pipewire Server ]
-└───────┘
 ```
-The program is split between two threads, with most stuff happening inside the GTK thread.
+The program is split between two cooperating threads.
-The GTK thread will sit in a GTK event processing loop, while the pipewire thread will sit in a
+The GTK thread (displayed on the left side) will sit in a GTK event processing loop, while the pipewire thread (displayed on the right side) will sit in a pipewire event processing loop.
-pipewire event processing loop.
 
-The `Application` object inside the GTK thread is the centerpiece of this architecture.
+The `Application` object inside the GTK thread communicates with the pipewire thread using two channels,
-It communicates with the pipewire thread using two channels,
 where each message sent by one thread will trigger the loop of the other thread to invoke a callback
 with the received message.
 
-For each change on the remote pipewire server, the `Application` in the GTK thread is notified by the pipewire thread
+For each change on the remote pipewire server, the pipewire thread updates the state and notifies
-and updates the view to reflect those changes, and additionally memorizes anything it might need later in the state.
+the `Application` in the GTK thread if changes are needed.
+The `Application` then updates the view to reflect those changes.
 
 Additionally, a user may also make changes using the view.
 For each change, the view notifies the `Application` by emitting a matching signal.
-The `Application` will then request the pipewire thread to make those changes on the remote. \
+The `Application` will then ask the pipewire thread to make those changes on the remote. \
 These changes will then be applied to the view like any other remote changes as explained above.
 
 # View Architecture

org.freedesktop.ryuukyu.Helvum.json

@@ -0,0 +1,36 @@
+{
+    "app-id": "org.freedesktop.ryuukyu.Helvum",
+    "runtime": "org.gnome.Platform",
+    "runtime-version": "40",
+    "sdk": "org.gnome.Sdk",
+    "sdk-extensions": ["org.freedesktop.Sdk.Extension.rust-stable"],
+    "command": "helvum",
+    "finish-args" : [
+        "--socket=fallback-x11",
+        "--socket=wayland",
+        "--device=dri",
+        "--share=ipc",
+        "--filesystem=xdg-run/pipewire-0"
+    ],
+    "build-options" : {
+        "append-path" : "/usr/lib/sdk/rust-stable/bin",
+        "build-args" : [
+            "--share=network"
+        ]
+    },
+    "modules": [
+        {
+            "name": "Helvum",
+            "buildsystem": "simple",
+            "build-commands": [
+                "cargo install --path . --root /app --no-track"
+            ],
+            "sources": [
+                {
+                    "type": "dir",
+                    "path": "./"
+                }
+            ]
+        }
+    ]
+}

src/application.rs

@@ -1,4 +1,4 @@
-use std::{cell::RefCell, collections::HashMap};
+use std::cell::RefCell;
 
 use gtk::{
     gio,
@@ -11,33 +11,10 @@ use pipewire::{channel::Sender, spa::Direction};
 
 use crate::{
     view::{self},
-    GtkMessage, PipewireLink, PipewireMessage,
+    GtkMessage, MediaType, PipewireLink, PipewireMessage,
 };
 
-#[derive(Debug, Copy, Clone)]
+static STYLE: &str = include_str!("style.css");
-pub enum MediaType {
-    Audio,
-    Video,
-    Midi,
-}
-
-// FIXME: This should be in its own .css file.
-static STYLE: &str = "
-.audio {
-    background: rgb(50,100,240);
-	color: black;
-}
-
-.video {
-    background: rgb(200,200,0);
-	color: black;
-}
-
-.midi {
-    background: rgb(200,0,50);
-    color: black;
-}
-";
 
 mod imp {
     use super::*;
@@ -47,7 +24,6 @@ mod imp {
     #[derive(Default)]
     pub struct Application {
         pub(super) graphview: view::GraphView,
-        pub(super) state: RefCell<State>,
         pub(super) pw_sender: OnceCell<RefCell<Sender<GtkMessage>>>,
     }
 
@@ -107,7 +83,7 @@ impl Application {
         pw_sender: Sender<GtkMessage>,
     ) -> Self {
         let app: Application =
-            glib::Object::new(&[("application-id", &"org.freedesktop.ryuukyu.helvum")])
+            glib::Object::new(&[("application-id", &"org.freedesktop.ryuukyu.Helvum")])
                 .expect("Failed to create new Application");
 
         let imp = imp::Application::from_instance(&app);
@@ -132,19 +108,13 @@ impl Application {
                 @weak app => @default-return Continue(true),
                 move |msg| {
                     match msg {
-                        PipewireMessage::NodeAdded {
+                        PipewireMessage::NodeAdded{ id, name } => app.add_node(id, name.as_str()),
-                            id,
+                        PipewireMessage::PortAdded{ id, node_id, name, direction, media_type } => app.add_port(id, name.as_str(), node_id, direction, media_type),
-                            name,
+                        PipewireMessage::LinkAdded{ id, node_from, port_from, node_to, port_to, active} => app.add_link(id, node_from, port_from, node_to, port_to, active),
-                            media_type,
+                        PipewireMessage::LinkStateChanged { id, active } => app.link_state_changed(id, active), // TODO
-                        } => app.add_node(id, name, media_type),
+                        PipewireMessage::NodeRemoved { id } => app.remove_node(id),
-                        PipewireMessage::PortAdded {
+                        PipewireMessage::PortRemoved { id, node_id } => app.remove_port(id, node_id),
-                            id,
+                        PipewireMessage::LinkRemoved { id } => app.remove_link(id)
-                            node_id,
-                            name,
-                            direction,
-                        } => app.add_port(id, name, node_id, direction),
-                        PipewireMessage::LinkAdded { id, link } => app.add_link(id, link),
-                        PipewireMessage::ObjectRemoved { id } => app.remove_global(id),
                     };
                     Continue(true)
                 }
@@ -155,41 +125,28 @@ impl Application {
     }
 
     /// Add a new node to the view.
-    pub fn add_node(&self, id: u32, name: String, media_type: Option<MediaType>) {
+    fn add_node(&self, id: u32, name: &str) {
         info!("Adding node to graph: id {}", id);
 
-        let imp = imp::Application::from_instance(self);
+        imp::Application::from_instance(self)
-
+            .graphview
-        imp.state.borrow_mut().insert(
+            .add_node(id, view::Node::new(name));
-            id,
-            Item::Node {
-                // widget: node_widget,
-                media_type,
-            },
-        );
-
-        imp.graphview.add_node(id, view::Node::new(name.as_str()));
     }
 
     /// Add a new port to the view.
