Add support for -qwindowicon command line argument.

[ChangeLog][QtGui][QGuiApplication] Add support for -icon command line
argument on X11, add -qwindowicon on all platforms.

Change-Id: Iacc602466699bf634d8b34aab7ed73c83fd9844f
Reviewed-by: Frederik Gladhorn <frederik.gladhorn@digia.com>
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>

3 files changed, 11 insertions, 1 deletions

diff --git a/src/gui/kernel/qguiapplication.cpp b/src/gui/kernel/qguiapplication.cpp
index f0ef39e809..01b888919d 100644
--- a/src/gui/kernel/qguiapplication.cpp
+++ b/src/gui/kernel/qguiapplication.cpp
@@ -495,6 +495,7 @@ static QWindowGeometrySpecification windowGeometrySpecification;
             \l{Session Management}{session}.
         \li  -qwindowgeometry, sets the geometry of the first window
         \li  -qwindowtitle, sets the title of the first window
+        \li  -qwindowicon, sets the default window icon
     \endlist
 
     The following standard command line options are available for X11:
@@ -1115,6 +1116,11 @@ void QGuiApplicationPrivate::createPlatformIntegration()
         } else if (arg == "-qwindowtitle" || (platformName == "xcb" && arg == "-title")) {
             if (++i < argc)
                 firstWindowTitle = QString::fromLocal8Bit(argv[i]);
+        } else if (arg == "-qwindowicon" || (platformName == "xcb" && arg == "-icon")) {
+            if (++i < argc) {
+                const QString icon = QString::fromLocal8Bit(argv[i]);
+                forcedWindowIcon = QDir::isAbsolutePath(icon) ? QIcon(icon) : QIcon::fromTheme(icon);
+            }
         } else {
             argv[j++] = argv[i];
         }
diff --git a/src/gui/kernel/qguiapplication_p.h b/src/gui/kernel/qguiapplication_p.h
index 8f6149d1ed..782a4b34b3 100644
--- a/src/gui/kernel/qguiapplication_p.h
+++ b/src/gui/kernel/qguiapplication_p.h
@@ -234,6 +234,7 @@ public:
     QInputMethod *inputMethod;
 
     QString firstWindowTitle;
+    QIcon forcedWindowIcon;
 
     static QList<QObject *> generic_plugin_list;
 #ifndef QT_NO_SHORTCUT
diff --git a/src/gui/kernel/qwindow.cpp b/src/gui/kernel/qwindow.cpp
index 6dcc3df166..2b0c95b2b6 100644
--- a/src/gui/kernel/qwindow.cpp
+++ b/src/gui/kernel/qwindow.cpp
@@ -436,11 +436,14 @@ void QWindow::setVisible(bool visible)
         QCoreApplication::removePostedEvents(qApp, QEvent::Quit);
 
         if (type() == Qt::Window) {
-            QString &firstWindowTitle = QGuiApplicationPrivate::instance()->firstWindowTitle;
+            QGuiApplicationPrivate *app_priv = QGuiApplicationPrivate::instance();
+            QString &firstWindowTitle = app_priv->firstWindowTitle;
             if (!firstWindowTitle.isEmpty()) {
                 setTitle(firstWindowTitle);
                 firstWindowTitle = QString();
             }
+            if (!app_priv->forcedWindowIcon.isNull())
+                setIcon(app_priv->forcedWindowIcon);
         }
 
         QShowEvent showEvent;