[accerciser] Use Gtk.TreeModelFilter to filter the view

[Samuel Thibault <sthibaul src gnome org>]

commit ce016556434e4d4b8fba4e1942e53890cb7d53c5
Author: Jan-Marek Glogowski <glogow fbihome de>
Date:   Wed May 29 00:50:01 2019 +0200

    Use Gtk.TreeModelFilter to filter the view
    
    This gets rid of all the manual filtering code in the model,
    which already has problems when filtering is enabled and new
    applications show up.
    
    This means we get a self.filter in addition to the self.model.
    The GtkTreeView now works with values from the filter. Most
    times we still work on the whole model, so the values must be
    converted using Gtk.TreeModelFilter functions.
    
    As a major improvement this fixes the slow addChild handling
    when filtering was enabled, due to a 5s sleep per child. This
    made LibreOffice StarMath crawl when changing the element
    category, as this replaces all the current buttons.

 src/lib/accerciser/accessible_treeview.py | 149 +++++++++---------------------
 1 file changed, 44 insertions(+), 105 deletions(-)
---
diff --git a/src/lib/accerciser/accessible_treeview.py b/src/lib/accerciser/accessible_treeview.py
index 49bf72d..b5ad6ea 100644
--- a/src/lib/accerciser/accessible_treeview.py
+++ b/src/lib/accerciser/accessible_treeview.py
@@ -35,8 +35,6 @@ COL_FILLED = 4
 COL_DUMMY = 5
 COL_ACC = 6
 
-ACCESSIBLE_LOADING = 5
-
 class AccessibleModel(gtk.TreeStore, ToolsAccessor):
   '''
   Stores the desktop accessible tree. Only populates sections of the tree
@@ -74,25 +72,6 @@ class AccessibleModel(gtk.TreeStore, ToolsAccessor):
     self.desktop = desktop_acc
     self._path_to_populate = None
     self._populating_tasks = 0
-    self._hide_leaves = False
-
-
-  def _hideShowLeaves(self):
-    '''
-    Change _hide_leaves state, allowing leaves either to appear or to be hidden
-    in the accessible treeview.
-    '''
-    self._hide_leaves = not self._hide_leaves
-
-  def getHideLeaves(self):
-    '''
-    Return a boolean that indicates whether accessibles with no children
-    (leaves) should be hidden.
-
-    @return: A boolean indicating if leaves should be hidden.
-    @rtype: boolean
-    '''
-    return self._hide_leaves
 
   def _onRowChanged(self, model, path, iter):
     '''
@@ -235,16 +214,7 @@ class AccessibleModel(gtk.TreeStore, ToolsAccessor):
     @return: A list with children ids.
     @rtype: list
     '''
-
-    if not self._hide_leaves:
-      return [i for i in range(accessible.childCount)]
-    else:
-      children_ids = []
-      for i in range(accessible.childCount):
-        child = accessible.getChildAtIndex(i)
-        if child.childCount > 0 or child.getRoleName() != 'application':
-          children_ids.append(i)
-      return children_ids
+    return [i for i in range(accessible.childCount)]
 
   def _selectChild(self, parent, index):
     '''
@@ -258,12 +228,7 @@ class AccessibleModel(gtk.TreeStore, ToolsAccessor):
     @return: A child id.
     @rtype: integer
     '''
-
-    if not self._hide_leaves:
-      return index
-    else:
-      children = self._childrenIndexesInParent(parent)
-      return children[index]
+    return index
 
   def children_number(self, parent):
     '''
@@ -275,12 +240,7 @@ class AccessibleModel(gtk.TreeStore, ToolsAccessor):
     @return: The number of children (including leaves or not) an accessible has.
     @rtype: integer
     '''
-
-    if not self._hide_leaves:
-      return parent.childCount
-    else:
-      children = self._childrenIndexesInParent(parent)
-      return len(children)
+    return parent.childCount
 
