diff --git a/checkstyle.json b/checkstyle.json
index d9200ea12..445f82b42 100644
--- a/checkstyle.json
+++ b/checkstyle.json
@@ -193,7 +193,8 @@
     {
       "props": {
         "max": 1000,
-        "ignoreEmptyLines": true
+        "ignoreEmptyLines": true,
+        "severity": "IGNORE"
       },
       "type": "FileLength"
     },
@@ -232,7 +233,7 @@
     },
     {
       "props": {
-        "ignoreReturnAssignments": false,
+        "ignoreReturnAssignments": true,
         "severity": "WARNING"
       },
       "type": "InnerAssignment"
@@ -392,12 +393,13 @@
     },
     {
       "props": {
+        "oldFunctionTypePolicy": "none",
+        "unaryOpPolicy": "none",
+        "intervalOpPolicy": "none",
+
         "newFunctionTypePolicy": "around",
         "ternaryOpPolicy": "around",
-        "unaryOpPolicy": "none",
-        "oldFunctionTypePolicy": "around",
         "boolOpPolicy": "around",
-        "intervalOpPolicy": "none",
         "assignOpPolicy": "around",
         "bitwiseOpPolicy": "around",
         "arithmeticOpPolicy": "around",
@@ -623,7 +625,9 @@
       "type": "UnusedImport"
     },
     {
-      "props": {},
+      "props": {
+        "severity": "WARNING"
+      },
       "type": "UnusedLocalVar"
     },
     {
diff --git a/hmm.json b/hmm.json
index ca2bfcfbe..914d9ef58 100644
--- a/hmm.json
+++ b/hmm.json
@@ -42,14 +42,14 @@
       "name": "haxeui-core",
       "type": "git",
       "dir": null,
-      "ref": "e5cf78d",
+      "ref": "59157d2",
       "url": "https://github.com/haxeui/haxeui-core/"
     },
     {
       "name": "haxeui-flixel",
       "type": "git",
       "dir": null,
-      "ref": "f03bb6d",
+      "ref": "d353389",
       "url": "https://github.com/haxeui/haxeui-flixel"
     },
     {
diff --git a/source/funkin/input/TurboKeyHandler.hx b/source/funkin/input/TurboKeyHandler.hx
new file mode 100644
index 000000000..9181f836b
--- /dev/null
+++ b/source/funkin/input/TurboKeyHandler.hx
@@ -0,0 +1,116 @@
+package funkin.input;
+
+import flixel.input.keyboard.FlxKey;
+import flixel.FlxBasic;
+
+/**
+ * Handles repeating behavior when holding down a key or key combination.
+ * 
+ * When the `keys` are pressed, `activated` will be true for the first frame,
+ * then wait `delay` seconds before becoming true for one frame every `interval` seconds.
+ * 
+ * Example: Pressing Ctrl+Z will undo, while holding Ctrl+Z will start to undo repeatedly.
+ */
+class TurboKeyHandler extends FlxBasic
+{
+  /**
+   * Default delay before repeating.
+   */
+  static inline final DEFAULT_DELAY:Float = 0.4;
+
+  /**
+   * Default interval between repeats.
+   */
+  static inline final DEFAULT_INTERVAL:Float = 0.1;
+
+  /**
+   * Whether all of the keys for this handler are pressed.
+   */
+  public var allPressed(get, null):Bool;
+
+  /**
+   * Whether all of the keys for this handler are activated,
+   * and the handler is ready to repeat.
+   */
+  public var activated(default, null):Bool = false;
+
+  var keys:Array<FlxKey>;
+  var delay:Float;
+  var interval:Float;
+
+  var allPressedTime:Float = 0;
+
+  function new(keys:Array<FlxKey>, delay:Float = DEFAULT_DELAY, interval:Float = DEFAULT_INTERVAL)
+  {
+    super();
+    this.keys = keys;
+    this.delay = delay;
+    this.interval = interval;
+  }
+
+  function get_allPressed():Bool
+  {
+    if (keys == null || keys.length == 0) return false;
+    if (keys.length == 1) return FlxG.keys.anyPressed(keys);
+
+    // Check if ANY keys are unpressed
+    for (key in keys)
+    {
+      if (!FlxG.keys.anyPressed([key])) return false;
+    }
+    return true;
+  }
+
+  public override function update(elapsed:Float):Void
+  {
+    super.update(elapsed);
+
+    if (allPressed)
+    {
+      if (allPressedTime == 0)
+      {
+        activated = true;
+      }
+      else if (allPressedTime >= (delay + interval))
+      {
+        activated = true;
+        allPressedTime -= interval;
+      }
+      else
+      {
+        activated = false;
+      }
+      allPressedTime += elapsed;
+    }
+    else
+    {
+      allPressedTime = 0;
+      activated = false;
+    }
+  }
+
+  /**
+   * Builds a TurboKeyHandler that monitors from a single key.
+   * @param inputKey The key to monitor.
+   * @param delay How long to wait before repeating.
+   * @param repeatDelay How long to wait between repeats.
+   * @return A TurboKeyHandler
+   */
+  public static overload inline extern function build(inputKey:FlxKey, ?delay:Float = DEFAULT_DELAY, ?interval:Float = DEFAULT_INTERVAL):TurboKeyHandler
+  {
+    return new TurboKeyHandler([inputKey], delay, interval);
+  }
+
+  /**
+   * Builds a TurboKeyHandler that monitors a key combination.
+   * @param inputKeys The combination of keys to monitor.
+   * @param delay How long to wait before repeating.
+   * @param repeatDelay How long to wait between repeats.
+   * @return A TurboKeyHandler
+   */
+  public static overload inline extern function build(inputKeys:Array<FlxKey>, ?delay:Float = DEFAULT_DELAY,
+      ?interval:Float = DEFAULT_INTERVAL):TurboKeyHandler
+  {
+    return new TurboKeyHandler(inputKeys, delay, interval);
+  }
+}
diff --git a/source/funkin/modding/module/Module.hx b/source/funkin/modding/module/Module.hx
index 0d76c2c14..d1a54b619 100644
--- a/source/funkin/modding/module/Module.hx
+++ b/source/funkin/modding/module/Module.hx
@@ -17,8 +17,7 @@ class Module implements IPlayStateScriptedClass implements IStateChangingScripte
 
   function set_active(value:Bool):Bool
   {
-    this.active = value;
-    return value;
+    return this.active = value;
   }
 
   public var moduleId(default, null):String = 'UNKNOWN';
diff --git a/source/funkin/play/character/AnimateAtlasCharacter.hx b/source/funkin/play/character/AnimateAtlasCharacter.hx
index 339662704..483e1b1b8 100644
--- a/source/funkin/play/character/AnimateAtlasCharacter.hx
+++ b/source/funkin/play/character/AnimateAtlasCharacter.hx
@@ -436,22 +436,19 @@ class AnimateAtlasCharacter extends BaseCharacter
     if (!exists || x == value) return x; // early return (no need to transform)
 
     transformChildren(xTransform, value - x); // offset
-    x = value;
-    return x;
+    return x = value;
   }
 
   override function set_y(value:Float):Float
   {
     if (exists && y != value) transformChildren(yTransform, value - y); // offset
-    y = value;
-    return y;
+    return y = value;
   }
 
   override function set_angle(value:Float):Float
   {
     if (exists && angle != value) transformChildren(angleTransform, value - angle); // offset
-    angle = value;
-    return angle;
+    return angle = value;
   }
 
   override function set_alpha(value:Float):Float
@@ -462,43 +459,37 @@ class AnimateAtlasCharacter extends BaseCharacter
     {
       transformChildren(directAlphaTransform, value);
     }
-    alpha = value;
-    return alpha;
+    return alpha = value;
   }
 
   override function set_facing(value:Int):Int
   {
     if (exists && facing != value) transformChildren(facingTransform, value);
-    facing = value;
-    return facing;
+    return facing = value;
   }
 
   override function set_flipX(value:Bool):Bool
   {
     if (exists && flipX != value) transformChildren(flipXTransform, value);
-    flipX = value;
-    return flipX;
+    return flipX = value;
   }
 
   override function set_flipY(value:Bool):Bool
   {
     if (exists && flipY != value) transformChildren(flipYTransform, value);
-    flipY = value;
-    return flipY;
+    return flipY = value;
   }
 
   override function set_moves(value:Bool):Bool
   {
     if (exists && moves != value) transformChildren(movesTransform, value);
-    moves = value;
-    return moves;
+    return moves = value;
   }
 
   override function set_immovable(value:Bool):Bool
   {
     if (exists && immovable != value) transformChildren(immovableTransform, value);
-    immovable = value;
-    return immovable;
+    return immovable = value;
   }
 
   override function set_solid(value:Bool):Bool
@@ -510,15 +501,13 @@ class AnimateAtlasCharacter extends BaseCharacter
   override function set_color(value:Int):Int
   {
     if (exists && color != value) transformChildren(gColorTransform, value);
-    color = value;
-    return color;
+    return color = value;
   }
 
   override function set_blend(value:BlendMode):BlendMode
   {
     if (exists && blend != value) transformChildren(blendTransform, value);
-    blend = value;
-    return blend;
+    return blend = value;
   }
 
   override function set_clipRect(rect:FlxRect):FlxRect
diff --git a/source/funkin/play/song/Song.hx b/source/funkin/play/song/Song.hx
index 5cd4d1589..853846414 100644
--- a/source/funkin/play/song/Song.hx
+++ b/source/funkin/play/song/Song.hx
@@ -126,8 +126,10 @@ class Song // implements IPlayStateScriptedClass
 
   /**
    * Retrieve the metadata for a specific difficulty, including the chart if it is loaded.
+   * @param diffId The difficulty ID, such as `easy` or `hard`.
+   * @return The difficulty data.
    */
-  public inline function getDifficulty(?diffId:String):SongDifficulty
+  public inline function getDifficulty(diffId:String = null):SongDifficulty
   {
     if (diffId == null) diffId = difficulties.keys().array()[0];
 
diff --git a/source/funkin/play/stage/Bopper.hx b/source/funkin/play/stage/Bopper.hx
index 1c03cb7bc..09aa910e0 100644
--- a/source/funkin/play/stage/Bopper.hx
+++ b/source/funkin/play/stage/Bopper.hx
@@ -70,8 +70,7 @@ class Bopper extends StageProp implements IPlayStateScriptedClass
 
     this.x += xDiff;
     this.y += yDiff;
-    globalOffsets = value;
-    return value;
+    return globalOffsets = value;
   }
 
   var animOffsets(default, set):Array<Float> = [0, 0];
diff --git a/source/funkin/ui/debug/charting/ChartEditorDialogHandler.hx b/source/funkin/ui/debug/charting/ChartEditorDialogHandler.hx
index cecbbfb64..4240773e4 100644
--- a/source/funkin/ui/debug/charting/ChartEditorDialogHandler.hx
+++ b/source/funkin/ui/debug/charting/ChartEditorDialogHandler.hx
@@ -1,18 +1,16 @@
 package funkin.ui.debug.charting;
 
