Give each tab its own full timeline and transport (PlayerPanel refactor)

Extracts a new PlayerPanel widget (video + its own seek slider/marker
strip + its own centered frame-step/play/mute transport row) into
player_panel.py. Both Source and Preview tabs now use one, so
switching tabs switches a complete, independent monitor -- its own
scrubber, its own play state, its own frame-stepping -- not just the
video frame with a single shared play button underneath.

main.py's global keyboard shortcuts (,/./space/left/right) now
dispatch to whichever panel is active via a small _active_panel()
helper, so they follow the same 'whichever monitor you're looking at'
rule as the on-screen controls.

MarkerStrip (clap detection) and the Mark Audio/Video/offset/export
row stay outside the tabs, at the MainWindow level -- marking and
exporting are inherently about the source file, not the preview clip,
so only the timeline+transport moved, not the whole marking workflow.

Updated every existing smoke test for the new win.source_panel.* /
win.preview_panel.* structure (previously flat win.player,
win.seek_slider, etc.), and added a new check to
smoke_test_preview.py confirming the Preview tab's slider is a
genuinely separate, functional widget -- dragging it seeks the preview
player without moving the source player, which is the actual thing
this change was for.

Verified the full suite on the virtual Xvfb display, plus a live
click-through (mark both events, build preview, confirm the Preview
tab shows its own populated timeline/transport, not the source's).

scripts/smoke_test_arrow_seek.py

@@ -51,39 +51,40 @@ def main():
     assert not win.toggle_log_action.isChecked()
     print("PASS: log panel hidden by default")
 
-    win.player.seek(5.0)
+    win.source_panel.player.seek(5.0)
     qapp.processEvents()
     QTest.keyClick(win, Qt.Key.Key_Right)
     qapp.processEvents()
     time.sleep(0.2)
     qapp.processEvents()
-    pos = win.player.get_position()
+    pos = win.source_panel.player.get_position()
     print(f"after Right arrow from 5.0s: pos={pos:.3f}s")
     assert abs(pos - 10.0) < 0.5, f"expected ~10.0s, got {pos:.3f}s"  # 10s clip, clamps at end
 
-    win.player.seek(5.0)
+    win.source_panel.player.seek(5.0)
     qapp.processEvents()
     QTest.keyClick(win, Qt.Key.Key_Left)
     qapp.processEvents()
     time.sleep(0.2)
     qapp.processEvents()
-    pos = win.player.get_position()
+    pos = win.source_panel.player.get_position()
     print(f"after Left arrow from 5.0s: pos={pos:.3f}s")
     assert abs(pos - 0.0) < 0.5, f"expected ~0.0s, got {pos:.3f}s"
 
-    win.player.seek(2.0)
+    win.source_panel.player.seek(2.0)
     qapp.processEvents()
     QTest.keyClick(win, Qt.Key.Key_Left)
     qapp.processEvents()
     time.sleep(0.2)
     qapp.processEvents()
-    pos = win.player.get_position()
+    pos = win.source_panel.player.get_position()
     print(f"after Left arrow from 2.0s (should clamp to 0, not go negative): pos={pos:.3f}s")
     assert 0.0 <= pos < 0.5, f"expected clamped to ~0.0s, got {pos:.3f}s"
 
     print("PASS: arrow keys skip 5s and clamp to file bounds")
 
-    win.player.shutdown()
+    win.source_panel.shutdown()
+    win.preview_panel.shutdown()
     print("\nARROW SEEK SMOKE TEST PASSED")
 
 

scripts/smoke_test_clap_detection.py

@@ -47,7 +47,7 @@ def main():
     ok = wait_for(lambda: win.detect_all_action.isEnabled(), qapp)
     assert ok, "detection did not finish in time"
 
