Refactored gesture api

Rewritten the api almost from scratch, making it simplier and more
flexible at the same time.

The current implementation will not have complex gseturemanager class
inside Qt, but the QGesture base class, which represents both a
gesture recognizer and a gesture itself with a set of properties. A
set of common gestures that can use used in third-party applications
(and in Qt itself internally) is supposed to be found in
qstandardgestures.h, and a base class for user-defined gestures is in
qgesture.h

Gesture implementation for Pan on Windows7 has also been added as a
reference implementation for platform gestures.

8 files changed, 106 insertions, 3 deletions

diff --git a/src/gui/widgets/qabstractscrollarea.cpp b/src/gui/widgets/qabstractscrollarea.cpp
index e1beb98..66572b8 100644
--- a/src/gui/widgets/qabstractscrollarea.cpp
+++ b/src/gui/widgets/qabstractscrollarea.cpp
@@ -51,10 +51,13 @@
 #include "qdebug.h"
 #include "qboxlayout.h"
 #include "qpainter.h"
+#include "qstandardgestures.h"
 
 #include "qabstractscrollarea_p.h"
 #include <qwidget.h>
 
+#include <private/qapplication_p.h>
+
 #ifdef Q_WS_MAC
 #include <private/qt_mac_p.h>
 #include <private/qt_cocoa_helpers_mac_p.h>
@@ -157,6 +160,9 @@ QAbstractScrollAreaPrivate::QAbstractScrollAreaPrivate()
     :hbar(0), vbar(0), vbarpolicy(Qt::ScrollBarAsNeeded), hbarpolicy(Qt::ScrollBarAsNeeded),
      viewport(0), cornerWidget(0), left(0), top(0), right(0), bottom(0),
      xoffset(0), yoffset(0), viewportFilter(0)
+#ifdef Q_WS_WIN
+     , singleFingerPanEnabled(false)
+#endif
 {
 }
 
@@ -290,6 +296,31 @@ void QAbstractScrollAreaPrivate::init()
     layoutChildren();
 }
 
+void QAbstractScrollAreaPrivate::setupGestures()
+{
+#ifdef Q_OS_WIN
+    if (!viewport)
+        return;
+    QApplicationPrivate *qAppPriv = getQApplicationPrivateInternal();
+    bool needh = (hbarpolicy == Qt::ScrollBarAlwaysOn
+                  || (hbarpolicy == Qt::ScrollBarAsNeeded && hbar->minimum() < hbar->maximum()));
+
+    bool needv = (vbarpolicy == Qt::ScrollBarAlwaysOn
+                  || (vbarpolicy == Qt::ScrollBarAsNeeded && vbar->minimum() < vbar->maximum()));
+    if (qAppPriv->SetGestureConfig && (needh || needv)) {
+        GESTURECONFIG gc[1];
+        gc[0].dwID = GID_PAN;
+        gc[0].dwWant = GC_PAN;
+        gc[0].dwBlock = 0;
+        if (needv && singleFingerPanEnabled)
+            gc[0].dwWant |= GC_PAN_WITH_SINGLE_FINGER_VERTICALLY;
+        if (needh && singleFingerPanEnabled)
+            gc[0].dwWant |= GC_PAN_WITH_SINGLE_FINGER_HORIZONTALLY;
+        qAppPriv->SetGestureConfig(viewport->winId(), 0, 1, gc, sizeof(gc));
+    }
+#endif // Q_OS_WIN
+}
+
 void QAbstractScrollAreaPrivate::layoutChildren()
 {
     Q_Q(QAbstractScrollArea);
@@ -909,8 +940,6 @@ bool QAbstractScrollArea::event(QEvent *e)
     case QEvent::DragMove:
     case QEvent::DragLeave:
 #endif
-    case QEvent::Gesture:
-        return false;
     case QEvent::StyleChange:
     case QEvent::LayoutDirectionChange:
     case QEvent::ApplicationLayoutDirectionChange:
@@ -1239,6 +1268,7 @@ void QAbstractScrollAreaPrivate::_q_vslide(int y)
 void QAbstractScrollAreaPrivate::_q_showOrHideScrollBars()
 {
     layoutChildren();
+    setupGestures();
 }
 