-    pub fn add_port(&self, id: u32, name: String, node_id: u32, direction: Direction) {
+    fn add_port(
+        &self,
+        id: u32,
+        name: &str,
+        node_id: u32,
+        direction: Direction,
+        media_type: Option<MediaType>,
+    ) {
         info!("Adding port to graph: id {}", id);
 
         let imp = imp::Application::from_instance(self);
 
-        // Find out the nodes media type so that the port can be colored.
+        let port = view::Port::new(id, name, direction, media_type);
-        let media_type =
-            if let Some(Item::Node { media_type, .. }) = imp.state.borrow().get(node_id) {
-                media_type.to_owned()
-            } else {
-                warn!("Node not found for Port {}", id);
-                None
-            };
-
-        // Save node_id so we can delete this port easily.
-        imp.state.borrow_mut().insert(id, Item::Port { node_id });
-
-        let port = view::Port::new(id, name.as_str(), direction, media_type);
 
         // Create or delete a link if the widget emits the "port-toggled" signal.
         if let Err(e) = port.connect_local(
@@ -212,77 +169,51 @@ impl Application {
     }
 
     /// Add a new link to the view.
-    pub fn add_link(&self, id: u32, link: PipewireLink) {
+    fn add_link(
+        &self,
+        id: u32,
+        node_from: u32,
+        port_from: u32,
+        node_to: u32,
+        port_to: u32,
+        active: bool,
+    ) {
         info!("Adding link to graph: id {}", id);
 
-        let imp = imp::Application::from_instance(self);
-
         // FIXME: Links should be colored depending on the data they carry (video, audio, midi) like ports are.
 
-        imp.state.borrow_mut().insert(
+        // Update graph to contain the new link.
+        imp::Application::from_instance(self).graphview.add_link(
             id,
-            Item::Link {
+            PipewireLink {
-                output_port: link.port_from,
+                node_from,
-                input_port: link.port_to,
+                port_from,
+                node_to,
+                port_to,
             },
+            active,
+        );
+    }
+
+    fn link_state_changed(&self, id: u32, active: bool) {
+        info!(
+            "Link state changed: Link (id={}) is now {}",
+            id,
+            if active { "active" } else { "inactive" }
         );
 
-        // Update graph to contain the new link.
+        imp::Application::from_instance(self)
-        imp.graphview.add_link(id, link);
+            .graphview
+            .set_link_state(id, active);
     }
 
     // Toggle a link between the two specified ports on the remote pipewire server.
     fn toggle_link(&self, port_from: u32, port_to: u32) {
         let imp = imp::Application::from_instance(self);
         let sender = imp.pw_sender.get().expect("pw_sender not set").borrow_mut();
-        let state = imp.state.borrow_mut();
-
-        if let Some(id) = state.get_link_id(port_from, port_to) {
-            info!("Requesting removal of link with id {}", id);
-
         sender
-                .send(GtkMessage::DestroyGlobal(id))
+            .send(GtkMessage::ToggleLink { port_from, port_to })
             .expect("Failed to send message");
-        } else {
-            info!(
-                "Requesting creation of link from port id:{} to port id:{}",
-                port_from, port_to
-            );
-
-            let node_from = state
-                .get_node_of_port(port_from)
-                .expect("Requested port not in state");
-            let node_to = state
-                .get_node_of_port(port_to)
-                .expect("Requested port not in state");
-
-            sender
-                .send(GtkMessage::CreateLink(PipewireLink {
-                    node_from,
-                    port_from,
-                    node_to,
-                    port_to,
-                }))
-                .expect("Failed to send message");
-        }
-    }
-
-    /// Handle a global object being removed.
-    pub fn remove_global(&self, id: u32) {
-        let imp = imp::Application::from_instance(self);
-
-        if let Some(item) = imp.state.borrow_mut().remove(id) {
-            match item {
-                Item::Node { .. } => self.remove_node(id),
-                Item::Port { node_id } => self.remove_port(id, node_id),
-                Item::Link { .. } => self.remove_link(id),
-            }
-        } else {
-            warn!(
-                "Attempted to remove item with id {} that is not saved in state",
-                id
-            );
-        }
     }
 
     /// Remove the node with the specified id from the view.
@@ -310,83 +241,3 @@ impl Application {
         imp.graphview.remove_link(id);
     }
 }
-
-/// Any pipewire item we need to keep track of.
-/// These will be saved in the [`Application`]s `state` struct associated with their id.
-enum Item {
-    Node {
-        // Keep track of the nodes media type to color ports on it.
-        media_type: Option<MediaType>,
-    },
-    Port {
-        // Save the id of the node this is on so we can remove the port from it
-        // when it is deleted.
-        node_id: u32,
-    },
-    // We don't need to memorize anything about links right now, but we need to
-    // be able to find out an id is a link.
-    Link {
-        output_port: u32,
-        input_port: u32,
-    },
-}
-
-/// This struct keeps track of any relevant items and stores them under their IDs.
-///
-/// Given two port ids, it can also efficiently find the id of the link that connects them.
-#[derive(Default)]
-struct State {
-    /// Map pipewire ids to items.
-    items: HashMap<u32, Item>,
-    /// Map `(output port id, input port id)` tuples to the id of the link that connects them.
-    links: HashMap<(u32, u32), u32>,
-}
-
-impl State {
-    /// Add a new item under the specified id.
-    fn insert(&mut self, id: u32, item: Item) {
-        if let Item::Link {
-            output_port,
-            input_port,
-        } = item
-        {
-            self.links.insert((output_port, input_port), id);
-        }
-
-        self.items.insert(id, item);
-    }
-
-    /// Get the item that has the specified id.
-    fn get(&self, id: u32) -> Option<&Item> {
-        self.items.get(&id)
-    }
-
-    /// Get the id of the link that links the two specified ports.
-    fn get_link_id(&self, output_port: u32, input_port: u32) -> Option<u32> {
-        self.links.get(&(output_port, input_port)).copied()
-    }
-
-    /// Remove the item with the specified id, returning it if it exists.
-    fn remove(&mut self, id: u32) -> Option<Item> {
-        let removed = self.items.remove(&id);
-
-        if let Some(Item::Link {
-            output_port,
-            input_port,
-        }) = removed
-        {
-            self.links.remove(&(output_port, input_port));
-        }
-
-        removed
-    }
-
-    /// Convenience function: Get the id of the node a port is on
-    fn get_node_of_port(&self, port: u32) -> Option<u32> {
-        if let Some(Item::Port { node_id }) = self.get(port) {
-            Some(*node_id)
-        } else {
-            None
-        }
-    }
-}

src/main.rs

@@ -2,44 +2,64 @@ mod application;
 mod pipewire_connection;
 mod view;
 
-use application::MediaType;
 use gtk::{
     glib::{self, PRIORITY_DEFAULT},
     prelude::*,
 };
 use pipewire::spa::Direction;
 
-/// Messages used GTK thread to command the pipewire thread.
