feat: AudioEditorDialog scaffold + Edit-clip entry point (ops stubbed)

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

main.py

@@ -4096,6 +4096,91 @@ class AudioWaveform(QWidget):
         self._zoom_at_x(e.position().x(), factor)
 
 
+class AudioEditorDialog(QDialog):
+    """Destructive single-clip editor: shows a file's waveform and (via 3c.3)
+    applies cut/silence/reverse/trim with undo/redo over a stack of rendered
+    version files."""
+
+    _EDIT_DECODE_CAP = 600.0   # seconds of audio to decode for the waveform
+
+    def __init__(self, path: str, parent=None):
+        super().__init__(parent)
+        self.setWindowTitle("Audio editor")
+        self.resize(720, 260)
+        self._versions: list[str] = [path]
+        self._ver_idx = 0
+        self._temps: set[str] = set()      # rendered version temps to clean up
+
+        self._wave = AudioWaveform()
+        self._btn_delete = QPushButton("Delete")
+        self._btn_silence = QPushButton("Silence")
+        self._btn_reverse = QPushButton("Reverse")
+        self._btn_trim = QPushButton("Trim to selection")
+        self._btn_undo = QPushButton("Undo")
+        self._btn_redo = QPushButton("Redo")
+        self._btn_play = QPushButton("▶ Play")
+        self._btn_play.setCheckable(True)
+        self._btn_save_as = QPushButton("Save as…")
+        self._btn_close = QPushButton("Close")
+        for b, slot in ((self._btn_delete, self._on_delete),
+                        (self._btn_silence, self._on_silence),
+                        (self._btn_reverse, self._on_reverse),
+                        (self._btn_trim, self._on_trim),
+                        (self._btn_undo, self._on_undo),
+                        (self._btn_redo, self._on_redo),
+                        (self._btn_play, self._on_play),
+                        (self._btn_save_as, self._on_save_as),
+                        (self._btn_close, self.close)):
+            b.clicked.connect(slot)
+
+        outer = QVBoxLayout(self)
+        outer.addWidget(self._wave)
+        ops = QHBoxLayout()
+        for b in (self._btn_delete, self._btn_silence, self._btn_reverse,
+                  self._btn_trim):
+            ops.addWidget(b)
+        outer.addLayout(ops)
+        bottom = QHBoxLayout()
+        for b in (self._btn_undo, self._btn_redo, self._btn_play):
+            bottom.addWidget(b)
+        bottom.addStretch()
+        bottom.addWidget(self._btn_save_as)
+        bottom.addWidget(self._btn_close)
+        outer.addLayout(bottom)
+
+        self._reload()
+
+    def _current(self) -> str:
+        return self._versions[self._ver_idx]
+
+    def _reload(self) -> None:
+        """Decode the current version into the waveform + refresh undo/redo."""
+        from core.waveform import load_region_samples, peaks
+        from core.ffmpeg import probe_duration
+        path = self._current()
+        dur = probe_duration(path) or 0.0
+        if dur > 0:
+            samples = load_region_samples(path, 0.0, min(dur, self._EDIT_DECODE_CAP))
+            self._wave.set_view(0.0, dur)
+            self._wave.set_peaks(peaks(samples))
+            self._wave.set_selection(0.0, dur)
+        else:
+            self._wave.set_view(0.0, 0.0)
+            self._wave.set_peaks([])
+        self._btn_undo.setEnabled(self._ver_idx > 0)
+        self._btn_redo.setEnabled(self._ver_idx < len(self._versions) - 1)
+
+    # ── op / history / save handlers — STUBBED (implemented in 3c.3/3c.4) ──
+    def _on_delete(self):  pass
+    def _on_silence(self): pass
+    def _on_reverse(self): pass
+    def _on_trim(self):    pass
+    def _on_undo(self):    pass
+    def _on_redo(self):    pass
+    def _on_play(self):    pass
+    def _on_save_as(self): pass
+
+
 class MainWindow(QMainWindow):
     def __init__(self):
         super().__init__()
@@ -4659,6 +4744,10 @@ class MainWindow(QMainWindow):
         self._btn_wave_refresh.setToolTip(
             "Decode the current audio area and draw its waveform")
         self._btn_wave_refresh.clicked.connect(self._on_wave_refresh)
+        self._btn_edit_clip = QPushButton("✎ Edit clip…")
+        self._btn_edit_clip.setToolTip(
+            "Open the current audio area in the destructive editor")
+        self._btn_edit_clip.clicked.connect(self._on_edit_clip)
         self._wave.selection_changed.connect(self._on_wave_selection_changed)
         self._wave.view_changed.connect(self._on_wave_view_changed)
         self._wave_pending_view = None
@@ -5027,9 +5116,10 @@ class MainWindow(QMainWindow):
         g.addWidget(self._wave, 4, 0, 1, 4)
         g.addWidget(self._btn_wave_refresh, 5, 0, 1, 2)
         g.addWidget(self._btn_audio_play, 5, 2, 1, 2)
-        g.addWidget(self._btn_extract_audio, 6, 0, 1, 4)
+        g.addWidget(self._btn_edit_clip, 6, 0, 1, 4)   # own row: destructive editor entry
+        g.addWidget(self._btn_extract_audio, 7, 0, 1, 4)
         g.setColumnStretch(4, 1)   # spare gutter column clusters label/field pairs to the left
-        g.setRowStretch(7, 1)      # anchor content to the top
+        g.setRowStretch(8, 1)      # anchor content to the top
         tb.addItem(extract_page, "Extract & Edit")
 
