add setDragToScroll, makes the webview to work like a touchscreen, it

selects the text instead of dragging if the move is less than 250
milliseconds after the mouse press, not really reliable but don't know
how to save both functionalities

svn path=/trunk/KDE/kdelibs/; revision=946794

widgets/webview.cpp

@@ -26,6 +26,7 @@
 #include <fixx11h.h>
 #include <QtWebKit/QWebFrame>
 #include <QtWebKit/QWebPage>
+#include <QtCore/QTimer>
 
 #include <kdebug.h>
 
@@ -38,17 +39,26 @@ class WebViewPrivate
 {
 public:
     WebViewPrivate(WebView *parent)
-        : q(parent)
+        : q(parent),
+          dragToScroll(false),
+          dragging(false),
+          dragTimeout(false),
+          dragTimeoutTimer(0)
     {
     }
 
     void loadingFinished(bool success);
     void updateRequested(const QRect &dirtyRect);
     void scrollRequested(int dx, int dy, const QRect &scrollRect);
+    void dragTimeoutExpired();
 
     WebView *q;
     QWebPage *page;
     bool loaded;
+    bool dragToScroll;
+    bool dragging;
+    bool dragTimeout;
+    QTimer *dragTimeoutTimer;
 };
 
 WebView::WebView(QGraphicsItem *parent)
@@ -138,6 +148,16 @@ QWebFrame *WebView::mainFrame() const
     return d->page ? d->page->mainFrame() : 0;
 }
 
+void WebView::setDragToScroll(bool drag)
+{
+    d->dragToScroll = drag;
+}
+
+bool WebView::dragToScroll()
+{
+    return d->dragToScroll;
+}
+
 void WebView::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget)
 {
     Q_UNUSED(widget)
@@ -155,11 +175,21 @@ void WebView::mouseMoveEvent(QGraphicsSceneMouseEvent *event)
         return;
     }
 
-    QMouseEvent me(QEvent::MouseMove, event->pos().toPoint(), event->button(),
-                   event->buttons(), event->modifiers());
-    d->page->event(&me);
-    if (me.isAccepted()) {
-        event->accept();
+    if (d->dragToScroll && d->dragTimeout) {
+        QPointF deltaPos = event->pos() - event->lastPos();
+        d->page->mainFrame()->setScrollBarValue(Qt::Horizontal, d->page->mainFrame()->scrollBarValue(Qt::Horizontal) - deltaPos.x());
+        d->page->mainFrame()->setScrollBarValue(Qt::Vertical, d->page->mainFrame()->scrollBarValue(Qt::Vertical) - deltaPos.y());
+        d->dragging = true;
+    } else {
+        if (d->dragTimeoutTimer) {
+            d->dragTimeoutTimer->stop();
+        }
+        QMouseEvent me(QEvent::MouseMove, event->pos().toPoint(), event->button(),
+                      event->buttons(), event->modifiers());
+        d->page->event(&me);
+        if (me.isAccepted()) {
+            event->accept();
+        }
     }
 }
 
@@ -184,6 +214,14 @@ void WebView::mousePressEvent(QGraphicsSceneMouseEvent *event)
         return;
     }
 
+    d->dragTimeout = false;
+    if (!d->dragTimeoutTimer) {
+        d->dragTimeoutTimer = new QTimer(this);
+        d->dragTimeoutTimer->setSingleShot(true);
+        connect(d->dragTimeoutTimer, SIGNAL(timeout()), this, SLOT(dragTimeoutExpired()));
+    }
+    d->dragTimeoutTimer->start(250);
+
     setFocus();
 
     QMouseEvent me(QEvent::MouseButtonPress, event->pos().toPoint(), event->button(),
@@ -211,7 +249,8 @@ void WebView::mouseDoubleClickEvent(QGraphicsSceneMouseEvent *event)
 
 void WebView::mouseReleaseEvent(QGraphicsSceneMouseEvent *event)
 {
-    if (!d->page) {
+    if (!d->page || d->dragging) {
+        d->dragging = false;
         QGraphicsWidget::mouseReleaseEvent(event);
         return;
     }
@@ -273,7 +312,7 @@ void WebView::keyPressEvent(QKeyEvent * event)
     }
 
     d->page->event(event);
-kWarning()<<event;
+
     if (!event->isAccepted()) {
         QGraphicsWidget::keyPressEvent(event);
     }
@@ -402,6 +441,11 @@ void WebViewPrivate::scrollRequested(int dx, int dy, const QRect &scrollRect)
     updateRequested(scrollRect);
 }
 
+void WebViewPrivate::dragTimeoutExpired()
+{
+    dragTimeout = true;
+}
+
 } // namespace Plasma
 
 #include "webview.moc"

widgets/webview.h

@@ -104,6 +104,16 @@ class PLASMA_EXPORT WebView : public QGraphicsWidget
          */
         QWebFrame *mainFrame() const;
 
+        /**
+         * Sets if the page can be scrolled around by dragging the contents with the mouse
+         */
+        void setDragToScroll(bool drag);
+
+        /**
+         * @return true if the page can be scrolled by dragging the mouse
+         */
+        bool dragToScroll();
+
         /**
          * Reimplementation
          */
@@ -151,6 +161,7 @@ class PLASMA_EXPORT WebView : public QGraphicsWidget
         Q_PRIVATE_SLOT(d, void loadingFinished(bool success))
         Q_PRIVATE_SLOT(d, void updateRequested(const QRect& dirtyRect))
         Q_PRIVATE_SLOT(d, void scrollRequested(int dx, int dy, const QRect &scrollRect))
+        Q_PRIVATE_SLOT(d, void dragTimeoutExpired())
 
         WebViewPrivate * const d;
         friend class WebViewPrivate;