+/// Messages sent by the GTK thread to notify the pipewire thread.
 #[derive(Debug, Clone)]
 enum GtkMessage {
-    /// Create a new link.
+    /// Toggle a link between the two specified ports.
-    CreateLink(PipewireLink),
+    ToggleLink { port_from: u32, port_to: u32 },
-    /// Destroy the global with the specified id.
-    DestroyGlobal(u32),
     /// Quit the event loop and let the thread finish.
     Terminate,
 }
 
-/// Messages used pipewire thread to notify the GTK thread.
+/// Messages sent by the pipewire thread to notify the GTK thread.
 #[derive(Debug, Clone)]
 enum PipewireMessage {
-    /// A new node has appeared.
     NodeAdded {
         id: u32,
         name: String,
-        media_type: Option<MediaType>,
     },
-    /// A new port has appeared.
     PortAdded {
         id: u32,
         node_id: u32,
         name: String,
         direction: Direction,
+        media_type: Option<MediaType>,
     },
-    /// A new link has appeared.
+    LinkAdded {
-    LinkAdded { id: u32, link: PipewireLink },
+        id: u32,
-    /// An object was removed
+        node_from: u32,
-    ObjectRemoved { id: u32 },
+        port_from: u32,
+        node_to: u32,
+        port_to: u32,
+        active: bool,
+    },
+    LinkStateChanged {
+        id: u32,
+        active: bool,
+    },
+    NodeRemoved {
+        id: u32,
+    },
+    PortRemoved {
+        id: u32,
+        node_id: u32,
+    },
+    LinkRemoved {
+        id: u32,
+    },
+}
+
+#[derive(Debug, Copy, Clone)]
+pub enum MediaType {
+    Audio,
+    Video,
+    Midi,
 }
 
 #[derive(Debug, Clone)]
@@ -54,6 +74,10 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
     env_logger::init();
     gtk::init()?;
 
+    // Aquire main context so that we can attach the gtk channel later.
+    let ctx = glib::MainContext::default();
+    let _guard = ctx.acquire().unwrap();
+
     // Start the pipewire thread with channels in both directions.
     let (gtk_sender, gtk_receiver) = glib::MainContext::channel(PRIORITY_DEFAULT);
     let (pw_sender, pw_receiver) = pipewire::channel::channel();

src/pipewire_connection.rs

@@ -1,18 +1,28 @@
-use std::rc::Rc;
+mod state;
+
+use std::{cell::RefCell, collections::HashMap, rc::Rc};
 
 use gtk::glib::{self, clone};
-use log::warn;
+use log::{debug, info, warn};
 use pipewire::{
-    link::Link,
+    link::{Link, LinkChangeMask, LinkListener, LinkState},
     prelude::*,
     properties,
-    registry::GlobalObject,
+    registry::{GlobalObject, Registry},
     spa::{Direction, ForeignDict},
     types::ObjectType,
-    Context, MainLoop,
+    Context, Core, MainLoop,
 };
 
-use crate::{application::MediaType, GtkMessage, PipewireMessage};
+use crate::{GtkMessage, MediaType, PipewireMessage};
+use state::{Item, State};
+
+enum ProxyItem {
+    Link {
+        _proxy: Link,
+        _listener: LinkListener,
+    },
+}
 
 /// The "main" function of the pipewire thread.
 pub(super) fn thread_main(
@@ -21,59 +31,60 @@ pub(super) fn thread_main(
 ) {
     let mainloop = MainLoop::new().expect("Failed to create mainloop");
     let context = Context::new(&mainloop).expect("Failed to create context");
-    let core = context.connect(None).expect("Failed to connect to remote");
+    let core = Rc::new(context.connect(None).expect("Failed to connect to remote"));
     let registry = Rc::new(core.get_registry().expect("Failed to get registry"));
 
+    // Keep proxies and their listeners alive so that we can receive info events.
+    let proxies = Rc::new(RefCell::new(HashMap::new()));
+
+    let state = Rc::new(RefCell::new(State::new()));
+
     let _receiver = pw_receiver.attach(&mainloop, {
-        let mainloop = mainloop.clone();
+        clone!(@strong mainloop, @weak core, @weak registry, @strong state => move |msg| match msg {
-        clone!(@weak registry => move |msg| match msg {
+            GtkMessage::ToggleLink { port_from, port_to } => toggle_link(port_from, port_to, &core, &registry, &state),
-            GtkMessage::CreateLink(link) => {
-                if let Err(e) = core.create_object::<Link, _>(
-                    "link-factory",
-                    &properties! {
-                        "link.output.node" => link.node_from.to_string(),
-                        "link.output.port" => link.port_from.to_string(),
-                        "link.input.node" => link.node_to.to_string(),
-                        "link.input.port" => link.port_to.to_string(),
-                        "object.linger" => "1"
-                    },
-                ) {
-                    warn!("Failed to create link: {}", e);
-                }
-            }
-            GtkMessage::DestroyGlobal(id) => {
-                // FIXME: Handle error
-                registry.destroy_global(id);
-            }
             GtkMessage::Terminate => mainloop.quit(),
         })
     });
 
     let _listener = registry
         .add_listener_local()
-        .global({
+        .global(clone!(@strong gtk_sender, @weak registry, @strong proxies, @strong state =>
-            let sender = gtk_sender.clone();
             move |global| match global.type_ {
-                ObjectType::Node => handle_node(global, &sender),
+                ObjectType::Node => handle_node(global, &gtk_sender, &state),
-                ObjectType::Port => handle_port(global, &sender),
+                ObjectType::Port => handle_port(global, &gtk_sender, &state),
-                ObjectType::Link => handle_link(global, &sender),
+                ObjectType::Link => handle_link(global, &gtk_sender, &registry, &proxies, &state),
                 _ => {
                     // Other objects are not interesting to us
                 }
             }
-        })
+        ))
-        .global_remove(move |id| {
+        .global_remove(clone!(@strong proxies, @strong state => move |id| {
-            gtk_sender
+            if let Some(item) = state.borrow_mut().remove(id) {
-                .send(PipewireMessage::ObjectRemoved { id })
+                gtk_sender.send(match item {
-                .expect("Failed to send message")
+                    Item::Node { .. } => PipewireMessage::NodeRemoved {id},
-        })
+                    Item::Port { node_id } => PipewireMessage::PortRemoved {id, node_id},
+                    Item::Link { .. } => PipewireMessage::LinkRemoved {id},
+                }).expect("Failed to send message");
+            } else {
+                warn!(
+                    "Attempted to remove item with id {} that is not saved in state",
+                    id
+                );
+            }
+
+            proxies.borrow_mut().remove(&id);
+        }))
         .register();
 
     mainloop.run();
 }
 
 /// Handle a new node being added
-fn handle_node(node: &GlobalObject<ForeignDict>, sender: &glib::Sender<PipewireMessage>) {
+fn handle_node(
+    node: &GlobalObject<ForeignDict>,
+    sender: &glib::Sender<PipewireMessage>,
+    state: &Rc<RefCell<State>>,
+) {
     let props = node
         .props
         .as_ref()
@@ -88,10 +99,8 @@ fn handle_node(node: &GlobalObject<ForeignDict>, sender: &glib::Sender<PipewireM
             .unwrap_or_default(),
     );
 
-    // FIXME: This relies on the node being passed to us by the pipwire server before its port.
