fix: preserve playback state when seeking video steps

apps/showcase_ui/src/app/components/floating-video-player/floating-video-player.component.html

@@ -338,6 +338,8 @@ limitations under the License.
                         playsinline
                         (loadedmetadata)="onLoadedMetadata()"
                         (timeupdate)="onTimeUpdate()"
+                        (seeked)="onSeeked()"
+                        (emptied)="onPause()"
                         (play)="onPlay()"
                         (pause)="onPause()"
                         (ended)="onEnded()"

apps/showcase_ui/src/app/components/floating-video-player/floating-video-player.component.spec.ts

@@ -1,17 +1,26 @@
-import { TestBed } from '@angular/core/testing';
+import { ComponentFixture, TestBed } from '@angular/core/testing';
 import { signal } from '@angular/core';
 import { AgentService } from '../../services/agent.service';
 import { StepReplayFrame } from '../../core/models/stream.model';
 import { FloatingVideoPlayerComponent } from './floating-video-player.component';
 
 describe('FloatingVideoPlayerComponent video markers', () => {
-  it('shows a recorded step on the video timeline and seeks when clicked', () => {
+  let fixture: ComponentFixture<FloatingVideoPlayerComponent>;
+  let component: FloatingVideoPlayerComponent;
+  let video: HTMLVideoElement;
+  let paused: boolean;
+  let seeking: boolean;
+  let time: number;
+  let play: jasmine.Spy;
+  let agentService: ReturnType<typeof createAgentService>;
+
+  function createAgentService() {
     const start = 1_800_000_000;
     const frame: StepReplayFrame = {
       index: 0, stepNumber: 1, title: '步骤 1: 点击设置', imageUrl: 'step.png',
       actionText: '点击设置', timestamp: start + 5
     };
-    const agentService = {
+    return {
       isVideoWindowOpen: signal(true),
       isVideoMinimized: signal(false),
       recordingPlaybackStatus: signal('ready'),
@@ -25,15 +34,57 @@ describe('FloatingVideoPlayerComponent video markers', () => {
       currentSession: signal({ session_id: 'test', start_time: start }),
       currentSessionId: signal('test'),
       videoSeekRequest: signal(null),
-      stepSeekRequest: signal(null)
+      stepSeekRequest: signal(null),
+      consumeVideoAutoplay: jasmine.createSpy('consumeVideoAutoplay').and.returnValue(false)
     };
+  }
+
+  beforeEach(() => {
+    agentService = createAgentService();
     TestBed.configureTestingModule({
       imports: [FloatingVideoPlayerComponent],
       providers: [{ provide: AgentService, useValue: agentService }]
     });
 
