[libcamera-devel] [PATCH v9 1/7] qcam: Use QDialog for selection of cameras at startup

Utkarsh Tiwari utkarsh02t at gmail.com
Wed Aug 31 07:49:32 CEST 2022


Currently we use QInputDialog convenience dialogs to allow the user to
select a camera. This doesn't allow adding of more information (such as
camera location, model etc).

Create a QDialog with a QFormLayout that shows a QComboBox with camera
Ids. Use a QDialogButtonBox to provide buttons for accepting and
cancelling the action.

The CameraSelectorDialog is only initialized the first time when the
MainWindow is created.

>From this commit we cease to auto select the camera if only a single
camera is available to libcamera. We would always display the selection
dialog with the exception being that being if the camera is supplied on
the command line.

Signed-off-by: Utkarsh Tiwari <utkarsh02t at gmail.com>
Reviewed-by: Kieran Bingham <kieran.bingham at ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
---
Difference from v8:
    1. s/by the console/on the command line in the commit msg
    2. Removed <string> header from cam_select_dialog.cpp
    3. Drop <QDialog> from cam_select_dialog.cpp
    4. QComboBox is forward-declared in cam_select_dialog.h
    5. ~CameraSelectorDialog() implementation now resides in .cpp
    6. CameraSelectorDialog is forward-declared in main_window.h
 src/qcam/cam_select_dialog.cpp | 50 ++++++++++++++++++++++++++++++++++
 src/qcam/cam_select_dialog.h   | 35 ++++++++++++++++++++++++
 src/qcam/main_window.cpp       | 27 ++++--------------
 src/qcam/main_window.h         |  3 ++
 src/qcam/meson.build           |  2 ++
 5 files changed, 96 insertions(+), 21 deletions(-)
 create mode 100644 src/qcam/cam_select_dialog.cpp
 create mode 100644 src/qcam/cam_select_dialog.h

diff --git a/src/qcam/cam_select_dialog.cpp b/src/qcam/cam_select_dialog.cpp
new file mode 100644
index 00000000..a49d822b
--- /dev/null
+++ b/src/qcam/cam_select_dialog.cpp
@@ -0,0 +1,50 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2022, Utkarsh Tiwari <utkarsh02t at gmail.com>
+ *
+ * cam_select_dialog.cpp - qcam - Camera Selection dialog
+ */
+
+#include "cam_select_dialog.h"
+
+#include <libcamera/camera.h>
+#include <libcamera/camera_manager.h>
+
+#include <QComboBox>
+#include <QDialogButtonBox>
+#include <QFormLayout>
+#include <QString>
+
+CameraSelectorDialog::CameraSelectorDialog(libcamera::CameraManager *cameraManager,
+					   QWidget *parent)
+	: QDialog(parent), cm_(cameraManager)
+{
+	/* Use a QFormLayout for the dialog. */
+	QFormLayout *layout = new QFormLayout(this);
+
+	/* Setup the camera id combo-box. */
+	cameraIdComboBox_ = new QComboBox;
+	for (const auto &cam : cm_->cameras())
+		cameraIdComboBox_->addItem(QString::fromStdString(cam->id()));
+
+	/* Setup the QDialogButton Box */
+	QDialogButtonBox *buttonBox =
+		new QDialogButtonBox(QDialogButtonBox::Ok |
+				     QDialogButtonBox::Cancel);
+
+	connect(buttonBox, &QDialogButtonBox::accepted,
+		this, &QDialog::accept);
+	connect(buttonBox, &QDialogButtonBox::rejected,
+		this, &QDialog::reject);
+
+	/* Set the layout. */
+	layout->addRow("Camera:", cameraIdComboBox_);
+	layout->addWidget(buttonBox);
+}
+
+CameraSelectorDialog::~CameraSelectorDialog() = default;
+
+std::string CameraSelectorDialog::getCameraId()
+{
+	return cameraIdComboBox_->currentText().toStdString();
+}
diff --git a/src/qcam/cam_select_dialog.h b/src/qcam/cam_select_dialog.h
new file mode 100644
index 00000000..c31f4f82
--- /dev/null
+++ b/src/qcam/cam_select_dialog.h
@@ -0,0 +1,35 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2022, Utkarsh Tiwari <utkarsh02t at gmail.com>
+ *
+ * cam_select_dialog.h - qcam - Camera Selection dialog
+ */
+
+#pragma once
+
+#include <string>
+
+#include <libcamera/camera.h>
+#include <libcamera/camera_manager.h>
+
+#include <QDialog>
+
+class QComboBox;
+
+class CameraSelectorDialog : public QDialog
+{
+	Q_OBJECT
+public:
+	CameraSelectorDialog(libcamera::CameraManager *cameraManager,
+			     QWidget *parent);
+
+	~CameraSelectorDialog();
+
+	std::string getCameraId();
+
+private:
+	libcamera::CameraManager *cm_;
+
+	/* UI elements. */
+	QComboBox *cameraIdComboBox_;
+};
diff --git a/src/qcam/main_window.cpp b/src/qcam/main_window.cpp
index 7433d647..14bcf03e 100644
--- a/src/qcam/main_window.cpp
+++ b/src/qcam/main_window.cpp
@@ -19,7 +19,6 @@
 #include <QFileDialog>
 #include <QImage>
 #include <QImageWriter>
-#include <QInputDialog>
 #include <QMutexLocker>
 #include <QStandardPaths>
 #include <QStringList>
@@ -30,6 +29,7 @@
 