+    // FIXME: Instead of checking these props, the "EnumFormat" parameter should be checked instead.
-    let media_type = props
+    let media_type = props.get("media.class").and_then(|class| {
-        .get("media.class")
-        .map(|class| {
         if class.contains("Audio") {
             Some(MediaType::Audio)
         } else if class.contains("Video") {
@@ -101,20 +110,27 @@ fn handle_node(node: &GlobalObject<ForeignDict>, sender: &glib::Sender<PipewireM
         } else {
             None
         }
-        })
+    });
-        .flatten();
+
+    state.borrow_mut().insert(
+        node.id,
+        Item::Node {
+            // widget: node_widget,
+            media_type,
+        },
+    );
 
     sender
-        .send(PipewireMessage::NodeAdded {
+        .send(PipewireMessage::NodeAdded { id: node.id, name })
-            id: node.id,
-            name,
-            media_type,
-        })
         .expect("Failed to send message");
 }
 
 /// Handle a new port being added
-fn handle_port(port: &GlobalObject<ForeignDict>, sender: &glib::Sender<PipewireMessage>) {
+fn handle_port(
+    port: &GlobalObject<ForeignDict>,
+    sender: &glib::Sender<PipewireMessage>,
+    state: &Rc<RefCell<State>>,
+) {
     let props = port
         .props
         .as_ref()
@@ -131,52 +147,131 @@ fn handle_port(port: &GlobalObject<ForeignDict>, sender: &glib::Sender<PipewireM
         Direction::Output
     };
 
+    // Find out the nodes media type so that the port can be colored.
+    let media_type = if let Some(Item::Node { media_type, .. }) = state.borrow().get(node_id) {
+        media_type.to_owned()
+    } else {
+        warn!("Node not found for Port {}", port.id);
+        None
+    };
+
+    // Save node_id so we can delete this port easily.
+    state.borrow_mut().insert(port.id, Item::Port { node_id });
+
     sender
         .send(PipewireMessage::PortAdded {
             id: port.id,
             node_id,
             name,
             direction,
+            media_type,
         })
         .expect("Failed to send message");
 }
 
 /// Handle a new link being added
-fn handle_link(link: &GlobalObject<ForeignDict>, sender: &glib::Sender<PipewireMessage>) {
+fn handle_link(
-    let props = link
+    link: &GlobalObject<ForeignDict>,
-        .props
+    sender: &glib::Sender<PipewireMessage>,
-        .as_ref()
+    registry: &Rc<Registry>,
-        .expect("Link object is missing properties");
+    proxies: &Rc<RefCell<HashMap<u32, ProxyItem>>>,
-    let node_from: u32 = props
+    state: &Rc<RefCell<State>>,
-        .get("link.output.node")
+) {
-        .expect("Link has no link.input.node property")
+    debug!(
-        .parse()
+        "New link (id:{}) appeared, setting up info listener.",
-        .expect("Could not parse link.input.node property");
+        link.id
-    let port_from: u32 = props
+    );
-        .get("link.output.port")
-        .expect("Link has no link.output.port property")
-        .parse()
-        .expect("Could not parse link.output.port property");
-    let node_to: u32 = props
-        .get("link.input.node")
-        .expect("Link has no link.input.node property")
-        .parse()
-        .expect("Could not parse link.input.node property");
-    let port_to: u32 = props
-        .get("link.input.port")
-        .expect("Link has no link.input.port property")
-        .parse()
-        .expect("Could not parse link.input.port property");
 
-    sender
+    let proxy: Link = registry.bind(link).expect("Failed to bind to link proxy");
-        .send(PipewireMessage::LinkAdded {
+    let listener = proxy
-            id: link.id,
+        .add_listener_local()
-            link: crate::PipewireLink {
+        .info(clone!(@strong state, @strong sender => move |info| {
+            debug!("Received link info: {:?}", info);
+
+            let id = info.id();
+
+            let mut state = state.borrow_mut();
+            if let Some(Item::Link { .. }) = state.get(id) {
+                // Info was an update - figure out if we should notify the gtk thread
+                if info.change_mask().contains(LinkChangeMask::STATE) {
+                    sender.send(PipewireMessage::LinkStateChanged {
+                        id,
+                        active: matches!(info.state(), LinkState::Active)
+                    }).expect("Failed to send message");
+                }
+                // TODO -- check other values that might have changed
+            } else {
+                // First time we get info. We can now notify the gtk thread of a new link.
+                let node_from = info.output_node_id();
+                let port_from = info.output_port_id();
+                let node_to = info.input_node_id();
+                let port_to = info.input_port_id();
+
+                state.insert(id, Item::Link {
+                    port_from, port_to
+                });
+
+                sender.send(PipewireMessage::LinkAdded {
+                    id,
                     node_from,
                     port_from,
                     node_to,
                     port_to,
-            },
+                    active: matches!(info.state(), LinkState::Active)
-        })
+                }).expect(
-        .expect("Failed to send message");
+                    "Failed to send message"
+                );
+            }
+        }))
+        .register();
+
+    proxies.borrow_mut().insert(
+        link.id,
+        ProxyItem::Link {
+            _proxy: proxy,
+            _listener: listener,
+        },
+    );
+}
+
+/// Toggle a link between the two specified ports.
