[gitg/wip/albfan/diff-images-as-text: 14/14] Allow to diff images as text if its mime type supports it

[Alberto Fanjul <albfan src gnome org>]

commit 231bc4b56b39c9ccd0a9528aae7d34e065921555
Author: Alberto Fanjul <albertofanjul gmail com>
Date:   Wed Oct 16 14:34:23 2019 +0200

    Allow to diff images as text if its mime type supports it

 libgitg/gitg-diff-view.vala | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)
---
diff --git a/libgitg/gitg-diff-view.vala b/libgitg/gitg-diff-view.vala
index 2ec9c031..5b8e273d 100644
--- a/libgitg/gitg-diff-view.vala
+++ b/libgitg/gitg-diff-view.vala
@@ -823,7 +823,14 @@ public class Gitg.DiffView : Gtk.Grid
                                                mime_type_for_image = 
ContentType.get_mime_type(info.new_file_content_type);
                                        }
 
-                                       if (mime_type_for_image != null && 
s_image_mime_types.contains(mime_type_for_image))
+                                       //TODO: this bool come from the user selection. A button that only 
appears if
+                                       //image can be seen as text too.
+                                       bool image_diff_selected = false;
+                                       bool can_diff_as_text = ContentType.is_mime_type(mime_type_for_image, 
"text/plain");
+
+                                       if (mime_type_for_image != null
+                                               && s_image_mime_types.contains(mime_type_for_image)
+                                               && (!can_diff_as_text || image_diff_selected))
                                        {
                                                current_file = new Gitg.DiffViewFile.image(repository, delta);
                                        }