qcam: viewfinder: Display icon when stopping capture

When stopping capture, display an icon instead of the last frame. This
is required to be able to release the last buffer when the viewfinder
operators in zero-copy mode.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

1 files changed, 31 insertions, 1 deletions

diff --git a/src/qcam/viewfinder.cpp b/src/qcam/viewfinder.cpp
index 3f984efb..45e226b5 100644
--- a/src/qcam/viewfinder.cpp
+++ b/src/qcam/viewfinder.cpp
@@ -20,6 +20,7 @@
 ViewFinder::ViewFinder(QWidget *parent)
 	: QWidget(parent), buffer_(nullptr)
 {
+	icon_ = QIcon(":camera-off.svg");
 }
 
 ViewFinder::~ViewFinder()
@@ -114,7 +115,36 @@ QImage ViewFinder::getCurrentImage()
 void ViewFinder::paintEvent(QPaintEvent *)
 {
 	QPainter painter(this);
-	painter.drawImage(rect(), image_, image_.rect());
+
+	/* If we have an image, draw it. */
+	if (!image_.isNull()) {
+		painter.drawImage(rect(), image_, image_.rect());
+		return;
+	}
+
+	/*
+	 * Otherwise, draw the camera stopped icon. Render it to the pixmap if
+	 * the size has changed.
+	 */
+	constexpr int margin = 20;
+
+	if (vfSize_ != size() || pixmap_.isNull()) {
+		QSize vfSize = size() - QSize{ 2 * margin, 2 * margin };
+		QSize pixmapSize{ 1, 1 };
+		pixmapSize.scale(vfSize, Qt::KeepAspectRatio);
+		pixmap_ = icon_.pixmap(pixmapSize);
+
+		vfSize_ = size();
+	}
+
+	QPoint point{ margin, margin };
+	if (pixmap_.width() < width() - 2 * margin)
+		point.setX((width() - pixmap_.width()) / 2);
+	else
+		point.setY((height() - pixmap_.height()) / 2);
+
+	painter.setBackgroundMode(Qt::OpaqueMode);
+	painter.drawPixmap(point, pixmap_);
 }
 
 QSize ViewFinder::sizeHint() const