Move GdkPixbufFromSkBitmap to gtk_util so it can easily be shared.

Review URL: http://codereview.chromium.org/38009


git-svn-id: svn://svn.chromium.org/chrome/trunk/src@11327 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 45 insertions, 0 deletions

diff --git a/base/gfx/gtk_util.cc b/base/gfx/gtk_util.cc
index 26601ca..e12bb6e 100755
--- a/base/gfx/gtk_util.cc
+++ b/base/gfx/gtk_util.cc
@@ -7,6 +7,7 @@
 #include <gdk/gdk.h>
 
 #include "base/gfx/rect.h"
+#include "skia/include/SkBitmap.h"
 
 namespace gfx {
 
@@ -21,4 +22,42 @@ void SubtractRectanglesFromRegion(GdkRegion* region,
   }
 }
 
+static void FreePixels(guchar* pixels, gpointer data) {
+  free(data);
+}
+
+GdkPixbuf* GdkPixbufFromSkBitmap(const SkBitmap* bitmap) {
+  bitmap->lockPixels();
+  int width = bitmap->width();
+  int height = bitmap->height();
+  int stride = bitmap->rowBytes();
+  const guchar* orig_data = static_cast<guchar*>(bitmap->getPixels());
+  guchar* data = static_cast<guchar*>(malloc(height * stride));
+
+  // We have to copy the pixels and swap from BGRA to RGBA.
+  for (int i = 0; i < height; ++i) {
+    for (int j = 0; j < width; ++j) {
+      int idx = i * stride + j * 4;
+      data[idx] = orig_data[idx + 2];
+      data[idx + 1] = orig_data[idx + 1];
+      data[idx + 2] = orig_data[idx];
+      data[idx + 3] = orig_data[idx + 3];
+    }
+  }
+
+  // This pixbuf takes ownership of our malloc()ed data and will
+  // free it for us when it is destroyed.
+  GdkPixbuf* pixbuf = gdk_pixbuf_new_from_data(
+      data,
+      GDK_COLORSPACE_RGB,  // The only colorspace gtk supports.
+      true,  // There is an alpha channel.
+      8,
+      width, height, stride, &FreePixels, data);
+
+  // Assume ownership of pixbuf.
+  g_object_ref_sink(pixbuf);
+  bitmap->unlockPixels();
+  return pixbuf;
+}
+
 }  // namespace gfx
diff --git a/base/gfx/gtk_util.h b/base/gfx/gtk_util.h
index 7062d59..bf6e6aa 100755
--- a/base/gfx/gtk_util.h
+++ b/base/gfx/gtk_util.h
@@ -7,7 +7,9 @@
 
 #include <vector>
 
+typedef struct _GdkPixbuf GdkPixbuf;
 typedef struct _GdkRegion GdkRegion;
+class SkBitmap;
 
 namespace gfx {
 
@@ -17,6 +19,10 @@ class Rect;
 void SubtractRectanglesFromRegion(GdkRegion* region,
                                   const std::vector<gfx::Rect>& cutouts);
 
+// Convert and copy a SkBitmap to a GdkPixbuf.  NOTE: This is an expensive
+// operation, all of the pixels must be copied and their order swapped.
+GdkPixbuf* GdkPixbufFromSkBitmap(const SkBitmap* bitmap);
+
 }  // namespace gfx
 
 #endif  // BASE_GFX_GTK_UTIL_H_