From b63ad414f697bc2050296456194381c7a423d4d6 Mon Sep 17 00:00:00 2001
From: Gonzalo Odiard <godiard@sugarlabs.org>
Date: Thu, 07 Oct 2010 12:49:34 +0000
Subject: generate preview image for downloaded images (SL#1106)

---
diff --git a/downloadmanager.py b/downloadmanager.py
index 34e18e2..cec673e 100644
--- a/downloadmanager.py
+++ b/downloadmanager.py
@@ -194,10 +194,8 @@ class Download:
                 sniffed_mime_type = mime.get_for_file(self._target_file.path)
                 self.dl_jobject.metadata['mime_type'] = sniffed_mime_type
 
-            if self._mime_type in ('image/bmp','image/gif','image/jpeg','image/png','image/tiff'):
-                self.dl_jobject.metadata['preview'] = self.__get_preview_image()
-            else:
-                self.dl_jobject.metadata['preview'] = ''
+            if self._check_image_mime_type():
+                self.dl_jobject.metadata['preview'] = self._get_preview_image()
 
             datastore.write(self.dl_jobject,
                             transfer_ownership=True,
@@ -205,26 +203,38 @@ class Download:
                             error_handler=self._internal_save_error_cb,
                             timeout=360 * DBUS_PYTHON_TIMEOUT_UNITS_PER_SECOND)
 
-    def __get_preview_image(self):
+    def _check_image_mime_type(self):
+        for pixbuf_format in gtk.gdk.pixbuf_get_formats():
+            if self._mime_type in pixbuf_format['mime_types']:
+                return True
+        return False
+
+    def _get_preview_image(self):
+        preview_width, preview_height = style.zoom(300), style.zoom(225)
+
         pixbuf = gtk.gdk.pixbuf_new_from_file(self._target_file.path)
         width, height = pixbuf.get_width(), pixbuf.get_height()
 
-        preview_width = style.zoom(300)
-        preview_height =  style.zoom(225)
-
+        scale = 1
         if (width > preview_width) or (height > preview_height):
-            scale_x = float(width) / preview_width
-            scale_y = float(height) / preview_height
-            scale = max(scale_x,scale_y)
-       
-            pixbuf = pixbuf.scale_simple(float(width) / scale, height / scale,
-                                     gtk.gdk.INTERP_BILINEAR)
-        pixbuf2 = gtk.gdk.Pixbuf(gtk.gdk.COLORSPACE_RGB,pixbuf.get_has_alpha(),8,preview_width,preview_height)
-        pixbuf2.fill(0xffffffff)
-        margin_x = (preview_width - pixbuf.get_width()) / 2
-        margin_y = (preview_height - pixbuf.get_height()) / 2
-
-        pixbuf.copy_area(0,0,pixbuf.get_width(),pixbuf.get_height(),pixbuf2,margin_x,margin_y)
+            scale_x = preview_width / float(width)
+            scale_y = preview_height / float(height)
+            scale = min(scale_x, scale_y)
+
+        pixbuf2 = gtk.gdk.Pixbuf(gtk.gdk.COLORSPACE_RGB, \
+                            pixbuf.get_has_alpha(), \
+                            pixbuf.get_bits_per_sample(), \
+                            preview_width, preview_height)
+        pixbuf2.fill(style.COLOR_WHITE.get_int())
+
+        margin_x = int((preview_width - (width * scale)) / 2)
+        margin_y = int((preview_height - (height * scale)) / 2)
+
+        pixbuf.scale(pixbuf2, margin_x, margin_y, \
+                            preview_width - (margin_x * 2), \
+                            preview_height - (margin_y * 2), \
+                            margin_x, margin_y, scale, scale, \
+                            gtk.gdk.INTERP_BILINEAR)
 
         preview_data = []
         def save_func(buf, data):
--
cgit v0.9.1