[libcamera-devel] [PATCH 6/6] qcam: Provide save image functionality

[Kieran Bingham]

Implement a save image button on the toolbar which will take a current
viewfinder image and present the user with a QFileDialog to allow them
to choose where to save the image.

Utilise the QImageWriter to perform the output task.

Signed-off-by: Kieran Bingham <kieran.bingham at ideasonboard.com>
---
 src/qcam/main_window.cpp | 22 ++++++++++++++++++++++
 src/qcam/main_window.h   |  1 +
 src/qcam/viewfinder.cpp  |  7 +++++++
 src/qcam/viewfinder.h    |  2 ++
 4 files changed, 32 insertions(+)

diff --git a/src/qcam/main_window.cpp b/src/qcam/main_window.cpp
index 0ae4c60b8699..0e994b1e9197 100644
--- a/src/qcam/main_window.cpp
+++ b/src/qcam/main_window.cpp
@@ -11,7 +11,10 @@
 #include <sys/mman.h>
 
 #include <QCoreApplication>
+#include <QFileDialog>
 #include <QIcon>
+#include <QImage>
+#include <QImageWriter>
 #include <QInputDialog>
 #include <QTimer>
 #include <QToolBar>
@@ -89,6 +92,9 @@ int MainWindow::createToolbars(CameraManager *cm)
 	action = toolbar_->addAction(QIcon(":stop-circle.svg"), "stop");
 	connect(action, &QAction::triggered, this, &MainWindow::stopCapture);
 
+	action = toolbar_->addAction(QIcon(":save.svg"), "save");
+	connect(action, &QAction::triggered, this, &MainWindow::saveImage);
+
 	return 0;
 }
 
@@ -339,6 +345,22 @@ void MainWindow::stopCapture()
 	setWindowTitle(title_);
 }
 
+void MainWindow::saveImage()
+{
+	/* Take a lock to prevent updating the backed image, copy,
+	 * then ask where to save with lock released */
+
+	QImage image = viewfinder_->getCurrentImage();
+
+	QString filename = QFileDialog::getSaveFileName(this, "Save Image", "",
+							"Image Files (*.png *.jpg *.jpeg)");
+
+	std::cerr << "Save jpeg to " << filename.toStdString() << std::endl;
+
+	QImageWriter writer(filename);
+	writer.write(image);
+}
+
 void MainWindow::requestComplete(Request *request)
 {
 	if (request->status() == Request::RequestCancelled)
diff --git a/src/qcam/main_window.h b/src/qcam/main_window.h
index b0bf16dd2a09..fc85b6a46491 100644
--- a/src/qcam/main_window.h
+++ b/src/qcam/main_window.h
@@ -48,6 +48,7 @@ private Q_SLOTS:
 
 	int startCapture();
 	void stopCapture();
+	void saveImage();
 
 private:
 	int createToolbars(CameraManager *cm);
diff --git a/src/qcam/viewfinder.cpp b/src/qcam/viewfinder.cpp
index 6de284d1b782..3fa4a326c342 100644
--- a/src/qcam/viewfinder.cpp
+++ b/src/qcam/viewfinder.cpp
@@ -6,6 +6,7 @@
  */
 
 #include <QImage>
+#include <QImageWriter>
 #include <QPainter>
 
 #include "format_converter.h"
@@ -27,6 +28,12 @@ void ViewFinder::display(const unsigned char *raw, size_t size)
 	update();
 }
 
+QImage ViewFinder::getCurrentImage()
+{
+	/* Ideally need to lock, return/copy, then unlock... Can a scoped lock work? */
+	return *image_;
+}
+
 int ViewFinder::setFormat(unsigned int format, unsigned int width,
 			  unsigned int height)
 {
diff --git a/src/qcam/viewfinder.h b/src/qcam/viewfinder.h
index ef5fd45b264a..1da79d3e67aa 100644
--- a/src/qcam/viewfinder.h
+++ b/src/qcam/viewfinder.h
@@ -23,6 +23,8 @@ public:
 		      unsigned int height);
 	void display(const unsigned char *rgb, size_t size);
 
+	QImage getCurrentImage();
+
 protected:
 	void paintEvent(QPaintEvent *) override;
 	QSize sizeHint() const override;
-- 
2.20.1