Apply QWindowCapture to the screen capturing example

The example is pretty useful for testing.

Change-Id: I6206e445738e0cdd694c58146d4da5303e2eb6cf
Reviewed-by: Jøger Hansegård <joger.hansegard@qt.io>
Reviewed-by: Lars Knoll <lars@knoll.priv.no>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
(cherry picked from commit 3edff8e367b9060dd138a2b67cb87d2246a4a3e6)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

4 files changed, 116 insertions, 52 deletions

diff --git a/examples/multimedia/screencapture/screencapturepreview.cpp b/examples/multimedia/screencapture/screencapturepreview.cpp
index 6d217261a..41ff02212 100644
--- a/examples/multimedia/screencapture/screencapturepreview.cpp
+++ b/examples/multimedia/screencapture/screencapturepreview.cpp
@@ -16,31 +16,28 @@
 #include <QMessageBox>
 #include <QPushButton>
 
-#include <QGuiApplication>
-
 ScreenCapturePreview::ScreenCapturePreview(QWidget *parent)
     : QWidget(parent),
       screenListView(new QListView(this)),
       windowListView(new QListView(this)),
       screenCapture(new QScreenCapture(this)),
-      windows(QWindowCapture::capturableWindows()),
+      windowCapture(new QWindowCapture(this)),
       mediaCaptureSession(new QMediaCaptureSession(this)),
       videoWidget(new QVideoWidget(this)),
       gridLayout(new QGridLayout(this)),
-      startStopButton(new QPushButton(tr("Stop screencapture"), this)),
-      screenLabel(new QLabel(tr("Double-click screen to capture:"), this)),
-      windowLabel(new QLabel(tr("Double-click window to capture:"), this)),
-      videoWidgetLabel(new QLabel(tr("QScreenCapture output:"), this))
+      startStopButton(new QPushButton(this)),
+      screenLabel(new QLabel(tr("Select screen to capture:"), this)),
+      windowLabel(new QLabel(tr("Select window to capture:"), this)),
+      videoWidgetLabel(new QLabel(tr("Capture output:"), this))
 {
     // Get lists of screens and windows:
     screenListModel = new ScreenListModel(this);
-    windowListModel = new WindowListModel(windows, this);
+    windowListModel = new WindowListModel(this);
 
     // Setup QScreenCapture with initial source:
 
-    screenCapture->setScreen(QGuiApplication::primaryScreen());
-    screenCapture->start();
     mediaCaptureSession->setScreenCapture(screenCapture);
+    mediaCaptureSession->setWindowCapture(windowCapture);
     mediaCaptureSession->setVideoOutput(videoWidget);
 
     // Setup UI:
@@ -62,51 +59,111 @@ ScreenCapturePreview::ScreenCapturePreview(QWidget *parent)
     gridLayout->setColumnMinimumWidth(1, 400);
     gridLayout->setRowMinimumHeight(3, 1);
 
-    connect(screenListView, &QAbstractItemView::activated, this, &ScreenCapturePreview::onScreenSelectionChanged);
-    connect(windowListView, &QAbstractItemView::activated, this,
-            &ScreenCapturePreview::onWindowSelectionChanged);
+    connect(screenListView->selectionModel(), &QItemSelectionModel::selectionChanged, this,
+            &ScreenCapturePreview::onCurrentScreenSelectionChanged);
+    connect(windowListView->selectionModel(), &QItemSelectionModel::selectionChanged, this,
+            &ScreenCapturePreview::onCurrentWindowSelectionChanged);
     connect(startStopButton, &QPushButton::clicked, this,
             &ScreenCapturePreview::onStartStopButtonClicked);
-    connect(screenCapture, &QScreenCapture::errorOccurred, this, &ScreenCapturePreview::onScreenCaptureErrorOccured);
+    connect(screenCapture, &QScreenCapture::errorOccurred, this,
+            &ScreenCapturePreview::onScreenCaptureErrorOccured, Qt::QueuedConnection);
+    connect(windowCapture, &QWindowCapture::errorOccurred, this,
+            &ScreenCapturePreview::onWindowCaptureErrorOccured, Qt::QueuedConnection);
+
+    updateActive(SourceType::Screen, true);
 }
 
 ScreenCapturePreview::~ScreenCapturePreview() = default;
 
