tde-packaging/opensuse/tdelibs/smooth-scrolling.diff

Index: khtml/khtmlview.cpp
===================================================================
--- khtml/khtmlview.cpp.orig
+++ khtml/khtmlview.cpp
@@ -151,6 +151,9 @@ public:
 
     KHTMLViewPrivate()
         : underMouse( 0 ), underMouseNonShared( 0 ), visibleWidgets( 107 )
+#ifndef NO_SMOOTH_SCROLL_HACK
+          , dx(0), dy(0), ddx(0), ddy(0), rdx(0), rdy(0), scrolling(false)
+#endif
     {
 #ifndef KHTML_NO_CARET
 	m_caretViewContext = 0;
@@ -396,6 +399,17 @@ public:
     short m_mouseScroll_byY;
     QTimer *m_mouseScrollTimer;
     QWidget *m_mouseScrollIndicator;
+#ifndef NO_SMOOTH_SCROLL_HACK
+    QTimer timer2;
+    int dx;
+    int dy;
+    // Step size * 16 and residual to avoid huge difference between 1px/step and 2px/step
+    int ddx;
+    int ddy;
+    int rdx;
+    int rdy;
+    bool scrolling;
+#endif
 };
 
 #ifndef QT_NO_TOOLTIP
@@ -504,6 +518,11 @@ KHTMLView::KHTMLView( KHTMLPart *part, Q
     init();
 
     viewport()->show();
+#ifndef NO_SMOOTH_SCROLL_HACK
+#define timer timer2
+    connect(&d->timer, SIGNAL(timeout()), this, SLOT(scrollTick()));
+#undef timer
+#endif
 }
 
 KHTMLView::~KHTMLView()
@@ -1544,7 +1563,7 @@ void KHTMLView::keyPressEvent( QKeyEvent
         case Key_Down:
         case Key_J:
             if (!d->scrollTimerId || d->scrollSuspended)
-                scrollBy( 0, 10 );
+                scrollBy( 0, 10 * _ke->count() );
             if (d->scrollTimerId)
                 d->newScrollTimer(this, 0);
             break;
@@ -1559,7 +1578,7 @@ void KHTMLView::keyPressEvent( QKeyEvent
         case Key_Up:
         case Key_K:
             if (!d->scrollTimerId || d->scrollSuspended)
-                scrollBy( 0, -10 );
+                scrollBy( 0, -10 * _ke->count());
             if (d->scrollTimerId)
                 d->newScrollTimer(this, 0);
             break;
@@ -1572,14 +1591,14 @@ void KHTMLView::keyPressEvent( QKeyEvent
         case Key_Right:
         case Key_L:
             if (!d->scrollTimerId || d->scrollSuspended)
-                scrollBy( 10, 0 );
+                scrollBy( 10 * _ke->count(), 0 );
             if (d->scrollTimerId)
                 d->newScrollTimer(this, 0);
             break;
         case Key_Left:
         case Key_H:
             if (!d->scrollTimerId || d->scrollSuspended)
-                scrollBy( -10, 0 );
+                scrollBy( -10 * _ke->count(), 0 );
             if (d->scrollTimerId)
                 d->newScrollTimer(this, 0);
             break;
@@ -1712,8 +1731,16 @@ void KHTMLView::keyReleaseEvent(QKeyEven
         d->scrollSuspendPreActivate = false;
     if( _ke->key() == Key_Shift && d->scrollSuspendPreActivate && _ke->state() == Qt::ShiftButton
         && !(KApplication::keyboardMouseState() & Qt::ShiftButton))
+    {
         if (d->scrollTimerId)
-                d->scrollSuspended = !d->scrollSuspended;
+        {
+            d->scrollSuspended = !d->scrollSuspended;
+#ifndef NO_SMOOTH_SCROLL_HACK
+            if( d->scrollSuspended )
+                stopScrolling();
+#endif
+        }
+    }
 
     if (d->accessKeysEnabled)
     {
@@ -3259,7 +3286,11 @@ void KHTMLView::viewportWheelEvent(QWhee
     else
     {
         d->scrollBarMoved = true;
+#ifndef NO_SMOOTH_SCROLL_HACK
+        scrollViewWheelEvent( e );
+#else
         QScrollView::viewportWheelEvent( e );
+#endif
 
         QMouseEvent *tempEvent = new QMouseEvent( QEvent::MouseMove, QPoint(-1,-1), QPoint(-1,-1), Qt::NoButton, e->state() );
         emit viewportMouseMoveEvent ( tempEvent );
@@ -4462,4 +4493,117 @@ void KHTMLView::moveCaretToLineEnd()
 
