From cff522f98666e1bf24c36a3a0a2abe3fb2e1abe8 Mon Sep 17 00:00:00 2001
From: Timothy Pearson <kb9vqf@pearsoncomputing.net>
Date: Mon, 18 Feb 2013 20:37:37 -0600
Subject: Automated update from Qt3

---
 src/iconview/ntqiconview.h |  1 +
 src/iconview/qiconview.cpp | 47 +++++++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 47 insertions(+), 1 deletion(-)

(limited to 'src/iconview')

diff --git a/src/iconview/ntqiconview.h b/src/iconview/ntqiconview.h
index bda8273f4..e45cfca65 100644
--- a/src/iconview/ntqiconview.h
+++ b/src/iconview/ntqiconview.h
@@ -452,6 +452,7 @@ protected:
     void contentsDropEvent( TQDropEvent *e );
 #endif
 
+    void bufferedPaintEvent( TQPaintEvent* );
     void resizeEvent( TQResizeEvent* e );
     void keyPressEvent( TQKeyEvent *e );
     void focusInEvent( TQFocusEvent *e );
diff --git a/src/iconview/qiconview.cpp b/src/iconview/qiconview.cpp
index ee4a0fe36..dbf764a0f 100644
--- a/src/iconview/qiconview.cpp
+++ b/src/iconview/qiconview.cpp
@@ -214,6 +214,7 @@ public:
     TQIconViewItem *currentItem, *tmpCurrentItem, *highlightedItem,
 	*startDragItem, *pressedItem, *selectAnchor, *renamingItem;
     TQRect *rubber;
+    TQPixmap *backBuffer;
     TQTimer *scrollTimer, *adjustTimer, *updateTimer, *inputTimer,
 	*fullRedrawTimer;
     int rastX, rastY, spacing;
@@ -2800,6 +2801,7 @@ TQIconView::TQIconView( TQWidget *parent, const char *name, WFlags f )
     d->currentItem = 0;
     d->highlightedItem = 0;
     d->rubber = 0;
+    d->backBuffer = 0;
     d->scrollTimer = 0;
     d->startDragItem = 0;
     d->tmpCurrentItem = 0;
@@ -2953,6 +2955,8 @@ TQIconView::~TQIconView()
 	delete item;
 	item = tmp;
     }
+    delete d->backBuffer;
+    d->backBuffer = 0;
     delete d->fm;
     d->fm = 0;
 #ifndef QT_NO_TOOLTIP
@@ -4972,6 +4976,47 @@ void TQIconView::contentsDropEvent( TQDropEvent *e )
 }
 #endif
 
+/*!
+    This function grabs all paintevents that otherwise would have been
+    processed by the TQScrollView::viewportPaintEvent(). Here we use a
+    doublebuffer to reduce 'on-paint' flickering on TQIconView
+    (and of course its children).
+    
+    \sa TQScrollView::viewportPaintEvent(), TQIconView::drawContents()
+*/
+
+void TQIconView::bufferedPaintEvent( TQPaintEvent* pe )
+{
+    TQWidget* vp = viewport();
+    TQRect 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 TQPixmap(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 );
+    }
+
+    TQPainter 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
 */
@@ -5756,7 +5801,7 @@ bool TQIconView::eventFilter( TQObject * o, TQEvent * e )
 		    if ( !d->rubber )
 			drawDragShapes( d->oldDragPos );
 		}
-		viewportPaintEvent( (TQPaintEvent*)e );
+		bufferedPaintEvent( (TQPaintEvent*)e );
 		if ( d->dragging ) {
 		    if ( !d->rubber )
 			drawDragShapes( d->oldDragPos );
-- 
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