copy first keyframe button

AnimationDirector.js

@@ -21,6 +21,8 @@
   let packFoldersAction;
   let previousStagePoseAction;
   let loopPoseAction;
+  let autoplayStagesAction, autoplayLoopOriginal, autoplayLoopWrapper;
+  let autoplayTransitioning = false;
   const POSE_BUTTON_EVENTS = ['select_animation', 'select_project', 'unselect_project', 'load_project', 'undo', 'redo', 'add_animation', 'remove_animation'];
   const PROP_PREVIEWS_PROPERTY = 'animationdirector_prop_previews';
   const PROP_SLOTS = { left: 'propleft', right: 'propright', floor: 'propfloor' };
@@ -2489,6 +2491,63 @@
     return { source: matches[0], previous };
   }
 
+  function nextAutoplayStage(animation) {
+    const current = parseAfwStageAnimationName(animation);
+    if (!current) return null;
+    const stages = Animation.all.map(parseAfwStageAnimationName)
+      .filter((stage) => stage?.id === current.id && stage.stageNumber > current.stageNumber)
+      .sort((a, b) => a.stageNumber - b.stageNumber);
+    if (!stages.length || stages.filter((stage) => stage.stageNumber === stages[0].stageNumber).length !== 1) return null;
+    return stages[0].animation;
+  }
+
+  function updateAutoplayIconColor() {
+    if (!autoplayStagesAction) return;
+    const color = autoplayStagesAction.value ? '#000000' : '#b8a6cc';
+    autoplayStagesAction.color = color;
+    if (autoplayStagesAction.icon_node) autoplayStagesAction.icon_node.style.color = color;
+    for (const node of autoplayStagesAction.nodes || []) {
+      const icon = node.querySelector('.icon');
+      if (icon) icon.style.color = color;
+    }
+  }
+
+  function installStageAutoplay() {
+    autoplayLoopOriginal = Timeline.loop;
+    // Native playback resets once-clips before emitting pause. Observe the completed
+    // playback step instead of treating a user's pause as a stage transition.
+    autoplayLoopWrapper = function (...args) {
+      // start() invokes loop() immediately. Defer that nested step to the next
+      // normal playback frame, but render the new pose synchronously below.
+      if (autoplayTransitioning) return;
+      const animation = Animation.selected;
+      const eligible = autoplayStagesAction?.value && Format.id === 'geckolib_model'
+        && Timeline.playing && animation?.length > 0 && animation.loop !== 'loop'
+        && !(Timeline.custom_range?.[0] || Timeline.custom_range?.[1]);
+      const result = autoplayLoopOriginal.apply(this, args);
+      if (eligible && autoplayStagesAction?.value && Animation.selected === animation && !Timeline.playing) {
+        const next = nextAutoplayStage(animation);
+        if (next) {
+          autoplayTransitioning = true;
+          try {
+            Timeline.setTime(0);
+            next.select();
+            Timeline.start();
+            Animator.preview(true);
+          } finally {
+            autoplayTransitioning = false;
+          }
+        }
+      }
+      return result;
+    };
+    Timeline.loop = autoplayLoopWrapper;
+  }
+
+  function removeStageAutoplay() {
+    if (Timeline.loop === autoplayLoopWrapper) Timeline.loop = autoplayLoopOriginal;
+  }
+
   function refreshPreviousStagePoseButton() {
     if (!previousStagePoseAction) return;
     const { reason } = previousStagePoseSource();
@@ -5822,6 +5881,22 @@ You can import or export complete AFW animation IDs as one file containing all s
     version: '2.0.0',
     variant: 'both',
     onload() {
+      autoplayStagesAction = new Toggle('animationdirector_autoplay_stages', {
+        name: 'Autoplay Stages', icon: 'resume', color: '#b8a6cc', category: 'animation',
+        description: 'Automatically play the next stage when a non-looping stage finishes. Looping stages stay on their current clip.',
+        default: false, save_on_restart: true,
+        onChange: updateAutoplayIconColor,
+        condition: () => typeof Format !== 'undefined' && Format.id === 'geckolib_model',
+      });
+      if (typeof Toolbars !== 'undefined') {
+        const toolbar = Toolbars.animations;
+        if (toolbar) {
+          const length = toolbar.children.findIndex((item) => item === 'slider_animation_length' || item?.id === 'slider_animation_length');
+          toolbar.add(autoplayStagesAction, length >= 0 ? length + 1 : 0);
+        }
+      }
+      updateAutoplayIconColor();
+      installStageAutoplay();
       previousStagePoseAction = new Action('animationdirector_previous_stage_pose', {
         name: 'Copy Previous Stage Pose', icon: 'move_down', color: '#b8a6cc', category: 'animation',
         description: 'Copy the final actor pose of the previous stage into time 0.',
@@ -6073,6 +6148,8 @@ You can import or export complete AFW animation IDs as one file containing all s
       MenuBar.update();
     },
     onunload() {
+      removeStageAutoplay();
+      autoplayStagesAction?.delete(); autoplayStagesAction = undefined;
       for (const event of [...POSE_BUTTON_EVENTS, 'update_animation_length']) Blockbench.removeListener(event, refreshLoopPoseButton);
       loopPoseAction?.delete(); loopPoseAction = undefined;
       for (const event of POSE_BUTTON_EVENTS) Blockbench.removeListener(event, refreshPreviousStagePoseButton);