Brush up the screencapture example

- Fix compiler warnings about unused parameters
- Fix spacing
- Reorder includes by module
- Translate user-visible texts
- Use QList::size() instead of deprecated count()
- Fix clang warnings about else after return
- Streamline some code

Pick-to: 6.5
Change-Id: Ic7640d72018b59f05c84224ca006a3f60a26f7ea
Reviewed-by: Artem Dyomin <artem.dyomin@qt.io>
Reviewed-by: Lars Knoll <lars@knoll.priv.no>

5 files changed, 34 insertions, 38 deletions

diff --git a/examples/multimedia/screencapture/screencapturepreview.cpp b/examples/multimedia/screencapture/screencapturepreview.cpp
index 1d514596b..f7aee01fe 100644
--- a/examples/multimedia/screencapture/screencapturepreview.cpp
+++ b/examples/multimedia/screencapture/screencapturepreview.cpp
@@ -5,22 +5,26 @@
 #include "screenlistmodel.h"
 #include "windowlistmodel.h"
 
-#include <QGuiApplication>
-#include <QGridLayout>
-#include <QListWidget>
 #include <QMediaCaptureSession>
-#include <QPushButton>
 #include <QScreenCapture>
-#include <QLineEdit>
 #include <QVideoWidget>
-#include <QMessageBox>
+
+#include <QGridLayout>
 #include <QLabel>
+#include <QLineEdit>
+#include <QListWidget>
+#include <QMessageBox>
+#include <QPushButton>
+
+#include <QGuiApplication>
 
 ScreenCapturePreview::ScreenCapturePreview(QWidget *parent)
     : QWidget(parent),
       screenListView(new QListView(this)),
       windowListView(new QListView(this)),
       screenCapture(new QScreenCapture(this)),
+      screens(QGuiApplication::screens()),
+      windows(QGuiApplication::allWindows()),
       mediaCaptureSession(new QMediaCaptureSession(this)),
       videoWidget(new QVideoWidget(this)),
       gridLayout(new QGridLayout(this)),
@@ -34,9 +38,6 @@ ScreenCapturePreview::ScreenCapturePreview(QWidget *parent)
       videoWidgetLabel(new QLabel("QScreenCapture output:", this))
 {
     // Get lists of screens and windows:
-
-    screens = QGuiApplication::screens();
-    windows = QGuiApplication::allWindows();
     screenListModel = new ScreenListModel(screens, this);
     windowListModel = new WindowListModel(windows, this);
     qDebug() << "return value from QGuiApplication::screens(): " << screens;
@@ -44,7 +45,7 @@ ScreenCapturePreview::ScreenCapturePreview(QWidget *parent)
 
     // Setup QScreenCapture with initial source:
 
-    screenCapture->setScreen((!screens.isEmpty()) ? screens.first() : nullptr);
+    screenCapture->setScreen(QGuiApplication::primaryScreen());
     screenCapture->start();
     mediaCaptureSession->setScreenCapture(screenCapture);
     mediaCaptureSession->setVideoOutput(videoWidget);
@@ -54,7 +55,7 @@ ScreenCapturePreview::ScreenCapturePreview(QWidget *parent)
     screenListView->setModel(screenListModel);
     windowListView->setModel(windowListModel);
     // Sets initial lineEdit text to the WId of the second QWindow from QGuiApplication::allWindows()
-    if (windows.count() > 1)
+    if (windows.size() > 1)
         lineEdit->setText(QString::number(windows[1]->winId()));
 
     gridLayout->addWidget(screenLabel, 0, 0);
@@ -81,12 +82,9 @@ ScreenCapturePreview::ScreenCapturePreview(QWidget *parent)
     connect(startStopButton, &QPushButton::clicked, this, &ScreenCapturePreview::onStartStopButtonClicked);
     connect(lineEdit, &QLineEdit::returnPressed, this, &ScreenCapturePreview::onWindowIdSelectionChanged);
     connect(screenCapture, &QScreenCapture::errorOccurred, this, &ScreenCapturePreview::onScreenCaptureErrorOccured);
-
 }
 
-ScreenCapturePreview::~ScreenCapturePreview()
-{
-}
+ScreenCapturePreview::~ScreenCapturePreview() = default;
 
 void ScreenCapturePreview::onScreenSelectionChanged(QModelIndex index)
 {
@@ -100,7 +98,7 @@ void ScreenCapturePreview::onWindowSelectionChanged(QModelIndex index)
 
 void ScreenCapturePreview::onWindowIdSelectionChanged()
 {
-    unsigned long long input = lineEdit->text().toULongLong(nullptr, 0);
+    unsigned long long input = lineEdit->text().trimmed().toULongLong(nullptr, 0);
     screenCapture->setWindowId(input);
 }
 