   def _popOnIdle(self, row_reference):
     '''
@@ -395,16 +355,7 @@ class AccessibleModel(gtk.TreeStore, ToolsAccessor):
     @return: The child's index or -1 if it wasn't found
     @rtype: integer
     '''
-    if not self._hide_leaves:
-      return child.getIndexInParent()
-    else:
-      parent = child.parent
-      children = self._childrenIndexesInParent(parent)
-
-      for i in children:
-        if parent.getChildAtIndex(i) == child:
-          return children.index(i)
-      return -1
+    return child.getIndexInParent()
 
   def getAccPath(self, acc):
     '''
@@ -429,11 +380,11 @@ class AccessibleModel(gtk.TreeStore, ToolsAccessor):
       except Exception as e:
         return None
       child = child.get_parent()
-    if not self._hide_leaves:
-      try:
-        path = (list(self.desktop).index(child),) + path
-      except Exception as e:
-        return None
+
+    try:
+      path = (list(self.desktop).index(child),) + path
+    except Exception as e:
+      return None
 
     return path
 
@@ -502,7 +453,10 @@ class AccessibleTreeView(gtk.TreeView, ToolsAccessor):
     self.connect('row-activated', self._onRowActivated)
 
     self.model = AccessibleModel(self.desktop)
-    self.set_model(self.model)
+    self.filter = self.model.filter_new()
+    self.filter.set_visible_func(self._filterNoChildApps, data=None)
+    self.set_model(self.filter)
+
     crt = gtk.CellRendererText()
     crp = gtk.CellRendererPixbuf()
     tvc = gtk.TreeViewColumn(_('Name'))
@@ -514,6 +468,7 @@ class AccessibleTreeView(gtk.TreeView, ToolsAccessor):
     tvc.set_cell_data_func(crt, self._accCellDataFunc)
     tvc.set_cell_data_func(crp, self._accCellDataFunc)
     self.append_column(tvc)
+
     crt= gtk.CellRendererText()
     tvc = gtk.TreeViewColumn(_('Role'))
     tvc.pack_start(crt, True)
@@ -521,6 +476,7 @@ class AccessibleTreeView(gtk.TreeView, ToolsAccessor):
     tvc.set_resizable(True)
     tvc.set_cell_data_func(crt, self._accCellDataFunc)
     self.append_column(tvc)
+
     crt = gtk.CellRendererText()
     tvc = gtk.TreeViewColumn(_('Children'))
     tvc.pack_start(crt, True)
@@ -549,6 +505,7 @@ class AccessibleTreeView(gtk.TreeView, ToolsAccessor):
         self._accEventNameChanged, 
         'object:property-change:accessible-name')
 
+    self._hide_leaves = False
     self.action_group = gtk.ActionGroup.new('TreeActions')
     self.action_group.add_toggle_actions(
       [('HideShowLeaves', None, _('_Hide/Show Applications without children'), None,
@@ -575,6 +532,13 @@ class AccessibleTreeView(gtk.TreeView, ToolsAccessor):
 
     self.connect('cursor-changed', self._onCursorChanged)
 
+  def _filterNoChildApps(self, model, iter, data):
+    '''
+    Filter all rows of applications without children
+    '''
+    return not self._hide_leaves or model.iter_parent(iter) != None \
+      or model[iter][COL_CHILDCOUNT] != 0 or self.isMyApp(model[iter][COL_ACC])
+
   def _onCursorChanged(self, tree):
     '''
     Set sensitivity of refresh function only if the tree cursor is 
@@ -651,20 +615,20 @@ class AccessibleTreeView(gtk.TreeView, ToolsAccessor):
     @type: gtk.Action
     '''
     path = self.get_cursor()[0]
-    if path == None: return
+    if path == None:
+      return
     is_expanded = self.row_expanded(path)
-    self._refreshChildren(self.model.get_iter(path))
+    self._refreshChildren(self.filter.convert_iter_to_child_iter(self.filter.get_iter(path)))
     if is_expanded:
       self.expand_row(path, False)
-      self._onExpanded(self, self.model.get_iter(path), path)
+      self._onExpanded(self, self.filter.get_iter(path), path)
 
   def _onHideShowLeaves(self, option):
     '''
     Hides/Shows all leaves (accessibles with no children) from the accessible treeview.
     '''
-
-    self.model._hideShowLeaves()
-    self._refreshTopLevel()
+    self._hide_leaves = not self._hide_leaves
+    self.filter.refilter()
 
