10 files changed, 98 insertions, 0 deletions
diff --git a/src/gui/image/qpixmap.cpp b/src/gui/image/qpixmap.cpp
index 8684a1b..e563fc9 100644
--- a/src/gui/image/qpixmap.cpp
+++ b/src/gui/image/qpixmap.cpp
@@ -379,6 +379,56 @@ QPixmap QPixmap::copy(const QRect &rect) const
 }
 
 /*!
+    \fn QPixmap::scroll(int dx, int dy, int x, int y, int width, int height, QRegion *exposed)
+
+    This convenience function is equivalent to calling QPixmap::scroll(\a dx,
+    \a dy, QRect(\a x, \a y, \a width, \a height), \a exposed).
+
+    \sa QWidget::scroll(), QGraphicsItem::scroll()
+*/
+
+/*!
+    Scrolls the area \a rect of this pixmap by (\a dx, \a dy). The exposed
+    region is left unchanged. You can optionally pass a pointer to an empty
+    QRegion to get the region that is \a exposed by the scroll operation.
+
+    \snippet doc/src/snippets/code/src_gui_image_qpixmap.cpp 2
+
+    You cannot scroll while there is an active painter on the pixmap.
+
+    \sa QWidget::scroll(), QGraphicsItem::scroll()
+*/
+void QPixmap::scroll(int dx, int dy, const QRect &rect, QRegion *exposed)
+{
+    if (isNull() || (dx == 0 && dy == 0))
+        return;
+    QRect dest = rect & this->rect();
+    QRect src = dest.translated(-dx, -dy) & dest;
+    if (src.isEmpty()) {
+        if (exposed)
+            *exposed += dest;
+        return;
+    }
+
+    detach();
+
+    if (!data->scroll(dx, dy, src)) {
+        // Fallback
+        QPixmap pix = *this;
+        QPainter painter(&pix);
+        painter.setCompositionMode(QPainter::CompositionMode_Source);
+        painter.drawPixmap(src.translated(dx, dy), *this, src);
+        painter.end();
+        *this = pix;
+    }
+
+    if (exposed) {
+        *exposed += dest;
+        *exposed -= src.translated(dx, dy);
+    }
+}
+
+/*!
     Assigns the given \a pixmap to this pixmap and returns a reference
     to this pixmap.
 
diff --git a/src/gui/image/qpixmap.h b/src/gui/image/qpixmap.h
index 1863273..cd3b465 100644
--- a/src/gui/image/qpixmap.h
+++ b/src/gui/image/qpixmap.h
@@ -155,6 +155,9 @@ public:
     inline QPixmap copy(int x, int y, int width, int height) const;
     QPixmap copy(const QRect &rect = QRect()) const;
 
+    inline void scroll(int dx, int dy, int x, int y, int width, int height, QRegion *exposed = 0);
+    void scroll(int dx, int dy, const QRect &rect, QRegion *exposed = 0);
+
     int serialNumber() const;
     qint64 cacheKey() const;
 
@@ -274,6 +277,11 @@ inline QPixmap QPixmap::copy(int ax, int ay, int awidth, int aheight) const
     return copy(QRect(ax, ay, awidth, aheight));
 }
 
+inline void QPixmap::scroll(int dx, int dy, int ax, int ay, int awidth, int aheight, QRegion *exposed)
+{
+    scroll(dx, dy, QRect(ax, ay, awidth, aheight), exposed);
+}
+
 inline bool QPixmap::loadFromData(const QByteArray &buf, const char *format,
                                   Qt::ImageConversionFlags flags)
 {
diff --git a/src/gui/image/qpixmap_mac.cpp b/src/gui/image/qpixmap_mac.cpp
index 26d9618..973cd78 100644
--- a/src/gui/image/qpixmap_mac.cpp
+++ b/src/gui/image/qpixmap_mac.cpp
@@ -1290,6 +1290,14 @@ void QMacPixmapData::copy(const QPixmapData *data, const QRect &rect)
     has_mask = macData->has_mask;
 }
 
+bool QMacPixmapData::scroll(int dx, int dy, const QRect &rect)
+{
+    Q_UNUSED(dx);
+    Q_UNUSED(dy);
+    Q_UNUSED(rect);
+    return false;
+}
+
 /*!
     \since 4.2
 
diff --git a/src/gui/image/qpixmap_mac_p.h b/src/gui/image/qpixmap_mac_p.h
index 75525c4..2b22e6b 100644
--- a/src/gui/image/qpixmap_mac_p.h
+++ b/src/gui/image/qpixmap_mac_p.h
@@ -68,6 +68,7 @@ public:
     void resize(int width, int height);
     void fromImage(const QImage &image, Qt::ImageConversionFlags flags);
     void copy(const QPixmapData *data, const QRect &rect);
+    bool scroll(int dx, int dy, const QRect &rect);
 
     int metric(QPaintDevice::PaintDeviceMetric metric) const;
     void fill(const QColor &color);
diff --git a/src/gui/image/qpixmap_raster.cpp b/src/gui/image/qpixmap_raster.cpp
index 7dfab70..145b02a 100644
--- a/src/gui/image/qpixmap_raster.cpp
+++ b/src/gui/image/qpixmap_raster.cpp
@@ -181,6 +181,16 @@ void QRasterPixmapData::fromImage(const QImage &sourceImage,
     setSerialNumber(image.serialNumber());
 }
 