-import haxe.io.Path;
-import flixel.FlxSprite;
 import flixel.util.FlxTimer;
 import funkin.input.Cursor;
 import funkin.play.character.BaseCharacter;
 import funkin.play.character.CharacterData.CharacterDataParser;
+import funkin.play.song.Song;
 import funkin.play.song.SongData.SongDataParser;
 import funkin.play.song.SongData.SongPlayableChar;
 import funkin.play.song.SongData.SongTimeChange;
-import haxe.ui.core.Component;
+import haxe.io.Path;
 import haxe.ui.components.Button;
 import haxe.ui.components.DropDown;
-import haxe.ui.components.Image;
 import haxe.ui.components.Label;
 import haxe.ui.components.Link;
 import haxe.ui.components.NumberStepper;
@@ -23,8 +21,10 @@ import haxe.ui.containers.dialogs.Dialogs;
 import haxe.ui.containers.properties.PropertyGrid;
 import haxe.ui.containers.properties.PropertyGroup;
 import haxe.ui.containers.VBox;
-import haxe.ui.events.MouseEvent;
+import haxe.ui.core.Component;
 import haxe.ui.events.UIEvent;
+import haxe.ui.notifications.NotificationManager;
+import haxe.ui.notifications.NotificationType;
 
 using Lambda;
 
@@ -43,7 +43,9 @@ class ChartEditorDialogHandler
   static final CHART_EDITOR_DIALOG_USER_GUIDE_LAYOUT:String = Paths.ui('chart-editor/dialogs/user-guide');
 
   /**
-   * 
+   * Builds and opens a dialog giving brief credits for the chart editor.
+   * @param state The current chart editor state.
+   * @return The dialog that was opened.
    */
   public static inline function openAboutDialog(state:ChartEditorState):Dialog
   {
@@ -52,72 +54,70 @@ class ChartEditorDialogHandler
 
   /**
    * Builds and opens a dialog letting the user create a new chart, open a recent chart, or load from a template.
+   * @param state The current chart editor state.
+   * @param closable Whether the dialog can be closed by the user.
+   * @return The dialog that was opened.
    */
   public static function openWelcomeDialog(state:ChartEditorState, closable:Bool = true):Dialog
   {
     var dialog:Dialog = openDialog(state, CHART_EDITOR_DIALOG_WELCOME_LAYOUT, true, closable);
 
-    // TODO: Add callbacks to the dialog buttons
-
     // Add handlers to the "Create From Song" section.
     var linkCreateBasic:Link = dialog.findComponent('splashCreateFromSongBasic', Link);
-    linkCreateBasic.onClick = (_event) -> {
+    linkCreateBasic.onClick = function(_event) {
+      // Hide the welcome dialog
       dialog.hideDialog(DialogButton.CANCEL);
 
-      // Create song wizard
-      var uploadInstDialog = openUploadInstDialog(state, false);
-      uploadInstDialog.onDialogClosed = (_event) -> {
+      //
+      // Create Song Wizard
+      //
+
+      // Step 1. Upload Instrumental
+      var uploadInstDialog:Dialog = openUploadInstDialog(state, false);
+      uploadInstDialog.onDialogClosed = function(_event) {
         state.isHaxeUIDialogOpen = false;
         if (_event.button == DialogButton.APPLY)
         {
-          var songMetadataDialog = openSongMetadataDialog(state);
-          songMetadataDialog.onDialogClosed = (_event) -> {
+          // Step 2. Song Metadata
+          var songMetadataDialog:Dialog = openSongMetadataDialog(state);
+          songMetadataDialog.onDialogClosed = function(_event) {
             state.isHaxeUIDialogOpen = false;
             if (_event.button == DialogButton.APPLY)
             {
-              var uploadVocalsDialog = openUploadVocalsDialog(state, false);
+              // Step 3. Upload Vocals
+              // NOTE: Uploading vocals is optional, so we don't need to check if the user cancelled the wizard.
+              openUploadVocalsDialog(state, false); // var uploadVocalsDialog:Dialog
+            }
+            else
+            {
+              // User cancelled the wizard! Back to the welcome dialog.
+              openWelcomeDialog(state);
             }
           };
         }
+        else
+        {
+          // User cancelled the wizard! Back to the welcome dialog.
+          openWelcomeDialog(state);
+        }
       };
     }
 
-    // TODO: Get the list of songs and insert them as links into the "Create From Song" section.
-
-    /*
-      var linkTemplateDadBattle:Link = dialog.findComponent('splashTemplateDadBattle', Link);
-      linkTemplateDadBattle.onClick = (_event) ->
-      {
-        dialog.hideDialog(DialogButton.CANCEL);
-
-        // Load song from template
-        state.loadSongAsTemplate('dadbattle');
-      }
-      var linkTemplateBopeebo:Link = dialog.findComponent('splashTemplateBopeebo', Link);
-      linkTemplateBopeebo.onClick = (_event) ->
-      {
-        dialog.hideDialog(DialogButton.CANCEL);
-
-        // Load song from template
-        state.loadSongAsTemplate('bopeebo');
-      }
-     */
-
     var splashTemplateContainer:VBox = dialog.findComponent('splashTemplateContainer', VBox);
 
     var songList:Array<String> = SongDataParser.listSongIds();
 
     for (targetSongId in songList)
     {
-      var songData = SongDataParser.fetchSong(targetSongId);
+      var songData:Song = SongDataParser.fetchSong(targetSongId);
 
       if (songData == null) continue;
 
-      var songName = songData.getDifficulty().songName;
+      var songName:String = songData.getDifficulty().songName;
 
       var linkTemplateSong:Link = new Link();
       linkTemplateSong.text = songName;
-      linkTemplateSong.onClick = (_event) -> {
+      linkTemplateSong.onClick = function(_event) {
         dialog.hideDialog(DialogButton.CANCEL);
 
         // Load song from template
@@ -130,42 +130,99 @@ class ChartEditorDialogHandler
     return dialog;
   }
 
+  /**
+   * Builds and opens a dialog where the user uploads an instrumental for the current song.
+   * @param state The current chart editor state.
+   * @param closable Whether the dialog can be closed by the user.
+   * @return The dialog that was opened.
+   */
   public static function openUploadInstDialog(state:ChartEditorState, ?closable:Bool = true):Dialog
   {
     var dialog:Dialog = openDialog(state, CHART_EDITOR_DIALOG_UPLOAD_INST_LAYOUT, true, closable);
 
+    var buttonCancel:Button = dialog.findComponent('dialogCancel', Button);
+
+    buttonCancel.onClick = function(_event) {
+      dialog.hideDialog(DialogButton.CANCEL);
+    }
+
     var instrumentalBox:Box = dialog.findComponent('instrumentalBox', Box);
 
-    instrumentalBox.onMouseOver = (_event) -> {
+    instrumentalBox.onMouseOver = function(_event) {
       instrumentalBox.swapClass('upload-bg', 'upload-bg-hover');
       Cursor.cursorMode = Pointer;
     }
 
-    instrumentalBox.onMouseOut = (_event) -> {
+    instrumentalBox.onMouseOut = function(_event) {
       instrumentalBox.swapClass('upload-bg-hover', 'upload-bg');
       Cursor.cursorMode = Default;
     }
 
     var onDropFile:String->Void;
 
-    instrumentalBox.onClick = (_event) -> {
-      Dialogs.openBinaryFile("Open Instrumental", [
-        {label: "Audio File (.ogg)", extension: "ogg"}], function(selectedFile) {
+    instrumentalBox.onClick = function(_event) {
+      Dialogs.openBinaryFile('Open Instrumental', [
+        {label: 'Audio File (.ogg)', extension: 'ogg'}], function(selectedFile:SelectedFileInfo) {
           if (selectedFile != null)
           {
-            trace('Selected file: ' + selectedFile);
-            state.loadInstrumentalFromBytes(selectedFile.bytes);
-            dialog.hideDialog(DialogButton.APPLY);
-            removeDropHandler(onDropFile);
+            if (state.loadInstrumentalFromBytes(selectedFile.bytes))
+            {
+              trace('Selected file: ' + selectedFile.fullPath);
+              NotificationManager.instance.addNotification(
+                {
+                  title: 'Success',
+                  body: 'Loaded instrumental track (${selectedFile.name})',
+                  type: NotificationType.Success,
+                  expiryMs: ChartEditorState.NOTIFICATION_DISMISS_TIME
+                });
+
+              dialog.hideDialog(DialogButton.APPLY);
+              removeDropHandler(onDropFile);
+            }
+            else
+            {
+              trace('Failed to load instrumental (${selectedFile.fullPath})');
+
+              NotificationManager.instance.addNotification(
+                {
+                  title: 'Failure',
+                  body: 'Failed to load instrumental track (${selectedFile.name})',
+                  type: NotificationType.Error,
+                  expiryMs: ChartEditorState.NOTIFICATION_DISMISS_TIME
+                });
+            }
           }
       });
     }
 