+fn toggle_link(
+    port_from: u32,
+    port_to: u32,
+    core: &Rc<Core>,
+    registry: &Rc<Registry>,
+    state: &Rc<RefCell<State>>,
+) {
+    let state = state.borrow_mut();
+    if let Some(id) = state.get_link_id(port_from, port_to) {
+        info!("Requesting removal of link with id {}", id);
+
+        // FIXME: Handle error
+        registry.destroy_global(id);
+    } else {
+        info!(
+            "Requesting creation of link from port id:{} to port id:{}",
+            port_from, port_to
+        );
+
+        let node_from = state
+            .get_node_of_port(port_from)
+            .expect("Requested port not in state");
+        let node_to = state
+            .get_node_of_port(port_to)
+            .expect("Requested port not in state");
+
+        if let Err(e) = core.create_object::<Link, _>(
+            "link-factory",
+            &properties! {
+                "link.output.node" => node_from.to_string(),
+                "link.output.port" => port_from.to_string(),
+                "link.input.node" => node_to.to_string(),
+                "link.input.port" => port_to.to_string(),
+                "object.linger" => "1"
+            },
+        ) {
+            warn!("Failed to create link: {}", e);
+        }
+    }
 }

src/pipewire_connection/state.rs

@@ -0,0 +1,81 @@
+use std::collections::HashMap;
+
+use crate::MediaType;
+
+/// Any pipewire item we need to keep track of.
+/// These will be saved in the `State` struct associated with their id.
+pub(super) enum Item {
+    Node {
+        // Keep track of the nodes media type to color ports on it.
+        media_type: Option<MediaType>,
+    },
+    Port {
+        // Save the id of the node this is on so we can remove the port from it
+        // when it is deleted.
+        node_id: u32,
+    },
+    Link {
+        port_from: u32,
+        port_to: u32,
+    },
+}
+
+/// This struct keeps track of any relevant items and stores them under their IDs.
+///
+/// Given two port ids, it can also efficiently find the id of the link that connects them.
+#[derive(Default)]
+pub(super) struct State {
+    /// Map pipewire ids to items.
+    items: HashMap<u32, Item>,
+    /// Map `(output port id, input port id)` tuples to the id of the link that connects them.
+    links: HashMap<(u32, u32), u32>,
+}
+
+impl State {
+    /// Create a new, empty state.
+    pub fn new() -> Self {
+        Self::default()
+    }
+
+    /// Add a new item under the specified id.
+    pub fn insert(&mut self, id: u32, item: Item) {
+        if let Item::Link {
+            port_from, port_to, ..
+        } = item
+        {
+            self.links.insert((port_from, port_to), id);
+        }
+
+        self.items.insert(id, item);
+    }
+
+    /// Get the item that has the specified id.
+    pub fn get(&self, id: u32) -> Option<&Item> {
+        self.items.get(&id)
+    }
+
+    /// Get the id of the link that links the two specified ports.
+    pub fn get_link_id(&self, output_port: u32, input_port: u32) -> Option<u32> {
+        self.links.get(&(output_port, input_port)).copied()
+    }
+
+    /// Remove the item with the specified id, returning it if it exists.
+    pub fn remove(&mut self, id: u32) -> Option<Item> {
+        let removed = self.items.remove(&id);
+
+        if let Some(Item::Link { port_from, port_to }) = removed {
+            self.links.remove(&(port_from, port_to));
+        }
+
+        removed
+    }
+
+    /// Convenience function: Get the id of the node a port is on
+    pub fn get_node_of_port(&self, port: u32) -> Option<u32> {
+        if let Some(Item::Port { node_id }) = self.get(port) {
+            Some(*node_id)
+        } else {
+            None
+        }
+    }
+}

src/style.css

@@ -0,0 +1,14 @@
+.audio {
+    background: rgb(50,100,240);
+    color: black;
+}
+
+.video {
+    background: rgb(200,200,0);
+    color: black;
+}
+
+.midi {
+    background: rgb(200,0,50);
+    color: black;
+}

src/view/graph_view.rs

@@ -1,6 +1,12 @@
-use super::Node;
+use super::{Node, Port};
 
-use gtk::{gdk, glib, graphene, gsk, prelude::*, subclass::prelude::*};
+use gtk::{
+    glib::{self, clone},
+    graphene, gsk,
+    prelude::*,
+    subclass::prelude::*,
+};
+use log::{error, warn};
 
 use std::collections::HashMap;
 
@@ -14,8 +20,8 @@ mod imp {
     #[derive(Default)]
     pub struct GraphView {
         pub(super) nodes: RefCell<HashMap<u32, Node>>,
-        pub(super) links: RefCell<HashMap<u32, crate::PipewireLink>>,
+        /// Stores the link and whether it is currently active.
-        pub(super) dragged: Rc<RefCell<Option<gtk::Widget>>>,
+        pub(super) links: RefCell<HashMap<u32, (crate::PipewireLink, bool)>>,
     }
 
     #[glib::object_subclass]
@@ -34,28 +40,47 @@ mod imp {
         fn constructed(&self, obj: &Self::Type) {
             self.parent_constructed(obj);
 
-            // Move the Node that is currently being dragged to the cursor position as long as Mouse Button 1 is held.
+            let drag_state = Rc::new(RefCell::new(None));
-            let motion_controller = gtk::EventControllerMotion::new();
+            let drag_controller = gtk::GestureDrag::new();
-            motion_controller.connect_motion(|controller, x, y| {
-                let instance = controller
-                    .widget()
-                    .unwrap()
-                    .dynamic_cast::<Self::Type>()
-                    .unwrap();
-                let this = imp::GraphView::from_instance(&instance);
 
-                if let Some(ref widget) = *this.dragged.borrow() {
+            drag_controller.connect_drag_begin(
-                    if controller
+                clone!(@strong drag_state => move |drag_controller, x, y| {
-                        .current_event()
+                let mut drag_state = drag_state.borrow_mut();
-                        .unwrap()
+                let widget = drag_controller
-                        .modifier_state()
+                    .widget()
-                        .contains(gdk::ModifierType::BUTTON1_MASK)
+                    .expect("drag-begin event has no widget")
-                    {
+                    .dynamic_cast::<Self::Type>()
-                        instance.move_node(&widget, x as f32, y as f32);
+                    .expect("drag-begin event is not on the GraphView");
+                // pick() should at least return the widget itself.
+                let target = widget.pick(x, y, gtk::PickFlags::DEFAULT).expect("drag-begin pick() did not return a widget");
+                *drag_state = if target.ancestor(Port::static_type()).is_some() {
+                    // The user targeted a port, so the dragging should be handled by the Port
+                    // component instead of here.
+                    None
+                } else if let Some(target) = target.ancestor(Node::static_type()) {
+                    // The user targeted a Node without targeting a specific Port.
+                    // Drag the Node around the screen.
