feat: Add keybinds to minimal example

gst/src/pipeline.rs

@@ -60,6 +60,15 @@ impl Pipeline {
         Ok(())
     }
 
+    #[track_caller]
+    pub fn stop(&self) -> Result<()> {
+        self.inner
+            .set_state(gstreamer::State::Null)
+            .change_context(Error)
+            .attach("Failed to set pipeline to Null state")?;
+        Ok(())
+    }
+
     #[track_caller]
     pub fn set_state(&self, state: gstreamer::State) -> Result<gstreamer::StateChangeSuccess> {
         let result = self
@@ -165,6 +174,12 @@ pub trait PipelineExt: ChildOf<Pipeline> + Sync {
     fn ready(&self) -> Result<()> {
         self.upcast_ref().ready()
     }
+
+    #[track_caller]
+    fn stop(&self) -> Result<()> {
+        self.upcast_ref().stop()
+    }
+
     #[track_caller]
     fn set_state(&self, state: gstreamer::State) -> Result<gstreamer::StateChangeSuccess> {
         self.upcast_ref().set_state(state)