[gimp] Add new virtual function GimpDrawable::convert_type()

[Michael Natterer <mitch src gnome org>]

commit 86a264e9f2c4e7291d9c7f29d939b0303bb4a11a
Author: Michael Natterer <mitch gimp org>
Date:   Fri Sep 11 21:23:35 2009 +0200

    Add new virtual function GimpDrawable::convert_type()
    
    This may look like duplication of GimpItem::convert() but in fact will
    fix the longstanding uglyness that GimpItem::convert() both transfers
    an item to another image *and* converts the image type of drawables.
    When this refactoring is done, GimpItem::convert() will only move an
    item to another image, and its implementation in GimpDrawable classes
    will call GimpDrawable::convert_type() to convert the pixels to
    whatever format.
    
    Takes a "dest_image" parameter anyway because for converting to
    indexed we need the destination colormap. The default impl in
    GimpDrawable can only convert to gray and rgb however.

 app/core/gimpdrawable.c |   47 +++++++++++++++++++++++++++++++++++++++++++++++
 app/core/gimpdrawable.h |    7 +++++++
 2 files changed, 54 insertions(+), 0 deletions(-)
---
diff --git a/app/core/gimpdrawable.c b/app/core/gimpdrawable.c
index c49e9c6..0be4f5c 100644
--- a/app/core/gimpdrawable.c
+++ b/app/core/gimpdrawable.c
@@ -35,6 +35,7 @@
 #include "gimpchannel.h"
 #include "gimpcontext.h"
 #include "gimpdrawable-combine.h"
+#include "gimpdrawable-convert.h"
 #include "gimpdrawable-preview.h"
 #include "gimpdrawable-private.h"
 #include "gimpdrawable-shadow.h"
@@ -125,6 +126,10 @@ static gint64  gimp_drawable_real_estimate_memsize (const GimpDrawable *drawable
                                                     gint               width,
                                                     gint               height);
 
+static void       gimp_drawable_real_convert_type  (GimpDrawable      *drawable,
+                                                    GimpImage         *dest_image,
+                                                    GimpImageBaseType  new_base_type);
+
 static TileManager * gimp_drawable_real_get_tiles  (GimpDrawable      *drawable);
 static void       gimp_drawable_real_set_tiles     (GimpDrawable      *drawable,
                                                     gboolean           push_undo,
@@ -226,6 +231,7 @@ gimp_drawable_class_init (GimpDrawableClass *klass)
   klass->estimate_memsize            = gimp_drawable_real_estimate_memsize;
   klass->invalidate_boundary         = NULL;
   klass->get_active_components       = NULL;
+  klass->convert_type                = gimp_drawable_real_convert_type;
   klass->apply_region                = gimp_drawable_real_apply_region;
   klass->replace_region              = gimp_drawable_real_replace_region;
   klass->get_tiles                   = gimp_drawable_real_get_tiles;
@@ -719,6 +725,28 @@ gimp_drawable_real_estimate_memsize (const GimpDrawable *drawable,
   return (gint64) gimp_drawable_bytes (drawable) * width * height;
 }
 
+static void
+gimp_drawable_real_convert_type (GimpDrawable      *drawable,
+                                 GimpImage         *dest_image,
+                                 GimpImageBaseType  new_base_type)
+{
+  g_return_if_fail (new_base_type != GIMP_INDEXED);
+
+  switch (new_base_type)
+    {
+    case GIMP_RGB:
+      gimp_drawable_convert_rgb (drawable);
+      break;
+
+    case GIMP_GRAY:
+      gimp_drawable_convert_grayscale (drawable);
+      break;
+
+    default:
+      break;
+    }
+}
+
 static TileManager *
 gimp_drawable_real_get_tiles (GimpDrawable *drawable)
 {
@@ -1200,6 +1228,25 @@ gimp_drawable_get_active_components (const GimpDrawable *drawable,
 }
 
 void
+gimp_drawable_convert_type (GimpDrawable      *drawable,
+                            GimpImage         *dest_image,
+                            GimpImageBaseType  new_base_type)
+{
+  GimpImageType type;
+
+  g_return_if_fail (GIMP_IS_DRAWABLE (drawable));
+  g_return_if_fail (dest_image == NULL || GIMP_IS_IMAGE (dest_image));
+  g_return_if_fail (new_base_type != GIMP_INDEXED || GIMP_IS_IMAGE (dest_image));
+
+  type = gimp_drawable_type (drawable);
+
+  g_return_if_fail (new_base_type != GIMP_IMAGE_TYPE_BASE_TYPE (type));
+
+  GIMP_DRAWABLE_GET_CLASS (drawable)->convert_type (drawable, dest_image,
+                                                    new_base_type);
+}
+
+void
 gimp_drawable_apply_region (GimpDrawable         *drawable,
                             PixelRegion          *src2PR,
                             gboolean              push_undo,
diff --git a/app/core/gimpdrawable.h b/app/core/gimpdrawable.h
index e358d12..3b338ab 100644
--- a/app/core/gimpdrawable.h
+++ b/app/core/gimpdrawable.h
@@ -63,6 +63,9 @@ struct _GimpDrawableClass
   void          (* invalidate_boundary)   (GimpDrawable         *drawable);
   void          (* get_active_components) (const GimpDrawable   *drawable,
                                            gboolean             *active);
+  void          (* convert_type)          (GimpDrawable         *drawable,
+                                           GimpImage            *dest_image,
+                                           GimpImageBaseType     new_base_type);
   void          (* apply_region)          (GimpDrawable         *drawable,
                                            PixelRegion          *src2PR,
                                            gboolean              push_undo,
@@ -140,6 +143,10 @@ void           gimp_drawable_invalidate_boundary (GimpDrawable       *drawable);
 void         gimp_drawable_get_active_components (const GimpDrawable *drawable,
                                                   gboolean           *active);
 
+void            gimp_drawable_convert_type       (GimpDrawable       *drawable,
+                                                  GimpImage          *dest_image,
+                                                  GimpImageBaseType   new_base_type);
+
 void            gimp_drawable_apply_region       (GimpDrawable       *drawable,
                                                   PixelRegion        *src2PR,
                                                   gboolean            push_undo,