@@ -114,10 +112,10 @@ void ScreenCapturePreview::onStartStopButtonClicked()
 {
     if (screenCapture->isActive()) {
         screenCapture->stop();
-        startStopButton->setText("Start screencapture");
+        startStopButton->setText(tr("Start screencapture"));
     } else {
         screenCapture->start();
-        startStopButton->setText("Stop screencapture");
+        startStopButton->setText(tr("Stop screencapture"));
     }
 }
 
diff --git a/examples/multimedia/screencapture/screencapturepreview.h b/examples/multimedia/screencapture/screencapturepreview.h
index e3ae60711..fd5cc08ee 100644
--- a/examples/multimedia/screencapture/screencapturepreview.h
+++ b/examples/multimedia/screencapture/screencapturepreview.h
@@ -29,12 +29,10 @@ class ScreenCapturePreview : public QWidget
     Q_OBJECT
 
 public:
-
-    ScreenCapturePreview(QWidget *parent = nullptr);
+    explicit ScreenCapturePreview(QWidget *parent = nullptr);
     ~ScreenCapturePreview();
 
 public slots:
-
     void onScreenSelectionChanged(QModelIndex index);
     void onWindowSelectionChanged(QModelIndex index);
     void onWindowIdSelectionChanged();
@@ -42,14 +40,13 @@ public slots:
     void onStartStopButtonClicked();
 
 private:
-
     ScreenListModel *screenListModel = nullptr;
     WindowListModel *windowListModel = nullptr;
     QListView *screenListView = nullptr;
     QListView *windowListView = nullptr;
     QScreenCapture *screenCapture = nullptr;
-    QList<QScreen *> screens = QList<QScreen *>();
-    QList<QWindow *> windows = QList<QWindow *>();
+    QList<QScreen *> screens;
+    QWindowList windows;
     QMediaCaptureSession *mediaCaptureSession = nullptr;
     QVideoWidget *videoWidget = nullptr;
     QGridLayout *gridLayout = nullptr;
@@ -61,6 +58,6 @@ private:
     QLabel *windowLabel = nullptr;
     QLabel *windowIdLabel = nullptr;
     QLabel *videoWidgetLabel = nullptr;
-
 };
+
 #endif // SCREENCAPTUREPREVIEW_H
diff --git a/examples/multimedia/screencapture/screenlistmodel.cpp b/examples/multimedia/screencapture/screenlistmodel.cpp
index 0b0662a17..6a3a1efd7 100644
--- a/examples/multimedia/screencapture/screenlistmodel.cpp
+++ b/examples/multimedia/screencapture/screenlistmodel.cpp
@@ -5,28 +5,29 @@
 
 #include <QScreen>
 
-ScreenListModel::ScreenListModel(QList<QScreen *> data, QObject *parent)
-    : QAbstractListModel(parent), screenList(data)
+ScreenListModel::ScreenListModel(const QList<QScreen *> &data, QObject *parent) :
+      QAbstractListModel(parent),
+      screenList(data)
 {
 }
 
-int ScreenListModel::rowCount(const QModelIndex &parent) const
+int ScreenListModel::rowCount(const QModelIndex &) const
 {
-    return screenList.count();
+    return screenList.size();
 }
 
 QVariant ScreenListModel::data(const QModelIndex &index, int role) const
 {
     Q_ASSERT(index.isValid());
-    Q_ASSERT(index.row() <= screenList.count());
+    Q_ASSERT(index.row() <= screenList.size());
 
     if (role == Qt::DisplayRole) {
         auto screen = screenList.at(index.row());
         return QString("%1: %2").arg(screen->metaObject()->className(),
                                      screen->name());
-    } else {
-        return QVariant();
     }
+
+    return {};
 }
 
 QScreen *ScreenListModel::screen(const QModelIndex &index) const
diff --git a/examples/multimedia/screencapture/screenlistmodel.h b/examples/multimedia/screencapture/screenlistmodel.h
index 4069a1f3f..83cc1e664 100644
--- a/examples/multimedia/screencapture/screenlistmodel.h
+++ b/examples/multimedia/screencapture/screenlistmodel.h
@@ -17,7 +17,7 @@ class ScreenListModel : public QAbstractListModel
     Q_OBJECT
 
 public:
-    explicit ScreenListModel(QList<QScreen *> data = QList<QScreen *>(), QObject *parent = nullptr);
+    explicit ScreenListModel(const QList<QScreen *> &data, QObject *parent = nullptr);
 
     int rowCount(const QModelIndex &parent = QModelIndex()) const override;
     QVariant data(const QModelIndex &index, int role = Qt::DisplayRole) const override;
diff --git a/examples/multimedia/screencapture/windowlistmodel.cpp b/examples/multimedia/screencapture/windowlistmodel.cpp
index 8772223c9..aba28a1db 100644
--- a/examples/multimedia/screencapture/windowlistmodel.cpp
+++ b/examples/multimedia/screencapture/windowlistmodel.cpp
@@ -10,15 +10,15 @@ WindowListModel::WindowListModel(QList<QWindow *> data, QObject *parent)
 {
 }
 
-int WindowListModel::rowCount(const QModelIndex &parent) const
+int WindowListModel::rowCount(const QModelIndex &) const
 {
-    return windowList.count();
+    return windowList.size();
 }
 
 QVariant WindowListModel::data(const QModelIndex &index, int role) const
 {
     Q_ASSERT(index.isValid());
-    Q_ASSERT(index.row() <= windowList.count());
+    Q_ASSERT(index.row() <= windowList.size());
 
     if (role == Qt::DisplayRole) {
         auto window = windowList.at(index.row());
@@ -26,9 +26,9 @@ QVariant WindowListModel::data(const QModelIndex &index, int role) const
                 .arg(window->metaObject()->className())
                 .arg(window->winId())
                 .arg(window->objectName());
-    } else {
-        return QVariant();
     }
+
+    return {};
 }
 
 QWindow *WindowListModel::window(const QModelIndex &index) const