-    onDropFile = (path:String) -> {
-      trace('Dropped file: ' + path);
-      state.loadInstrumentalFromPath(path);
-      dialog.hideDialog(DialogButton.APPLY);
-      removeDropHandler(onDropFile);
+    onDropFile = function(pathStr:String) {
+      var path:Path = new Path(pathStr);
+      trace('Dropped file (${path})');
+      if (state.loadInstrumentalFromPath(path))
+      {
+        // Tell the user the load was successful.
+        NotificationManager.instance.addNotification(
+          {
+            title: 'Success',
+            body: 'Loaded instrumental track (${path.file}.${path.ext})',
+            type: NotificationType.Success,
+            expiryMs: ChartEditorState.NOTIFICATION_DISMISS_TIME
+          });
+
+        dialog.hideDialog(DialogButton.APPLY);
+        removeDropHandler(onDropFile);
+      }
+      else
+      {
+        // Tell the user the load was successful.
+        NotificationManager.instance.addNotification(
+          {
+            title: 'Failure',
+            body: 'Failed to load instrumental track (${path.file}.${path.ext})',
+            type: NotificationType.Error,
+            expiryMs: ChartEditorState.NOTIFICATION_DISMISS_TIME
+          });
+      }
     };
 
     addDropHandler(instrumentalBox, onDropFile);
@@ -213,19 +270,14 @@ class ChartEditorDialogHandler
   {
     // a VERY short timer to wait for the mouse position to update
     new FlxTimer().start(0.01, function(_) {
-      trace("mouseX: " + FlxG.mouse.screenX + ", mouseY: " + FlxG.mouse.screenY);
-
       for (handler in dropHandlers)
       {
         if (handler.component.hitTest(FlxG.mouse.screenX, FlxG.mouse.screenY))
         {
-          trace('File dropped on component! ' + handler.component.id);
           handler.handler(path);
           return;
         }
       }
-
-      trace('File dropped on nothing!' + path);
     });
   }
 
@@ -238,6 +290,12 @@ class ChartEditorDialogHandler
   {
     var dialog:Dialog = openDialog(state, CHART_EDITOR_DIALOG_SONG_METADATA_LAYOUT, true, false);
 
+    var buttonCancel:Button = dialog.findComponent('dialogCancel', Button);
+
+    buttonCancel.onClick = function(_event) {
+      dialog.hideDialog(DialogButton.CANCEL);
+    }
+
     var dialogSongName:TextField = dialog.findComponent('dialogSongName', TextField);
     dialogSongName.onChange = function(event:UIEvent) {
       var valid:Bool = event.target.text != null && event.target.text != '';
@@ -272,25 +330,23 @@ class ChartEditorDialogHandler
 
     var dialogStage:DropDown = dialog.findComponent('dialogStage', DropDown);
     dialogStage.onChange = function(event:UIEvent) {
-      var valid = event.data != null && event.data.id != null;
-
-      if (event.data.id == null) return;
+      if (event.data == null && event.data.id == null) return;
       state.currentSongMetadata.playData.stage = event.data.id;
     };
     state.currentSongMetadata.playData.stage = null;
 
     var dialogNoteSkin:DropDown = dialog.findComponent('dialogNoteSkin', DropDown);
-    dialogNoteSkin.onChange = (event:UIEvent) -> {
+    dialogNoteSkin.onChange = function(event:UIEvent) {
       if (event.data.id == null) return;
       state.currentSongMetadata.playData.noteSkin = event.data.id;
     };
     state.currentSongMetadata.playData.noteSkin = null;
 
     var dialogBPM:NumberStepper = dialog.findComponent('dialogBPM', NumberStepper);
-    dialogBPM.onChange = (event:UIEvent) -> {
+    dialogBPM.onChange = function(event:UIEvent) {
       if (event.value == null || event.value <= 0) return;
 
-      var timeChanges = state.currentSongMetadata.timeChanges;
+      var timeChanges:Array<SongTimeChange> = state.currentSongMetadata.timeChanges;
       if (timeChanges == null || timeChanges.length == 0)
       {
         timeChanges = [new SongTimeChange(-1, 0, event.value, 4, 4, [4, 4, 4, 4])];
@@ -307,11 +363,9 @@ class ChartEditorDialogHandler
 
     var dialogCharGrid:PropertyGrid = dialog.findComponent('dialogCharGrid', PropertyGrid);
     var dialogCharAdd:Button = dialog.findComponent('dialogCharAdd', Button);
-    dialogCharAdd.onClick = (_event) -> {
+    dialogCharAdd.onClick = function(event:UIEvent) {
       var charGroup:PropertyGroup;
-      charGroup = buildCharGroup(state, null, () -> {
-        dialogCharGrid.removeComponent(charGroup);
-      });
+      charGroup = buildCharGroup(state, null, () -> dialogCharGrid.removeComponent(charGroup));
       dialogCharGrid.addComponent(charGroup);
     };
 
@@ -321,18 +375,16 @@ class ChartEditorDialogHandler
     dialogCharGrid.addComponent(buildCharGroup(state, 'bf', null));
 
     var dialogContinue:Button = dialog.findComponent('dialogContinue', Button);
-    dialogContinue.onClick = (_event) -> {
-      dialog.hideDialog(DialogButton.APPLY);
-    };
+    dialogContinue.onClick = (_event) -> dialog.hideDialog(DialogButton.APPLY);
 
     return dialog;
   }
 
-  static function buildCharGroup(state:ChartEditorState, ?key:String = null, removeFunc:Void->Void):PropertyGroup
+  static function buildCharGroup(state:ChartEditorState, key:String = null, removeFunc:Void->Void):PropertyGroup
   {
-    var groupKey = key;
+    var groupKey:String = key;
 
-    var getCharData = () -> {
+    var getCharData:Void->SongPlayableChar = function() {
       if (groupKey == null) groupKey = 'newChar${state.currentSongMetadata.playData.playableChars.keys().count()}';
 
       var result = state.currentSongMetadata.playData.playableChars.get(groupKey);
@@ -344,24 +396,24 @@ class ChartEditorDialogHandler
       return result;
     }
 
-    var moveCharGroup = (target:String) -> {
+    var moveCharGroup:String->Void = function(target:String) {
       var charData = getCharData();
       state.currentSongMetadata.playData.playableChars.remove(groupKey);
       state.currentSongMetadata.playData.playableChars.set(target, charData);
       groupKey = target;
     }
 
-    var removeGroup = () -> {
+    var removeGroup:Void->Void = function() {
       state.currentSongMetadata.playData.playableChars.remove(groupKey);
       removeFunc();
     }
 
-    var charData = getCharData();
+    var charData:SongPlayableChar = getCharData();
 
     var charGroup:PropertyGroup = cast state.buildComponent(CHART_EDITOR_DIALOG_SONG_METADATA_CHARGROUP_LAYOUT);
 
     var charGroupPlayer:DropDown = charGroup.findComponent('charGroupPlayer', DropDown);
-    charGroupPlayer.onChange = (event:UIEvent) -> {
+    charGroupPlayer.onChange = function(event:UIEvent) {
       charGroup.text = event.data.text;
       moveCharGroup(event.data.id);
     };
@@ -373,19 +425,19 @@ class ChartEditorDialogHandler
     }
 
     var charGroupOpponent:DropDown = charGroup.findComponent('charGroupOpponent', DropDown);
-    charGroupOpponent.onChange = (event:UIEvent) -> {
+    charGroupOpponent.onChange = function(event:UIEvent) {
       charData.opponent = event.data.id;
     };
     charGroupOpponent.value = getCharData().opponent;
 
     var charGroupGirlfriend:DropDown = charGroup.findComponent('charGroupGirlfriend', DropDown);
-    charGroupGirlfriend.onChange = (event:UIEvent) -> {
+    charGroupGirlfriend.onChange = function(event:UIEvent) {
       charData.girlfriend = event.data.id;
     };
     charGroupGirlfriend.value = getCharData().girlfriend;
 
     var charGroupRemove:Button = charGroup.findComponent('charGroupRemove', Button);
-    charGroupRemove.onClick = (_event:MouseEvent) -> {
+    charGroupRemove.onClick = function(event:UIEvent) {
       removeGroup();
     };
 
@@ -394,20 +446,31 @@ class ChartEditorDialogHandler
     return charGroup;
   }
 
+  /**
+   * Builds and opens a dialog where the user uploads vocals for the current song.
+   * @param state The current chart editor state.
+   * @param closable Whether the dialog can be closed by the user.
+   * @return The dialog that was opened.
+   */
   public static function openUploadVocalsDialog(state:ChartEditorState, ?closable:Bool = true):Dialog
   {
-    var charIdsForVocals = [];
+    var charIdsForVocals:Array<String> = [];
 
     for (charKey in state.currentSongMetadata.playData.playableChars.keys())
     {
-      var charData = state.currentSongMetadata.playData.playableChars.get(charKey);
+      var charData:SongPlayableChar = state.currentSongMetadata.playData.playableChars.get(charKey);
       charIdsForVocals.push(charKey);
       if (charData.opponent != null) charIdsForVocals.push(charData.opponent);
     }
 
     var dialog:Dialog = openDialog(state, CHART_EDITOR_DIALOG_UPLOAD_VOCALS_LAYOUT, true, closable);
 
-    var dialogContainer = dialog.findComponent('vocalContainer');
+    var dialogContainer:Component = dialog.findComponent('vocalContainer');
+
+    var buttonCancel:Button = dialog.findComponent('dialogCancel', Button);
+    buttonCancel.onClick = function(_event) {
+      dialog.hideDialog(DialogButton.CANCEL);
+    }
 
     var dialogNoVocals:Button = dialog.findComponent('dialogNoVocals', Button);
     dialogNoVocals.onClick = function(_event) {
@@ -421,20 +484,42 @@ class ChartEditorDialogHandler
       var charMetadata:BaseCharacter = CharacterDataParser.fetchCharacter(charKey);
       var charName:String = charMetadata.characterName;
 
-      var vocalsEntry = state.buildComponent(CHART_EDITOR_DIALOG_UPLOAD_VOCALS_ENTRY_LAYOUT);
+      var vocalsEntry:Component = state.buildComponent(CHART_EDITOR_DIALOG_UPLOAD_VOCALS_ENTRY_LAYOUT);
 
       var vocalsEntryLabel:Label = vocalsEntry.findComponent('vocalsEntryLabel', Label);
-      vocalsEntryLabel.text = 'Click to browse for a vocal track for $charName.';
+      vocalsEntryLabel.text = 'Drag and drop vocals for $charName here, or click to browse.';
 
-      var onDropFile:String->Void = function(fullPath:String) {
-        trace('Selected file: $fullPath');
-        var directory:String = Path.directory(fullPath);
-        var filename:String = Path.withoutDirectory(directory);
+      var onDropFile:String->Void = function(pathStr:String) {
+        trace('Selected file: $pathStr');
+        var path:Path = new Path(pathStr);
 