-    const fixture = TestBed.createComponent(FloatingVideoPlayerComponent);
+    fixture = TestBed.createComponent(FloatingVideoPlayerComponent);
     fixture.detectChanges();
+    component = fixture.componentInstance;
+    video = component.videoRef!.nativeElement;
+    paused = true;
+    seeking = false;
+    time = 0;
+    Object.defineProperties(video, {
+      paused: { configurable: true, get: () => paused },
+      seeking: { configurable: true, get: () => seeking },
+      ended: { configurable: true, get: () => false },
+      duration: { configurable: true, get: () => 20 },
+      currentTime: {
+        configurable: true, get: () => time,
+        set: (value: number) => { time = value; seeking = true; }
+      }
+    });
+    spyOn(video, 'pause').and.callFake(() => {
+      paused = true;
+      video.dispatchEvent(new Event('pause'));
+    });
+    play = spyOn(video, 'play').and.callFake(() => {
+      paused = false;
+      video.dispatchEvent(new Event('play'));
+      return Promise.resolve();
+    });
+  });
+
+  function finishSeek(): void {
+    seeking = false;
+    video.dispatchEvent(new Event('seeked'));
+    fixture.detectChanges();
+  }
+
+  function playButton(): HTMLButtonElement {
+    return fixture.nativeElement.querySelector('.play-btn');
+  }
+
+  it('shows a recorded step on the video timeline and seeks when clicked', () => {
     const marker = fixture.nativeElement.querySelector('.video-marker') as HTMLButtonElement;
     expect(marker).not.toBeNull();
     expect(marker.getAttribute('aria-label')).toContain('步骤 1');
@@ -43,4 +94,150 @@ describe('FloatingVideoPlayerComponent video markers', () => {
     marker.click();
     expect(seek).toHaveBeenCalledOnceWith(5);
   });
+
+  it('resumes a playing video after a marker seek finishes and synchronizes the button', async () => {
+    component.togglePlay();
+    await Promise.resolve();
+    play.calls.reset();
+    fixture.nativeElement.querySelector('.video-marker').click();
+    expect(time).toBe(5);
+    expect(play).not.toHaveBeenCalled();
+    finishSeek();
+    await Promise.resolve();
+    fixture.detectChanges();
+    expect(paused).toBeFalse();
+    expect(play).toHaveBeenCalledTimes(1);
+    expect(playButton().title).toBe('暂停');
+  });
+
+  it('keeps a paused video paused after a marker seek and resumes with one click', async () => {
+    fixture.nativeElement.querySelector('.video-marker').click();
+    finishSeek();
+    expect(paused).toBeTrue();
+    expect(play).not.toHaveBeenCalled();
+    expect(playButton().title).toBe('播放');
+    playButton().click();
+    await Promise.resolve();
+    fixture.detectChanges();
+    expect(paused).toBeFalse();
+    expect(playButton().title).toBe('暂停');
+  });
+
+  it('preserves playing intent across rapid consecutive marker seeks', () => {
+    component.togglePlay();
+    component.seek(5);
+    component.seek(8);
+    play.calls.reset();
+    finishSeek();
+    expect(time).toBe(8);
+    expect(play).toHaveBeenCalledTimes(1);
+    expect(paused).toBeFalse();
+  });
+
+  it('honors play and pause clicks while the destination is still seeking', () => {
+    component.togglePlay();
+    component.seek(5);
+    play.calls.reset();
+    fixture.detectChanges();
+    expect(playButton().title).toBe('播放');
+    playButton().click();
+    fixture.detectChanges();
+    expect(playButton().title).toBe('暂停');
+    expect(play).not.toHaveBeenCalled();
+    playButton().click();
+    finishSeek();
+    expect(paused).toBeTrue();
+    expect(play).not.toHaveBeenCalled();
+    expect(playButton().title).toBe('播放');
+  });
+
+  it('waits for the destination segment to seek before resuming playback', () => {
+    agentService.activeVideoSegments.set([
+      { url: '/test.mp4', start: 0, duration: 20, width: 400, height: 800 },
+      { url: '/second.mp4', start: 20, duration: 20, width: 400, height: 800 }
+    ]);
+    fixture.detectChanges();
+    component.togglePlay();
+    component.seek(25);
+    play.calls.reset();
+    fixture.detectChanges();
+    video.dispatchEvent(new Event('loadedmetadata'));
+    expect(component.activeSegmentIndex()).toBe(1);
+    expect(time).toBe(5);
+    expect(play).not.toHaveBeenCalled();
+    finishSeek();
+    expect(play).toHaveBeenCalledTimes(1);
+    expect(paused).toBeFalse();
+    expect(component.currentTime()).toBe(25);
+  });
+
+  it('keeps a paused video paused when jumping to another segment', () => {
+    agentService.activeVideoSegments.set([
+      { url: '/test.mp4', start: 0, duration: 20, width: 400, height: 800 },
+      { url: '/second.mp4', start: 20, duration: 20, width: 400, height: 800 }
+    ]);
+    fixture.detectChanges();
+    component.seek(25);
+    fixture.detectChanges();
+    video.dispatchEvent(new Event('loadedmetadata'));
+    finishSeek();
+    expect(time).toBe(5);
+    expect(paused).toBeTrue();
+    expect(play).not.toHaveBeenCalled();
+    expect(playButton().title).toBe('播放');
+  });
+
+  it('resumes after seeking a recording without a segment manifest', () => {
+    agentService.activeVideoSegments.set([]);
+    fixture.detectChanges();
+    video.dispatchEvent(new Event('loadedmetadata'));
+    component.togglePlay();
+    component.seek(5);
+    play.calls.reset();
+    finishSeek();
+    expect(time).toBe(5);
+    expect(component.currentTime()).toBe(5);
+    expect(paused).toBeFalse();
+    expect(play).toHaveBeenCalledTimes(1);
+  });
+
+  it('resets a rejected play request so a single subsequent click can resume', async () => {
+    play.and.callFake(() => {
+      paused = false;
+      video.dispatchEvent(new Event('play'));
+      return Promise.reject(new DOMException('Interrupted', 'AbortError'));
+    });
+    component.seek(5, true);
+    finishSeek();
+    await Promise.resolve();
+    await Promise.resolve();
+    fixture.detectChanges();
+    expect(paused).toBeTrue();
+    expect(playButton().title).toBe('播放');
+    play.and.callFake(() => {
+      paused = false;
+      video.dispatchEvent(new Event('play'));
+      return Promise.resolve();
+    });
+    playButton().click();
+    await Promise.resolve();
+    fixture.detectChanges();
+    expect(paused).toBeFalse();
+    expect(playButton().title).toBe('暂停');
+  });
+
+  it('ignores an older aborted play request after a newer seek resumes', async () => {
+    let rejectOldPlay!: (reason: unknown) => void;
+    play.and.returnValue(new Promise<void>((_, reject) => { rejectOldPlay = reject; }));
+    component.togglePlay();
+    paused = false;
+    component.seek(5);
+    play.and.callFake(() => { paused = false; return Promise.resolve(); });
+    finishSeek();
+    rejectOldPlay(new DOMException('Interrupted', 'AbortError'));
+    await Promise.resolve();
+    await Promise.resolve();
+    expect(paused).toBeFalse();
+    expect(component.isPlaying()).toBeTrue();
+  });
 });