-void ScreenCapturePreview::onScreenSelectionChanged(QModelIndex index)
+void ScreenCapturePreview::onCurrentScreenSelectionChanged(QItemSelection selection)
 {
-    screenCapture->setScreen(screenListModel->screen(index));
-    screenSelected = true;
-    updateCapture();
+    if (auto indexes = selection.indexes(); !indexes.empty()) {
+        screenCapture->setScreen(screenListModel->screen(indexes.front()));
+        updateActive(SourceType::Screen, isActive());
+
+        windowListView->clearSelection();
+    } else {
+        screenCapture->setScreen(nullptr);
+    }
 }
 
-void ScreenCapturePreview::onWindowSelectionChanged(QModelIndex index)
+void ScreenCapturePreview::onCurrentWindowSelectionChanged(QItemSelection selection)
+{
+    if (auto indexes = selection.indexes(); !indexes.empty()) {
+        auto window = windowListModel->window(indexes.front());
+        qDebug() << indexes.front() << window.description();
+        if (!window.isValid()) {
+            const auto questionResust = QMessageBox::question(
+                    this, tr("Invalid window"),
+                    tr("The window is no longer valid. Update the list of windows?"));
+            if (questionResust == QMessageBox::Yes) {
+                updateActive(SourceType::Window, false);
+
+                windowListView->clearSelection();
+                windowListModel->populate();
+                return;
+            }
+        }
+
+        windowCapture->setWindow(window);
+        updateActive(SourceType::Window, isActive());
+
+        screenListView->clearSelection();
+    } else {
+        windowCapture->setWindow({});
+    }
+}
+
+void ScreenCapturePreview::onWindowCaptureErrorOccured(QWindowCapture::Error,
+                                                       const QString &errorString)
 {
-    windowCapture->setWindow(windowListModel->window(index));
-    screenSelected = false;
-    updateCapture();
+    QMessageBox::warning(this, tr("QWindowCapture: Error occurred"), errorString);
 }
 
-void ScreenCapturePreview::onScreenCaptureErrorOccured([[maybe_unused]] QScreenCapture::Error error,
+void ScreenCapturePreview::onScreenCaptureErrorOccured(QScreenCapture::Error,
                                                        const QString &errorString)
 {
-    QMessageBox::warning(this, "QScreenCapture: Error occurred", errorString);
+    QMessageBox::warning(this, tr("QScreenCapture: Error occurred"), errorString);
 }
 
 void ScreenCapturePreview::onStartStopButtonClicked()
 {
-    started = !started;
-    startStopButton->setText(started ? tr("Stop screencapture") : tr("Start screencapture"));
-    updateCapture();
+    updateActive(sourceType, !isActive());
 }
 
-void ScreenCapturePreview::updateCapture()
+void ScreenCapturePreview::updateStartStopButtonText()
 {
-    if (screenSelected) {
-        if (started != screenCapture->isActive())
-            screenCapture->setActive(started);
-    } else {
-        if (started != windowCapture->isActive())
-            windowCapture->setActive(started);
+    switch (sourceType) {
+    case SourceType::Window:
+        startStopButton->setText(isActive() ? tr("Stop window capture")
+                                            : tr("Start window capture"));
+        break;
+    case SourceType::Screen:
+        startStopButton->setText(isActive() ? tr("Stop screen capture")
+                                            : tr("Start screen capture"));
+        break;
+    }
+}
+
+void ScreenCapturePreview::updateActive(SourceType sourceType, bool active)
+{
+    this->sourceType = sourceType;
+
+    screenCapture->setActive(active && sourceType == SourceType::Screen);
+    windowCapture->setActive(active && sourceType == SourceType::Window);
+
+    updateStartStopButtonText();
+}
+
+bool ScreenCapturePreview::isActive() const
+{
+    switch (sourceType) {
+    case SourceType::Window:
+        return windowCapture->isActive();
+    case SourceType::Screen:
+        return screenCapture->isActive();
+    default:
+        return false;
     }
 }
 
diff --git a/examples/multimedia/screencapture/screencapturepreview.h b/examples/multimedia/screencapture/screencapturepreview.h
index ec8bf260a..c03097c02 100644
--- a/examples/multimedia/screencapture/screencapturepreview.h
+++ b/examples/multimedia/screencapture/screencapturepreview.h
@@ -7,7 +7,7 @@
 #include <QScreenCapture>
 #include <QWindowCapture>
 #include <QWidget>
-#include <QModelIndex>
+#include <QItemSelection>
 
 class ScreenListModel;
 class WindowListModel;
@@ -31,16 +31,21 @@ class ScreenCapturePreview : public QWidget
 
 public:
     explicit ScreenCapturePreview(QWidget *parent = nullptr);
-    ~ScreenCapturePreview();
+    ~ScreenCapturePreview() override;
 