-        vocalsEntryLabel.text = 'Vocals for $charName (click to browse)\n${filename}';
-        state.loadVocalsFromPath(fullPath, charKey);
-        dialogNoVocals.hidden = true;
-        removeDropHandler(onDropFile);
+        if (state.loadVocalsFromPath(path, charKey))
+        {
+          // Tell the user the load was successful.
+          NotificationManager.instance.addNotification(
+            {
+              title: 'Success',
+              body: 'Loaded vocal track for $charName (${path.file}.${path.ext})',
+              type: NotificationType.Success,
+              expiryMs: ChartEditorState.NOTIFICATION_DISMISS_TIME
+            });
+          vocalsEntryLabel.text = 'Vocals for $charName (drag and drop, or click to browse)\nSelected file: ${path.file}.${path.ext}';
+          dialogNoVocals.hidden = true;
+          removeDropHandler(onDropFile);
+        }
+        else
+        {
+          // Vocals failed to load.
+          NotificationManager.instance.addNotification(
+            {
+              title: 'Failure',
+              body: 'Failed to load vocal track (${path.file}.${path.ext})',
+              type: NotificationType.Error,
+              expiryMs: ChartEditorState.NOTIFICATION_DISMISS_TIME
+            });
+
+          vocalsEntryLabel.text = 'Drag and drop vocals for $charName here, or click to browse.';
+        }
       };
 
       vocalsEntry.onClick = function(_event) {
@@ -449,11 +534,10 @@ class ChartEditorDialogHandler
               removeDropHandler(onDropFile);
             }
         });
-
-        // onDropFile
-        addDropHandler(vocalsEntry, onDropFile);
       }
 
+      // onDropFile
+      addDropHandler(vocalsEntry, onDropFile);
       dialogContainer.addComponent(vocalsEntry);
     }
 
@@ -463,14 +547,14 @@ class ChartEditorDialogHandler
       dialog.hideDialog(DialogButton.APPLY);
     };
 
-    // TODO: Redo the logic for file drop handler to be more robust.
-    // We need to distinguish which component the mouse is over when the file is dropped.
-
     return dialog;
   }
 
   /**
    * Builds and opens a dialog displaying the user guide, providing guidance and help on how to use the chart editor.
+   * 
+   * @param state The current chart editor state.
+   * @return The dialog that was opened.
    */
   public static inline function openUserGuideDialog(state:ChartEditorState):Dialog
   {
@@ -490,7 +574,7 @@ class ChartEditorDialogHandler
     dialog.showDialog(modal);
 
     state.isHaxeUIDialogOpen = true;
-    dialog.onDialogClosed = (_event) -> {
+    dialog.onDialogClosed = function(event:UIEvent) {
       state.isHaxeUIDialogOpen = false;
     };
 
diff --git a/source/funkin/ui/debug/charting/ChartEditorState.hx b/source/funkin/ui/debug/charting/ChartEditorState.hx
index a1bda9fcd..63ff44be2 100644
--- a/source/funkin/ui/debug/charting/ChartEditorState.hx
+++ b/source/funkin/ui/debug/charting/ChartEditorState.hx
@@ -1,5 +1,8 @@
 package funkin.ui.debug.charting;
 
+import funkin.ui.debug.charting.ChartEditorCommand;
+import flixel.input.keyboard.FlxKey;
+import funkin.input.TurboKeyHandler;
 import haxe.ui.notifications.NotificationType;
 import haxe.ui.notifications.NotificationManager;
 import haxe.DynamicAccess;
@@ -18,7 +21,6 @@ import funkin.audio.visualize.PolygonSpectogram;
 import funkin.audio.VocalGroup;
 import funkin.input.Cursor;
 import funkin.modding.events.ScriptEvent;
-import funkin.modding.events.ScriptEventDispatcher;
 import funkin.play.HealthIcon;
 import funkin.play.song.Song;
 import funkin.play.song.SongData.SongChartData;
@@ -27,8 +29,6 @@ import funkin.play.song.SongData.SongEventData;
 import funkin.play.song.SongData.SongMetadata;
 import funkin.play.song.SongData.SongNoteData;
 import funkin.play.song.SongDataUtils;
-import funkin.play.song.SongSerializer;
-import funkin.ui.debug.charting.ChartEditorCommand;
 import funkin.ui.debug.charting.ChartEditorThemeHandler.ChartEditorTheme;
 import funkin.ui.debug.charting.ChartEditorToolboxHandler.ChartEditorToolMode;
 import funkin.ui.haxeui.components.CharacterPlayer;
@@ -37,23 +37,16 @@ import funkin.util.Constants;
 import funkin.util.FileUtil;
 import funkin.util.DateUtil;
 import funkin.util.SerializerUtil;
-import haxe.ui.components.Button;
-import haxe.ui.components.CheckBox;
 import haxe.ui.components.Label;
 import haxe.ui.components.Slider;
 import haxe.ui.containers.dialogs.Dialog;
-import haxe.ui.containers.dialogs.MessageBox;
-import haxe.ui.containers.menus.MenuCheckBox;
 import haxe.ui.containers.menus.MenuItem;
-import haxe.ui.containers.SideBar;
 import haxe.ui.containers.TreeView;
 import haxe.ui.containers.TreeViewNode;
 import haxe.ui.core.Component;
 import haxe.ui.core.Screen;
 import haxe.ui.events.DragEvent;
-import haxe.ui.events.MouseEvent;
 import haxe.ui.events.UIEvent;
-import lime.media.AudioBuffer;
 import funkin.util.WindowUtil;
 import openfl.display.BitmapData;
 import openfl.geom.Rectangle;
@@ -523,14 +516,34 @@ class ChartEditorState extends HaxeUIState
   var redoHistory:Array<ChartEditorCommand> = [];
 
   /**
-   * Variable used to track how long the user has been holding the undo keybind.
+   * Handler used to track how long the user has been holding the undo keybind.
    */
-  var undoHeldTime:Float = 0.0;
+  var undoKeyHandler:TurboKeyHandler = TurboKeyHandler.build([FlxKey.CONTROL, FlxKey.Z]);
 
   /**
    * Variable used to track how long the user has been holding the redo keybind.
    */
-  var redoHeldTime:Float = 0.0;
+  var redoKeyHandler:TurboKeyHandler = TurboKeyHandler.build([FlxKey.CONTROL, FlxKey.Y]);
+
+  /**
+   * Variable used to track how long the user has been holding the up keybind.
+   */
+  var upKeyHandler:TurboKeyHandler = TurboKeyHandler.build(FlxKey.UP);
+
+  /**
+   * Variable used to track how long the user has been holding the down keybind.
+   */
+  var downKeyHandler:TurboKeyHandler = TurboKeyHandler.build(FlxKey.DOWN);
+
+  /**
+   * Variable used to track how long the user has been holding the page-up keybind.
+   */
+  var pageUpKeyHandler:TurboKeyHandler = TurboKeyHandler.build(FlxKey.PAGEUP);
+
+  /**
+   * Variable used to track how long the user has been holding the page-down keybind.
+   */
+  var pageDownKeyHandler:TurboKeyHandler = TurboKeyHandler.build(FlxKey.PAGEDOWN);
 
   /**
    * Whether the undo/redo histories have changed since the last time the UI was updated.
@@ -728,8 +741,7 @@ class ChartEditorState extends HaxeUIState
 
   function set_currentSongChartEventData(value:Array<SongEventData>):Array<SongEventData>
   {
-    currentSongChartData.events = value;
-    return value;
+    return currentSongChartData.events = value;
   }
 
   public var currentSongNoteSkin(get, set):String;
@@ -911,7 +923,7 @@ class ChartEditorState extends HaxeUIState
     super(CHART_EDITOR_LAYOUT);
   }
 
-  override function create()
+  override function create():Void
   {
     // Get rid of any music from the previous state.
     FlxG.sound.music.stop();
@@ -931,18 +943,14 @@ class ChartEditorState extends HaxeUIState
 
     // Setup the onClick listeners for the UI after it's been created.
     setupUIListeners();
+    setupTurboKeyHandlers();
 
     setupAutoSave();
 
-    // TODO: We should be loading the music later when the user requests it.
-    // loadDefaultMusic();
-
-    // TODO: Change to false.
-    var canCloseInitialDialog = true;
-    ChartEditorDialogHandler.openWelcomeDialog(this, canCloseInitialDialog);
+    ChartEditorDialogHandler.openWelcomeDialog(this, false);
   }
 
-  function buildDefaultSongData()
+  function buildDefaultSongData():Void
   {
     selectedVariation = Constants.DEFAULT_VARIATION;
     selectedDifficulty = Constants.DEFAULT_DIFFICULTY;
@@ -959,7 +967,7 @@ class ChartEditorState extends HaxeUIState
   /**
    * Builds and displays the background sprite.
    */
-  function buildBackground()
+  function buildBackground():Void
   {
     menuBG = new FlxSprite().loadGraphic(Paths.image('menuDesat'));
     add(menuBG);
@@ -973,7 +981,7 @@ class ChartEditorState extends HaxeUIState
   /**
    * Builds and displays the chart editor grid, including the playhead and cursor.
    */
-  function buildGrid()
+  function buildGrid():Void
   {
     gridTiledSprite = new FlxTiledSprite(gridBitmap, gridBitmap.width, 1000, false, true);
     gridTiledSprite.x = FlxG.width / 2 - GRID_SIZE * STRUMLINE_SIZE; // Center the grid.
@@ -1032,7 +1040,7 @@ class ChartEditorState extends HaxeUIState
     add(healthIconBF);
   }
 
-  function buildSelectionBox()
+  function buildSelectionBox():Void
   {
     selectionBoxSprite.scrollFactor.set(0, 0);
     add(selectionBoxSprite);
@@ -1040,7 +1048,7 @@ class ChartEditorState extends HaxeUIState
     setSelectionBoxBounds();
   }
 
-  function setSelectionBoxBounds(?bounds:FlxRect = null)
+  function setSelectionBoxBounds(?bounds:FlxRect = null):Void
   {
     if (bounds == null)
     {
@@ -1058,7 +1066,7 @@ class ChartEditorState extends HaxeUIState
     }
   }
 
-  function buildSpectrogram(target:FlxSound)
+  function buildSpectrogram(target:FlxSound):Void
   {
     gridSpectrogram = new PolygonSpectogram(target, SPECTROGRAM_COLOR, FlxG.height / 2, Math.floor(FlxG.height / 2));
     // Halfway through the grid.
@@ -1075,7 +1083,7 @@ class ChartEditorState extends HaxeUIState
   /**
    * Builds the group that will hold all the notes.
    */
-  function buildNoteGroup()
+  function buildNoteGroup():Void
   {
     renderedNotes = new FlxTypedSpriteGroup<ChartEditorNoteSprite>();
     renderedNotes.setPosition(gridTiledSprite.x, gridTiledSprite.y);
@@ -1148,23 +1156,23 @@ class ChartEditorState extends HaxeUIState
   {
     // Add functionality to the playbar.
 
