Doublebuffer QIconView to reduce flicker

This closes Bug 1408
pull/2/head
Timothy Pearson 12 years ago
parent 5015438cc4
commit 82b71e4960

@ -214,6 +214,7 @@ public:
QIconViewItem *currentItem, *tmpCurrentItem, *highlightedItem, QIconViewItem *currentItem, *tmpCurrentItem, *highlightedItem,
*startDragItem, *pressedItem, *selectAnchor, *renamingItem; *startDragItem, *pressedItem, *selectAnchor, *renamingItem;
QRect *rubber; QRect *rubber;
QPixmap *backBuffer;
QTimer *scrollTimer, *adjustTimer, *updateTimer, *inputTimer, QTimer *scrollTimer, *adjustTimer, *updateTimer, *inputTimer,
*fullRedrawTimer; *fullRedrawTimer;
int rastX, rastY, spacing; int rastX, rastY, spacing;
@ -2800,6 +2801,7 @@ QIconView::QIconView( QWidget *parent, const char *name, WFlags f )
d->currentItem = 0; d->currentItem = 0;
d->highlightedItem = 0; d->highlightedItem = 0;
d->rubber = 0; d->rubber = 0;
d->backBuffer = 0;
d->scrollTimer = 0; d->scrollTimer = 0;
d->startDragItem = 0; d->startDragItem = 0;
d->tmpCurrentItem = 0; d->tmpCurrentItem = 0;
@ -2953,6 +2955,8 @@ QIconView::~QIconView()
delete item; delete item;
item = tmp; item = tmp;
} }
delete d->backBuffer;
d->backBuffer = 0;
delete d->fm; delete d->fm;
d->fm = 0; d->fm = 0;
#ifndef QT_NO_TOOLTIP #ifndef QT_NO_TOOLTIP
@ -4972,6 +4976,47 @@ void QIconView::contentsDropEvent( QDropEvent *e )
} }
#endif #endif
/*!
This function grabs all paintevents that otherwise would have been
processed by the QScrollView::viewportPaintEvent(). Here we use a
doublebuffer to reduce 'on-paint' flickering on QIconView
(and of course its children).
\sa QScrollView::viewportPaintEvent(), QIconView::drawContents()
*/
void QIconView::bufferedPaintEvent( QPaintEvent* pe )
{
QWidget* vp = viewport();
QRect r = pe->rect() & vp->rect();
int ex = r.x() + contentsX();
int ey = r.y() + contentsY();
int ew = r.width();
int eh = r.height();
if ( !d->backBuffer )
d->backBuffer = new QPixmap(vp->size());
if ( d->backBuffer->size() != vp->size() ) {
// Resize function (with hysteresis). Uses a good compromise between memory
// consumption and speed (number) of resizes.
float newWidth = (float)vp->width();
float newHeight = (float)vp->height();
if ( newWidth > d->backBuffer->width() || newHeight > d->backBuffer->height() )
{
newWidth *= 1.1892;
newHeight *= 1.1892;
d->backBuffer->resize( (int)newWidth, (int)newHeight );
} else if ( 1.5*newWidth < d->backBuffer->width() || 1.5*newHeight < d->backBuffer->height() )
d->backBuffer->resize( (int)newWidth, (int)newHeight );
}
QPainter p;
p.begin(d->backBuffer, vp);
drawContentsOffset(&p, contentsX(), contentsY(), ex, ey, ew, eh);
p.end();
bitBlt(vp, r.x(), r.y(), d->backBuffer, r.x(), r.y(), ew, eh);
}
/*! /*!
\reimp \reimp
*/ */
@ -5756,7 +5801,7 @@ bool QIconView::eventFilter( QObject * o, QEvent * e )
if ( !d->rubber ) if ( !d->rubber )
drawDragShapes( d->oldDragPos ); drawDragShapes( d->oldDragPos );
} }
viewportPaintEvent( (QPaintEvent*)e ); bufferedPaintEvent( (QPaintEvent*)e );
if ( d->dragging ) { if ( d->dragging ) {
if ( !d->rubber ) if ( !d->rubber )
drawDragShapes( d->oldDragPos ); drawDragShapes( d->oldDragPos );

@ -452,6 +452,7 @@ protected:
void contentsDropEvent( QDropEvent *e ); void contentsDropEvent( QDropEvent *e );
#endif #endif
void bufferedPaintEvent( QPaintEvent* );
void resizeEvent( QResizeEvent* e ); void resizeEvent( QResizeEvent* e );
void keyPressEvent( QKeyEvent *e ); void keyPressEvent( QKeyEvent *e );
void focusInEvent( QFocusEvent *e ); void focusInEvent( QFocusEvent *e );

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