Windows QPA: Move the touch types API from platformheaders into QtGui

Change TouchWindowTouchType(s) to be (global) property of
QGuiApplication's native Windows interface since it does not make
sense to set it per window.

It appears the previous code setting the types per Window has never
worked since registerTouchWindow() bailed out due to the checks for
the flags TouchRegistered and IsTouchWindow() (setting in
HCBT_CREATEWND). In addition, registering windows for touch after
plugging in a device would not observe the setting.

Move the checks around to make this work.

Task-number: QTBUG-41433
Task-number: QTBUG-48849
Task-number: QTBUG-83252
Change-Id: I4306fdf13208f6eef22655875f3bd1769270e617
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>

src/gui/kernel/qguiapplication_p.h

@@ -382,6 +382,17 @@ struct Q_GUI_EXPORT QWindowsApplication
         AlwaysActivateWindow
     };
 
+    enum TouchWindowTouchType {
+        NormalTouch   = 0x00000000,
+        FineTouch     = 0x00000001,
+        WantPalmTouch = 0x00000002
+    };
+
+    Q_DECLARE_FLAGS(TouchWindowTouchTypes, TouchWindowTouchType)
+
+    virtual void setTouchWindowTouchType(TouchWindowTouchTypes type) = 0;
+    virtual TouchWindowTouchTypes touchWindowTouchType() const = 0;
+
     virtual WindowActivationBehavior windowActivationBehavior() const = 0;
     virtual void setWindowActivationBehavior(WindowActivationBehavior behavior) = 0;
 
@@ -394,6 +405,10 @@ struct Q_GUI_EXPORT QWindowsApplication
 
 } // QPlatformInterface::Private
 
+#if defined(Q_OS_WIN)
+Q_DECLARE_OPERATORS_FOR_FLAGS(QPlatformInterface::Private::QWindowsApplication::TouchWindowTouchTypes)
+#endif
+
 QT_END_NAMESPACE
 
 #endif // QGUIAPPLICATION_P_H

src/platformheaders/windowsfunctions/qwindowswindowfunctions.qdoc

@@ -41,36 +41,6 @@
     version it was developed against.
 */
 
-/*!
-    \enum QWindowsWindowFunctions::TouchWindowTouchType
-
-    This enum represents the supported TouchWindow touch flags for RegisterTouchWindow().
-
-    \value NormalTouch
-    \value FineTouch
-    \value WantPalmTouch
-*/
-
-/*!
-    \typedef QWindowsWindowFunctions::SetTouchWindowTouchType
-
-    This is the typedef for the function returned by QGuiApplication::platformFunction when passed setTouchWindowTouchTypeIdentifier.
-*/
-
-/*!
-    \fn QByteArray QWindowsWindowFunctions::setTouchWindowTouchTypeIdentifier()
-
-    This function returns the bytearray that can be used to query
-    QGuiApplication::platformFunction to retrieve the SetTouchWindowTouchType function.
-*/
-
-/*!
-    \fn void QWindowsWindowFunctions::setTouchWindowTouchType(QWindow *window, TouchWindowTouchTypes type)
-
-    This is a convenience function that can be used directly instead of resolving the function pointer.
-    \a window and \a type will be relayed to the function retrieved by QGuiApplication
-*/
-
 /*!
     \typedef QWindowsWindowFunctions::SetHasBorderInFullScreen
 

src/platformheaders/windowsfunctions/qwindowswindowfunctions_p.h

@@ -60,24 +60,6 @@ class QWindow;
 
 class QWindowsWindowFunctions {
 public:
-    enum TouchWindowTouchType {
-        NormalTouch   = 0x00000000,
-        FineTouch     = 0x00000001,
-        WantPalmTouch = 0x00000002
-    };
-
-    Q_DECLARE_FLAGS(TouchWindowTouchTypes, TouchWindowTouchType)
-
-    typedef void (*SetTouchWindowTouchType)(QWindow *window, QWindowsWindowFunctions::TouchWindowTouchTypes touchType);
-    static const QByteArray setTouchWindowTouchTypeIdentifier() { return QByteArrayLiteral("WindowsSetTouchWindowTouchType"); }
-
-    static void setTouchWindowTouchType(QWindow *window, TouchWindowTouchTypes type)
-    {
-        SetTouchWindowTouchType func = reinterpret_cast<SetTouchWindowTouchType>(QGuiApplication::platformFunction(setTouchWindowTouchTypeIdentifier()));
-        if (func)
-            func(window, type);
-    }
-
     typedef void (*SetHasBorderInFullScreen)(QWindow *window, bool border);
     static const QByteArray setHasBorderInFullScreenIdentifier() { return QByteArrayLiteral("WindowsSetHasBorderInFullScreen"); }
     static void setHasBorderInFullScreen(QWindow *window, bool border)
@@ -98,8 +80,6 @@ public:
 
 };
 
-Q_DECLARE_OPERATORS_FOR_FLAGS(QWindowsWindowFunctions::TouchWindowTouchTypes)
-
 QT_END_NAMESPACE
 