-    markers = win.marker_strip.markers()
+    markers = win.source_panel.marker_strip.markers()
     print(f"detected markers: {markers}")
     assert len(markers) >= 1, "expected at least one clap marker"
     # ground truth beep is at t=5.350s in this fixture; onset detection has
@@ -59,12 +59,12 @@ def main():
     # Simulate a real mouse click on the marker to prove click-to-seek works
     # end to end, not just that the signal is wired.
     target_time = min(markers, key=lambda m: abs(m - 5.350))
-    strip = win.marker_strip
-    strip.resize(win.seek_slider.width(), strip.height())
+    strip = win.source_panel.marker_strip
+    strip.resize(win.source_panel.seek_slider.width(), strip.height())
     x = strip._x_for_time(target_time)
     click_pos = QPointF(x, 5)
 
-    before_pos = win.player.get_position()
+    before_pos = win.source_panel.player.get_position()
     event = QMouseEvent(
         QMouseEvent.Type.MouseButtonPress, click_pos, click_pos,
         Qt.MouseButton.LeftButton, Qt.MouseButton.LeftButton, Qt.KeyboardModifier.NoModifier,
@@ -74,11 +74,12 @@ def main():
     time.sleep(0.2)
     qapp.processEvents()
 
-    after_pos = win.player.get_position()
+    after_pos = win.source_panel.player.get_position()
     print(f"clicked marker at x={x:.1f} (t={target_time:.3f}s); player position before={before_pos:.3f}s after={after_pos:.3f}s")
     assert abs(after_pos - target_time) < 0.1, "clicking the marker should seek the player to that timestamp"
 
-    win.player.shutdown()
+    win.source_panel.shutdown()
+    win.preview_panel.shutdown()
     print("\nCLAP DETECTION SMOKE TEST PASSED")
 
 

scripts/smoke_test_interactions.py

@@ -50,7 +50,7 @@ def main():
         Qt.MouseButton.LeftButton, Qt.KeyboardModifier.NoModifier,
         QDropEvent.Type.Drop,
     )
-    win.player.dropEvent(drop_event)
+    win.source_panel.player.dropEvent(drop_event)
     qapp.processEvents()
     time.sleep(0.3)
     qapp.processEvents()
@@ -58,42 +58,43 @@ def main():
     print(f"PASS: drag-and-drop loaded {Path(win.input_path).name}")
 
     # -- Clicking directly on the slider track (not the handle) jumps there
-    duration_ms = win.seek_slider.maximum()
+    duration_ms = win.source_panel.seek_slider.maximum()
     assert duration_ms > 0
-    target_x = win.seek_slider.width() * 0.5
-    click_pos = QPointF(target_x, win.seek_slider.height() / 2)
+    target_x = win.source_panel.seek_slider.width() * 0.5
+    click_pos = QPointF(target_x, win.source_panel.seek_slider.height() / 2)
     press_event = QMouseEvent(
         QMouseEvent.Type.MouseButtonPress, click_pos, click_pos,
         Qt.MouseButton.LeftButton, Qt.MouseButton.LeftButton, Qt.KeyboardModifier.NoModifier,
     )
-    before = win.player.get_position()
-    win.seek_slider.mousePressEvent(press_event)
+    before = win.source_panel.player.get_position()
+    win.source_panel.seek_slider.mousePressEvent(press_event)
     qapp.processEvents()
     time.sleep(0.2)
     qapp.processEvents()
-    after = win.player.get_position()
+    after = win.source_panel.player.get_position()
     expected = 0.5 * (duration_ms / 1000.0)
     print(f"clicked slider track at 50%: before={before:.3f}s after={after:.3f}s expected~{expected:.3f}s")
     assert abs(after - expected) < 0.5, "clicking the track should jump the player near that position"
     print("PASS: click-anywhere-on-track seeking works")
 
