context.scene not updated when context.screen.scene changed in an operator called from a panel. #41486

New Issue

hudson barkley · 2014-08-19T02:46:11+02:00

hudson barkley commented

2014-08-19 02:46:11 +02:00

System Information
Windows 7 64bit

Blender Version
Broken: 2.71
Worked: 2.70

Short description of error
In a python script, if a panel calls an operator, and that operator changes the scene by setting 'bpy.context.screen.scene', bpy.context.scene is not updated. This causes operators to run on the previous scene.

Exact steps for others to reproduce the error
The following script is as simple as I could make it, also see http://www.pasteall.org/53521/python
(sorry, couldn't get attached files to work)

import bpy
 
class TestPanel(bpy.types.Panel):
    bl_label = "Test Panel"
    bl_space_type = 'PROPERTIES'
    bl_region_type = 'WINDOW'
    bl_context = "scene"
    def draw(self, context):
        layout = self.layout
        row = layout.row()
        row.operator('test.operator')
 
class TestOperator(bpy.types.Operator):
    bl_label = "Test Operator"
    bl_idname = 'test.operator'
    def execute(self, context):
        scene = bpy.data.scenes.new('test')
        bpy.context.screen.scene = scene
        print(bpy.context.scene)
        return{'FINISHED'}
         
def register():
    bpy.utils.register_module(__name__)
     
if __name__ == "__main__":
    register()

**System Information** Windows 7 64bit **Blender Version** Broken: 2.71 Worked: 2.70 **Short description of error** In a python script, if a panel calls an operator, and that operator changes the scene by setting 'bpy.context.screen.scene', bpy.context.scene is not updated. This causes operators to run on the previous scene. **Exact steps for others to reproduce the error** The following script is as simple as I could make it, also see http://www.pasteall.org/53521/python (sorry, couldn't get attached files to work) import bpy class TestPanel(bpy.types.Panel): bl_label = "Test Panel" bl_space_type = 'PROPERTIES' bl_region_type = 'WINDOW' bl_context = "scene" def draw(self, context): layout = self.layout row = layout.row() row.operator('test.operator') class TestOperator(bpy.types.Operator): bl_label = "Test Operator" bl_idname = 'test.operator' def execute(self, context): scene = bpy.data.scenes.new('test') bpy.context.screen.scene = scene print(bpy.context.scene) return{'FINISHED'} def register(): bpy.utils.register_module(__name__) if __name__ == "__main__": register()

hudson barkley commented

2014-08-19 02:46:11 +02:00

Changed status to: 'Open'

hudson barkley commented

2014-08-19 02:46:11 +02:00

Added subscriber: @snuq

Campbell Barton commented

2014-08-19 07:03:58 +02:00

Changed status from 'Open' to: 'Archived'

Campbell Barton closed this issue

2014-08-19 07:03:58 +02:00

Campbell Barton self-assigned this 2014-08-19 07:03:58 +02:00

Campbell Barton commented

2014-08-19 07:03:58 +02:00

This is a quirk of how the API works, switching the scene is handled by a notifier, so the result isn't available immediately. Realize this can be problematic.

We could add some way for Python to handle notifiers while the script runs. (wrap wm_event_do_notifiers, eg context.window_manager.handle_notifiers()) .

But this is more an API limit then a bug.

This is a quirk of how the API works, switching the scene is handled by a notifier, so the result isn't available immediately. Realize this can be problematic. We could add some way for Python to handle notifiers while the script runs. (wrap `wm_event_do_notifiers`, eg `context.window_manager.handle_notifiers()`) . But this is more an API limit then a bug.

hudson barkley commented

2014-08-19 08:21:32 +02:00

If it's an api limitation, why did it work in 2.70? Also if that same operator is called from the console, it behaves as expected, it's only doing this when called from a panel

Campbell Barton commented

2015-07-28 07:22:18 +02:00

Update, this example can be made to work by adding row.operator_context = 'INVOKE_SCREEN' before row.operator('test.operator')

This works because using INVOKE_SCREEN bypasses the buttons context which is default for panels, The buttons context doesn't get updated when assigning a variable to the screen. But the screen context does.

Update, this example can be made to work by adding `row.operator_context = 'INVOKE_SCREEN'` before `row.operator('test.operator')` This works because using `INVOKE_SCREEN` bypasses the `buttons` context which is default for panels, The buttons context doesn't get updated when assigning a variable to the screen. But the screen context does.

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context.scene not updated when context.screen.scene changed in an operator called from a panel. #41486