fixed crash when adding/removing audio bus + fixed crashes in undo/redo

- #930

editor/src/audio/mod.rs

@@ -51,7 +51,7 @@ use crate::{
     plugins::inspector::editors::resource::{ResourceFieldBuilder, ResourceFieldMessage},
     scene::{
         commands::{
-            effect::{AddAudioBusCommand, LinkAudioBuses, RemoveAudioBusCommand},
+            effect::{AddOrRemoveAudioBusCommand, LinkAudioBuses},
             sound_context::{
                 SetDistanceModelCommand, SetHrtfRendererHrirSphereResource, SetRendererCommand,
             },
@@ -189,10 +189,11 @@ fn fetch_possible_parent_buses(
     let mut stack = vec![graph.primary_bus_handle()];
     let mut result = Vec::new();
     while let Some(other_bus) = stack.pop() {
-        let other_bus_ref = graph.try_get_bus_ref(other_bus).expect("Malformed graph!");
-        if other_bus != bus {
-            result.push((other_bus, other_bus_ref.name().to_owned()));
-            stack.extend_from_slice(other_bus_ref.children());
+        if let Ok(other_bus_ref) = graph.try_get_bus_ref(other_bus) {
+            if other_bus != bus {
+                result.push((other_bus, other_bus_ref.name().to_owned()));
+                stack.extend_from_slice(other_bus_ref.children());
+            }
         }
     }
     result
@@ -375,7 +376,7 @@ impl AudioPanel {
     ) {
         if let Some(ButtonMessage::Click) = message.data() {
             if message.destination() == self.add_bus {
-                sender.do_command(AddAudioBusCommand::new(AudioBus::new(
+                sender.do_command(AddOrRemoveAudioBusCommand::new_add(AudioBus::new(
                     "AudioBus".to_string(),
                 )))
             } else if message.destination() == self.remove_bus {
@@ -385,7 +386,7 @@ impl AudioPanel {
                     ))];
 
                     for &bus in &selection.buses {
-                        commands.push(Command::new(RemoveAudioBusCommand::new(bus)));
+                        commands.push(Command::new(AddOrRemoveAudioBusCommand::new_remove(bus)));
                     }
 
                     sender.do_command(CommandGroup::from(commands));

editor/src/scene/commands/effect.rs

@@ -25,107 +25,85 @@ use crate::fyrox::{
 use crate::{command::CommandContext, CommandTrait, GameSceneContext};
 
 #[derive(Debug)]
-pub struct AddAudioBusCommand {
+pub struct AddOrRemoveAudioBusCommand {
     bus: Option<AudioBus>,
     handle: Handle<AudioBus>,
     ticket: Option<Ticket<AudioBus>>,
+    add: bool,
 }
 
-impl AddAudioBusCommand {
-    pub fn new(bus: AudioBus) -> Self {
+impl AddOrRemoveAudioBusCommand {
+    pub fn new_add(bus: AudioBus) -> Self {
         Self {
             bus: Some(bus),
             handle: Default::default(),
             ticket: None,
+            add: true,
         }
     }
-}
 
-impl CommandTrait for AddAudioBusCommand {
-    fn name(&mut self, _: &dyn CommandContext) -> String {
-        "Add Effect".to_owned()
-    }
-
-    fn execute(&mut self, context: &mut dyn CommandContext) {
-        let context = context.get_mut::<GameSceneContext>();
-        let mut state = context.scene.graph.sound_context.state();
-        let parent = state.bus_graph_ref().primary_bus_handle();
-        self.handle = state
-            .bus_graph_mut()
-            .add_bus(self.bus.take().unwrap(), parent);
-    }
-
-    fn revert(&mut self, context: &mut dyn CommandContext) {
-        let context = context.get_mut::<GameSceneContext>();
-        let (ticket, effect) = context
-            .scene
-            .graph
-            .sound_context
-            .state()
-            .bus_graph_mut()
-            .try_take_reserve_bus(self.handle)
-            .unwrap();
-        self.bus = Some(effect);
-        self.ticket = Some(ticket);
-    }
-
-    fn finalize(&mut self, context: &mut dyn CommandContext) {
-        let context = context.get_mut::<GameSceneContext>();
-        if let Some(ticket) = self.ticket.take() {
-            context
-                .scene
-                .graph
-                .sound_context
-                .state()
-                .bus_graph_mut()
-                .forget_bus_ticket(ticket);
-        }
-    }
-}
-
-#[derive(Debug)]
-pub struct RemoveAudioBusCommand {
-    bus: Option<AudioBus>,
-    handle: Handle<AudioBus>,
-    ticket: Option<Ticket<AudioBus>>,
-}
-
-impl RemoveAudioBusCommand {
-    pub fn new(handle: Handle<AudioBus>) -> Self {
+    pub fn new_remove(handle: Handle<AudioBus>) -> Self {
         Self {
             bus: None,
             handle,
             ticket: None,
+            add: false,
         }
     }
-}
 
-impl CommandTrait for RemoveAudioBusCommand {
-    fn name(&mut self, _: &dyn CommandContext) -> String {
-        "Remove Effect".to_owned()
+    fn add(&mut self, context: &mut dyn CommandContext) {
+        let context = context.get_mut::<GameSceneContext>();
+        let mut state = context.scene.graph.sound_context.state();
+        let parent = state.bus_graph_ref().primary_bus_handle();
+        if let Some(bus) = self.bus.take() {
+            let bus_graph = state.bus_graph_mut();
+            if let Some(ticket) = self.ticket.take() {
+                self.handle = bus_graph.put_bus_back(ticket, bus);
+            } else {
+                self.handle = bus_graph.add_bus(bus, parent);
+            }
+        }
     }
 
-    fn execute(&mut self, context: &mut dyn CommandContext) {
+    fn remove(&mut self, context: &mut dyn CommandContext) {
         let context = context.get_mut::<GameSceneContext>();
-        let (ticket, effect) = context
+        if let Ok((ticket, effect)) = context
             .scene
             .graph
             .sound_context
             .state()
             .bus_graph_mut()
             .try_take_reserve_bus(self.handle)
-            .unwrap();
-        self.bus = Some(effect);
-        self.ticket = Some(ticket);
+        {
+            self.bus = Some(effect);
+            self.ticket = Some(ticket);
+        }
+    }
+}
+
+impl CommandTrait for AddOrRemoveAudioBusCommand {
+    fn name(&mut self, _: &dyn CommandContext) -> String {
+        if self.add {
+            "Add Audio Bus".to_owned()
+        } else {
+            "Remove Audio Bus".to_owned()
+        }
+    }
+
+    fn execute(&mut self, context: &mut dyn CommandContext) {
+        if self.add {
+            self.add(context)
+        } else {
+            self.remove(context)
+        }
     }
 
     fn revert(&mut self, context: &mut dyn CommandContext) {
-        let context = context.get_mut::<GameSceneContext>();
-        let mut state = context.scene.graph.sound_context.state();
-        let parent = state.bus_graph_ref().primary_bus_handle();
-        self.handle = state
-            .bus_graph_mut()
-            .add_bus(self.bus.take().unwrap(), parent);
+        if self.add {
+            self.remove(context);
+        } else {
+            self.add(context);
+        }
     }
 
     fn finalize(&mut self, context: &mut dyn CommandContext) {