Implement initial structure and core functionality for Duck Preview application

duck_preview/main_window.py

@@ -0,0 +1,118 @@
+from __future__ import annotations
+
+from PySide6.QtGui import QAction, QCloseEvent
+from PySide6.QtMultimedia import QCameraDevice, QMediaDevices
+from PySide6.QtWidgets import QGridLayout, QMainWindow, QWidget
+
+from duck_preview.camera.service import CameraService
+from duck_preview.rendering.overlay import OverlayWidget
+from duck_preview.rendering.video_widget import VideoWidget
+
+
+class MainWindow(QMainWindow):
+    def __init__(
+        self,
+        camera_service: CameraService,
+        video_widget: VideoWidget,
+        overlay_widget: OverlayWidget,
+        parent: QWidget | None = None,
+    ) -> None:
+        super().__init__(parent)
+        self._camera = camera_service
+        self._video_widget = video_widget
+        self._overlay = overlay_widget
+        self._media_devices = QMediaDevices()
+
+        self.setWindowTitle("Duck Preview")
+        self.resize(1280, 720)
+
+        central = QWidget()
+        self.setCentralWidget(central)
+        layout = QGridLayout(central)
+        layout.setContentsMargins(0, 0, 0, 0)
+        layout.setSpacing(0)
+        layout.addWidget(video_widget, 0, 0)
+        layout.addWidget(overlay_widget, 0, 0)
+
+        self._setup_menus()
+
+        self._media_devices.videoInputsChanged.connect(self._rebuild_camera_menu)
+
+    def _setup_menus(self) -> None:
+        menu_bar = self.menuBar()
+
+        self._camera_menu = menu_bar.addMenu("Camera")
+        self._rebuild_camera_menu()
+
+        self._resolution_menu = menu_bar.addMenu("Resolution")
+        self._resolution_menu.setEnabled(False)
+
+        self._fps_menu = menu_bar.addMenu("FPS")
+        self._fps_menu.setEnabled(False)
+
+        debug_menu = menu_bar.addMenu("Debug")
+        toggle_overlay = QAction("Show Metrics", self)
+        toggle_overlay.setCheckable(True)
+        toggle_overlay.setChecked(True)
+        toggle_overlay.triggered.connect(self._overlay.set_visible)
+        debug_menu.addAction(toggle_overlay)
+
+    def _rebuild_camera_menu(self) -> None:
+        self._camera_menu.clear()
+        cameras = CameraService.available_cameras()
+        for device in cameras:
+            action = QAction(device.description(), self)
+            action.triggered.connect(lambda checked, d=device: self._on_camera_selected(d))
+            self._camera_menu.addAction(action)
+        if not cameras:
+            action = QAction("No cameras detected", self)
+            action.setEnabled(False)
+            self._camera_menu.addAction(action)
+
+    def _on_camera_selected(self, device: QCameraDevice) -> None:
+        self._camera.start(device)
+        self._rebuild_resolution_menu(device)
+
+    def _rebuild_resolution_menu(self, device: QCameraDevice) -> None:
+        self._resolution_menu.clear()
+        self._resolution_menu.setEnabled(True)
+        formats = device.videoFormats()
+        seen: set[tuple[int, int]] = set()
+        for fmt in formats:
+            res = fmt.resolution()
+            key = (res.width(), res.height())
+            if key not in seen:
+                seen.add(key)
+                action = QAction(f"{res.width()}x{res.height()}", self)
+                action.triggered.connect(
+                    lambda checked, d=device, w=res.width(), h=res.height(): (
+                        self._on_resolution_selected(d, w, h)
+                    )
+                )
+                self._resolution_menu.addAction(action)
+
+    def _on_resolution_selected(self, device: QCameraDevice, width: int, height: int) -> None:
+        self._rebuild_fps_menu(device, width, height)
+
+    def _rebuild_fps_menu(self, device: QCameraDevice, width: int, height: int) -> None:
+        self._fps_menu.clear()
+        self._fps_menu.setEnabled(True)
+        formats = device.videoFormats()
+        seen_labels: set[str] = set()
+        for fmt in formats:
+            res = fmt.resolution()
+            if res.width() == width and res.height() == height:
+                min_fps = round(fmt.minFrameRate())
+                max_fps = round(fmt.maxFrameRate())
+                label = f"{max_fps} FPS" if min_fps == max_fps else f"{min_fps}-{max_fps} FPS"
+                if label not in seen_labels:
+                    seen_labels.add(label)
+                    action = QAction(label, self)
+                    action.triggered.connect(
+                        lambda checked, f=fmt: self._camera.set_camera_format(f)
+                    )
+                    self._fps_menu.addAction(action)
+
+    def closeEvent(self, event: QCloseEvent) -> None:  # noqa: N802
+        self._camera.stop()
+        super().closeEvent(event)