+                    let (x, y) = widget.get_node_position(&target);
+                    Some((target, x, y))
+                } else {
+                    None
                 }
-                };
+            }));
-            });
+            drag_controller.connect_drag_update(
-            obj.add_controller(&motion_controller);
+                clone!(@strong drag_state => move |drag_controller, x, y| {
+                    let widget = drag_controller
+                        .widget()
+                        .expect("drag-update event has no widget")
+                        .dynamic_cast::<Self::Type>()
+                        .expect("drag-update event is not on the GraphView");
+                    let drag_state = drag_state.borrow();
+                    if let Some((ref node, x1, y1)) = *drag_state {
+                        widget.move_node(node, x1 + x as f32, y1 + y as f32);
+                    }
+                }
+                ),
+            );
+            obj.add_controller(&drag_controller);
         }
 
         fn dispose(&self, _obj: &Self::Type) {
@@ -73,7 +98,7 @@ mod imp {
 
             let alloc = widget.allocation();
 
-            let cr = snapshot
+            let background_cr = snapshot
                 .append_cairo(&graphene::Rect::new(
                     0.0,
                     0.0,
@@ -84,51 +109,79 @@ mod imp {
 
             // Try to replace the background color with a darker one from the theme.
             if let Some(rgba) = widget.style_context().lookup_color("text_view_bg") {
-                cr.set_source_rgb(rgba.red.into(), rgba.green.into(), rgba.blue.into());
+                background_cr.set_source_rgb(rgba.red.into(), rgba.green.into(), rgba.blue.into());
-                if let Err(e) = cr.paint() {
+                if let Err(e) = background_cr.paint() {
                     warn!("Failed to paint graphview background: {}", e);
                 };
             } // TODO: else log colour not found
 
             // Draw a nice grid on the background.
-            cr.set_source_rgb(0.18, 0.18, 0.18);
+            background_cr.set_source_rgb(0.18, 0.18, 0.18);
-            cr.set_line_width(0.2); // TODO: Set to 1px
+            background_cr.set_line_width(0.2); // TODO: Set to 1px
             let mut y = 0.0;
             while y < alloc.height.into() {
-                cr.move_to(0.0, y);
+                background_cr.move_to(0.0, y);
-                cr.line_to(alloc.width as f64, y);
+                background_cr.line_to(alloc.width.into(), y);
                 y += 20.0; // TODO: Change to em;
             }
             let mut x = 0.0;
-            while x < alloc.width as f64 {
+            while x < alloc.width.into() {
-                cr.move_to(x, 0.0);
+                background_cr.move_to(x, 0.0);
-                cr.line_to(x, alloc.height as f64);
+                background_cr.line_to(x, alloc.height.into());
                 x += 20.0; // TODO: Change to em;
             }
-            if let Err(e) = cr.stroke() {
+            if let Err(e) = background_cr.stroke() {
                 warn!("Failed to draw graphview grid: {}", e);
             };
 
-            // Draw all links
-            cr.set_line_width(2.0);
-            cr.set_source_rgb(0.0, 0.0, 0.0);
-            for link in self.links.borrow().values() {
-                if let Some((from_x, from_y, to_x, to_y)) = self.get_link_coordinates(link) {
-                    cr.move_to(from_x, from_y);
-                    cr.curve_to(from_x + 75.0, from_y, to_x - 75.0, to_y, to_x, to_y);
-                    if let Err(e) = cr.stroke() {
-                        warn!("Failed to draw graphview links: {}", e);
-                    };
-                } else {
-                    log::warn!("Could not get allocation of ports of link: {:?}", link);
-                }
-            }
-
             // Draw all children
             self.nodes
                 .borrow()
                 .values()
                 .for_each(|node| self.instance().snapshot_child(node, snapshot));
+
+            // Draw all links
+            let link_cr = snapshot
+                .append_cairo(&graphene::Rect::new(
+                    0.0,
+                    0.0,
+                    alloc.width as f32,
+                    alloc.height as f32,
+                ))
+                .expect("Failed to get cairo context");
+            link_cr.set_line_width(2.0);
+            link_cr.set_source_rgb(0.0, 0.0, 0.0);
+            for (link, active) in self.links.borrow().values() {
+                if let Some((from_x, from_y, to_x, to_y)) = self.get_link_coordinates(link) {
+                    link_cr.move_to(from_x, from_y);
+
+                    // Use dashed line for inactive links, full line otherwise.
+                    if *active {
+                        link_cr.set_dash(&[], 0.0);
+                    } else {
+                        link_cr.set_dash(&[10.0, 5.0], 0.0);
+                    }
+
+                    // Place curve control offset by half the x distance between the two points.
+                    // This makes the curve scale well for varying distances between the two ports,
+                    // especially when the output port is farther right than the input port.
+                    let half_x_dist = f64::abs(from_x - to_x) / 2.0;
+                    link_cr.curve_to(
+                        from_x + half_x_dist,
+                        from_y,
+                        to_x - half_x_dist,
+                        to_y,
+                        to_x,
+                        to_y,
+                    );
+
+                    if let Err(e) = link_cr.stroke() {
+                        warn!("Failed to draw graphview links: {}", e);
+                    };
+                } else {
+                    warn!("Could not get allocation of ports of link: {:?}", link);
+                }
+            }
         }
     }
 
@@ -136,7 +189,7 @@ mod imp {
         /// Get coordinates for the drawn link to start at and to end at.
         ///
         /// # Returns
-        /// Some((from_x, from_y, to_x, to_y)) if all objects the links refers to exist as widgets.
+        /// `Some((from_x, from_y, to_x, to_y))` if all objects the links refers to exist as widgets.
         fn get_link_coordinates(&self, link: &crate::PipewireLink) -> Option<(f64, f64, f64, f64)> {
             let nodes = self.nodes.borrow();
 
@@ -171,7 +224,7 @@ mod imp {
             tx += tnx;
             ty += tny + (th / 2);
 
-            Some((fx as f64, fy as f64, tx as f64, ty as f64))
+            Some((fx.into(), fy.into(), tx.into(), ty.into()))
         }
     }
 }
@@ -192,8 +245,8 @@ impl GraphView {
 
         // Place widgets in colums of 4, growing down, then right.
         // TODO: Make a better positioning algorithm.
-        let x = (private.nodes.borrow().len() / 4) as f32 * 400.0; // This relies on integer division rounding down.
+        let x = ((private.nodes.borrow().len() / 4) as f32 * 400.0) + 20.0; // This relies on integer division rounding down.