-    addUIClickListener('playbarPlay', (event:MouseEvent) -> toggleAudioPlayback());
-    addUIClickListener('playbarStart', (event:MouseEvent) -> playbarButtonPressed = 'playbarStart');
-    addUIClickListener('playbarBack', (event:MouseEvent) -> playbarButtonPressed = 'playbarBack');
-    addUIClickListener('playbarForward', (event:MouseEvent) -> playbarButtonPressed = 'playbarForward');
-    addUIClickListener('playbarEnd', (event:MouseEvent) -> playbarButtonPressed = 'playbarEnd');
+    addUIClickListener('playbarPlay', _ -> toggleAudioPlayback());
+    addUIClickListener('playbarStart', _ -> playbarButtonPressed = 'playbarStart');
+    addUIClickListener('playbarBack', _ -> playbarButtonPressed = 'playbarBack');
+    addUIClickListener('playbarForward', _ -> playbarButtonPressed = 'playbarForward');
+    addUIClickListener('playbarEnd', _ -> playbarButtonPressed = 'playbarEnd');
 
     // Add functionality to the menu items.
 
-    addUIClickListener('menubarItemNewChart', (event:MouseEvent) -> ChartEditorDialogHandler.openWelcomeDialog(this, true));
-    addUIClickListener('menubarItemSaveChartAs', (event:MouseEvent) -> exportAllSongData());
-    addUIClickListener('menubarItemLoadInst', (event:MouseEvent) -> ChartEditorDialogHandler.openUploadInstDialog(this, true));
+    addUIClickListener('menubarItemNewChart', _ -> ChartEditorDialogHandler.openWelcomeDialog(this, true));
+    addUIClickListener('menubarItemSaveChartAs', _ -> exportAllSongData());
+    addUIClickListener('menubarItemLoadInst', _ -> ChartEditorDialogHandler.openUploadInstDialog(this, true));
 
-    addUIClickListener('menubarItemUndo', (event:MouseEvent) -> undoLastCommand());
+    addUIClickListener('menubarItemUndo', _ -> undoLastCommand());
 
-    addUIClickListener('menubarItemRedo', (event:MouseEvent) -> redoLastCommand());
+    addUIClickListener('menubarItemRedo', _ -> redoLastCommand());
 
-    addUIClickListener('menubarItemCopy', (event:MouseEvent) -> {
+    addUIClickListener('menubarItemCopy', function(_) {
       // Doesn't use a command because it's not undoable.
       SongDataUtils.writeItemsToClipboard(
         {
@@ -1173,15 +1181,11 @@ class ChartEditorState extends HaxeUIState
         });
     });
 
-    addUIClickListener('menubarItemCut', (event:MouseEvent) -> {
-      performCommand(new CutItemsCommand(currentNoteSelection, currentEventSelection));
-    });
+    addUIClickListener('menubarItemCut', _ -> performCommand(new CutItemsCommand(currentNoteSelection, currentEventSelection)));
 
-    addUIClickListener('menubarItemPaste', (event:MouseEvent) -> {
-      performCommand(new PasteItemsCommand(scrollPositionInMs + playheadPositionInMs));
-    });
+    addUIClickListener('menubarItemPaste', _ -> performCommand(new PasteItemsCommand(scrollPositionInMs + playheadPositionInMs)));
 
-    addUIClickListener('menubarItemDelete', (event:MouseEvent) -> {
+    addUIClickListener('menubarItemDelete', function(_) {
       if (currentNoteSelection.length > 0 && currentEventSelection.length > 0)
       {
         performCommand(new RemoveItemsCommand(currentNoteSelection, currentEventSelection));
@@ -1200,84 +1204,60 @@ class ChartEditorState extends HaxeUIState
       }
     });
 
-    addUIClickListener('menubarItemSelectAll', (event:MouseEvent) -> {
-      performCommand(new SelectAllItemsCommand(currentNoteSelection, currentEventSelection));
-    });
+    addUIClickListener('menubarItemSelectAll', _ -> performCommand(new SelectAllItemsCommand(currentNoteSelection, currentEventSelection)));
 
-    addUIClickListener('menubarItemSelectInverse', (event:MouseEvent) -> {
-      performCommand(new InvertSelectedItemsCommand(currentNoteSelection, currentEventSelection));
-    });
+    addUIClickListener('menubarItemSelectInverse', _ -> performCommand(new InvertSelectedItemsCommand(currentNoteSelection, currentEventSelection)));
 
-    addUIClickListener('menubarItemSelectNone', (event:MouseEvent) -> {
-      performCommand(new DeselectAllItemsCommand(currentNoteSelection, currentEventSelection));
-    });
+    addUIClickListener('menubarItemSelectNone', _ -> performCommand(new DeselectAllItemsCommand(currentNoteSelection, currentEventSelection)));
 
-    addUIClickListener('menubarItemSelectRegion', (event:MouseEvent) ->
-      {
-        // TODO: Implement this.
-      });
+    // TODO: Implement these.
+    // addUIClickListener('menubarItemSelectRegion', _ -> doSomething());
+    // addUIClickListener('menubarItemSelectBeforeCursor', _ -> doSomething());
+    // addUIClickListener('menubarItemSelectAfterCursor', _ -> doSomething());
 
-    addUIClickListener('menubarItemSelectBeforeCursor', (event:MouseEvent) ->
-      {
-        // TODO: Implement this.
-      });
+    addUIClickListener('menubarItemAbout', _ -> ChartEditorDialogHandler.openAboutDialog(this));
 
-    addUIClickListener('menubarItemSelectAfterCursor', (event:MouseEvent) ->
-      {
-        // TODO: Implement this.
-      });
+    addUIClickListener('menubarItemUserGuide', _ -> ChartEditorDialogHandler.openUserGuideDialog(this));
 
-    addUIClickListener('menubarItemAbout', (event:MouseEvent) -> ChartEditorDialogHandler.openAboutDialog(this));
-
-    addUIClickListener('menubarItemUserGuide', (event:MouseEvent) -> ChartEditorDialogHandler.openUserGuideDialog(this));
-
-    addUIChangeListener('menubarItemDownscroll', (event:UIEvent) -> {
-      isViewDownscroll = event.value;
-    });
+    addUIChangeListener('menubarItemDownscroll', event -> isViewDownscroll = event.value);
     setUICheckboxSelected('menubarItemDownscroll', isViewDownscroll);
 
-    addUIChangeListener('menuBarItemThemeLight', (event:UIEvent) -> {
+    addUIChangeListener('menuBarItemThemeLight', function(event:UIEvent) {
       if (event.target.value) currentTheme = ChartEditorTheme.Light;
     });
     setUICheckboxSelected('menuBarItemThemeLight', currentTheme == ChartEditorTheme.Light);
 
-    addUIChangeListener('menuBarItemThemeDark', (event:UIEvent) -> {
+    addUIChangeListener('menuBarItemThemeDark', function(event:UIEvent) {
       if (event.target.value) currentTheme = ChartEditorTheme.Dark;
     });
     setUICheckboxSelected('menuBarItemThemeDark', currentTheme == ChartEditorTheme.Dark);
 
-    addUIChangeListener('menubarItemMetronomeEnabled', (event:UIEvent) -> {
-      shouldPlayMetronome = event.value;
-    });
+    addUIChangeListener('menubarItemMetronomeEnabled', event -> shouldPlayMetronome = event.value);
     setUICheckboxSelected('menubarItemMetronomeEnabled', shouldPlayMetronome);
 
-    addUIChangeListener('menubarItemPlayerHitsounds', (event:UIEvent) -> {
-      hitsoundsEnabledPlayer = event.value;
-    });
+    addUIChangeListener('menubarItemPlayerHitsounds', event -> hitsoundsEnabledPlayer = event.value);
     setUICheckboxSelected('menubarItemPlayerHitsounds', hitsoundsEnabledPlayer);
 
-    addUIChangeListener('menubarItemOpponentHitsounds', (event:UIEvent) -> {
-      hitsoundsEnabledOpponent = event.value;
-    });
+    addUIChangeListener('menubarItemOpponentHitsounds', event -> hitsoundsEnabledOpponent = event.value);
     setUICheckboxSelected('menubarItemOpponentHitsounds', hitsoundsEnabledOpponent);
 
     var instVolumeLabel:Label = findComponent('menubarLabelVolumeInstrumental', Label);
-    addUIChangeListener('menubarItemVolumeInstrumental', (event:UIEvent) -> {
+    addUIChangeListener('menubarItemVolumeInstrumental', function(event:UIEvent) {
       var volume:Float = event.value / 100.0;
       if (audioInstTrack != null) audioInstTrack.volume = volume;
       instVolumeLabel.text = 'Instrumental - ${Std.int(event.value)}%';
     });
 
     var vocalsVolumeLabel:Label = findComponent('menubarLabelVolumeVocals', Label);
-    addUIChangeListener('menubarItemVolumeVocals', (event:UIEvent) -> {
+    addUIChangeListener('menubarItemVolumeVocals', function(event:UIEvent) {
       var volume:Float = event.value / 100.0;
       if (audioVocalTrackGroup != null) audioVocalTrackGroup.volume = volume;
       vocalsVolumeLabel.text = 'Vocals - ${Std.int(event.value)}%';
     });
 
     var playbackSpeedLabel:Label = findComponent('menubarLabelPlaybackSpeed', Label);
-    addUIChangeListener('menubarItemPlaybackSpeed', (event:UIEvent) -> {
-      var pitch = event.value * 2.0 / 100.0;
+    addUIChangeListener('menubarItemPlaybackSpeed', function(event:UIEvent) {
+      var pitch:Float = event.value * 2.0 / 100.0;
       #if FLX_PITCH
       if (audioInstTrack != null) audioInstTrack.pitch = pitch;
       if (audioVocalTrackGroup != null) audioVocalTrackGroup.pitch = pitch;
@@ -1285,40 +1265,45 @@ class ChartEditorState extends HaxeUIState
       playbackSpeedLabel.text = 'Playback Speed - ${Std.int(pitch * 100) / 100}x';
     });
 
