[meld] Add a store column and a view pixbuf renderer to show filter validity

[Kai Willadsen <kaiw src gnome org>]

commit 822749666b04e01f32cefd1e94dde8ac79270743
Author: Kai Willadsen <kai willadsen gmail com>
Date:   Tue Feb 8 18:25:57 2011 +1000

    Add a store column and a view pixbuf renderer to show filter validity
    
    The validity renderer has a fixed size
    We want the validity renderer to reserve a portion of its cell,
    otherwise the first time an invalid pattern is entered, everything
    shuffles over, which looks bodgy.

 data/ui/EditableList.ui |   29 +++++++++++++++++++----------
 meld/preferences.py     |   19 +++++++++++++++++--
 2 files changed, 36 insertions(+), 12 deletions(-)
---
diff --git a/data/ui/EditableList.ui b/data/ui/EditableList.ui
index 36557af..fecda0b 100644
--- a/data/ui/EditableList.ui
+++ b/data/ui/EditableList.ui
@@ -10,6 +10,8 @@
       <column type="gboolean"/>
       <!-- column-name Pattern -->
       <column type="gchararray"/>
+      <!-- column-name ValidPattern -->
+      <column type="gboolean"/>
     </columns>
     <signal name="row-inserted" handler="_update_sensitivity" swapped="no"/>
     <signal name="rows-reordered" handler="_update_sensitivity" swapped="no"/>
@@ -48,35 +50,42 @@
                     <property name="rubber_banding">True</property>
                     <child>
                       <object class="GtkTreeViewColumn" id="treeviewcolumn1">
-                        <property name="title">Name</property>
+                        <property name="title" translatable="yes">Active</property>
                         <child>
-                          <object class="GtkCellRendererText" id="cellrenderertext1">
-                            <property name="editable">True</property>
-                            <signal name="edited" handler="on_name_edited" swapped="no"/>
+                          <object class="GtkCellRendererToggle" id="cellrenderertoggle1">
+                            <signal name="toggled" handler="on_cellrenderertoggle_toggled" swapped="no"/>
                           </object>
                           <attributes>
-                            <attribute name="text">0</attribute>
+                            <attribute name="activatable">3</attribute>
+                            <attribute name="active">1</attribute>
                           </attributes>
                         </child>
                       </object>
                     </child>
                     <child>
                       <object class="GtkTreeViewColumn" id="treeviewcolumn2">
-                        <property name="title" translatable="yes">Active</property>
+                        <property name="title" translatable="yes">Name</property>
                         <child>
-                          <object class="GtkCellRendererToggle" id="cellrenderertoggle1">
-                            <signal name="toggled" handler="on_cellrenderertoggle_toggled" swapped="no"/>
+                          <object class="GtkCellRendererText" id="cellrenderertext1">
+                            <property name="editable">True</property>
+                            <signal name="edited" handler="on_name_edited" swapped="no"/>
                           </object>
                           <attributes>
-                            <attribute name="active">1</attribute>
+                            <attribute name="text">0</attribute>
                           </attributes>
                         </child>
                       </object>
                     </child>
                     <child>
-                      <object class="GtkTreeViewColumn" id="treeviewcolumn3">
+                      <object class="GtkTreeViewColumn" id="pattern_column">
                         <property name="title" translatable="yes">Pattern</property>
                         <child>
+                          <object class="GtkCellRendererPixbuf" id="validity_renderer">
+                            <property name="width">16</property>
+                            <property name="height">16</property>
+                          </object>
+                        </child>
+                        <child>
                           <object class="GtkCellRendererText" id="cellrenderertext2">
                             <property name="editable">True</property>
                             <signal name="edited" handler="on_pattern_edited" swapped="no"/>
diff --git a/meld/preferences.py b/meld/preferences.py
index 39cf691..3a4f4d6 100644
--- a/meld/preferences.py
+++ b/meld/preferences.py
@@ -1,4 +1,5 @@
 ### Copyright (C) 2002-2009 Stephen Kennedy <stevek gnome org>
+### Copyright (C) 2010-2011 Kai Willadsen <kai willadsen gmail com>
 
 ### This program is free software; you can redistribute it and/or modify
 ### it under the terms of the GNU General Public License as published by
@@ -33,14 +34,20 @@ from util.sourceviewer import srcviewer
 class FilterList(listwidget.ListWidget):
 
     def __init__(self, prefs, key, filter_type):
-        default_entry = [_("label"), False, _("pattern")]
+        default_entry = [_("label"), False, _("pattern"), True]
         listwidget.ListWidget.__init__(self, default_entry)
         self.prefs = prefs
         self.key = key
+        self.filter_type = filter_type
+
+        self.pattern_column.set_cell_data_func(self.validity_renderer,
+                                               self.valid_icon_celldata)
 
         for filtstring in getattr(self.prefs, self.key).split("\n"):
             filt = meldapp.FilterEntry.parse(filtstring, filter_type)
-            self.model.append([filt.label, filt.active, filt.filter_string])
+            valid = filt.filter is not None
+            self.model.append([filt.label, filt.active,
+                               filt.filter_string, valid])
 
         for signal in ('row-changed', 'row-deleted', 'row-inserted',
                        'rows-reordered'):
@@ -48,6 +55,11 @@ class FilterList(listwidget.ListWidget):
 
         self._update_sensitivity()
 
+    def valid_icon_celldata(self, col, cell, model, it, user_data=None):
+        is_valid = model.get_value(it, 3)
+        icon_name = "gtk-dialog-warning" if not is_valid else None
+        cell.set_property("stock-id", icon_name)
+
     def on_name_edited(self, ren, path, text):
         self.model[path][0] = text
 
@@ -55,7 +67,10 @@ class FilterList(listwidget.ListWidget):
         self.model[path][1] = not ren.get_active()
 
     def on_pattern_edited(self, ren, path, text):
+        filt = meldapp.FilterEntry.compile_filter(text, self.filter_type)
+        valid = filt is not None
         self.model[path][2] = text
+        self.model[path][3] = valid
 
     def _update_filter_string(self, *args):
         pref = []