-        let y = private.nodes.borrow().len() as f32 % 4.0 * 100.0;
+        let y = (private.nodes.borrow().len() as f32 % 4.0 * 100.0) + 20.0;
 
         self.move_node(&node.clone().upcast(), x, y);
 
@@ -205,6 +258,8 @@ impl GraphView {
         let mut nodes = private.nodes.borrow_mut();
         if let Some(node) = nodes.remove(&id) {
             node.unparent();
+        } else {
+            warn!("Tried to remove non-existant node (id={}) from graph", id);
         }
     }
 
@@ -214,11 +269,9 @@ impl GraphView {
         if let Some(node) = private.nodes.borrow_mut().get_mut(&node_id) {
             node.add_port(port_id, port);
         } else {
-            // FIXME: Log this instead
+            error!(
-            log::error!(
                 "Node with id {} not found when trying to add port with id {} to graph",
-                node_id,
+                node_id, port_id
-                port_id
             );
         }
     }
@@ -231,16 +284,22 @@ impl GraphView {
         }
     }
 
-    /// Add a link to the graph.
+    pub fn add_link(&self, link_id: u32, link: crate::PipewireLink, active: bool) {
-    ///
-    /// `add_link` takes three arguments: `link_id` is the id of the link as assigned by the pipewire server,
-    /// `from` and `to` are the id's of the ingoing and outgoing port, respectively.
-    pub fn add_link(&self, link_id: u32, link: crate::PipewireLink) {
         let private = imp::GraphView::from_instance(self);
-        private.links.borrow_mut().insert(link_id, link);
+        private.links.borrow_mut().insert(link_id, (link, active));
         self.queue_draw();
     }
 
+    pub fn set_link_state(&self, link_id: u32, active: bool) {
+        let private = imp::GraphView::from_instance(self);
+        if let Some((_, state)) = private.links.borrow_mut().get_mut(&link_id) {
+            *state = active;
+            self.queue_draw();
+        } else {
+            warn!("Link state changed on unknown link (id={})", link_id);
+        }
+    }
+
     pub fn remove_link(&self, id: u32) {
         let private = imp::GraphView::from_instance(self);
         let mut links = private.links.borrow_mut();
@@ -249,8 +308,20 @@ impl GraphView {
         self.queue_draw();
     }
 
-    pub(super) fn set_dragged(&self, widget: Option<gtk::Widget>) {
+    pub(super) fn get_node_position(&self, node: &gtk::Widget) -> (f32, f32) {
-        *imp::GraphView::from_instance(self).dragged.borrow_mut() = widget;
+        let layout_manager = self
+            .layout_manager()
+            .expect("Failed to get layout manager")
+            .dynamic_cast::<gtk::FixedLayout>()
+            .expect("Failed to cast to FixedLayout");
+
+        let node = layout_manager
+            .layout_child(node)
+            .expect("Could not get layout child")
+            .dynamic_cast::<gtk::FixedLayoutChild>()
+            .expect("Could not cast to FixedLayoutChild");
+        let transform = node.transform().unwrap_or_default();
+        transform.to_translate()
     }
 
     pub(super) fn move_node(&self, node: &gtk::Widget, x: f32, y: f32) {

src/view/node.rs

@@ -1,9 +1,7 @@
-use super::graph_view::GraphView;
-
 use gtk::{glib, prelude::*, subclass::prelude::*};
 use pipewire::spa::Direction;
 
-use std::{collections::HashMap, rc::Rc};
+use std::collections::HashMap;
 
 mod imp {
     use super::*;
@@ -13,9 +11,9 @@ mod imp {
     pub struct Node {
         pub(super) grid: gtk::Grid,
         pub(super) label: gtk::Label,
-        pub(super) ports: RefCell<HashMap<u32, Rc<crate::view::port::Port>>>,
+        pub(super) ports: RefCell<HashMap<u32, crate::view::port::Port>>,
-        pub(super) num_ports_in: Cell<u32>,
+        pub(super) num_ports_in: Cell<i32>,
-        pub(super) num_ports_out: Cell<u32>,
+        pub(super) num_ports_out: Cell<i32>,
     }
 
     #[glib::object_subclass]
@@ -34,35 +32,6 @@ mod imp {
 
             grid.attach(&label, 0, 0, 2, 1);
 
-            let motion_controller = gtk::EventControllerMotion::new();
-            motion_controller.connect_enter(|controller, _, _| {
-                // Tell the graphview that the Node is the target of a drag when the mouse enters its label
-                let widget = controller
-                    .widget()
-                    .expect("Controller with enter event has no widget")
-                    .ancestor(super::Node::static_type())
-                    .expect("Node label does not have a node ancestor widget");
-                widget
-                    .ancestor(GraphView::static_type())
-                    .expect("Node with enter event is not on graph")
-                    .dynamic_cast::<GraphView>()
-                    .unwrap()
-                    .set_dragged(Some(widget));
-            });
-            motion_controller.connect_leave(|controller| {
-                // Tell the graphview that the Node is no longer the target of a drag when the mouse leaves.
-                // FIXME: Check that we are the current target before setting none.
-                controller
-                    .widget()
-                    .expect("Controller with leave event has no widget")
-                    .ancestor(GraphView::static_type())
-                    .expect("Node with leave event is not on graph")
-                    .dynamic_cast::<GraphView>()
-                    .unwrap()
-                    .set_dragged(None);
-            });
-            label.add_controller(&motion_controller);
-
             // Display a grab cursor when the mouse is over the label so the user knows the node can be dragged.
             label.set_cursor(gtk::gdk::Cursor::from_name("grab", None).as_ref());
 
@@ -112,21 +81,21 @@ impl Node {
             Direction::Input => {
                 private
                     .grid
-                    .attach(&port, 0, private.num_ports_in.get() as i32 + 1, 1, 1);
+                    .attach(&port, 0, private.num_ports_in.get() + 1, 1, 1);
                 private.num_ports_in.set(private.num_ports_in.get() + 1);
             }
             Direction::Output => {
                 private
                     .grid
-                    .attach(&port, 1, private.num_ports_out.get() as i32 + 1, 1, 1);
+                    .attach(&port, 1, private.num_ports_out.get() + 1, 1, 1);
                 private.num_ports_out.set(private.num_ports_out.get() + 1);
             }
         }
 
-        private.ports.borrow_mut().insert(id, Rc::new(port));
+        private.ports.borrow_mut().insert(id, port);
     }
 
-    pub fn get_port(&self, id: u32) -> Option<Rc<super::port::Port>> {
+    pub fn get_port(&self, id: u32) -> Option<super::port::Port> {
         let private = imp::Node::from_instance(self);
         private.ports.borrow_mut().get(&id).cloned()
     }

src/view/port.rs

@@ -1,13 +1,25 @@
 use gtk::{
     gdk,
-    glib::{self, subclass::Signal},
+    glib::{self, clone, subclass::Signal},
     prelude::*,
     subclass::prelude::*,
 };
-use log::warn;
+use log::{trace, warn};
 use pipewire::spa::Direction;
 
-use crate::application::MediaType;
+use crate::MediaType;
+
+/// A helper struct for linking a output port to an input port.