apps/showcase_ui/src/app/components/floating-video-player/floating-video-player.component.ts

@@ -71,6 +71,8 @@ export class FloatingVideoPlayerComponent implements OnDestroy {
   private pendingLocalTime: number | null = null;
   private pendingAutoplay = false;
   private pendingAbsoluteSeek: number | null = null;
+  private seekPlaybackIntent: boolean | null = null;
+  private playRequestId = 0;
 
   // Step Replay state signals
   public activeStepIndex = signal<number>(0);
@@ -138,6 +140,10 @@ export class FloatingVideoPlayerComponent implements OnDestroy {
         this.currentTime.set(0);
         this.duration.set(segments.reduce((sum, segment) => sum + segment.duration, 0));
         this.isPlaying.set(false);
+        this.pendingLocalTime = null;
+        this.pendingAutoplay = false;
+        this.seekPlaybackIntent = null;
+        this.playRequestId++;
       },
       { allowSignalWrites: true }
     );
@@ -315,20 +321,19 @@ export class FloatingVideoPlayerComponent implements OnDestroy {
         // that segment's metadata event apply pendingLocalTime.
         if (this.pendingLocalTime !== null) return;
       }
-      if (this.pendingLocalTime !== null) {
-        v.currentTime = Math.max(0, Math.min(v.duration || this.pendingLocalTime, this.pendingLocalTime));
-        this.pendingLocalTime = null;
-      }
-      if (this.pendingAutoplay) {
-        this.pendingAutoplay = false;
-        v.play().catch(() => {});
-      }
-      if (this.agentService.consumeVideoAutoplay()) {
+      const autoplay = this.agentService.consumeVideoAutoplay();
+      if (autoplay) {
         this.isMuted.set(true);
         v.muted = true;
-        v.play().catch(() => {
-          this.isPlaying.set(false);
-        });
+      }
+      const shouldPlay = this.pendingAutoplay || autoplay;
+      this.pendingAutoplay = false;
+      if (this.pendingLocalTime !== null) {
+        const localTime = Math.max(0, Math.min(v.duration || this.pendingLocalTime, this.pendingLocalTime));
+        this.pendingLocalTime = null;
+        this.seekWithinVideo(localTime, shouldPlay);
+      } else if (shouldPlay) {
+        this.playVideo();
       }
     }
   }
@@ -346,14 +351,28 @@ export class FloatingVideoPlayerComponent implements OnDestroy {
   }
 
   public onPlay(): void {
-    this.isPlaying.set(true);
+    this.isPlaying.set(!this.videoRef?.nativeElement.paused);
   }
 
   public onPause(): void {
     this.isPlaying.set(false);
   }
 
+  public onSeeked(): void {
+    const v = this.videoRef?.nativeElement;
+    if (!v || v.seeking || this.pendingLocalTime !== null) return;
+    const shouldPlay = this.seekPlaybackIntent;
+    this.seekPlaybackIntent = null;
+    this.onTimeUpdate();
+    if (shouldPlay) {
+      this.playVideo();
+    } else {
+      this.isPlaying.set(!v.paused && !v.ended);
+    }
+  }
+
   public onEnded(): void {
+    this.isPlaying.set(false);
     const segments = this.agentService.activeVideoSegments();
     if (segments.length && this.activeSegmentIndex() < segments.length - 1) {
       this.pendingLocalTime = 0;
@@ -369,6 +388,10 @@ export class FloatingVideoPlayerComponent implements OnDestroy {
   }
 