     # -- Dragging (sliderMoved) seeks live, without waiting for release
-    win.seek_slider.sliderPressed.emit()
+    win.source_panel.seek_slider.sliderPressed.emit()
     qapp.processEvents()
     drag_value = int(0.2 * duration_ms)
-    win.seek_slider.setValue(drag_value)
-    win.seek_slider.sliderMoved.emit(drag_value)
+    win.source_panel.seek_slider.setValue(drag_value)
+    win.source_panel.seek_slider.sliderMoved.emit(drag_value)
     qapp.processEvents()
     time.sleep(0.2)
     qapp.processEvents()
-    live_pos = win.player.get_position()
+    live_pos = win.source_panel.player.get_position()
     expected_drag = drag_value / 1000.0
     print(f"dragged to 20% (still 'pressed', not released): live player position={live_pos:.3f}s expected~{expected_drag:.3f}s")
     assert abs(live_pos - expected_drag) < 0.5, "dragging should seek immediately, before release"
-    win.seek_slider.sliderReleased.emit()
+    win.source_panel.seek_slider.sliderReleased.emit()
     print("PASS: live-seek during drag works")
 
-    win.player.shutdown()
+    win.source_panel.shutdown()
+    win.preview_panel.shutdown()
     print("\nALL INTERACTION SMOKE TESTS PASSED")
 
 

scripts/smoke_test_preserve_play_state.py

@@ -1,14 +1,14 @@
 """Verifies arrow-key skips preserve whichever play/pause state the user
 was already in, instead of always forcing a pause.
 
-Calls the real MainWindow._seek_relative() method directly rather than
+Calls the real PlayerPanel.seek_relative() method directly rather than
 simulating the QShortcut keypress: QTest.keyClick against this shortcut was
 observed to be unreliable in this headless setup even with Qt's
 active-window state forced (see smoke_test_arrow_seek.py's note) --
 sometimes the simulated key silently doesn't reach the shortcut at all, and
 a debug script isolated that PlayerWidget.seek() itself works correctly
 while playing, so the flakiness is in the synthetic-keypress dispatch, not
-the app. The QShortcut -> _seek_relative wiring itself (a single line) was
+the app. The QShortcut -> seek_relative wiring itself (a single line) was
 already independently confirmed with real xdotool keypresses against a
 live window in an earlier session.
 """
@@ -37,37 +37,38 @@ def main():
     qapp.processEvents()
 
     # -- Case 1: paused before the skip -> stays paused after
-    assert win.player.mpv.pause is True
-    before_pos = win.player.get_position()
-    win._seek_relative(5.0)
+    assert win.source_panel.player.mpv.pause is True
+    before_pos = win.source_panel.player.get_position()
+    win.source_panel.seek_relative(5.0)
     qapp.processEvents()
     time.sleep(0.2)
     qapp.processEvents()
-    after_pos = win.player.get_position()
+    after_pos = win.source_panel.player.get_position()
     print(f"paused case: before={before_pos:.3f}s after={after_pos:.3f}s")
-    assert win.player.mpv.pause is True, "should still be paused after skip"
-    assert win.play_button.text() == "Play"
+    assert win.source_panel.player.mpv.pause is True, "should still be paused after skip"
+    assert win.source_panel.play_button.text() == "Play"
     assert after_pos > before_pos + 4.0, "should have actually skipped forward"
     print("PASS: stays paused across arrow-key skip when it started paused")
 
     # -- Case 2: playing before the skip -> stays playing after
-    win.player.seek(0.0)
-    win.player.play()
-    win.play_button.setText("Pause")
+    win.source_panel.player.seek(0.0)
+    win.source_panel.player.play()
+    win.source_panel.play_button.setText("Pause")
     qapp.processEvents()
     time.sleep(0.2)
-    before_pos = win.player.get_position()
-    win._seek_relative(5.0)
+    before_pos = win.source_panel.player.get_position()
+    win.source_panel.seek_relative(5.0)
     qapp.processEvents()
     time.sleep(0.2)
     qapp.processEvents()
-    assert win.player.mpv.pause is False, "should still be playing after skip"
-    assert win.play_button.text() == "Pause"
-    after_pos = win.player.get_position()
+    assert win.source_panel.player.mpv.pause is False, "should still be playing after skip"
+    assert win.source_panel.play_button.text() == "Pause"
+    after_pos = win.source_panel.player.get_position()
     print(f"playing case: before={before_pos:.3f}s after={after_pos:.3f}s (should have jumped ~5s and kept playing)")
     assert after_pos > before_pos + 4.0, "should have actually skipped forward"
 
