Improved the gesture api.

Added a new widget attribute Qt::WA_DontUseStandardGestures that disables all
implicit gestures (i.e. gestures that are automatically enabled by Qt itself).

This change also changes the way gestures are handled on
QAbstractScrollArea-based widgets on Windows - the gestures are supposed to be
created on the viewport widget.

Reviewed-by: Bradley T. Hughes

5 files changed, 41 insertions, 50 deletions

diff --git a/src/gui/kernel/qgesture_p.h b/src/gui/kernel/qgesture_p.h
index 2cfabef..ddca79e 100644
--- a/src/gui/kernel/qgesture_p.h
+++ b/src/gui/kernel/qgesture_p.h
@@ -70,7 +70,7 @@ class QGesturePrivate : public QObjectPrivate
 public:
     QGesturePrivate()
         : gestureTarget(0), graphicsItem(0), eventFilterProxyGraphicsItem(0),
-          state(Qt::NoGesture)
+          state(Qt::NoGesture), implicitGesture(false)
     {
     }
 
@@ -81,6 +81,9 @@ public:
     QGraphicsItem *eventFilterProxyGraphicsItem;
 
     Qt::GestureState state;
+
+    // the flag specifies if the gesture was created implicitely by Qt.
+    bool implicitGesture;
 };
 
 QT_END_NAMESPACE
diff --git a/src/gui/kernel/qstandardgestures.cpp b/src/gui/kernel/qstandardgestures.cpp
index 4e0c27f..f6534d1 100644
--- a/src/gui/kernel/qstandardgestures.cpp
+++ b/src/gui/kernel/qstandardgestures.cpp
@@ -87,22 +87,15 @@ QPanGesture::QPanGesture(QWidget *gestureTarget, QObject *parent)
     setObjectName(QLatin1String("QPanGesture"));
 }
 
-/*!
-  \internal
-  An internal constructor to mark the gesture implicitely created by Qt.
-*/
-QPanGesture::QPanGesture(QWidget *gestureTarget, QObject *parent, void*)
-    : QGesture(*new QPanGesturePrivate, gestureTarget, parent)
-{
-    setObjectName(QLatin1String("QPanGesture"));
-}
-
 void QPanGesturePrivate::setupGestureTarget(QObject *newGestureTarget)
 {
     Q_Q(QPanGesture);
+    QApplicationPrivate *qAppPriv = QApplicationPrivate::instance();
+
     if (gestureTarget && gestureTarget->isWidgetType()) {
         QWidget *w = static_cast<QWidget*>(gestureTarget.data());
-        QApplicationPrivate::instance()->widgetGestures[w].pan = 0;
+        if (qAppPriv->widgetGestures[w].pan == q)
+            qAppPriv->widgetGestures[w].pan = 0;
 #if defined(Q_WS_WIN)
         qt_widget_private(w)->winSetupGestures();
 #elif defined(Q_WS_MAC)
@@ -113,7 +106,7 @@ void QPanGesturePrivate::setupGestureTarget(QObject *newGestureTarget)
 
     if (newGestureTarget && newGestureTarget->isWidgetType()) {
         QWidget *w = static_cast<QWidget*>(newGestureTarget);
-        QApplicationPrivate::instance()->widgetGestures[w].pan = q;
+        qAppPriv->widgetGestures[w].pan = q;
 #if defined(Q_WS_WIN)
         qt_widget_private(w)->winSetupGestures();
 #elif defined(Q_WS_MAC)
@@ -143,8 +136,13 @@ bool QPanGesture::event(QEvent *event)
 
 bool QPanGesture::eventFilter(QObject *receiver, QEvent *event)
 {
-#ifdef Q_WS_WIN
     Q_D(QPanGesture);
+
+    if (d->implicitGesture && d->gestureTarget && d->gestureTarget->isWidgetType() &&
+        static_cast<QWidget*>(d->gestureTarget.data())->testAttribute(Qt::WA_DontUseStandardGestures))
+        return false;
+
+#ifdef Q_WS_WIN
     if (receiver->isWidgetType() && event->type() == QEvent::NativeGesture) {
         QNativeGestureEvent *ev = static_cast<QNativeGestureEvent*>(event);
         QApplicationPrivate *qAppPriv = QApplicationPrivate::instance();
@@ -191,8 +189,13 @@ bool QPanGesture::eventFilter(QObject *receiver, QEvent *event)
 /*! \internal */
 bool QPanGesture::filterEvent(QEvent *event)
 {
-#if defined(Q_WS_WIN)
     Q_D(QPanGesture);
+
+    if (d->implicitGesture && d->gestureTarget && d->gestureTarget->isWidgetType() &&
+        static_cast<QWidget*>(d->gestureTarget.data())->testAttribute(Qt::WA_DontUseStandardGestures))
+        return false;
+
+#if defined(Q_WS_WIN)
     const QTouchEvent *ev = static_cast<const QTouchEvent*>(event);
 
     if (event->type() == QEvent::TouchBegin) {
@@ -229,7 +232,6 @@ bool QPanGesture::filterEvent(QEvent *event)
 #elif defined(QT_MAC_USE_COCOA)
     // The following implements single touch
     // panning on Mac:
-    Q_D(QPanGesture);
     const int panBeginDelay = 300;
     const int panBeginRadius = 3;
     const QTouchEvent *ev = static_cast<const QTouchEvent*>(event);
@@ -341,16 +343,6 @@ QPinchGesture::QPinchGesture(QWidget *gestureTarget, QObject *parent)
     setObjectName(QLatin1String("QPinchGesture"));
 }
 