 #endif // QWINDOWSWINDOWFUNCTIONS_H

src/plugins/platforms/windows/qwindowsapplication.cpp

@@ -45,6 +45,20 @@
 
 QT_BEGIN_NAMESPACE
 
+void QWindowsApplication::setTouchWindowTouchType(QWindowsApplication::TouchWindowTouchTypes type)
+{
+    if (m_touchWindowTouchTypes == type)
+        return;
+    m_touchWindowTouchTypes = type;
+    if (auto ctx = QWindowsContext::instance())
+        ctx->registerTouchWindows();
+}
+
+QWindowsApplication::TouchWindowTouchTypes QWindowsApplication::touchWindowTouchType() const
+{
+    return m_touchWindowTouchTypes;
+}
+
 QWindowsApplication::WindowActivationBehavior QWindowsApplication::windowActivationBehavior() const
 {
    return m_windowActivationBehavior;

src/plugins/platforms/windows/qwindowsapplication.h

@@ -47,6 +47,9 @@ QT_BEGIN_NAMESPACE
 class QWindowsApplication : public QPlatformInterface::Private::QWindowsApplication
 {
 public:
+    void setTouchWindowTouchType(TouchWindowTouchTypes type) override;
+    TouchWindowTouchTypes touchWindowTouchType() const override;
+
     WindowActivationBehavior windowActivationBehavior() const override;
     void setWindowActivationBehavior(WindowActivationBehavior behavior) override;
 
@@ -57,6 +60,7 @@ public:
 
 private:
     WindowActivationBehavior m_windowActivationBehavior = DefaultActivateWindow;
+    TouchWindowTouchTypes m_touchWindowTouchTypes = NormalTouch;
 };
 
 QT_END_NAMESPACE

src/plugins/platforms/windows/qwindowscontext.cpp

@@ -366,12 +366,18 @@ bool QWindowsContext::initTouch(unsigned integrationOptions)
     d->m_systemInfo |= QWindowsContext::SI_SupportsTouch;
 
     // A touch device was plugged while the app is running. Register all windows for touch.
-    if (QGuiApplicationPrivate::is_app_running) {
+    registerTouchWindows();
+
+    return true;
+}
+
+void QWindowsContext::registerTouchWindows()
+{
+    if (QGuiApplicationPrivate::is_app_running
+        && (d->m_systemInfo & QWindowsContext::SI_SupportsTouch) != 0) {
         for (QWindowsWindow *w : qAsConst(d->m_windows))
             w->registerTouchWindow();
     }
-
-    return true;
 }
 
 bool QWindowsContext::initTablet()

src/plugins/platforms/windows/qwindowscontext.h

@@ -173,6 +173,7 @@ public:
 
     bool initTouch();
     bool initTouch(unsigned integrationOptions); // For calls from QWindowsIntegration::QWindowsIntegration() only.
+    void registerTouchWindows();
     bool initTablet();
     bool initPointer(unsigned integrationOptions);
     bool disposeTablet();

src/plugins/platforms/windows/qwindowsnativeinterface.cpp

@@ -258,8 +258,6 @@ QFont QWindowsNativeInterface::logFontToQFont(const void *logFont, int verticalD
 
 QFunctionPointer QWindowsNativeInterface::platformFunction(const QByteArray &function) const
 {
-    if (function == QWindowsWindowFunctions::setTouchWindowTouchTypeIdentifier())
-        return QFunctionPointer(QWindowsWindow::setTouchWindowTouchTypeStatic);
     if (function == QWindowsWindowFunctions::setHasBorderInFullScreenIdentifier())
         return QFunctionPointer(QWindowsWindow::setHasBorderInFullScreenStatic);
     if (function == QWindowsWindowFunctions::setHasBorderInFullScreenDefaultIdentifier())

src/plugins/platforms/windows/qwindowswindow.cpp

@@ -1128,6 +1128,20 @@ QMargins QWindowsBaseWindow::frameMargins_sys() const
     return QWindowsGeometryHint::frame(handle(), style(), exStyle());
 }
 
+std::optional<QWindowsBaseWindow::TouchWindowTouchTypes>
+    QWindowsBaseWindow::touchWindowTouchTypes_sys() const
+{
+    ULONG touchFlags = 0;
+    if (IsTouchWindow(handle(), &touchFlags) == FALSE)
+        return {};
+    TouchWindowTouchTypes result;
+    if ((touchFlags & TWF_FINETOUCH) != 0)
+        result.setFlag(TouchWindowTouchType::FineTouch);
+    if ((touchFlags & TWF_WANTPALM) != 0)
+        result.setFlag(TouchWindowTouchType::WantPalmTouch);
+    return result;
+}
+
 void QWindowsBaseWindow::hide_sys() // Normal hide, do not activate other windows.
 {
     SetWindowPos(handle(), nullptr , 0, 0, 0, 0,
@@ -1345,7 +1359,11 @@ QWindowsWindow::QWindowsWindow(QWindow *aWindow, const QWindowsWindowData &data)
 #endif
     updateDropSite(window()->isTopLevel());
 
