Implement dual output for camera using QVideoWidget and QVideoSink, add camera permission handling, and enhance overlay error messaging

duck_preview/rendering/overlay.py

@@ -11,13 +11,13 @@ class OverlayWidget(QWidget):
         self.setAttribute(Qt.WA_TransparentForMouseEvents)
         self.setAttribute(Qt.WA_NoSystemBackground)
         self._visible = True
-        self._metrics: dict[str, float | int] = {}
+        self._metrics: dict[str, float | int | str] = {}
 
     def set_visible(self, visible: bool) -> None:
         self._visible = visible
         self.update()
 
-    def set_metrics(self, metrics: dict[str, float | int]) -> None:
+    def set_metrics(self, metrics: dict[str, float | int | str]) -> None:
         self._metrics = metrics
         self.update()
 
@@ -25,16 +25,22 @@ class OverlayWidget(QWidget):
         if not self._visible or not self._metrics:
             return
 
+        painter = QPainter(self)
+        painter.setRenderHint(QPainter.TextAntialiasing)
+
+        if "error" in self._metrics:
+            self._paint_error(painter)
+        else:
+            self._paint_metrics(painter)
+
+    def _paint_metrics(self, painter: QPainter) -> None:
         lines = [
             f"FPS:     {self._metrics.get('fps', 0):>7}",
             f"Frame:   {self._metrics.get('frame_time_ms', 0):>7.1f} ms",
             f"Frames:  {self._metrics.get('frame_count', 0):>7}",
         ]
 
-        painter = QPainter(self)
-        painter.setRenderHint(QPainter.TextAntialiasing)
-
-        font = QFont("Consolas", 11)
+        font = QFont("monospace", 11)
         painter.setFont(font)
         fm = QFontMetrics(font)
 
@@ -42,8 +48,26 @@ class OverlayWidget(QWidget):
         text_height = len(lines) * (fm.height() + 6) + 12
 
         painter.fillRect(8, 8, text_width, text_height, QColor(0, 0, 0, 160))
-
         painter.setPen(QColor(0, 255, 0))
+
+        for i, line in enumerate(lines):
+            y = 22 + i * (fm.height() + 6)
+            painter.drawText(16, y, line)
+
+    def _paint_error(self, painter: QPainter) -> None:
+        msg = str(self._metrics.get("error", "Unknown error"))
+        lines = msg.split("\n")
+
+        font = QFont("monospace", 12)
+        painter.setFont(font)
+        fm = QFontMetrics(font)
+
+        text_width = max(fm.horizontalAdvance(line) for line in lines) + 24
+        text_height = len(lines) * (fm.height() + 6) + 12
+
+        painter.fillRect(8, 8, text_width, text_height, QColor(0, 0, 0, 200))
+        painter.setPen(QColor(200, 50, 50))
+
         for i, line in enumerate(lines):
             y = 22 + i * (fm.height() + 6)
             painter.drawText(16, y, line)

duck_preview/rendering/video_widget.py

@@ -1,39 +1,10 @@
 from __future__ import annotations
 
-from PySide6.QtCore import Qt
-from PySide6.QtGui import QColor, QImage, QPainter
-from PySide6.QtMultimedia import QVideoFrame
+from PySide6.QtMultimediaWidgets import QVideoWidget
 from PySide6.QtWidgets import QWidget
 
 
-class VideoWidget(QWidget):
+class VideoWidget(QVideoWidget):
     def __init__(self, parent: QWidget | None = None) -> None:
         super().__init__(parent)
-        self._frame: QImage | None = None
-        self.setAttribute(Qt.WA_OpaquePaintEvent)
         self.setMinimumSize(320, 240)
-
-    def on_frame(self, frame: QVideoFrame) -> None:
-        image = frame.toImage()
-        if not image.isNull():
-            self._frame = image
-            self.update()
-
-    def paintEvent(self, event) -> None:  # noqa: N802
-        painter = QPainter(self)
-        painter.setRenderHint(QPainter.SmoothPixmapTransform)
-
-        if self._frame is not None:
-            painter.fillRect(self.rect(), QColor(0, 0, 0))
-            scaled = self._frame.scaled(
-                self.size(),
-                Qt.KeepAspectRatio,
-                Qt.SmoothTransformation,
-            )
-            x = (self.width() - scaled.width()) // 2
-            y = (self.height() - scaled.height()) // 2
-            painter.drawImage(x, y, scaled)
-        else:
-            painter.fillRect(self.rect(), QColor(20, 20, 20))
-            painter.setPen(QColor(100, 100, 100))
-            painter.drawText(self.rect(), Qt.AlignCenter, "No camera feed")