         # ── Page 2: Scan / Classify (moved verbatim) ─────────────
@@ -6823,6 +6913,36 @@ class MainWindow(QMainWindow):
                 pass
             self._show_status("Could not render selection", 3000)
 
+    def _on_edit_clip(self) -> None:
+        if not self._file_path:
+            self._show_status("Load a video first", 3000)
+            return
+        import tempfile
+        start = self._cursor
+        dur = self._spn_audio_len.value()
+        fd, tmp = tempfile.mkstemp(suffix=".wav", prefix="8cut_edit_")
+        os.close(fd)
+        cmd = build_audio_clip_command(self._file_path, start, dur, tmp,
+                                       filters=self._current_edit_filters() or None)
+        self._show_status("Preparing clip for editing…")
+        QApplication.setOverrideCursor(Qt.CursorShape.WaitCursor)
+        try:
+            proc = subprocess.run(cmd, capture_output=True, timeout=120)
+        except Exception:
+            proc = None
+        finally:
+            QApplication.restoreOverrideCursor()
+        if proc is None or proc.returncode != 0 or not os.path.exists(tmp):
+            try:
+                os.remove(tmp)
+            except OSError:
+                pass
+            self._show_status("Could not prepare clip", 3000)
+            return
+        self._merge_temps.add(tmp)          # reuse the close-time temp sweep
+        dlg = AudioEditorDialog(tmp, parent=self)
+        dlg.exec()
+
     def _merge_move(self, delta: int) -> None:
         row = self._merge_list.currentRow()
         if row < 0:

tests/test_ui_structure.py

@@ -637,3 +637,24 @@ def test_merge_double_click_last_is_noop(win, tmp_path):
     win._merge_list.clear(); win._merge_add_paths([str(a)])
     win._on_merge_item_double_clicked(win._merge_list.item(0))   # only/last -> no dialog, no raise
     assert win._merge_list.count() == 1
+
+
+def test_audio_editor_dialog_scaffold(win):
+    import main as win_module
+    from PyQt6.QtWidgets import QPushButton
+    dlg = win_module.AudioEditorDialog("/nonexistent.wav", parent=win)
+    # version stack starts with the initial file
+    assert dlg._versions == ["/nonexistent.wav"]
+    assert dlg._ver_idx == 0
+    assert dlg._current() == "/nonexistent.wav"
+    # widgets present
+    assert dlg._wave is not None
+    for name in ("_btn_delete", "_btn_silence", "_btn_reverse", "_btn_trim",
+                 "_btn_undo", "_btn_redo", "_btn_save_as"):
+        assert isinstance(getattr(dlg, name), QPushButton)
+    # undo disabled at the base version, redo disabled with no forward history
+    assert not dlg._btn_undo.isEnabled()
+    assert not dlg._btn_redo.isEnabled()
+    # a bad path decodes to an empty waveform without crashing
+    dlg._reload()
+    dlg.close()