 #endif // KHTML_NO_CARET
 
+#ifndef NO_SMOOTH_SCROLL_HACK
+#define timer timer2
+
+// All scrolls must be completed within 240ms of last keypress
+static const int SCROLL_TIME = 240;
+// Each step is 20 ms == 50 frames/second
+static const int SCROLL_TICK = 20;
+
+void KHTMLView::scrollBy(int dx, int dy)
+{
+    KConfigGroup cfg( KGlobal::config(), "KDE" );
+    if( !cfg.readBoolEntry( "SmoothScrolling", true )) {
+        QScrollView::scrollBy( dx, dy );
+        return;
+    }
+    // scrolling destination
+    int full_dx = d->dx + dx;
+    int full_dy = d->dy + dy;
+
+    // scrolling speed
+    int ddx = 0;
+    int ddy = 0;
+
+    int steps = SCROLL_TIME/SCROLL_TICK;
+
+    ddx = (full_dx*16)/steps;
+    ddy = (full_dy*16)/steps;
+
+    // don't go under 1px/step
+    if (ddx > 0 && ddx < 16) ddx = 16;
+    if (ddy > 0 && ddy < 16) ddy = 16;
+    if (ddx < 0 && ddx > -16) ddx = -16;
+    if (ddy < 0 && ddy > -16) ddy = -16;
+
+    d->dx = full_dx;
+    d->dy = full_dy;
+    d->ddx = ddx;
+    d->ddy = ddy;
+
+    if (!d->scrolling) {
+        scrollTick();
+        startScrolling();
+    }
+}
+
+void KHTMLView::scrollTick() {
+    if (d->dx == 0 && d->dy == 0) {
+        stopScrolling();
+        return;
+    }
+
+    int tddx = d->ddx + d->rdx;
+    int tddy = d->ddy + d->rdy;
+
+    int ddx = tddx / 16;
+    int ddy = tddy / 16;
+    d->rdx = tddx % 16;
+    d->rdy = tddy % 16;
+
+    if (d->dx > 0 && ddx > d->dx) ddx = d->dx;
+    else
+    if (d->dx < 0 && ddx < d->dx) ddx = d->dx;
+
+    if (d->dy > 0 && ddy > d->dy) ddy = d->dy;
+    else
+    if (d->dy < 0 && ddy < d->dy) ddy = d->dy;
+
+    d->dx -= ddx;
+    d->dy -= ddy;
+
+//    QScrollView::setContentsPos( contentsX() + ddx, contentsY() + ddy);
+    kapp->syncX();
+    QScrollView::scrollBy(ddx, ddy);
+// Unaccelerated X can get seriously overloaded by scrolling and for some reason
+// will send KeyPress events only infrequently. This should help to reduce
+// the load.
+    kapp->syncX();
+}
+
+void KHTMLView::startScrolling()
+{
+    d->scrolling = true;
+    d->timer.start(SCROLL_TICK, false);
+}
+
+void KHTMLView::stopScrolling()
+{
+    d->timer.stop();
+    d->dx = d->dy = 0;
+    d->scrolling = false;
+}
+
+// Overloaded from QScrollView and QScrollBar
+void KHTMLView::scrollViewWheelEvent( QWheelEvent *e )
+{
+    int pageStep = verticalScrollBar()->pageStep();
+    int lineStep = verticalScrollBar()->lineStep();
+    int step = QMIN( QApplication::wheelScrollLines()*lineStep, pageStep );
+    if ( ( e->state() & ControlButton ) || ( e->state() & ShiftButton ) )
+        step = pageStep;
+
+    if(e->orientation() == Horizontal)
+        scrollBy(-((e->delta()*step)/120), 0);
+    else if(e->orientation() == Vertical)
+        scrollBy(0,-((e->delta()*step)/120));
+
+    e->accept();
+}
+
+#undef timer
+
+#endif // NO_SMOOTH_SCROLL_HACK
+
 #undef DEBUG_CARETMODE
Index: khtml/khtmlview.h
===================================================================
--- khtml/khtmlview.h.orig
+++ khtml/khtmlview.h
@@ -181,6 +181,11 @@ signals:
     void hideAccessKeys();
     void repaintAccessKeys();
     void findAheadActive( bool );
+//#define NO_SMOOTH_SCROLL_HACK
+#ifndef NO_SMOOTH_SCROLL_HACK
+public slots:
+    void scrollBy(int dx, int dy);
+#endif
 
 protected:
     void clear();
@@ -211,9 +216,23 @@ protected:
     void contentsContextMenuEvent ( QContextMenuEvent *_ce );
     void doAutoScroll();
     void timerEvent ( QTimerEvent * );
+
+#ifndef NO_SMOOTH_SCROLL_HACK
+    void startScrolling();
+    void stopScrolling();
+#ifndef QT_NO_WHEELEVENT
+    void scrollViewWheelEvent( QWheelEvent* e );
+#endif
+#endif
+
 protected slots:
     void slotPaletteChanged();
     void slotScrollBarMoved();
+#ifndef NO_SMOOTH_SCROLL_HACK
+    void scrollTick();
+#else
+    void scrollTick() {}; // moc cannot handle #if
+#endif
 
 private slots:
     void tripleClickTimeout();