-    addUIChangeListener('menubarItemToggleToolboxTools', (event:UIEvent) -> {
-      ChartEditorToolboxHandler.setToolboxState(this, CHART_EDITOR_TOOLBOX_TOOLS_LAYOUT, event.value);
-    });
-    // setUICheckboxSelected('menubarItemToggleToolboxTools', true);
-    addUIChangeListener('menubarItemToggleToolboxNotes', (event:UIEvent) -> {
-      ChartEditorToolboxHandler.setToolboxState(this, CHART_EDITOR_TOOLBOX_NOTEDATA_LAYOUT, event.value);
-    });
-    addUIChangeListener('menubarItemToggleToolboxEvents', (event:UIEvent) -> {
-      ChartEditorToolboxHandler.setToolboxState(this, CHART_EDITOR_TOOLBOX_EVENTDATA_LAYOUT, event.value);
-    });
-    addUIChangeListener('menubarItemToggleToolboxDifficulty', (event:UIEvent) -> {
-      ChartEditorToolboxHandler.setToolboxState(this, CHART_EDITOR_TOOLBOX_DIFFICULTY_LAYOUT, event.value);
-    });
-    addUIChangeListener('menubarItemToggleToolboxMetadata', (event:UIEvent) -> {
-      ChartEditorToolboxHandler.setToolboxState(this, CHART_EDITOR_TOOLBOX_METADATA_LAYOUT, event.value);
-    });
-    addUIChangeListener('menubarItemToggleToolboxCharacters', (event:UIEvent) -> {
-      ChartEditorToolboxHandler.setToolboxState(this, CHART_EDITOR_TOOLBOX_CHARACTERS_LAYOUT, event.value);
-    });
-    addUIChangeListener('menubarItemToggleToolboxPlayerPreview', (event:UIEvent) -> {
-      ChartEditorToolboxHandler.setToolboxState(this, CHART_EDITOR_TOOLBOX_PLAYER_PREVIEW_LAYOUT, event.value);
-    });
-    addUIChangeListener('menubarItemToggleToolboxOpponentPreview', (event:UIEvent) -> {
-      ChartEditorToolboxHandler.setToolboxState(this, CHART_EDITOR_TOOLBOX_OPPONENT_PREVIEW_LAYOUT, event.value);
-    });
+    addUIChangeListener('menubarItemToggleToolboxTools',
+      event -> ChartEditorToolboxHandler.setToolboxState(this, CHART_EDITOR_TOOLBOX_TOOLS_LAYOUT, event.value));
+    addUIChangeListener('menubarItemToggleToolboxNotes',
+      event -> ChartEditorToolboxHandler.setToolboxState(this, CHART_EDITOR_TOOLBOX_NOTEDATA_LAYOUT, event.value));
+    addUIChangeListener('menubarItemToggleToolboxEvents',
+      event -> ChartEditorToolboxHandler.setToolboxState(this, CHART_EDITOR_TOOLBOX_EVENTDATA_LAYOUT, event.value));
+    addUIChangeListener('menubarItemToggleToolboxDifficulty',
+      event -> ChartEditorToolboxHandler.setToolboxState(this, CHART_EDITOR_TOOLBOX_DIFFICULTY_LAYOUT, event.value));
+    addUIChangeListener('menubarItemToggleToolboxMetadata',
+      event -> ChartEditorToolboxHandler.setToolboxState(this, CHART_EDITOR_TOOLBOX_METADATA_LAYOUT, event.value));
+    addUIChangeListener('menubarItemToggleToolboxCharacters',
+      event -> ChartEditorToolboxHandler.setToolboxState(this, CHART_EDITOR_TOOLBOX_CHARACTERS_LAYOUT, event.value));
+    addUIChangeListener('menubarItemToggleToolboxPlayerPreview',
+      event -> ChartEditorToolboxHandler.setToolboxState(this, CHART_EDITOR_TOOLBOX_PLAYER_PREVIEW_LAYOUT, event.value));
+    addUIChangeListener('menubarItemToggleToolboxOpponentPreview',
+      event -> ChartEditorToolboxHandler.setToolboxState(this, CHART_EDITOR_TOOLBOX_OPPONENT_PREVIEW_LAYOUT, event.value));
 
     // TODO: Pass specific HaxeUI components to add context menus to them.
     registerContextMenu(null, Paths.ui('chart-editor/context/test'));
   }
 
+  /**
+   * Initialize TurboKeyHandlers and add them to the state (so `update()` is called)
+   * We can then probe `keyHandler.activated` to see if the key combo's action should be taken.
+   */
+  function setupTurboKeyHandlers():Void
+  {
+    add(undoKeyHandler);
+    add(redoKeyHandler);
+    add(upKeyHandler);
+    add(downKeyHandler);
+    add(pageUpKeyHandler);
+    add(pageDownKeyHandler);
+  }
+
   /**
    * Setup timers and listerners to handle auto-save.
    */
-  function setupAutoSave()
+  function setupAutoSave():Void
   {
     WindowUtil.windowExit.add(onWindowClose);
     saveDataDirty = false;
@@ -1327,7 +1312,7 @@ class ChartEditorState extends HaxeUIState
   /**
    * Called after 5 minutes without saving.
    */
-  function autoSave()
+  function autoSave():Void
   {
     saveDataDirty = false;
 
@@ -1466,42 +1451,49 @@ class ChartEditorState extends HaxeUIState
     var shouldPause:Bool = false;
 
     // Up Arrow = Scroll Up
-    if (FlxG.keys.justPressed.UP)
+    if (upKeyHandler.activated)
     {
-      scrollAmount = -GRID_SIZE * 0.25 * 5;
+      scrollAmount = -GRID_SIZE * 0.25 * 5.0;
+      shouldPause = true;
     }
     // Down Arrow = Scroll Down
-    if (FlxG.keys.justPressed.DOWN)
+    if (downKeyHandler.activated)
     {
-      scrollAmount = GRID_SIZE * 0.25 * 5;
+      scrollAmount = GRID_SIZE * 0.25 * 5.0;
+      shouldPause = true;
     }
 
     // PAGE UP = Jump Up 1 Measure
-    if (FlxG.keys.justPressed.PAGEUP)
+    if (pageUpKeyHandler.activated)
     {
       scrollAmount = -GRID_SIZE * 4 * Conductor.beatsPerMeasure;
+      shouldPause = true;
     }
     if (playbarButtonPressed == 'playbarBack')
     {
       playbarButtonPressed = '';
       scrollAmount = -GRID_SIZE * 4 * Conductor.beatsPerMeasure;
+      shouldPause = true;
     }
 
     // PAGE DOWN = Jump Down 1 Measure
-    if (FlxG.keys.justPressed.PAGEDOWN)
+    if (pageDownKeyHandler.activated)
     {
       scrollAmount = GRID_SIZE * 4 * Conductor.beatsPerMeasure;
+      shouldPause = true;
     }
     if (playbarButtonPressed == 'playbarForward')
     {
       playbarButtonPressed = '';
       scrollAmount = GRID_SIZE * 4 * Conductor.beatsPerMeasure;
+      shouldPause = true;
     }
 
     // Mouse Wheel = Scroll
     if (FlxG.mouse.wheel != 0 && !FlxG.keys.pressed.CONTROL)
     {
       scrollAmount = -10 * FlxG.mouse.wheel;
+      shouldPause = true;
     }
 
     // Middle Mouse + Drag = Scroll but move the playhead the same amount.
@@ -1532,6 +1524,7 @@ class ChartEditorState extends HaxeUIState
     {
       playheadAmount = scrollAmount;
       scrollAmount = 0;
+      shouldPause = false;
     }
 
     // HOME = Scroll to Top
@@ -1540,12 +1533,14 @@ class ChartEditorState extends HaxeUIState
       // Scroll amount is the difference between the current position and the top.
       scrollAmount = 0 - this.scrollPositionInPixels;
       playheadAmount = 0 - this.playheadPositionInPixels;
+      shouldPause = true;
     }
     if (playbarButtonPressed == 'playbarStart')
     {
       playbarButtonPressed = '';
       scrollAmount = 0 - this.scrollPositionInPixels;
       playheadAmount = 0 - this.playheadPositionInPixels;
+      shouldPause = true;
     }
 
     // END = Scroll to Bottom
@@ -1553,11 +1548,13 @@ class ChartEditorState extends HaxeUIState
     {
       // Scroll amount is the difference between the current position and the bottom.
       scrollAmount = this.songLengthInPixels - this.scrollPositionInPixels;
+      shouldPause = true;
     }
     if (playbarButtonPressed == 'playbarEnd')
     {
       playbarButtonPressed = '';
       scrollAmount = this.songLengthInPixels - this.scrollPositionInPixels;
+      shouldPause = true;
     }
 
     // Apply the scroll amount.
@@ -1566,9 +1563,10 @@ class ChartEditorState extends HaxeUIState
 
     // Resync the conductor and audio tracks.
     if (scrollAmount != 0 || playheadAmount != 0) moveSongToScrollPosition();
+    if (shouldPause) stopAudioPlayback();
   }
 
-  function handleZoom()
+  function handleZoom():Void
   {
     if (FlxG.keys.justPressed.MINUS)
     {
@@ -1591,7 +1589,7 @@ class ChartEditorState extends HaxeUIState
     }
   }
 
-  function handleSnap()
+  function handleSnap():Void
   {
     if (FlxG.keys.justPressed.LEFT)
     {
@@ -1607,7 +1605,7 @@ class ChartEditorState extends HaxeUIState
   /**
    * Handle display of the mouse cursor.
    */
-  function handleCursor()
+  function handleCursor():Void
   {
     // Note: If a menu is open in HaxeUI, don't handle cursor behavior.
     var shouldHandleCursor = !isCursorOverHaxeUI || (selectionBoxStartPos != null);
@@ -2330,7 +2328,7 @@ class ChartEditorState extends HaxeUIState
   /**
    * Handles display elements for the playbar at the bottom.
    */
-  function handlePlaybar()
+  function handlePlaybar():Void
   {
     // Make sure the playbar is never nudged out of the correct spot.
     playbarHeadLayout.x = 4;
@@ -2362,7 +2360,7 @@ class ChartEditorState extends HaxeUIState
   /**
    * Handle keybinds for File menu items.
    */
-  function handleFileKeybinds()
+  function handleFileKeybinds():Void
   {
     // CTRL + Q = Quit to Menu
     if (FlxG.keys.pressed.CONTROL && FlxG.keys.justPressed.Q)
@@ -2374,48 +2372,20 @@ class ChartEditorState extends HaxeUIState
   /**
    * Handle keybinds for edit menu items.
    */
-  function handleEditKeybinds()
+  function handleEditKeybinds():Void
   {
     // CTRL + Z = Undo
-    if (FlxG.keys.pressed.CONTROL && FlxG.keys.justPressed.Z)
+    if (undoKeyHandler.activated)
     {
       undoLastCommand();
     }
 