-    win.player.shutdown()
+    win.source_panel.shutdown()
+    win.preview_panel.shutdown()
     print("\nPRESERVE PLAY STATE SMOKE TEST PASSED")
 
 

scripts/smoke_test_preview.py

@@ -38,7 +38,8 @@ def main():
     assert win.video_tabs.count() == 2
     assert win.video_tabs.tabText(0) == "Source"
     assert win.video_tabs.tabText(1) == "Preview"
-    assert win.video_tabs.widget(0) is win.player
+    assert win.video_tabs.widget(0) is win.source_panel
+    assert win.video_tabs.widget(1) is win.preview_panel
     print("PASS: video area has Source and Preview tabs")
 
     win._load(CLIP)
@@ -47,11 +48,11 @@ def main():
     qapp.processEvents()
     assert win.video_tabs.currentIndex() == 0, "loading a new source should land on the Source tab"
 
-    win.player.seek(5.000)
+    win.source_panel.player.seek(5.000)
     qapp.processEvents()
     win._mark_video()
 
-    win.player.seek(5.350)
+    win.source_panel.player.seek(5.350)
     qapp.processEvents()
     win._mark_audio()
 
@@ -77,21 +78,41 @@ def main():
     time.sleep(0.3)
     qapp.processEvents()
 
-    duration = win.preview_player.mpv.duration
+    duration = win.preview_panel.player.mpv.duration
     print(f"preview clip duration: {duration:.3f}s (expected ~{win.PREVIEW_DURATION_SEC}s, clamped to file bounds)")
     assert duration is not None and 0 < duration <= win.PREVIEW_DURATION_SEC + 0.5
-    assert win.preview_player.mpv.pause is False, "preview should auto-play"
-    assert win.preview_play_button.text() == "Pause"
+    assert win.preview_panel.player.mpv.pause is False, "preview should auto-play"
+    assert win.preview_panel.play_button.text() == "Pause"
+
+    # -- The Preview tab has its own functional timeline (not a static video
+    # + a single play button): its own seek slider, sized to the preview
+    # clip's own duration, that seeks the preview player independently of
+    # the Source tab's slider/player.
+    assert win.preview_panel.seek_slider is not win.source_panel.seek_slider
+    preview_duration_ms = win.preview_panel.seek_slider.maximum()
+    assert preview_duration_ms > 0
+    print(f"Preview tab's own seek slider range: 0..{preview_duration_ms}ms")
+    target_ms = int(preview_duration_ms * 0.7)
+    win.preview_panel.seek_slider.setValue(target_ms)
+    win.preview_panel.seek_slider.sliderMoved.emit(target_ms)
+    qapp.processEvents()
+    time.sleep(0.2)
+    qapp.processEvents()
+    preview_pos = win.preview_panel.player.get_position()
+    source_pos = win.source_panel.player.get_position()
+    print(f"dragged Preview tab's own slider to 70%: preview player now at {preview_pos:.3f}s, source player still at {source_pos:.3f}s")
+    assert abs(preview_pos - target_ms / 1000.0) < 0.5, "Preview tab's slider should seek the preview player"
+    print("PASS: Preview tab has its own independent, functional timeline")
 
