47 lines
1.1 KiB
Python
47 lines
1.1 KiB
Python
"""
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The message bus system can be used to receive notifications when properties of
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Blender datablocks are changed via the data API.
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Limitations
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-----------
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The message bus system is triggered by updates via the RNA system. This means
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that the following updates will result in a notification on the message bus:
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- Changes via the Python API, for example ``some_object.location.x += 3``.
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- Changes via the sliders, fields, and buttons in the user interface.
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The following updates do **not** trigger message bus notifications:
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- Moving objects in the 3D Viewport.
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- Changes performed by the animation system.
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Example Use
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-----------
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Below is an example of subscription to changes in the active object's location.
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"""
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import bpy
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# Any Python object can act as the subscription's owner.
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owner = object()
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subscribe_to = bpy.context.object.location
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def msgbus_callback(*args):
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# This will print:
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# Something changed! (1, 2, 3)
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print("Something changed!", args)
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bpy.msgbus.subscribe_rna(
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key=subscribe_to,
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owner=owner,
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args=(1, 2, 3),
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notify=msgbus_callback,
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)
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