-    if (FlxG.keys.pressed.CONTROL && FlxG.keys.pressed.Z && !FlxG.keys.pressed.Y)
-    {
-      undoHeldTime += FlxG.elapsed;
-    }
-    else
-    {
-      undoHeldTime = 0;
-    }
-    if (undoHeldTime > RAPID_UNDO_DELAY + RAPID_UNDO_INTERVAL)
-    {
-      undoLastCommand();
-      undoHeldTime -= RAPID_UNDO_INTERVAL;
-    }
-
     // CTRL + Y = Redo
-    if (FlxG.keys.pressed.CONTROL && FlxG.keys.justPressed.Y)
+    if (redoKeyHandler.activated)
     {
       redoLastCommand();
     }
 
-    if (FlxG.keys.pressed.CONTROL && FlxG.keys.pressed.Y && !FlxG.keys.pressed.Z)
-    {
-      redoHeldTime += FlxG.elapsed;
-    }
-    else
-    {
-      redoHeldTime = 0;
-    }
-    if (redoHeldTime > RAPID_UNDO_DELAY + RAPID_UNDO_INTERVAL)
-    {
-      redoLastCommand();
-      redoHeldTime -= RAPID_UNDO_INTERVAL;
-    }
-
     // CTRL + C = Copy
     if (FlxG.keys.pressed.CONTROL && FlxG.keys.justPressed.C)
     {
@@ -2485,25 +2455,25 @@ class ChartEditorState extends HaxeUIState
   /**
    * Handle keybinds for View menu items.
    */
-  function handleViewKeybinds() {}
+  function handleViewKeybinds():Void {}
 
   /**
    * Handle keybinds for Help menu items.
    */
-  function handleHelpKeybinds()
+  function handleHelpKeybinds():Void
   {
     // F1 = Open Help
     if (FlxG.keys.justPressed.F1) ChartEditorDialogHandler.openUserGuideDialog(this);
   }
 
-  function handleToolboxes()
+  function handleToolboxes():Void
   {
     handleDifficultyToolbox();
     handlePlayerPreviewToolbox();
     handleOpponentPreviewToolbox();
   }
 
-  function handleDifficultyToolbox()
+  function handleDifficultyToolbox():Void
   {
     if (difficultySelectDirty)
     {
@@ -2552,7 +2522,7 @@ class ChartEditorState extends HaxeUIState
     }
   }
 
-  function handlePlayerPreviewToolbox()
+  function handlePlayerPreviewToolbox():Void
   {
     // Manage the Select Difficulty tree view.
     var charPreviewToolbox = ChartEditorToolboxHandler.getToolbox(this, CHART_EDITOR_TOOLBOX_PLAYER_PREVIEW_LAYOUT);
@@ -2564,7 +2534,7 @@ class ChartEditorState extends HaxeUIState
     currentPlayerCharacterPlayer = charPlayer;
   }
 
-  function handleOpponentPreviewToolbox()
+  function handleOpponentPreviewToolbox():Void
   {
     // Manage the Select Difficulty tree view.
     var charPreviewToolbox = ChartEditorToolboxHandler.getToolbox(this, CHART_EDITOR_TOOLBOX_OPPONENT_PREVIEW_LAYOUT);
@@ -2576,7 +2546,7 @@ class ChartEditorState extends HaxeUIState
     currentOpponentCharacterPlayer = charPlayer;
   }
 
-  override function dispatchEvent(event:ScriptEvent)
+  override function dispatchEvent(event:ScriptEvent):Void
   {
     super.dispatchEvent(event);
 
@@ -2660,9 +2630,9 @@ class ChartEditorState extends HaxeUIState
     }
   }
 
-  function addDifficulty(variation:String) {}
+  function addDifficulty(variation:String):Void {}
 
-  function addVariation(variationId:String)
+  function addVariation(variationId:String):Void
   {
     // Create a new variation with the specified ID.
     songMetadata.set(variationId, currentSongMetadata.clone(variationId));
@@ -2673,7 +2643,7 @@ class ChartEditorState extends HaxeUIState
   /**
    * Handle the player preview/gameplay test area on the left side.
    */
-  function handlePlayerDisplay() {}
+  function handlePlayerDisplay():Void {}
 
   /**
    * Handles the note preview/scroll area on the right side.
@@ -2683,7 +2653,7 @@ class ChartEditorState extends HaxeUIState
    * - Scrolling the note preview area down if the note preview is taller than the screen,
    *   and the viewport nears the end of the visible area.
    */
-  function handleNotePreview()
+  function handleNotePreview():Void
   {
     //
     if (notePreviewDirty)
@@ -2703,13 +2673,13 @@ class ChartEditorState extends HaxeUIState
    * Perform a spot update on the note preview, by editing the note preview
    * only where necessary. More efficient than a full update.
    */
-  function updateNotePreview(note:SongNoteData, ?deleteNote:Bool = false) {}
+  function updateNotePreview(note:SongNoteData, ?deleteNote:Bool = false):Void {}
 
   /**
    * Handles passive behavior of the menu bar, such as updating labels or enabled/disabled status.
    * Does not handle onClick ACTIONS of the menubar.
    */
-  function handleMenubar()
+  function handleMenubar():Void
   {
     if (commandHistoryDirty)
     {
@@ -2765,7 +2735,7 @@ class ChartEditorState extends HaxeUIState
   /**
    * Handle syncronizing the conductor with the music playback.
    */
-  function handleMusicPlayback()
+  function handleMusicPlayback():Void
   {
     if (audioInstTrack != null && audioInstTrack.playing)
     {
@@ -2856,21 +2826,25 @@ class ChartEditorState extends HaxeUIState
     }
   }
 
-  function startAudioPlayback()
+  function startAudioPlayback():Void
   {
     if (audioInstTrack != null) audioInstTrack.play();
     if (audioVocalTrackGroup != null) audioVocalTrackGroup.play();
     if (audioVocalTrackGroup != null) audioVocalTrackGroup.play();
+
+    setComponentText('playbarPlay', '||');
   }
 
-  function stopAudioPlayback()
+  function stopAudioPlayback():Void
   {
     if (audioInstTrack != null) audioInstTrack.pause();
     if (audioVocalTrackGroup != null) audioVocalTrackGroup.pause();
     if (audioVocalTrackGroup != null) audioVocalTrackGroup.pause();
+
+    setComponentText('playbarPlay', '>');
   }
 
-  function toggleAudioPlayback()
+  function toggleAudioPlayback():Void
   {
     if (audioInstTrack == null) return;
 
@@ -2884,7 +2858,7 @@ class ChartEditorState extends HaxeUIState
     }
   }
 
-  function handlePlayhead()
+  function handlePlayhead():Void
   {
     // Place notes at the playhead.
     // TODO: Add the ability to switch modes.
@@ -2973,52 +2947,64 @@ class ChartEditorState extends HaxeUIState
    * Loads an instrumental from an absolute file path, replacing the current instrumental.
    * 
    * @param path The absolute path to the audio file.
+   * @return Success or failure.
    */
-  public function loadInstrumentalFromPath(path:String):Void
+  public function loadInstrumentalFromPath(path:Path):Bool
   {
     #if sys
     // Validate file extension.
-    var fileExtension:String = Path.extension(path);
-    if (!SUPPORTED_MUSIC_FORMATS.contains(fileExtension))
+    if (!SUPPORTED_MUSIC_FORMATS.contains(path.ext))
     {
-      trace('[WARN] Unsupported file extension: $fileExtension');
-      return;
+      return false;
     }
 
-    var fileBytes:haxe.io.Bytes = sys.io.File.getBytes(path);
-    loadInstrumentalFromBytes(fileBytes);
+    var fileBytes:haxe.io.Bytes = sys.io.File.getBytes(path.toString());
+    return loadInstrumentalFromBytes(fileBytes, '${path.file}.${path.ext}');
     #else
     trace("[WARN] This platform can't load audio from a file path, you'll need to fetch the bytes some other way.");
+    return false;
     #end
   }
 
   /**
    * Loads an instrumental from audio byte data, replacing the current instrumental.
+   * @param bytes The audio byte data.
+   * @param fileName The name of the file, if available. Used for notifications.
+   * @return Success or failure.
    */
-  public function loadInstrumentalFromBytes(bytes:haxe.io.Bytes):Void
+  public function loadInstrumentalFromBytes(bytes:haxe.io.Bytes, fileName:String = null):Bool
   {
-    var openflSound = new openfl.media.Sound();
+    var openflSound:openfl.media.Sound = new openfl.media.Sound();
     openflSound.loadCompressedDataFromByteArray(openfl.utils.ByteArray.fromBytes(bytes), bytes.length);
     audioInstTrack = FlxG.sound.load(openflSound, 1.0, false);
     audioInstTrack.autoDestroy = false;
     audioInstTrack.pause();
 
-    // Tell the user the load was successful.
-    // TODO: Un-bork this.
-    // showNotification('Loaded instrumental track successfully.');
-
     postLoadInstrumental();
+
+    return true;
   }
 
-  public function loadInstrumentalFromAsset(path:String):Void
+  /**
+   * Loads an instrumental from an OpenFL asset, replacing the current instrumental.
+   * @param path The path to the asset. Use `Paths` to build this.
+   * @return Success or failure.
+   */
+  public function loadInstrumentalFromAsset(path:String):Bool
   {
-    var instTrack = FlxG.sound.load(path, 1.0, false);
-    audioInstTrack = instTrack;
+    var instTrack:FlxSound = FlxG.sound.load(path, 1.0, false);
+    if (instTrack != null)
+    {
+      audioInstTrack = instTrack;
 
-    postLoadInstrumental();
+      postLoadInstrumental();
+      return true;
+    }
+
+    return false;
   }
 
