window_manager.progress doesn't work after .invoke + wm.read_homefile #113051

New Issue

Andrej · 2023-09-29T11:53:13+02:00

Andrej commented

2023-09-29 11:53:13 +02:00

Blender 3.6.3

The usecase for this was

User selects file they want to import
We reset context and the entire session by using bpy.ops.wm.read_homefile because imported file is some other separate format, not .blend
After bpy.ops.wm.read_homefile we're starting to import actual file and do stuff in new session.
Since 3rd step is time consuming there was some progress indication implemented with bpy.context.window_manager.progress_begin, bpy.context.window_manager.progress_update, bpy.context.window_manager.progress_end.
The issue is that progress doesn't seem to work in this case and it doesn't add display progress percent at the user's cursor (below is an example how it usually displays it).

Steps to reproduce the issue.

Run the code below in default blender session.
Go to modifiers and try to run "test with handler" or "test w/o" handler.
Select some other file in the system, it doesn't matter which.
There will be 3 seconds loading during which you won't be able see the progress value on the cursor which is the issue.
In real life example of this code since wm.read_homefile purges the context, I use load_handler the way described here. But this issue is unrelated to handlers as you can see running both buttons on step 2.
Comment out the entire operator's invoke method so it would go straight to .execute() and the issue is gone. So issue seems to be related to operator's invoke or operator running modal.

import bpy
import os
from time import sleep
from bpy.app.handlers import persistent

class TestOperator(bpy.types.Operator):
    bl_idname = "object.test_operator"
    bl_label = "Test Operator"
    bl_options = {"REGISTER", "UNDO"}

    use_handler: bpy.props.BoolProperty()

    def do_stuff(self):
        bpy.context.window_manager.progress_begin(0, 100)
        steps = 3
        for i in range(steps):
            bpy.context.window_manager.progress_update(int(i/steps*100))
            sleep(1)
        bpy.context.window_manager.progress_end()

    def execute(self, context):
        @persistent
        def load_handler(*args):
            bpy.app.handlers.load_post.remove(load_handler)
            # do stuff after default file was opened
            self.do_stuff()

        if self.use_handler:
            bpy.app.handlers.load_post.append(load_handler)
            bpy.ops.wm.read_homefile()
        else:
            bpy.ops.wm.read_homefile()
            self.do_stuff()
        return {"FINISHED"}
    
    def invoke(self, context, event):
        context.window_manager.fileselect_add(self)
        return {"RUNNING_MODAL"}


class ExampleModifierPanel(bpy.types.Panel):
    bl_label = "Example Modifier"
    bl_idname = "OBJECT_PT_example_modifier"
    bl_space_type = 'PROPERTIES'
    bl_region_type = 'WINDOW'
    bl_context = "modifier"

    def draw(self, context):
        layout = self.layout
        box = layout.box()
        box.operator("object.test_operator", text="test with handler").use_handler = True
        box.operator("object.test_operator", text="test w/o handler").use_handler = False

def register():
    bpy.utils.register_class(ExampleModifierPanel)
    bpy.utils.register_class(TestOperator)

def unregister():
    bpy.utils.unregister_class(ExampleModifierPanel)
    bpy.utils.unregister_class(TestOperator)


if __name__ == "__main__":
    register()

Blender 3.6.3 The usecase for this was 1) User selects file they want to import 2) We reset context and the entire session by using `bpy.ops.wm.read_homefile` because imported file is some other separate format, not .blend 3) After `bpy.ops.wm.read_homefile` we're starting to import actual file and do stuff in new session. 4) Since 3rd step is time consuming there was some progress indication implemented with `bpy.context.window_manager.progress_begin`, `bpy.context.window_manager.progress_update`, `bpy.context.window_manager.progress_end`. The issue is that progress doesn't seem to work in this case and it doesn't add display progress percent at the user's cursor (below is an example how it usually displays it). ![image](/attachments/443566ea-2f47-4ff5-ab49-41186135eb5f) Steps to reproduce the issue. 1. Run the code below in default blender session. 2. Go to modifiers and try to run "test with handler" or "test w/o" handler. 3. Select some other file in the system, it doesn't matter which. 4. There will be 3 seconds loading during which you won't be able see the progress value on the cursor which is the issue. 5. In real life example of this code since `wm.read_homefile` purges the context, I use `load_handler` the way described [here](https://blender.stackexchange.com/questions/51494/how-to-bring-the-context-back-after-running-read-homefile/). But this issue is unrelated to handlers as you can see running both buttons on step 2. 6. Comment out the entire operator's `invoke` method so it would go straight to `.execute()` and the issue is gone. So issue seems to be related to operator's invoke or operator running modal. ```python import bpy import os from time import sleep from bpy.app.handlers import persistent class TestOperator(bpy.types.Operator): bl_idname = "object.test_operator" bl_label = "Test Operator" bl_options = {"REGISTER", "UNDO"} use_handler: bpy.props.BoolProperty() def do_stuff(self): bpy.context.window_manager.progress_begin(0, 100) steps = 3 for i in range(steps): bpy.context.window_manager.progress_update(int(i/steps*100)) sleep(1) bpy.context.window_manager.progress_end() def execute(self, context): @persistent def load_handler(*args): bpy.app.handlers.load_post.remove(load_handler) # do stuff after default file was opened self.do_stuff() if self.use_handler: bpy.app.handlers.load_post.append(load_handler) bpy.ops.wm.read_homefile() else: bpy.ops.wm.read_homefile() self.do_stuff() return {"FINISHED"} def invoke(self, context, event): context.window_manager.fileselect_add(self) return {"RUNNING_MODAL"} class ExampleModifierPanel(bpy.types.Panel): bl_label = "Example Modifier" bl_idname = "OBJECT_PT_example_modifier" bl_space_type = 'PROPERTIES' bl_region_type = 'WINDOW' bl_context = "modifier" def draw(self, context): layout = self.layout box = layout.box() box.operator("object.test_operator", text="test with handler").use_handler = True box.operator("object.test_operator", text="test w/o handler").use_handler = False def register(): bpy.utils.register_class(ExampleModifierPanel) bpy.utils.register_class(TestOperator) def unregister(): bpy.utils.unregister_class(ExampleModifierPanel) bpy.utils.unregister_class(TestOperator) if __name__ == "__main__": register() ```