   def _onExpanded(self, treeview, iter, path):
     '''
@@ -679,11 +643,10 @@ class AccessibleTreeView(gtk.TreeView, ToolsAccessor):
     @type path: tuple
     '''
     # don't repopulate if it has been filled before
-    if self.model[iter][COL_FILLED]:
+    if self.filter[iter][COL_FILLED]:
       return
-    acc = self.model[iter][COL_ACC]
     # populate this level
-    self.model.popLevel(iter)
+    self.model.popLevel(self.filter.convert_iter_to_child_iter(iter))
 
   def _accEventNameChanged(self, event):
     '''
@@ -731,24 +694,6 @@ class AccessibleTreeView(gtk.TreeView, ToolsAccessor):
       if iter and self.model.iter_is_valid(iter):
         self.model[iter][COL_CHILDCOUNT] = event.source.childCount
 
-  def removeLeaves(self, accessibles):
-    '''
-    Removes accessibles with no children (leaves) from a list
-    of accessibles. 
-
-    @param accessibles: List of accessibles to be examined
-    @type accessibles: list
-
-    @return: The accessibles list without leaves
-    @rtype: list
-    '''
-
-    nonleaves = []
-    for acc in accessibles:
-      if acc.childCount > 0:
-        nonleaves.append(acc)
-    return nonleaves
-
   def _addChild(self, iter, parent):
     '''
     Add the new child to the given accessible.
@@ -758,16 +703,8 @@ class AccessibleTreeView(gtk.TreeView, ToolsAccessor):
     @param parent: The given row's accessible.
     @type parent: L{Accessibility.Accessible}
     '''
-    old_children = self.model.getChildrenAccs(iter)
-    new_children = list(parent) 
-    if self.model.getHideLeaves():
-      # time for new child load its children (if it has any),
-      # so it won't be confused with a leaf
-      sleep(ACCESSIBLE_LOADING)
-      new_children = self.removeLeaves(new_children)
-
-    old_children = set(old_children)
-    new_children = set(new_children)
+    old_children = set(self.model.getChildrenAccs(iter))
+    new_children = set(list(parent))
 
     added = new_children.difference(old_children)
     try:
@@ -817,12 +754,14 @@ class AccessibleTreeView(gtk.TreeView, ToolsAccessor):
       if self.model[iter][COL_ACC] not in parent:
         cursor_path = self.get_cursor()[0]
         if cursor_path != None:
-          iter_path = self.model.get_path(iter)
-          if iter_path.is_ancestor(cursor_path):
-            cursor_path = iter_path
-          if 0 == iter_path.compare(cursor_path):
-            if iter_path.prev() or iter_path.up():
-              self.set_cursor(iter_path, None, False)
+          (res, filter_iter) = self.filter.convert_child_iter_to_iter(iter)
+          if res:
+            filter_path = self.filter.get_path(filter_iter)
+            if filter_path.is_ancestor(cursor_path):
+              cursor_path = filter_path
+            if 0 == filter_path.compare(cursor_path):
+              if filter_path.prev() or filter_path.up():
+                self.set_cursor(filter_path, None, False)
         if not self.model.remove(iter):
           break
       else:
@@ -982,8 +921,8 @@ class AccessibleTreeView(gtk.TreeView, ToolsAccessor):
     @param iter: The iter at the given row.
     @type iter: L{gtk.TreeIter}
     '''
-    if model.iter_is_valid(iter_id):
-      acc = model.get_value(iter_id, COL_ACC)
+    if self.model.iter_is_valid(iter_id):
+      acc = self.model.get_value(iter_id, COL_ACC)
     else:
       acc = None
     if self.isMyApp(acc):
@@ -1003,7 +942,7 @@ class AccessibleTreeView(gtk.TreeView, ToolsAccessor):
     '''
     path = tuple(tree_path.get_indices())
 
-    acc = self.model[path][COL_ACC]
+    acc = self.filter[path][COL_ACC]
     return not self.isMyApp(acc)
 
   def _onRowActivated(self, treeview, path, view_column):