Change back ground colour when animation is playing

Question

Blender 3.6.7LTS

When I trigger play animation I would like a script to change the background to a reddish colour To indicate that the animation is playing and when I stop the animation player it defaults to it's original colour.

I tried to chat GTP this, but to no avail.

My basic logic was

1. Deafult = bpy.context.space_data.shading.background_type = 'THEME'

2. When animation is playing change bpy.context.space_data.shading.background_type = 'VIEWPORT' and make it's colour bpy.context.space_data.shading.background_color = (0.0169089, 0.00796443, 0.00961567)

3. When animation player has stopped, revert back to default.

Chat GTP can do the first 50%, it's fails knowing when the animation player has stopped, or my instructions are terrible.

I want this because sometimes the animation is playing in the background by mistake and it'll crunch my computer if I'm in weight mapping etc.

Answer 1

UPDATE

version for Blender 3.6.7

bl_info = {
    "name": "Active Background",
    "author": "Blender.Fun",
    "version": (0, 1),
    "blender": (2, 80, 0),
    "location": "View3D",
    "description": "Changes background when animation is playing.",
    "warning": "",
    "doc_url": "",
    "category": "Themes",
}

import bpy



def start(scene):
    bpy.context.preferences.themes[0].view_3d.space.gradients.high_gradient = (1.0, 0.0, 0.0)
    
def stop(scene):
    bpy.context.preferences.themes[0].view_3d.space.gradients.high_gradient = (0.2, 0.2, 0.2)
    
    
   
def register(): 
    bpy.app.handlers.animation_playback_post.append(stop)
    bpy.app.handlers.animation_playback_pre.append(start)

    
def unregister():
    bpy.app.handlers.animation_playback_post.remove(stop)
    bpy.app.handlers.animation_playback_pre.remove(start)
 
if __name__ == "__main__":
    register()

---

works for Blender 4.20:

insert this into your text editor:

bl_info = {
    "name": "Active Background",
    "author": "Blender.Fun",
    "version": (0, 1),
    "blender": (2, 80, 0),
    "location": "View3D",
    "description": "Changes background when animation is playing.",
    "warning": "",
    "doc_url": "",
    "category": "Themes",
}

import bpy



def my_handler(scene):
    
    print("is in handler")
    
    if bpy.context.screen.is_animation_playing:
        bpy.context.preferences.themes[0].view_3d.space.gradients.high_gradient = (1.0, 0.0, 0.0)
    else:
        bpy.context.preferences.themes[0].view_3d.space.gradients.high_gradient = (0.2, 0.2, 0.2)
    
    
def register(): 
    bpy.app.handlers.animation_playback_post.append(my_handler)
    bpy.app.handlers.animation_playback_pre.append(my_handler)

    
def unregister():
    bpy.app.handlers.animation_playback_post.remove(my_handler)
    bpy.app.handlers.animation_playback_pre.remove(my_handler)
 
if __name__ == "__main__":
    register()

Run the script.

Enjoy :)