   public onError(): void {
+    this.playRequestId++;
+    this.pendingLocalTime = null;
+    this.pendingAutoplay = false;
+    this.seekPlaybackIntent = null;
     this.videoLoadError.set(true);
     this.isPlaying.set(false);
   }
@@ -379,11 +402,52 @@ export class FloatingVideoPlayerComponent implements OnDestroy {
   public togglePlay(): void {
     const v = this.videoRef?.nativeElement;
     if (!v) return;
-    if (v.paused) {
-      v.play().catch(() => {});
-    } else {
-      v.pause();
+    if (this.pendingLocalTime !== null) {
+      this.pendingAutoplay = !this.isPlaying();
+      this.isPlaying.set(this.pendingAutoplay);
+      return;
     }
+    if (this.seekPlaybackIntent !== null) {
+      this.seekPlaybackIntent = !this.isPlaying();
+      this.isPlaying.set(this.seekPlaybackIntent);
+      return;
+    }
+    if (v.paused) {
+      this.playVideo();
+    } else {
+      this.playRequestId++;
+      v.pause();
+      this.isPlaying.set(false);
+    }
+  }
+
+  private playVideo(): void {
+    const v = this.videoRef?.nativeElement;
+    if (!v) return;
+    const requestId = ++this.playRequestId;
+    v.play().then(() => {
+      if (requestId === this.playRequestId) this.isPlaying.set(!v.paused && !v.ended);
+    }).catch(() => {
+      // A rejected play request can leave paused=false without advancing frames.
+      // Reset the native state too, so the next click really starts playback.
+      if (requestId === this.playRequestId) {
+        v.pause();
+        this.isPlaying.set(false);
+      }
+    });
+  }
+
+  private seekWithinVideo(seconds: number, shouldPlay: boolean): void {
+    const v = this.videoRef?.nativeElement;
+    if (!v) return;
+    this.playRequestId++;
+    this.seekPlaybackIntent = shouldPlay;
+    // Cancel any unfinished play request before seeking; resume only once the
+    // browser has decoded the destination, including after a source switch.
+    v.pause();
+    this.isPlaying.set(false);
+    v.currentTime = seconds;
+    if (!v.seeking) this.onSeeked();
   }
 
   public restart(): void {
@@ -421,19 +485,19 @@ export class FloatingVideoPlayerComponent implements OnDestroy {
     const target = Math.max(0, Math.min(this.duration(), seconds));
     const segments = this.agentService.activeVideoSegments();
     const location = locateTimelineTime(segments, target);
+    const shouldPlay = autoplay || this.pendingAutoplay || (this.seekPlaybackIntent ?? !v.paused);
     if (!location) {
-      v.currentTime = target;
-      if (autoplay) v.play().catch(() => {});
-      return;
-    }
-    const { index, localTime } = location;
-    if (index === this.activeSegmentIndex()) {
-      v.currentTime = localTime;
-      if (autoplay) v.play().catch(() => {});
+      this.seekWithinVideo(target, shouldPlay);
+    } else if (location.index === this.activeSegmentIndex() && this.pendingLocalTime === null) {
+      this.seekWithinVideo(location.localTime, shouldPlay);
     } else {
-      this.pendingLocalTime = localTime;
-      this.pendingAutoplay = autoplay || !v.paused;
-      this.activeSegmentIndex.set(index);
+      this.playRequestId++;
+      this.seekPlaybackIntent = null;
+      v.pause();
+      this.isPlaying.set(false);
+      this.pendingLocalTime = location.localTime;
+      this.pendingAutoplay = shouldPlay;
+      this.activeSegmentIndex.set(location.index);
     }
     this.currentTime.set(target);
   }
@@ -641,6 +705,7 @@ export class FloatingVideoPlayerComponent implements OnDestroy {
   }
 
   public ngOnDestroy(): void {
+    this.playRequestId++;
     if (this.stepTimer) {
       clearTimeout(this.stepTimer);
       this.stepTimer = null;