[glom] Print Layout: Slight improvement to image scaling.

[Murray Cumming <murrayc src gnome org>]

commit c429bc14b14c7765ae25c1067d61cc33e6f46a78
Author: Murray Cumming <murrayc murrayc com>
Date:   Tue Aug 30 09:52:07 2011 +0200

    Print Layout: Slight improvement to image scaling.
    
    * glom/utility_widgets/canvas/canvas_image_movable.cc: scale_to_size():
    Use the correct size in pixels to scale the image.
    However, it is still overscaled and cropped due to goocanvas bug #657592 .

 ChangeLog                                          |    8 +++++++
 .../utility_widgets/canvas/canvas_image_movable.cc |   21 +++++++++++++++++--
 2 files changed, 26 insertions(+), 3 deletions(-)
---
diff --git a/ChangeLog b/ChangeLog
index 69a2529..2086541 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2011-08-30  Murray Cumming  <murrayc murrayc com>
+
+	Print Layout: Slight improvement to image scaling.
+
+	* glom/utility_widgets/canvas/canvas_image_movable.cc: scale_to_size():
+	Use the correct size in pixels to scale the image.
+	However, it is still overscaled and cropped due to goocanvas bug #657592 .
+
 2011-08-29  Murray Cumming  <murrayc murrayc com>
 
 	Print Layout: Allow editing of line width and color.
diff --git a/glom/utility_widgets/canvas/canvas_image_movable.cc b/glom/utility_widgets/canvas/canvas_image_movable.cc
index d823437..395c3d4 100644
--- a/glom/utility_widgets/canvas/canvas_image_movable.cc
+++ b/glom/utility_widgets/canvas/canvas_image_movable.cc
@@ -173,16 +173,31 @@ void CanvasImageMovable::scale_to_size()
   double width = 0;
   double height = 0;
   get_width_height(width, height);
-  //std::cout << "debug: " << G_STRFUNC << ": width=" << width << ", height=" << height << std::endl;
+  Goocanvas::Canvas* canvas = get_canvas();
+  if(!canvas)
+  {
+    std::cerr << G_STRFUNC << ": canvas is null" << std::endl;
+    return;
+  }
   
-  if(width && height)
+  //Convert, because our canvas uses units (mm) but the pixbuf uses pixels:
+  double width_pixels = width;
+  double height_pixels = height;
+  canvas->convert_to_pixels(width_pixels, height_pixels);
+
+  if(width_pixels && height_pixels)
   {
-    Glib::RefPtr<Gdk::Pixbuf> pixbuf = Utils::image_scale_keeping_ratio(m_pixbuf, (int)height, (int)width);
+    Glib::RefPtr<Gdk::Pixbuf> pixbuf = Utils::image_scale_keeping_ratio(m_pixbuf, (int)height_pixels, (int)width_pixels);
     property_pixbuf() = pixbuf;
   }
 
   //Make sure that the size stays the same even if the scaling wasn't exact:
   set_width_height(width, height);
+  
+  //TODO: Fix this goocanvas bug http://bugzilla.gnome.org/show_bug.cgi?id=657592, 
+  //We can't work around it by forcing an extra scale in GooCanvasItem like so:
+  //property_scale_to_fit() = true;
+  //because that does not keep the aspect ratio.
 }
 
 void CanvasImageMovable::set_image_empty()