Fix undo history (#137)

Fixed undo bug by clearing all undo history after mode change
#12

Author: james-baber

ue2rigify/addon/__init__.py

@@ -14,7 +14,7 @@
     "author": "Epic Games Inc.",
     "description": "Allows you to convert a given rig and its animations to a Rigify rig.",
     "blender": (2, 83, 0),
-    "version": (1, 3, 10),
+    "version": (1, 3, 11),
     "location": "3D View > Tools > UE to Rigify",
     "wiki_url": "https://github.com/EpicGames/BlenderTools/wiki/UE-to-Rigify-Home",
     "warning": "",
@@ -56,6 +56,7 @@
     operators.ConstrainSourceToDeform,
     operators.RemoveConstraints,
     operators.SwitchModes,
+    operators.NullOperator,
     addon_preferences.Ue2RigifyAddonPreferences,
     view_3d.UE_RIGIFY_PT_RigTemplatePanel
 )
@@ -82,9 +83,6 @@ def register():
     bpy.app.handlers.load_post.append(utilities.load_properties)
     bpy.app.handlers.save_pre.append(utilities.save_properties)
 
-    # add an event handler that loads the saved scene properties after an undo
-    bpy.app.handlers.undo_post.append(utilities.undo)
-
 
 def unregister():
     """
@@ -97,7 +95,6 @@ def unregister():
     # remove event handlers
     bpy.app.handlers.load_post.remove(utilities.load_properties)
     bpy.app.handlers.save_pre.remove(utilities.save_properties)
-    bpy.app.handlers.undo_post.remove(utilities.undo)
 
     # remove the added system path
     sys.path.pop(0)

ue2rigify/addon/functions/scene.py

@@ -1323,6 +1323,7 @@ def switch_modes(self=None, context=None):
 
     # if the rig is not frozen run the following operations
     if not properties.freeze_rig:
+
         # save the metarig
         save_meta_rig(properties)
 
@@ -1353,5 +1354,8 @@ def switch_modes(self=None, context=None):
         if properties.selected_mode == properties.control_mode:
             convert_to_control_rig(properties)
 
+        # record this mode change in the history
+        utilities.clear_undo_history()
+
         # restore the context
         utilities.load_context(properties)

ue2rigify/addon/functions/utilities.py

@@ -7,6 +7,20 @@
 pie_menu_classes = []
 
 
+def get_modes():
+    """
+    This function gets all the ue2rigify modes
+    """
+    properties = bpy.context.window_manager.ue2rigify
+    return [
+        properties.source_mode,
+        properties.metarig_mode,
+        properties.fk_to_source_mode,
+        properties.source_to_deform_mode,
+        properties.control_mode
+    ]
+
+
 def get_picker_object():
     """
     This function gets or creates a new picker object if needed.
@@ -694,7 +708,7 @@ def save_properties(*args):
 
     # assign all the addon property values to the scene property values
     for attribute in dir(window_manager_properties):
-        if not attribute.startswith(('__', 'bl_', 'rna_type', 'group')):
+        if not attribute.startswith(('__', 'bl_', 'rna_type', 'group', 'idp_array')):
             value = getattr(window_manager_properties, attribute)
             try:
                 scene_properties[attribute] = value
@@ -763,22 +777,18 @@ def load_properties(*args):
                 setattr(window_manager_properties, attribute, scene_value)
 
 
-@bpy.app.handlers.persistent
-def undo(*args):
+def clear_undo_history():
     """
-    This function sets the selected mode back to the previous mode on an undo.
-
-    :param args: This soaks up the extra arguments for the app handler.
+    This function clears blenders undo history by doing a deselect all operation and repeatedly
+    pushing that operation into the undo stack until all previous history is cleared from the undo
+    history.
     """
-    properties = bpy.context.window_manager.ue2rigify
-    scene_properties = bpy.context.scene.ue2rigify
-
-    if bpy.context.space_data.type == 'VIEW_3D' and properties.selected_mode != properties.source_mode:
-        # load the scene properties
-        load_properties()
+    # run this null operator
+    bpy.ops.ue2rigify.null_operator()
 
-        # set the selected mode to the previous mode
-        properties.selected_mode = scene_properties['previous_mode']
+    # repeatedly push the last operator into the undo stack till there are no more undo steps
+    for item in range(0, bpy.context.preferences.edit.undo_steps+1):
+        bpy.ops.ed.undo_push(message='UE to Rigify Mode Change')
 
 
 def get_formatted_operator_parameter(parameter_name, regex, code_line):

ue2rigify/addon/operators.py

@@ -2,6 +2,7 @@
 
 import bpy
 from .ui import exporter
+from .functions import undo
 from .functions import scene
 from .functions import nodes
 from .functions import templates
@@ -279,3 +280,12 @@ def execute(self, context):
         scene.switch_modes()
         return {'FINISHED'}
 
+
+class NullOperator(bpy.types.Operator):
+    """This is an operator that changes nothing, but it used to clear the undo stack"""
+    bl_idname = "ue2rigify.null_operator"
+    bl_label = "Null Operator"
+
+    def execute(self, context):
+        return {'FINISHED'}
+