Use QtPlatformHeaders to set platform specific functionality

This involves exposing a new function in the QPlatformNativeInterface
which gets a public function for QGuiApplication

Proof of concept is done through implementing _NET_WM_WINDOW_TYPE
setters for xcb

Change-Id: Ic9544e775fb71cc9b30273595ec41b1cdb1c9d64
Reviewed-by: Laszlo Agocs <laszlo.agocs@digia.com>

4 files changed, 24 insertions, 0 deletions

diff --git a/src/gui/kernel/qguiapplication.cpp b/src/gui/kernel/qguiapplication.cpp
index 827bf0164b..2d5f717222 100644
--- a/src/gui/kernel/qguiapplication.cpp
+++ b/src/gui/kernel/qguiapplication.cpp
@@ -1413,6 +1413,20 @@ QPlatformNativeInterface *QGuiApplication::platformNativeInterface()
 }
 
 /*!
+    Returns a function pointer from the platformplugin matching \a function
+*/
+QFunctionPointer QGuiApplication::platformFunction(const QByteArray &function)
+{
+    QPlatformIntegration *pi = QGuiApplicationPrivate::platformIntegration();
+    if (!pi) {
+        qWarning() << "QGuiApplication::platformFunction(): Must construct a QGuiApplication before accessing a platform function";
+        return Q_NULLPTR;
+    }
+
+    return pi->nativeInterface() ? pi->nativeInterface()->platformFunction(function) : Q_NULLPTR;
+}
+
+/*!
     Enters the main event loop and waits until exit() is called, and then
     returns the value that was set to exit() (which is 0 if exit() is called
     via quit()).
diff --git a/src/gui/kernel/qguiapplication.h b/src/gui/kernel/qguiapplication.h
index 6d9a4b2376..50aefaadb5 100644
--- a/src/gui/kernel/qguiapplication.h
+++ b/src/gui/kernel/qguiapplication.h
@@ -143,6 +143,8 @@ public:
 
     static QPlatformNativeInterface *platformNativeInterface();
 
+    static QFunctionPointer platformFunction(const QByteArray &function);
+
     static void setQuitOnLastWindowClosed(bool quit);
     static bool quitOnLastWindowClosed();
 
diff --git a/src/gui/kernel/qplatformnativeinterface.cpp b/src/gui/kernel/qplatformnativeinterface.cpp
index 6571a47849..2e5485f1c2 100644
--- a/src/gui/kernel/qplatformnativeinterface.cpp
+++ b/src/gui/kernel/qplatformnativeinterface.cpp
@@ -118,6 +118,12 @@ QPlatformNativeInterface::NativeResourceForBackingStoreFunction QPlatformNativeI
     return 0;
 }
 
+QFunctionPointer QPlatformNativeInterface::platformFunction(const QByteArray &function) const
+{
+    Q_UNUSED(function);
+    return Q_NULLPTR;
+}
+
 /*!
     Contains generic window properties that the platform may utilize.
 */
diff --git a/src/gui/kernel/qplatformnativeinterface.h b/src/gui/kernel/qplatformnativeinterface.h
index eaa24a9e55..58d13c4320 100644
--- a/src/gui/kernel/qplatformnativeinterface.h
+++ b/src/gui/kernel/qplatformnativeinterface.h
@@ -85,6 +85,8 @@ public:
     virtual NativeResourceForWindowFunction nativeResourceFunctionForWindow(const QByteArray &resource);
     virtual NativeResourceForBackingStoreFunction nativeResourceFunctionForBackingStore(const QByteArray &resource);
 
+    virtual QFunctionPointer platformFunction(const QByteArray &function) const;
+
     virtual QVariantMap windowProperties(QPlatformWindow *window) const;
     virtual QVariant windowProperty(QPlatformWindow *window, const QString &name) const;
     virtual QVariant windowProperty(QPlatformWindow *window, const QString &name, const QVariant &defaultValue) const;