 QPoint QAbstractScrollAreaPrivate::contentsOffset() const
diff --git a/src/gui/widgets/qabstractscrollarea_p.h b/src/gui/widgets/qabstractscrollarea_p.h
index 71a83cc..5d3494b 100644
--- a/src/gui/widgets/qabstractscrollarea_p.h
+++ b/src/gui/widgets/qabstractscrollarea_p.h
@@ -99,6 +99,11 @@ public:
     inline bool viewportEvent(QEvent *event)
     { return q_func()->viewportEvent(event); }
     QObject *viewportFilter;
+
+#ifdef Q_WS_WIN
+    bool singleFingerPanEnabled;
+#endif
+    void setupGestures();
 };
 
 class QAbstractScrollAreaFilter : public QObject
diff --git a/src/gui/widgets/qplaintextedit.cpp b/src/gui/widgets/qplaintextedit.cpp
index bab6b89..c9d1d6e 100644
--- a/src/gui/widgets/qplaintextedit.cpp
+++ b/src/gui/widgets/qplaintextedit.cpp
@@ -66,6 +66,8 @@
 #include <qtexttable.h>
 #include <qvariant.h>
 
+#include <qstandardgestures.h>
+
 #include <qinputcontext.h>
 
 #ifndef QT_NO_TEXTEDIT
@@ -726,6 +728,9 @@ QPlainTextEditPrivate::QPlainTextEditPrivate()
     backgroundVisible = false;
     centerOnScroll = false;
     inDrag = false;
+#ifdef Q_WS_WIN
+    singleFingerPanEnabled = true;
+#endif
 }
 
 
@@ -781,6 +786,9 @@ void QPlainTextEditPrivate::init(const QString &txt)
 #ifndef QT_NO_CURSOR
     viewport->setCursor(Qt::IBeamCursor);
 #endif
+    originalOffsetY = 0;
+    panGesture = new QPanGesture(q);
+    QObject::connect(panGesture, SIGNAL(triggered()), q, SLOT(_q_gestureTriggered()));
 }
 
 void QPlainTextEditPrivate::_q_repaintContents(const QRectF &contentsRect)
@@ -2899,6 +2907,30 @@ QAbstractTextDocumentLayout::PaintContext QPlainTextEdit::getPaintContext() cons
     (\a available is true) or unavailable (\a available is false).
 */
 
+void QPlainTextEditPrivate::_q_gestureTriggered()
+{
+    Q_Q(QPlainTextEdit);
+    QPanGesture *g = qobject_cast<QPanGesture*>(q->sender());
+    if (!g)
+        return;
+    QScrollBar *hBar = q->horizontalScrollBar();
+    QScrollBar *vBar = q->verticalScrollBar();
+    if (g->state() == Qt::GestureStarted)
+        originalOffsetY = vBar->value();
+    QSize totalOffset = g->totalOffset();
+    if (!totalOffset.isNull()) {
+        if (QApplication::isRightToLeft())
+            totalOffset.rwidth() *= -1;
+        // QPlainTextEdit scrolls by lines only in vertical direction
+        QFontMetrics fm(q->document()->defaultFont());
+        int lineHeight = fm.height();
+        int newX = hBar->value() - g->lastOffset().width();
+        int newY = originalOffsetY - totalOffset.height()/lineHeight;
+        hbar->setValue(newX);
+        vbar->setValue(newY);
+    }
+}
+
 QT_END_NAMESPACE
 
 #include "moc_qplaintextedit.cpp"
diff --git a/src/gui/widgets/qplaintextedit.h b/src/gui/widgets/qplaintextedit.h
index dc0851b..35bbc37 100644
--- a/src/gui/widgets/qplaintextedit.h
+++ b/src/gui/widgets/qplaintextedit.h
@@ -269,6 +269,7 @@ private:
     Q_PRIVATE_SLOT(d_func(), void _q_adjustScrollbars())
     Q_PRIVATE_SLOT(d_func(), void _q_verticalScrollbarActionTriggered(int))
     Q_PRIVATE_SLOT(d_func(), void _q_cursorPositionChanged())
+    Q_PRIVATE_SLOT(d_func(), void _q_gestureTriggered())
     friend class QPlainTextEditControl;
 };
 
diff --git a/src/gui/widgets/qplaintextedit_p.h b/src/gui/widgets/qplaintextedit_p.h
index 5075fc4..ae584e0 100644
--- a/src/gui/widgets/qplaintextedit_p.h
+++ b/src/gui/widgets/qplaintextedit_p.h
@@ -72,6 +72,7 @@ class QMimeData;
 
 class QPlainTextEdit;
 class ExtraArea;
+class QPanGesture;
 
 class QPlainTextEditControl : public QTextControl
 {
@@ -173,6 +174,10 @@ public:
     void _q_cursorPositionChanged();
 
     void _q_modificationChanged(bool);
+
+    void _q_gestureTriggered();
+    int originalOffsetY;
+    QPanGesture *panGesture;
 };
 
