Implement QDirectFBPixmapData::scroll

This is a very operation in DirectFB and saves a fair bit of overhead.

Reviewed-by: Donald Carr <donald.carr@nokia.com>

2 files changed, 29 insertions, 3 deletions

diff --git a/src/plugins/gfxdrivers/directfb/qdirectfbpixmap.cpp b/src/plugins/gfxdrivers/directfb/qdirectfbpixmap.cpp
index 1cbfdaf..f27440e 100644
--- a/src/plugins/gfxdrivers/directfb/qdirectfbpixmap.cpp
+++ b/src/plugins/gfxdrivers/directfb/qdirectfbpixmap.cpp
@@ -552,6 +552,34 @@ QImage *QDirectFBPixmapData::buffer()
     return &lockedImage;
 }
 
+
+bool QDirectFBPixmapData::scroll(int dx, int dy, const QRect &rect)
+{
+    if (!dfbSurface) {
+        return false;
+    }
+    unlockSurface();
+    DFBResult result = dfbSurface->SetBlittingFlags(dfbSurface, DSBLIT_NOFX);
+    if (result != DFB_OK) {
+        DirectFBError("QDirectFBPixmapData::scroll", result);
+        return false;
+    }
+    result = dfbSurface->SetPorterDuff(dfbSurface, DSPD_NONE);
+    if (result != DFB_OK) {
+        DirectFBError("QDirectFBPixmapData::scroll", result);
+        return false;
+    }
+
+    const DFBRectangle source = { rect.x(), rect.y(), rect.width(), rect.height() };
+    result = dfbSurface->Blit(dfbSurface, dfbSurface, &source, source.x + dx, source.y + dy);
+    if (result != DFB_OK) {
+        DirectFBError("QDirectFBPixmapData::scroll", result);
+        return false;
+    }
+
+    return true;
+}
+
 void QDirectFBPixmapData::invalidate()
 {
     if (dfbSurface) {
@@ -568,6 +596,3 @@ void QDirectFBPixmapData::invalidate()
 QT_END_NAMESPACE
 
 #endif // QT_NO_QWS_DIRECTFB
-
-
-
diff --git a/src/plugins/gfxdrivers/directfb/qdirectfbpixmap.h b/src/plugins/gfxdrivers/directfb/qdirectfbpixmap.h
index f9b14a9..da6edc6 100644
--- a/src/plugins/gfxdrivers/directfb/qdirectfbpixmap.h
+++ b/src/plugins/gfxdrivers/directfb/qdirectfbpixmap.h
@@ -81,6 +81,7 @@ public:
     virtual QImage toImage() const;
     virtual QPaintEngine *paintEngine() const;
     virtual QImage *buffer();
+    virtual bool scroll(int dx, int dy, const QRect &rect);
     // Pure virtual in QPixmapData, so re-implement here and delegate to QDirectFBPaintDevice
     virtual int metric(QPaintDevice::PaintDeviceMetric m) const { return QDirectFBPaintDevice::metric(m); }