[ocrfeeder] Show error dialogs when not able to open messages

[Joaquim Manuel Pereira Rocha <jrocha src gnome org>]

commit c09a53575f28c9df331d44b5077761bd99fe3ba2
Author: Joaquim Rocha <jrocha igalia com>
Date:   Fri Mar 5 15:05:38 2010 +0100

    Show error dialogs when not able to open messages

 feeder/imageManipulation.py |   19 +++++++++++++++----
 studio/widgetModeler.py     |   11 +++++++++--
 studio/widgetPresenter.py   |    7 +++++++
 3 files changed, 31 insertions(+), 6 deletions(-)
---
diff --git a/feeder/imageManipulation.py b/feeder/imageManipulation.py
index 2eeab95..e50777c 100644
--- a/feeder/imageManipulation.py
+++ b/feeder/imageManipulation.py
@@ -21,14 +21,20 @@
 import tempfile
 from util.lib import debug
 
+import gettext
 import Image, ImageDraw
 import os.path
 from util import graphics
+import sys
+
+_ = gettext.gettext
 
 class ImageProcessor:
     
     def __init__(self, path_to_image, window_size = None):
         self.window_size = window_size
+        error_message = _("A problem occurred while trying to open the image:\n %s\n"
+                          "Ensure the image exists or try converting it to another format.") % path_to_image
         if os.path.isfile(path_to_image):
             try:
                 self.original_image = Image.open(path_to_image)
@@ -37,9 +43,11 @@ class ImageProcessor:
                     self.window_size = self.original_image.size[1] / 60.
                 debug('Window Size: ', self.window_size)
             except:
-                raise ImageManipulationError
+                debug(sys.exc_info())
+                raise ImageManipulationError(error_message)
         else:
-            raise IOError
+            debug(sys.exc_info())
+            raise ImageManipulationError(error_message)
             
     def __windowContrast(self, bgcolor, x, y, constrast_tolerance = 120):
         image = self.black_n_white_image
@@ -123,8 +131,11 @@ class ContentAnalyser:
 
 class ImageManipulationError(Exception):
     
-    def __init__(self):
-        pass
+    def __init__(self, value):
+        self.value = value
+    
+    def __str__(self):
+        return self.value
     
 class InsuficientPointsForPolygon(Exception):
     
diff --git a/studio/widgetModeler.py b/studio/widgetModeler.py
index 5c076fc..da111ce 100644
--- a/studio/widgetModeler.py
+++ b/studio/widgetModeler.py
@@ -29,7 +29,7 @@ from util import graphics, ALIGN_LEFT, ALIGN_RIGHT, ALIGN_CENTER, ALIGN_FILL, \
     PAPER_SIZES
 from util.lib import debug
 from widgetPresenter import BoxEditor, PagesToExportDialog, FileDialog, \
-    PageSizeDialog, getPopupMenu, QuestionDialog, UnpaperDialog
+    PageSizeDialog, getPopupMenu, WarningDialog, UnpaperDialog
 import gettext
 import gobject
 import gtk
@@ -381,7 +381,14 @@ class ImageReviewer_Controler:
             window_size = None
         else:
             window_size = float(window_size)
-        image_processor = ImageProcessor(image_reviewer.path_to_image, window_size)
+        try:
+            image_processor = ImageProcessor(image_reviewer.path_to_image, window_size)
+        except Exception as e:
+            message = '<b>%s</b>\n%s' % (_('Warning:'), str(e)) 
+            warning_dialog = WarningDialog(message)
+            warning_dialog.run()
+            warning_dialog.destroy()
+            return
         while gtk.events_pending():
             gtk.main_iteration()
         block_retriever = BlockRetriever(image_processor.imageToBinary())
diff --git a/studio/widgetPresenter.py b/studio/widgetPresenter.py
index 2f942b2..bacaa19 100644
--- a/studio/widgetPresenter.py
+++ b/studio/widgetPresenter.py
@@ -665,6 +665,13 @@ class QuestionDialog(gtk.MessageDialog):
         self.set_icon_from_file(WINDOW_ICON)
         self.set_markup(message)
 
+class WarningDialog(gtk.MessageDialog):
+
+    def __init__(self, message, buttons = gtk.BUTTONS_OK):
+        super(WarningDialog, self).__init__(type = gtk.MESSAGE_WARNING, buttons = buttons)
+        self.set_icon_from_file(WINDOW_ICON)
+        self.set_markup(message)
+
 class UnpaperDialog(gtk.Dialog):
     
     def __init__(self, reviewer , unpaper, temp_dir = '/tmp'):