+/// It carries the output ports id.
+#[derive(Clone, Debug, glib::GBoxed)]
+#[gboxed(type_name = "HelvumForwardLink")]
+struct ForwardLink(u32);
+
+/// A helper struct for linking an input to an output port.
+/// It carries the input ports id.
+#[derive(Clone, Debug, glib::GBoxed)]
+#[gboxed(type_name = "HelvumReversedLink")]
+struct ReversedLink(u32);
 
 mod imp {
     use once_cell::{sync::Lazy, unsync::OnceCell};
@@ -18,6 +30,7 @@ mod imp {
     /// Graphical representation of a pipewire port.
     #[derive(Default)]
     pub struct Port {
+        pub(super) label: OnceCell<gtk::Label>,
         pub(super) id: OnceCell<u32>,
         pub(super) direction: OnceCell<Direction>,
     }
@@ -26,10 +39,23 @@ mod imp {
     impl ObjectSubclass for Port {
         const NAME: &'static str = "Port";
         type Type = super::Port;
-        type ParentType = gtk::Button;
+        type ParentType = gtk::Widget;
+
+        fn class_init(klass: &mut Self::Class) {
+            klass.set_layout_manager_type::<gtk::BinLayout>();
+
+            // Make it look like a GTK button.
+            klass.set_css_name("button");
+        }
     }
 
     impl ObjectImpl for Port {
+        fn dispose(&self, _obj: &Self::Type) {
+            if let Some(label) = self.label.get() {
+                label.unparent()
+            }
+        }
+
         fn signals() -> &'static [Signal] {
             static SIGNALS: Lazy<Vec<Signal>> = Lazy::new(|| {
                 vec![Signal::builder(
@@ -46,18 +72,18 @@ mod imp {
         }
     }
     impl WidgetImpl for Port {}
-    impl ButtonImpl for Port {}
 }
 
 glib::wrapper! {
     pub struct Port(ObjectSubclass<imp::Port>)
-        @extends gtk::Button, gtk::Widget;
+        @extends gtk::Widget;
 }
 
 impl Port {
     pub fn new(id: u32, name: &str, direction: Direction, media_type: Option<MediaType>) -> Self {
         // Create the widget and initialize needed fields
         let res: Self = glib::Object::new(&[]).expect("Failed to create Port");
+
         let private = imp::Port::from_instance(&res);
         private.id.set(id).expect("Port id already set");
         private
@@ -65,22 +91,48 @@ impl Port {
             .set(direction)
             .expect("Port direction already set");
 
-        res.set_child(Some(&gtk::Label::new(Some(name))));
+        let label = gtk::Label::new(Some(name));
+        label.set_parent(&res);
+        private
+            .label
+            .set(label)
+            .expect("Port label was already set");
 
-        // Add either a drag source or drop target controller depending on direction,
+        // Add a drag source and drop target controller with the type depending on direction,
-        // they will be responsible for link creation by dragging an output port onto an input port.
+        // they will be responsible for link creation by dragging an output port onto an input port or the other way around.
-        //
+
-        // FIXME: The type used for dragging is simply a u32.
+        // FIXME: We should protect against different media types, e.g. it should not be possible to drop a video port on an audio port.
-        //   This means that anything that provides a u32 could be dragged onto a input port,
+
-        //   leading to that port trying to create a link to an invalid output port.
+        // The port will simply provide its pipewire id to the drag target.
-        //   We should use a newtype instead of a plain u32.
+        let drag_src = gtk::DragSourceBuilder::new()
-        //   Additionally, this does not protect against e.g. dropping an outgoing audio port on an ingoing video port.
+            .content(&gdk::ContentProvider::for_value(&match direction {
+                Direction::Input => ReversedLink(id).to_value(),
+                Direction::Output => ForwardLink(id).to_value(),
+            }))
+            .build();
+        drag_src.connect_drag_begin(move |_, _| {
+            trace!("Drag started from port {}", id);
+        });
+        drag_src.connect_drag_cancel(move |_, _, _| {
+            trace!("Drag from port {} was cancelled", id);
+            false
+        });
+        res.add_controller(&drag_src);
+
+        // The drop target will accept either a `ForwardLink` or `ReversedLink` depending in its own direction,
+        // and use it to emit its `port-toggled` signal.
+        let drop_target = gtk::DropTarget::new(
+            match direction {
+                Direction::Input => ForwardLink::static_type(),
+                Direction::Output => ReversedLink::static_type(),
+            },
+            gdk::DragAction::COPY,
+        );
         match direction {
             Direction::Input => {
-                let drop_target = gtk::DropTarget::new(u32::static_type(), gdk::DragAction::COPY);
+                drop_target.connect_drop(
-                let this = res.clone();
+                    clone!(@weak res as this => @default-panic, move |drop_target, val, _, _| {
-                drop_target.connect_drop(move |drop_target, val, _, _| {
+                        if let Ok(ForwardLink(source_id)) = val.get::<ForwardLink>() {
-                    if let Ok(source_id) = val.get::<u32>() {
                             // Get the callback registered in the widget and call it
                             drop_target
                                 .widget()
@@ -92,20 +144,32 @@ impl Port {
                         }
 
                         true
-                });
+                    }),
-                res.add_controller(&drop_target);
+                );
             }
             Direction::Output => {
-                // The port will simply provide its pipewire id to the drag target.
+                drop_target.connect_drop(
-                let drag_src = gtk::DragSourceBuilder::new()
+                    clone!(@weak res as this => @default-panic, move |drop_target, val, _, _| {
-                    .content(&gdk::ContentProvider::for_value(&(id.to_value())))
+                        if let Ok(ReversedLink(target_id)) = val.get::<ReversedLink>() {
-                    .build();
+                            // Get the callback registered in the widget and call it
-                res.add_controller(&drag_src);
+                            drop_target
+                                .widget()
+                                .expect("Drop target has no widget")
+                                .emit_by_name("port-toggled", &[&this.id(), &target_id])
+                                .expect("Failed to send signal");
+                        } else {
+                            warn!("Invalid type dropped on outgoing port");
+                        }
+
+                        true
+                    }),
+                );
+            }
+        }
+        res.add_controller(&drop_target);
 
         // Display a grab cursor when the mouse is over the port so the user knows it can be dragged to another port.
         res.set_cursor(gtk::gdk::Cursor::from_name("grab", None).as_ref());
-            }
-        }
 
         // Color the port according to its media type.
         match media_type {