 #include "../cam/image.h"
 
+#include "cam_select_dialog.h"
 #include "dng_writer.h"
 #ifndef QT_NO_OPENGL
 #include "viewfinder_gl.h"
@@ -144,6 +144,8 @@ MainWindow::MainWindow(CameraManager *cm, const OptionsParser::Options &options)
 	cm_->cameraAdded.connect(this, &MainWindow::addCamera);
 	cm_->cameraRemoved.connect(this, &MainWindow::removeCamera);
 
+	cameraSelectorDialog_ = new CameraSelectorDialog(cm_, this);
+
 	/* Open the camera and start capture. */
 	ret = openCamera();
 	if (ret < 0) {
@@ -290,34 +292,17 @@ void MainWindow::switchCamera(int index)
 
 std::string MainWindow::chooseCamera()
 {
-	QStringList cameras;
-	bool result;
-
-	/* If only one camera is available, use it automatically. */
-	if (cm_->cameras().size() == 1)
-		return cm_->cameras()[0]->id();
-
-	/* Present a dialog box to pick a camera. */
-	for (const std::shared_ptr<Camera> &cam : cm_->cameras())
-		cameras.append(QString::fromStdString(cam->id()));
-
-	QString id = QInputDialog::getItem(this, "Select Camera",
-					   "Camera:", cameras, 0,
-					   false, &result);
-	if (!result)
+	if (cameraSelectorDialog_->exec() != QDialog::Accepted)
 		return std::string();
 
-	return id.toStdString();
+	return cameraSelectorDialog_->getCameraId();
 }
 
 int MainWindow::openCamera()
 {
 	std::string cameraName;
 
-	/*
-	 * Use the camera specified on the command line, if any, or display the
-	 * camera selection dialog box otherwise.
-	 */
+	/* Use camera provided on the command line else prompt for selection.*/
 	if (options_.isSet(OptCamera))
 		cameraName = static_cast<std::string>(options_[OptCamera]);
 	else
diff --git a/src/qcam/main_window.h b/src/qcam/main_window.h
index fc70920f..def44605 100644
--- a/src/qcam/main_window.h
+++ b/src/qcam/main_window.h
@@ -35,6 +35,7 @@ class QComboBox;
 
 class Image;
 class HotplugEvent;
+class CameraSelectorDialog;
 
 enum {
 	OptCamera = 'c',
@@ -99,6 +100,8 @@ private:
 	QString title_;
 	QTimer titleTimer_;
 
+	CameraSelectorDialog *cameraSelectorDialog_;
+
 	/* Options */
 	const OptionsParser::Options &options_;
 
diff --git a/src/qcam/meson.build b/src/qcam/meson.build
index c46f4631..61861ea6 100644
--- a/src/qcam/meson.build
+++ b/src/qcam/meson.build
@@ -18,6 +18,7 @@ qcam_sources = files([
     '../cam/image.cpp',
     '../cam/options.cpp',
     '../cam/stream_options.cpp',
+    'cam_select_dialog.cpp',
     'format_converter.cpp',
     'main.cpp',
     'main_window.cpp',
@@ -26,6 +27,7 @@ qcam_sources = files([
 ])
 
 qcam_moc_headers = files([
+    'cam_select_dialog.h',
     'main_window.h',
     'viewfinder_qt.h',
 ])
-- 
2.34.1



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