-/*!
-  \internal
-  An internal constructor to mark the gesture implicitely created by Qt.
-*/
-QPinchGesture::QPinchGesture(QWidget *gestureTarget, QObject *parent, void*)
-    : QGesture(*new QPinchGesturePrivate, gestureTarget, parent)
-{
-    setObjectName(QLatin1String("QPinchGesture"));
-}
-
 void QPinchGesturePrivate::setupGestureTarget(QObject *newGestureTarget)
 {
     Q_Q(QPinchGesture);
@@ -380,8 +372,13 @@ bool QPinchGesture::event(QEvent *event)
 
 bool QPinchGesture::eventFilter(QObject *receiver, QEvent *event)
 {
-#if defined(Q_WS_WIN) || defined(Q_WS_MAC)
     Q_D(QPinchGesture);
+
+    if (d->implicitGesture && d->gestureTarget && d->gestureTarget->isWidgetType() &&
+        static_cast<QWidget*>(d->gestureTarget.data())->testAttribute(Qt::WA_DontUseStandardGestures))
+        return false;
+
+#if defined(Q_WS_WIN) || defined(Q_WS_MAC)
     if (receiver->isWidgetType() && event->type() == QEvent::NativeGesture) {
         QNativeGestureEvent *ev = static_cast<QNativeGestureEvent*>(event);
 #if defined(Q_WS_WIN)
@@ -458,6 +455,12 @@ bool QPinchGesture::eventFilter(QObject *receiver, QEvent *event)
 /*! \internal */
 bool QPinchGesture::filterEvent(QEvent *event)
 {
+    Q_D(QPinchGesture);
+
+    if (d->implicitGesture && d->gestureTarget && d->gestureTarget->isWidgetType() &&
+        static_cast<QWidget*>(d->gestureTarget.data())->testAttribute(Qt::WA_DontUseStandardGestures))
+        return false;
+
     Q_UNUSED(event);
     return false;
 }
diff --git a/src/gui/kernel/qstandardgestures.h b/src/gui/kernel/qstandardgestures.h
index bb6f3b6..33166fe 100644
--- a/src/gui/kernel/qstandardgestures.h
+++ b/src/gui/kernel/qstandardgestures.h
@@ -78,6 +78,7 @@ private:
     bool eventFilter(QObject *receiver, QEvent *event);
 
     friend class QWidget;
+    friend class QAbstractScrollAreaPrivate;
 };
 
 class QPinchGesturePrivate;
diff --git a/src/gui/kernel/qwidget.cpp b/src/gui/kernel/qwidget.cpp
index 863c43e..44f9db1 100644
--- a/src/gui/kernel/qwidget.cpp
+++ b/src/gui/kernel/qwidget.cpp
@@ -82,8 +82,6 @@
 #include "private/qstyle_p.h"
 #include "private/qinputcontext_p.h"
 #include "qfileinfo.h"
-#include "qstandardgestures.h"
-#include "qstandardgestures_p.h"
 
 #if defined (Q_WS_WIN)
 # include <private/qwininputcontext_p.h>
diff --git a/src/gui/kernel/qwidget_win.cpp b/src/gui/kernel/qwidget_win.cpp
index 8e60fb3..0ec7e7e 100644
--- a/src/gui/kernel/qwidget_win.cpp
+++ b/src/gui/kernel/qwidget_win.cpp
@@ -2062,29 +2062,21 @@ void QWidgetPrivate::registerTouchWindow()
 void QWidgetPrivate::winSetupGestures()
 {
     Q_Q(QWidget);
-    if (!q)
-        return;
-    if (!q->isVisible())
+    if (!q || !q->isVisible())
         return;
     QApplicationPrivate *qAppPriv = QApplicationPrivate::instance();
-    bool needh = false;
-    bool needv = false;
-    bool singleFingerPanEnabled = false;
     QApplicationPrivate::WidgetStandardGesturesMap::const_iterator it =
             qAppPriv->widgetGestures.find(q);
     if (it == qAppPriv->widgetGestures.end())
         return;
     const QStandardGestures &gestures = it.value();
-    WId winid = 0;
+    WId winid = q->effectiveWinId();
 
-    if (QAbstractScrollArea *asa = qobject_cast<QAbstractScrollArea*>(q)) {
-        winid = asa->viewport()->internalWinId();
-        if (!winid) {
-            QWidget *nativeParent = asa->viewport()->nativeParentWidget();
-            if (!nativeParent)
-                return;
-            winid = nativeParent->internalWinId();
-        }
+    bool needh = false;
+    bool needv = false;
+    bool singleFingerPanEnabled = false;
+
+    if (QAbstractScrollArea *asa = qobject_cast<QAbstractScrollArea*>(q->parent())) {
         QScrollBar *hbar = asa->horizontalScrollBar();
         QScrollBar *vbar = asa->verticalScrollBar();
         Qt::ScrollBarPolicy hbarpolicy = asa->horizontalScrollBarPolicy();
@@ -2094,12 +2086,6 @@ void QWidgetPrivate::winSetupGestures()
         needv = (vbarpolicy == Qt::ScrollBarAlwaysOn ||
                  (vbarpolicy == Qt::ScrollBarAsNeeded && vbar->minimum() < vbar->maximum()));
         singleFingerPanEnabled = asa->d_func()->singleFingerPanEnabled;
-    } else {
-        winid = q->internalWinId();
-        if (!winid) {
-            if (QWidget *nativeParent = q->nativeParentWidget())
-                winid = nativeParent->internalWinId();
-        }
     }
     if (winid && qAppPriv->SetGestureConfig) {
         GESTURECONFIG gc[3];