-public slots:
-    void onScreenSelectionChanged(QModelIndex index);
-    void onWindowSelectionChanged(QModelIndex index);
+private slots:
+    void onCurrentScreenSelectionChanged(QItemSelection index);
+    void onCurrentWindowSelectionChanged(QItemSelection index);
+    void onWindowCaptureErrorOccured(QWindowCapture::Error error, const QString &errorString);
     void onScreenCaptureErrorOccured(QScreenCapture::Error error, const QString &errorString);
     void onStartStopButtonClicked();
 
 private:
-    void updateCapture();
+    enum class SourceType { Screen, Window };
+
+    void updateActive(SourceType sourceType, bool active);
+    void updateStartStopButtonText();
+    bool isActive() const;
 
 private:
     ScreenListModel *screenListModel = nullptr;
@@ -49,7 +54,6 @@ private:
     QListView *windowListView = nullptr;
     QScreenCapture *screenCapture = nullptr;
     QWindowCapture *windowCapture = nullptr;
-    QList<QCapturableWindow> windows;
     QMediaCaptureSession *mediaCaptureSession = nullptr;
     QVideoWidget *videoWidget = nullptr;
     QGridLayout *gridLayout = nullptr;
@@ -57,8 +61,7 @@ private:
     QLabel *screenLabel = nullptr;
     QLabel *windowLabel = nullptr;
     QLabel *videoWidgetLabel = nullptr;
-    bool screenSelected = true;
-    bool started = true;
+    SourceType sourceType = SourceType::Screen;
 };
 
 #endif // SCREENCAPTUREPREVIEW_H
diff --git a/examples/multimedia/screencapture/windowlistmodel.cpp b/examples/multimedia/screencapture/windowlistmodel.cpp
index 961f495e3..45b8ceabd 100644
--- a/examples/multimedia/screencapture/windowlistmodel.cpp
+++ b/examples/multimedia/screencapture/windowlistmodel.cpp
@@ -2,11 +2,10 @@
 // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
 
 #include "windowlistmodel.h"
+#include <QWindowCapture>
 
-#include <QWindow>
-
-WindowListModel::WindowListModel(QList<QCapturableWindow> data, QObject *parent)
-    : QAbstractListModel(parent), windowList(data)
+WindowListModel::WindowListModel(QObject *parent)
+    : QAbstractListModel(parent), windowList(QWindowCapture::capturableWindows())
 {
 }
 
@@ -33,4 +32,11 @@ QCapturableWindow WindowListModel::window(const QModelIndex &index) const
     return windowList.at(index.row());
 }
 
+void WindowListModel::populate()
+{
+    beginResetModel();
+    windowList = QWindowCapture::capturableWindows();
+    endResetModel();
+}
+
 #include "moc_windowlistmodel.cpp"
diff --git a/examples/multimedia/screencapture/windowlistmodel.h b/examples/multimedia/screencapture/windowlistmodel.h
index b1608eba4..1a24b01f8 100644
--- a/examples/multimedia/screencapture/windowlistmodel.h
+++ b/examples/multimedia/screencapture/windowlistmodel.h
@@ -7,10 +7,6 @@
 #include <QAbstractListModel>
 #include <QCapturableWindow>
 
-QT_BEGIN_NAMESPACE
-class QWindow;
-QT_END_NAMESPACE
-
 QT_USE_NAMESPACE
 
 class WindowListModel : public QAbstractListModel
@@ -18,11 +14,13 @@ class WindowListModel : public QAbstractListModel
     Q_OBJECT
 
 public:
-    explicit WindowListModel(QList<QCapturableWindow> data = {}, QObject *parent = nullptr);
+    explicit WindowListModel(QObject *parent = nullptr);
 
     int rowCount(const QModelIndex &parent = QModelIndex()) const override;
     QVariant data(const QModelIndex &index, int role = Qt::DisplayRole) const override;
+
     QCapturableWindow window(const QModelIndex &index) const;
+    void populate();
 
 private:
     QList<QCapturableWindow> windowList;