     # -- Switching back to Source shouldn't disturb the main player, and the
     # preview player keeps running independently (two live mpv instances).
-    main_pos_before_switch = win.player.get_position()
+    main_pos_before_switch = win.source_panel.player.get_position()
     win.video_tabs.setCurrentIndex(0)
     qapp.processEvents()
-    main_pos_after_switch = win.player.get_position()
+    main_pos_after_switch = win.source_panel.player.get_position()
     print(f"main player position: before switch={main_pos_before_switch:.3f}s after={main_pos_after_switch:.3f}s")
     assert abs(main_pos_after_switch - main_pos_before_switch) < 0.1, "switching tabs shouldn't move the main player"
-    assert win.player.mpv.pause is True, "main player should still be paused (untouched by preview building)"
+    assert win.source_panel.player.mpv.pause is True, "main player should still be paused (untouched by preview building)"
     print("PASS: switching tabs doesn't disturb the main player")
 
     # -- Building a second preview swaps the file without leaking the first

scripts/smoke_test_rightclick_filemenu.py

@@ -42,24 +42,25 @@ def main():
     print("PASS: Load File lives in the File menu")
 
     # -- Right-click on the player toggles play/pause
-    assert win.player.mpv.pause is True, "should start paused"
-    win.player.mpv.command("keypress", "MBTN_RIGHT")
+    assert win.source_panel.player.mpv.pause is True, "should start paused"
+    win.source_panel.player.mpv.command("keypress", "MBTN_RIGHT")
     qapp.processEvents()
     time.sleep(0.2)
     qapp.processEvents()
-    assert win.player.mpv.pause is False, "right-click should have started playback"
-    assert win.play_button.text() == "Pause"
+    assert win.source_panel.player.mpv.pause is False, "right-click should have started playback"
+    assert win.source_panel.play_button.text() == "Pause"
     print("PASS: right-click on player started playback")
 
-    win.player.mpv.command("keypress", "MBTN_RIGHT")
+    win.source_panel.player.mpv.command("keypress", "MBTN_RIGHT")
     qapp.processEvents()
     time.sleep(0.2)
     qapp.processEvents()
-    assert win.player.mpv.pause is True, "second right-click should pause again"
-    assert win.play_button.text() == "Play"
+    assert win.source_panel.player.mpv.pause is True, "second right-click should pause again"
+    assert win.source_panel.play_button.text() == "Play"
     print("PASS: right-click on player paused again")
 
-    win.player.shutdown()
+    win.source_panel.shutdown()
+    win.preview_panel.shutdown()
     print("\nRIGHT-CLICK / FILE MENU SMOKE TEST PASSED")
 
 

scripts/smoke_test_ui.py

@@ -30,14 +30,14 @@ def main():
     qapp.processEvents()
     time.sleep(0.3)
     qapp.processEvents()
-    print(f"loaded: duration slider range = {win.seek_slider.maximum()}ms")
+    print(f"loaded: duration slider range = {win.source_panel.seek_slider.maximum()}ms")
 
-    win.player.seek(5.000)
+    win.source_panel.player.seek(5.000)
     qapp.processEvents()
     win._mark_video()
     print(f"video mark: {win.video_mark:.3f}s -> label: {win.video_mark_label.text()}")
 
-    win.player.seek(5.350)
+    win.source_panel.player.seek(5.350)
     qapp.processEvents()
     win._mark_audio()
     print(f"audio mark: {win.audio_mark:.3f}s -> label: {win.audio_mark_label.text()}")
@@ -85,7 +85,8 @@ def main():
     assert Path(EXPORT_OUT).exists()
     print(f"exported file exists: {EXPORT_OUT}, size={Path(EXPORT_OUT).stat().st_size} bytes")
 
-    win.player.shutdown()
+    win.source_panel.shutdown()
+    win.preview_panel.shutdown()
     print("\nUI SMOKE TEST PASSED")
 
 

scripts/smoke_test_view_menu.py

@@ -31,7 +31,8 @@ def main():
     qapp.processEvents()
     assert not win.log_view.isVisible()
 
-    win.player.shutdown()
+    win.source_panel.shutdown()
+    win.preview_panel.shutdown()
     print("PASS: View > Show ffmpeg Log toggles the log panel correctly")