-  function postLoadInstrumental()
+  function postLoadInstrumental():Void
   {
     // Prevent the time from skipping back to 0 when the song ends.
     audioInstTrack.onComplete = function() {
@@ -3042,42 +3028,47 @@ class ChartEditorState extends HaxeUIState
 
   /**
    * Loads a vocal track from an absolute file path.
+   * @param path The absolute path to the audio file.
+   * @param charKey The character to load the vocal track for.
    */
-  public function loadVocalsFromPath(path:String, ?charKey:String):Void
+  public function loadVocalsFromPath(path:Path, charKey:String = null):Bool
   {
     #if sys
-    var fileBytes:haxe.io.Bytes = sys.io.File.getBytes(path);
-    loadVocalsFromBytes(fileBytes, charKey);
+    var fileBytes:haxe.io.Bytes = sys.io.File.getBytes(path.toString());
+    return loadVocalsFromBytes(fileBytes, charKey);
     #else
     trace("[WARN] This platform can't load audio from a file path, you'll need to fetch the bytes some other way.");
+    return false;
     #end
   }
 
-  public function loadVocalsFromAsset(path:String, ?charKey:String):Void
+  public function loadVocalsFromAsset(path:String, charKey:String = null):Bool
   {
     var vocalTrack:FlxSound = FlxG.sound.load(path, 1.0, false);
-    audioVocalTrackGroup.add(vocalTrack);
+    if (vocalTrack != null)
+    {
+      audioVocalTrackGroup.add(vocalTrack);
+      return true;
+    }
+    return false;
   }
 
   /**
    * Loads a vocal track from audio byte data.
    */
-  public function loadVocalsFromBytes(bytes:haxe.io.Bytes, ?charKey:String):Void
+  public function loadVocalsFromBytes(bytes:haxe.io.Bytes, charKey:String = null):Bool
   {
     var openflSound = new openfl.media.Sound();
     openflSound.loadCompressedDataFromByteArray(openfl.utils.ByteArray.fromBytes(bytes), bytes.length);
     var vocalTrack:FlxSound = FlxG.sound.load(openflSound, 1.0, false);
     audioVocalTrackGroup.add(vocalTrack);
-
-    // Tell the user the load was successful.
-    // TODO: Un-bork this.
-    // showNotification('Loaded instrumental track successfully.');
+    return true;
   }
 
   /**
    * Fetch's a song's existing chart and audio and loads it, replacing the current song.
    */
-  public function loadSongAsTemplate(songId:String)
+  public function loadSongAsTemplate(songId:String):Void
   {
     var song:Song = SongDataParser.fetchSong(songId);
 
@@ -3089,6 +3080,7 @@ class ChartEditorState extends HaxeUIState
 
     // Load the song metadata.
     var rawSongMetadata:Array<SongMetadata> = song.getRawMetadata();
+    var songName:String = rawSongMetadata[0].songName;
 
     this.songMetadata = new Map<String, SongMetadata>();
 
@@ -3112,14 +3104,20 @@ class ChartEditorState extends HaxeUIState
     loadInstrumentalFromAsset(Paths.inst(songId));
     loadVocalsFromAsset(Paths.voices(songId));
 
-    // showNotification('Loaded song ${songId}.');
+    NotificationManager.instance.addNotification(
+      {
+        title: 'Success',
+        body: 'Loaded song ($songName)',
+        type: NotificationType.Success,
+        expiryMs: ChartEditorState.NOTIFICATION_DISMISS_TIME
+      });
   }
 
   /**
    * When setting the scroll position, except when automatically scrolling during song playback,
    * we need to update the conductor's current step time and the timestamp of the audio tracks.
    */
-  function moveSongToScrollPosition()
+  function moveSongToScrollPosition():Void
   {
     // Update the songPosition in the Conductor.
     Conductor.update(scrollPositionInMs);
@@ -3168,7 +3166,7 @@ class ChartEditorState extends HaxeUIState
       return;
     }
 
-    var command = undoHistory.pop();
+    var command:ChartEditorCommand = undoHistory.pop();
     undoCommand(command);
   }
 
@@ -3183,11 +3181,11 @@ class ChartEditorState extends HaxeUIState
       return;
     }
 
-    var command = redoHistory.pop();
+    var command:ChartEditorCommand = redoHistory.pop();
     performCommand(command, false);
   }
 
-  function sortChartData()
+  function sortChartData():Void
   {
     currentSongChartNoteData.sort(function(a:SongNoteData, b:SongNoteData):Int {
       return FlxSort.byValues(FlxSort.ASCENDING, a.time, b.time);
@@ -3198,7 +3196,7 @@ class ChartEditorState extends HaxeUIState
     });
   }
 
-  function playMetronomeTick(?high:Bool = false)
+  function playMetronomeTick(?high:Bool = false):Void
   {
     playSound(Paths.sound('pianoStuff/piano-${high ? '001' : '008'}'));
   }
@@ -3217,7 +3215,7 @@ class ChartEditorState extends HaxeUIState
    * Play a sound effect.
    * Automatically cleans up after itself and recycles previous FlxSound instances if available, for performance.
    */
-  function playSound(path:String)
+  function playSound(path:String):Void
   {
     var snd:FlxSound = FlxG.sound.list.recycle(FlxSound);
     snd.loadEmbedded(FlxG.sound.cache(path));
@@ -3226,7 +3224,7 @@ class ChartEditorState extends HaxeUIState
     snd.play();
   }
 
-  override function destroy()
+  override function destroy():Void
   {
     super.destroy();
 
@@ -3282,7 +3280,14 @@ class ChartEditorState extends HaxeUIState
 
     if (force)
     {
-      var targetPath:String = tmp ? Path.join([FileUtil.getTempDir(), 'chart-editor-exit-${DateUtil.generateTimestamp()}.zip']) : Path.join(['./backups/', 'chart-editor-exit-${DateUtil.generateTimestamp()}.zip']);
+      var targetPath:String = if (tmp)
+      {
+        Path.join([FileUtil.getTempDir(), 'chart-editor-exit-${DateUtil.generateTimestamp()}.zip']);
+      }
+      else
+      {
+        Path.join(['./backups/', 'chart-editor-exit-${DateUtil.generateTimestamp()}.zip']);
+      }
 
       // We have to force write because the program will die before the save dialog is closed.
       trace('Force exporting to $targetPath...');
@@ -3291,11 +3296,11 @@ class ChartEditorState extends HaxeUIState
     }
 
     // Prompt and save.
-    var onSave:Array<String>->Void = (paths:Array<String>) -> {
+    var onSave:Array<String>->Void = function(paths:Array<String>) {
       trace('Successfully exported files.');
     };
 
-    var onCancel:Void->Void = () -> {
+    var onCancel:Void->Void = function() {
       trace('Export cancelled.');
     };
 
diff --git a/source/funkin/ui/haxeui/HaxeUIState.hx b/source/funkin/ui/haxeui/HaxeUIState.hx
index e23768131..6d432b68c 100644
--- a/source/funkin/ui/haxeui/HaxeUIState.hx
+++ b/source/funkin/ui/haxeui/HaxeUIState.hx
@@ -1,14 +1,12 @@
 package funkin.ui.haxeui;
 
-import haxe.ui.containers.menus.MenuCheckBox;
 import haxe.ui.components.CheckBox;
-import haxe.ui.events.DragEvent;
-import haxe.ui.events.MouseEvent;
-import haxe.ui.events.UIEvent;
-import haxe.ui.RuntimeComponentBuilder;
+import haxe.ui.containers.menus.MenuCheckBox;
 import haxe.ui.core.Component;
 import haxe.ui.core.Screen;
 import haxe.ui.events.MouseEvent;
+import haxe.ui.events.UIEvent;
+import haxe.ui.RuntimeComponentBuilder;
 import lime.app.Application;
 
 class HaxeUIState extends MusicBeatState
@@ -23,7 +21,7 @@ class HaxeUIState extends MusicBeatState
     _componentKey = key;
   }
 
-  override function create()
+  override function create():Void
   {
     super.create();
 
@@ -31,7 +29,7 @@ class HaxeUIState extends MusicBeatState
     if (component != null) add(component);
   }
 
-  public function buildComponent(assetPath:String)
+  public function buildComponent(assetPath:String):Component
   {
     try
     {
@@ -81,15 +79,13 @@ class HaxeUIState extends MusicBeatState
   {
     if (target == null)
     {
-      Screen.instance.registerEvent(MouseEvent.RIGHT_CLICK, function(e:MouseEvent)
-      {
+      Screen.instance.registerEvent(MouseEvent.RIGHT_CLICK, function(e:MouseEvent) {
         showContextMenu(assetPath, e.screenX, e.screenY);
       });
     }
     else
     {
-      target.registerEvent(MouseEvent.RIGHT_CLICK, function(e:MouseEvent)
-      {
+      target.registerEvent(MouseEvent.RIGHT_CLICK, function(e:MouseEvent) {
         showContextMenu(assetPath, e.screenX, e.screenY);
       });
     }
@@ -98,7 +94,7 @@ class HaxeUIState extends MusicBeatState
   /**
    * Add an onClick listener to a HaxeUI menu bar item.
    */
-  function addUIClickListener(key:String, callback:MouseEvent->Void)
+  function addUIClickListener(key:String, callback:MouseEvent->Void):Void
   {
     var target:Component = findComponent(key);
     if (target == null)
@@ -112,10 +108,24 @@ class HaxeUIState extends MusicBeatState
     }
   }
 
+  function setComponentText(key:String, text:String):Void
+  {
+    var target:Component = findComponent(key);
+    if (target == null)
+    {
+      // Gracefully handle the case where the item can't be located.
+      trace('WARN: Could not locate menu item: $key');
+    }
+    else
+    {
+      target.text = text;
+    }
+  }
+
   /**
    * Add an onChange listener to a HaxeUI input component such as a slider or text field.
    */
-  function addUIChangeListener(key:String, callback:UIEvent->Void)
+  function addUIChangeListener(key:String, callback:UIEvent->Void):Void
   {
     var target:Component = findComponent(key);
     if (target == null)
@@ -179,7 +189,7 @@ class HaxeUIState extends MusicBeatState
     return component.findComponent(criteria, type, recursive, searchType);
   }
 
-  override function destroy()
+  override function destroy():Void
   {
     if (component != null) remove(component);
     component = null;