[libcamera-devel] [PATCH v2 1/4] qcam: Use QDialog for selection of cameras at startup

[Utkarsh Tiwari]

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.

Signed-off-by: Utkarsh Tiwari <utkarsh02t at gmail.com>
---
Difference from V1:
The biggest change here is the introduction of class,  inside of
the class the layout remains same.
 src/qcam/cam_select_dialog.h | 64 ++++++++++++++++++++++++++++++++++++
 src/qcam/main_window.cpp     | 22 +++----------
 src/qcam/main_window.h       |  4 +++
 src/qcam/meson.build         |  1 +
 4 files changed, 74 insertions(+), 17 deletions(-)
 create mode 100644 src/qcam/cam_select_dialog.h

diff --git a/src/qcam/cam_select_dialog.h b/src/qcam/cam_select_dialog.h
new file mode 100644
index 00000000..c23bad59
--- /dev/null
+++ b/src/qcam/cam_select_dialog.h
@@ -0,0 +1,64 @@
+
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2019, Google Inc.
+ *
+ * cam_select_dialog.h - qcam - Camera Selection dialog
+ */
+
+#pragma once
+
+#include <string>
+
+#include <libcamera/camera.h>
+#include <libcamera/camera_manager.h>
+
+#include <QComboBox>
+#include <QDialog>
+#include <QDialogButtonBox>
+#include <QFormLayout>
+#include <QString>
+
+class CamSelectDialog : public QDialog
+{
+	Q_OBJECT
+public:
+	CamSelectDialog(libcamera::CameraManager *cameraManager, QWidget *parent)
+		: QDialog(parent), cm_(cameraManager)
+	{
+		/* Use a QFormLayout for the dialog. */
+		QFormLayout *camSelectDialogLayout = 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 *dialogButtonBox =
+			new QDialogButtonBox(QDialogButtonBox::Ok |
+					     QDialogButtonBox::Cancel);
+
+		connect(dialogButtonBox, &QDialogButtonBox::accepted,
+			this, &QDialog::accept);
+		connect(dialogButtonBox, &QDialogButtonBox::rejected,
+			this, &QDialog::reject);
+
+		/* Set the layout. */
+		camSelectDialogLayout->addRow("Camera: ", cameraIdComboBox_);
+		camSelectDialogLayout->addWidget(dialogButtonBox);
+	}
+
+	~CamSelectDialog() = default;
+
+	std::string getCameraId()
+	{
+		return cameraIdComboBox_->currentText().toStdString();
+	}
+
+private:
+	libcamera::CameraManager *cm_;
+
+	/* UI elements. */
+	QComboBox *cameraIdComboBox_;
+};
diff --git a/src/qcam/main_window.cpp b/src/qcam/main_window.cpp
index 7433d647..758e2c94 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"
@@ -290,24 +290,12 @@ void MainWindow::switchCamera(int index)
 
 std::string MainWindow::chooseCamera()
 {
-	QStringList cameras;
-	bool result;
+	camSelectDialog_ = new CamSelectDialog(cm_, this);
 
-	/* 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 (camSelectDialog_->exec() == QDialog::Accepted)
+		return camSelectDialog_->getCameraId();
+	else
 		return std::string();
-
-	return id.toStdString();
 }
 
 int MainWindow::openCamera()
diff --git a/src/qcam/main_window.h b/src/qcam/main_window.h
index fc70920f..6d80b5be 100644
--- a/src/qcam/main_window.h
+++ b/src/qcam/main_window.h
@@ -23,11 +23,13 @@
 #include <QMainWindow>
 #include <QMutex>
 #include <QObject>
+#include <QPointer>
 #include <QQueue>
 #include <QTimer>
 
 #include "../cam/stream_options.h"
 
+#include "cam_select_dialog.h"
 #include "viewfinder.h"
 
 class QAction;
@@ -99,6 +101,8 @@ private:
 	QString title_;
 	QTimer titleTimer_;
 
+	QPointer<CamSelectDialog> camSelectDialog_;
+
 	/* Options */
 	const OptionsParser::Options &options_;
 
diff --git a/src/qcam/meson.build b/src/qcam/meson.build
index c46f4631..70615e92 100644
--- a/src/qcam/meson.build
+++ b/src/qcam/meson.build
@@ -26,6 +26,7 @@ qcam_sources = files([
 ])
 
 qcam_moc_headers = files([
+    'cam_select_dialog.h',
     'main_window.h',
     'viewfinder_qt.h',
 ])
-- 
2.25.1