 QT_END_NAMESPACE
diff --git a/src/gui/widgets/qtextedit.cpp b/src/gui/widgets/qtextedit.cpp
index c8d8d04..e80df92 100644
--- a/src/gui/widgets/qtextedit.cpp
+++ b/src/gui/widgets/qtextedit.cpp
@@ -67,6 +67,8 @@
 #include <qtexttable.h>
 #include <qvariant.h>
 
+#include <qstandardgestures.h>
+
 #include <qinputcontext.h>
 #endif
 
@@ -111,6 +113,9 @@ QTextEditPrivate::QTextEditPrivate()
     preferRichText = false;
     showCursorOnInitialShow = true;
     inDrag = false;
+#ifdef Q_WS_WIN
+    singleFingerPanEnabled = true;
+#endif
 }
 
 void QTextEditPrivate::createAutoBulletList()
@@ -178,6 +183,8 @@ void QTextEditPrivate::init(const QString &html)
 #ifndef QT_NO_CURSOR
     viewport->setCursor(Qt::IBeamCursor);
 #endif
+    panGesture = new QPanGesture(q);
+    QObject::connect(panGesture, SIGNAL(triggered()), q, SLOT(_q_gestureTriggered()));
 }
 
 void QTextEditPrivate::_q_repaintContents(const QRectF &contentsRect)
@@ -2610,6 +2617,25 @@ void QTextEdit::ensureCursorVisible()
     d->control->ensureCursorVisible();
 }
 
+void QTextEditPrivate::_q_gestureTriggered()
+{
+    Q_Q(QTextEdit);
+    QPanGesture *g = qobject_cast<QPanGesture*>(q->sender());
+    if (!g)
+        return;
+    QScrollBar *hBar = q->horizontalScrollBar();
+    QScrollBar *vBar = q->verticalScrollBar();
+    QPoint delta = g->pos() - (g->lastPos().isNull() ? g->pos() : g->lastPos());
+    if (!delta.isNull()) {
+        if (QApplication::isRightToLeft())
+            delta.rx() *= -1;
+        int newX = hBar->value() - delta.x();
+        int newY = vBar->value() - delta.y();
+        hbar->setValue(newX);
+        vbar->setValue(newY);
+    }
+}
+
 
 /*!
     \enum QTextEdit::KeyboardAction
diff --git a/src/gui/widgets/qtextedit.h b/src/gui/widgets/qtextedit.h
index 617822a..9e10e07 100644
--- a/src/gui/widgets/qtextedit.h
+++ b/src/gui/widgets/qtextedit.h
@@ -414,6 +414,7 @@ private:
     Q_PRIVATE_SLOT(d_func(), void _q_currentCharFormatChanged(const QTextCharFormat &))
     Q_PRIVATE_SLOT(d_func(), void _q_adjustScrollbars())
     Q_PRIVATE_SLOT(d_func(), void _q_ensureVisible(const QRectF &))
+    Q_PRIVATE_SLOT(d_func(), void _q_gestureTriggered())
     friend class QTextEditControl;
     friend class QTextDocument;
     friend class QTextControl;
diff --git a/src/gui/widgets/qtextedit_p.h b/src/gui/widgets/qtextedit_p.h
index e7609d6..249331e 100644
--- a/src/gui/widgets/qtextedit_p.h
+++ b/src/gui/widgets/qtextedit_p.h
@@ -70,7 +70,7 @@ QT_BEGIN_NAMESPACE
 #ifndef QT_NO_TEXTEDIT
 
 class QMimeData;
-
+class QPanGesture;
 class QTextEditPrivate : public QAbstractScrollAreaPrivate
 {
     Q_DECLARE_PUBLIC(QTextEdit)
@@ -129,6 +129,9 @@ public:
 
     QString anchorToScrollToWhenVisible;
 
+    void _q_gestureTriggered();
+    QPanGesture *panGesture;
+
 #ifdef QT_KEYPAD_NAVIGATION
     QBasicTimer deleteAllTimer;
 #endif