+// from qwindowsurface.cpp
+extern void qt_scrollRectInImage(QImage &img, const QRect &rect, const QPoint &offset);
+
+bool QRasterPixmapData::scroll(int dx, int dy, const QRect &rect)
+{
+    if (!image.isNull())
+        qt_scrollRectInImage(image, rect, QPoint(dx, dy));
+    return true;
+}
+
 void QRasterPixmapData::fill(const QColor &color)
 {
     uint pixel;
diff --git a/src/gui/image/qpixmap_raster_p.h b/src/gui/image/qpixmap_raster_p.h
index 095f378..48d5cf8 100644
--- a/src/gui/image/qpixmap_raster_p.h
+++ b/src/gui/image/qpixmap_raster_p.h
@@ -75,6 +75,7 @@ public:
     void fromFile(const QString &filename, Qt::ImageConversionFlags flags);
     void fromImage(const QImage &image, Qt::ImageConversionFlags flags);
 
+    bool scroll(int dx, int dy, const QRect &rect);
     void fill(const QColor &color);
     void setMask(const QBitmap &mask);
     bool hasAlphaChannel() const;
diff --git a/src/gui/image/qpixmap_x11.cpp b/src/gui/image/qpixmap_x11.cpp
index ff7c1b6..725caeb 100644
--- a/src/gui/image/qpixmap_x11.cpp
+++ b/src/gui/image/qpixmap_x11.cpp
@@ -2205,6 +2205,16 @@ void QX11PixmapData::copy(const QPixmapData *data, const QRect &rect)
     }
 }
 
+bool QX11PixmapData::scroll(int dx, int dy, const QRect &rect)
+{
+    GC gc = XCreateGC(X11->display, hd, 0, 0);
+    XCopyArea(X11->display, hd, hd, gc,
+              rect.left(), rect.top(), rect.width(), rect.height(),
+              rect.left() + dx, rect.top() + dy);
+    XFreeGC(X11->display, gc);
+    return true;
+}
+
 #if !defined(QT_NO_XRENDER)
 void QX11PixmapData::convertToARGB32(bool preserveContents)
 {
diff --git a/src/gui/image/qpixmap_x11_p.h b/src/gui/image/qpixmap_x11_p.h
index 980b10e..c526402 100644
--- a/src/gui/image/qpixmap_x11_p.h
+++ b/src/gui/image/qpixmap_x11_p.h
@@ -74,6 +74,7 @@ public:
     void resize(int width, int height);
     void fromImage(const QImage &image, Qt::ImageConversionFlags flags);
     void copy(const QPixmapData *data, const QRect &rect);
+    bool scroll(int dx, int dy, const QRect &rect);
 
     void fill(const QColor &color);
     QBitmap mask() const;
diff --git a/src/gui/image/qpixmapdata.cpp b/src/gui/image/qpixmapdata.cpp
index 3d88f4b..245a866 100644
--- a/src/gui/image/qpixmapdata.cpp
+++ b/src/gui/image/qpixmapdata.cpp
@@ -73,6 +73,14 @@ void QPixmapData::copy(const QPixmapData *data, const QRect &rect)
     fromImage(data->toImage().copy(rect), Qt::AutoColor);
 }
 
+bool QPixmapData::scroll(int dx, int dy, const QRect &rect)
+{
+    Q_UNUSED(dx);
+    Q_UNUSED(dy);
+    Q_UNUSED(rect);
+    return false;
+}
+
 void QPixmapData::setMask(const QBitmap &mask)
 {
     if (mask.size().isEmpty()) {
diff --git a/src/gui/image/qpixmapdata_p.h b/src/gui/image/qpixmapdata_p.h
index 7296426..abb3181 100644
--- a/src/gui/image/qpixmapdata_p.h
+++ b/src/gui/image/qpixmapdata_p.h
@@ -78,6 +78,7 @@ public:
     virtual void fromFile(const QString &filename, const char *format,
                           Qt::ImageConversionFlags flags);
     virtual void copy(const QPixmapData *data, const QRect &rect);
+    virtual bool scroll(int dx, int dy, const QRect &rect);
 
     virtual int metric(QPaintDevice::PaintDeviceMetric metric) const = 0;
     virtual void fill(const QColor &color) = 0;