Factorize code for formatting window titles into QPlatformWindow.

Change-Id: I0dcccd08916fc2ea1b795681e9b98a9550ef51b6
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>

src/gui/kernel/qplatformwindow.cpp

@@ -42,6 +42,7 @@
 #include "qplatformwindow.h"
 #include "qplatformwindow_p.h"
 
+#include <private/qguiapplication_p.h>
 #include <qpa/qwindowsysteminterface.h>
 #include <QtGui/qwindow.h>
 #include <QtGui/qscreen.h>
@@ -424,6 +425,29 @@ bool QPlatformWindow::frameStrutEventsEnabled() const
     return false;
 }
 
+/*!
+    Call this method to put together a window title composed of
+    \a title
+    \a separator
+    the application display name
+
+    If the display name isn't set, and the title is empty, the raw app name is used.
+*/
+QString QPlatformWindow::formatWindowTitle(const QString &title, const QString &separator)
+{
+    QString fullTitle = title;
+    if (QGuiApplicationPrivate::displayName) {
+        // Append display name, if set.
+        if (!fullTitle.isEmpty())
+            fullTitle += separator;
+        fullTitle += *QGuiApplicationPrivate::displayName;
+    } else if (fullTitle.isEmpty()) {
+        // Don't let the window title be completely empty, use the app name as fallback.
+        fullTitle = QCoreApplication::applicationName();
+    }
+    return fullTitle;
+}
+
 /*!
     \class QPlatformWindow
     \since 4.8

src/gui/kernel/qplatformwindow.h

@@ -131,6 +131,8 @@ public:
     virtual bool frameStrutEventsEnabled() const;
 
 protected:
+    static QString formatWindowTitle(const QString &title, const QString &separator);
+
     QScopedPointer<QPlatformWindowPrivate> d_ptr;
 private:
     Q_DISABLE_COPY(QPlatformWindow)

src/plugins/platforms/windows/qwindowswindow.cpp

@@ -1216,18 +1216,7 @@ void QWindowsWindow::setWindowTitle(const QString &title)
     if (QWindowsContext::verboseWindows)
         qDebug() << __FUNCTION__ << this << window() <<title;
     if (m_data.hwnd) {
-
+        const QString fullTitle = formatWindowTitle(title, QStringLiteral(" - "));
-        QString fullTitle = title;
-        if (QGuiApplicationPrivate::displayName) {
-            // Append display name, if set.
-            if (!fullTitle.isEmpty())
-                fullTitle += QStringLiteral(" - ");
-            fullTitle += *QGuiApplicationPrivate::displayName;
-        } else if (fullTitle.isEmpty()) {
-            // Don't let the window title be completely empty, use the app name as fallback.
-            fullTitle = QCoreApplication::applicationName();
-        }
-
         SetWindowText(m_data.hwnd, (const wchar_t*)fullTitle.utf16());
     }
 }

src/plugins/platforms/xcb/qxcbwindow.cpp

@@ -1122,18 +1122,8 @@ void QXcbWindow::setParent(const QPlatformWindow *parent)
 
 void QXcbWindow::setWindowTitle(const QString &title)
 {
-    QString fullTitle = title;
+    const QString fullTitle = formatWindowTitle(title, QString::fromUtf8(" \xe2\x80\x94 ")); // unicode character U+2014, EM DASH
-    if (QGuiApplicationPrivate::displayName) {
-        // Append display name, if set.
-        if (!fullTitle.isEmpty())
-            fullTitle += QString::fromUtf8(" \xe2\x80\x94 "); // unicode character U+2014, EM DASH
-        fullTitle += *QGuiApplicationPrivate::displayName;
-    } else if (fullTitle.isEmpty()) {
-        // Don't let the window title be completely empty, use the app name as fallback.
-        fullTitle = QCoreApplication::applicationName();
-    }
     const QByteArray ba = fullTitle.toUtf8();
-
     Q_XCB_CALL(xcb_change_property(xcb_connection(),
                                    XCB_PROP_MODE_REPLACE,
                                    m_window,