+    // Register touch unless if the flags are already set by a hook
+    // such as HCBT_CREATEWND
+    if (!touchWindowTouchTypes_sys().has_value())
         registerTouchWindow();
+
     const qreal opacity = qt_window_private(aWindow)->opacity;
     if (!qFuzzyCompare(opacity, qreal(1.0)))
         setOpacity(opacity);
@@ -3040,28 +3058,28 @@ void QWindowsWindow::invalidateSurface()
 #endif // QT_NO_OPENGL
 }
 
-void QWindowsWindow::setTouchWindowTouchTypeStatic(QWindow *window, QWindowsWindowFunctions::TouchWindowTouchTypes touchTypes)
+void QWindowsWindow::registerTouchWindow()
 {
-    if (!window->handle())
+    if ((QWindowsContext::instance()->systemInfo() & QWindowsContext::SI_SupportsTouch) == 0)
         return;
-    static_cast<QWindowsWindow *>(window->handle())->registerTouchWindow(touchTypes);
-}
 
-void QWindowsWindow::registerTouchWindow(QWindowsWindowFunctions::TouchWindowTouchTypes touchTypes)
+    // Initially register or re-register to change the flags
-{
+    const auto touchTypes = QWindowsIntegration::instance()->touchWindowTouchType();
-    if ((QWindowsContext::instance()->systemInfo() & QWindowsContext::SI_SupportsTouch)
+    if (testFlag(TouchRegistered)) {
-        && !testFlag(TouchRegistered)) {
+        const auto currentTouchTypes = touchWindowTouchTypes_sys();
-        ULONG touchFlags = 0;
+        if (currentTouchTypes.has_value() && currentTouchTypes.value() == touchTypes)
-        const bool ret = IsTouchWindow(m_data.hwnd, &touchFlags);
-        // Return if it is not a touch window or the flags are already set by a hook
-        // such as HCBT_CREATEWND
-        if (ret || touchFlags != 0)
             return;
-        if (RegisterTouchWindow(m_data.hwnd, ULONG(touchTypes)))
+    }
+
+    ULONG touchFlags = 0;
+    if (touchTypes.testFlag(TouchWindowTouchType::FineTouch))
+        touchFlags |= TWF_FINETOUCH;
+    if (touchTypes.testFlag(TouchWindowTouchType::WantPalmTouch))
+        touchFlags |= TWF_WANTPALM;
+    if (RegisterTouchWindow(m_data.hwnd, touchFlags))
         setFlag(TouchRegistered);
     else
         qErrnoWarning("RegisterTouchWindow() failed for window '%s'.", qPrintable(window()->objectName()));
-    }
 }
 
 void QWindowsWindow::aboutToMakeCurrent()

src/plugins/platforms/windows/qwindowswindow.h

@@ -42,6 +42,7 @@
 
 #include <QtCore/qt_windows.h>
 #include <QtCore/qpointer.h>
+#include "qwindowsapplication.h"
 #include "qwindowscursor.h"
 
 #include <qpa/qplatformwindow.h>
@@ -51,6 +52,8 @@
 #include "qwindowsvulkaninstance.h"
 #endif
 
+#include <optional>
+
 QT_BEGIN_NAMESPACE
 
 class QWindowsOleDropTarget;
@@ -125,6 +128,9 @@ class QWindowsBaseWindow : public QPlatformWindow
 {
     Q_DISABLE_COPY_MOVE(QWindowsBaseWindow)
 public:
+    using TouchWindowTouchType = QPlatformInterface::Private::QWindowsApplication::TouchWindowTouchType;
+    using TouchWindowTouchTypes = QPlatformInterface::Private::QWindowsApplication::TouchWindowTouchTypes;
+
     explicit QWindowsBaseWindow(QWindow *window) : QPlatformWindow(window) {}
 
     WId winId() const override { return WId(handle()); }
@@ -153,6 +159,7 @@ protected:
     QRect geometry_sys() const;
     void setGeometry_sys(const QRect &rect) const;
     QMargins frameMargins_sys() const;
+    std::optional<TouchWindowTouchTypes> touchWindowTouchTypes_sys() const;
     void hide_sys();
     void raise_sys();
     void lower_sys();
@@ -348,8 +355,7 @@ public:
     enum ScreenChangeMode { FromGeometryChange, FromDpiChange };
     void checkForScreenChanged(ScreenChangeMode mode = FromGeometryChange);
 
-    static void setTouchWindowTouchTypeStatic(QWindow *window, QWindowsWindowFunctions::TouchWindowTouchTypes touchTypes);
+    void registerTouchWindow();
-    void registerTouchWindow(QWindowsWindowFunctions::TouchWindowTouchTypes touchTypes = QWindowsWindowFunctions::NormalTouch);
     static void setHasBorderInFullScreenStatic(QWindow *window, bool border);
     static void setHasBorderInFullScreenDefault(bool border);
     void setHasBorderInFullScreen(bool border);