image.png

20 KiB

Andrej added the

labels 2023-09-29 11:53:13 +02:00

Andrej commented

2023-09-29 12:12:19 +02:00

And perhaps a bit similar issue - window_manager.progress also doesn't work if you start it from --python-expr. Which would also useful since I've associated some file format with Blender python expression and progress would indiciate the loading progress. I guess other usecase for this is starting render from command line and being able to see it's progress.

It can reproduced with this rather hacky example (usually you would just call operator that does that under the hood).

blender --python-expr "import bpy; from time import sleep; bpy.context.window_manager.progress_begin(0, 100); steps = 10; list(map(lambda i: (bpy.context.window_manager.progress_update(int(i/steps*100)), sleep(1)), range(steps))); bpy.context.window_manager.progress_end();"

And perhaps a bit similar issue - `window_manager.progress` also doesn't work if you start it from `--python-expr`. Which would also useful since I've associated some file format with Blender python expression and `progress` would indiciate the loading progress. I guess other usecase for this is starting render from command line and being able to see it's progress. It can reproduced with this rather hacky example (usually you would just call operator that does that under the hood). ``` blender --python-expr "import bpy; from time import sleep; bpy.context.window_manager.progress_begin(0, 100); steps = 10; list(map(lambda i: (bpy.context.window_manager.progress_update(int(i/steps*100)), sleep(1)), range(steps))); bpy.context.window_manager.progress_end();" ```

Germano Cavalcante commented

2023-10-02 18:35:13 +02:00

The progress cursor display is fragile as it depends on winactive which can become nullptr during an operator when any changes to the windows are made. When winactive is nullptr, the progress cursor is not displayed.

See the comment at:
https://projects.blender.org/blender/blender/blame/src/main/source/blender/makesdna/DNA_windowmanager_types.h#L130-L135

Also see https://projects.blender.org/blender/blender/src/branch/main/source/blender/makesrna/intern/rna_wm_api.cc#L191-L192

Perhaps this could be resolved/improved if we used context.window instead, but this code is old and would need to be carefully reviewed.

The progress cursor display is fragile as it depends on `winactive` which can become `nullptr` during an operator when any changes to the windows are made. When `winactive` is `nullptr`, the progress cursor is not displayed. See the comment at: https://projects.blender.org/blender/blender/blame/src/main/source/blender/makesdna/DNA_windowmanager_types.h#L130-L135 Also see https://projects.blender.org/blender/blender/src/branch/main/source/blender/makesrna/intern/rna_wm_api.cc#L191-L192 Perhaps this could be resolved/improved if we used `context.window` instead, but this code is old and would need to be carefully reviewed.

Germano Cavalcante added

and removed

labels 2023-10-02 18:35:40 +02:00

Andrej commented

2023-10-02 18:48:39 +02:00

The progress cursor display is fragile as it depends on winactive which can become nullptr during an operator when any changes to the windows are made. When winactive is nullptr, the progress cursor is not displayed.

See the comment at:
https://projects.blender.org/blender/blender/blame/src/main/source/blender/makesdna/DNA_windowmanager_types.h#L130-L135

Also see https://projects.blender.org/blender/blender/src/branch/main/source/blender/makesrna/intern/rna_wm_api.cc#L191-L192

Perhaps this could be resolved/improved if we used context.window instead, but this code is old and would need to be carefully reviewed.

@mano-wii Is there some way to update winactive manually from the python code? Thought that perhaps screen update can help (bpy.ops.wm.redraw_timer(type="DRAW_WIN_SWAP", iterations=1)) but it didn't worked

> The progress cursor display is fragile as it depends on `winactive` which can become `nullptr` during an operator when any changes to the windows are made. When `winactive` is `nullptr`, the progress cursor is not displayed. > > See the comment at: > https://projects.blender.org/blender/blender/blame/src/main/source/blender/makesdna/DNA_windowmanager_types.h#L130-L135 > > Also see https://projects.blender.org/blender/blender/src/branch/main/source/blender/makesrna/intern/rna_wm_api.cc#L191-L192 > > Perhaps this could be resolved/improved if we used `context.window` instead, but this code is old and would need to be carefully reviewed. @mano-wii Is there some way to update `winactive` manually from the python code? Thought that perhaps screen update can help (`bpy.ops.wm.redraw_timer(type="DRAW_WIN_SWAP", iterations=1)`) but it didn't worked

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window_manager.progress doesn't work after .invoke + wm.read_homefile #113051

`window_manager.progress` doesn't work after `.invoke` + `wm.read_homefile` #113051