Adding a new operator to an existing (built-in) panel

Technical Support Python Support
1

Hi,
I am interested in adding a new opperator to the Background Images Panel in the View3d Properties area. Is it possible to do this with an add-in? I know that I can do it by editing the relivant python code already in the Blender release, but I would prefer to have my add-in modify that panel so that I can keep all of the code together rather than tweeking stuff in the .py files that are part of the blender release.

Cheers,

Marphia

2

Hi

you can append / prepend to the draw method of the existing panel. Get its class using “view_source” when you right click on prop in that panel. For background images Panel


import bpy


def extra_button(self, context):
    layout = self.layout
    layout.operator('some.operator')  # change this to a real operator.
    
    
bpy.types.VIEW3D_PT_background_image.append(extra_button)

Another method I like is to override the draw method.

Here I display my own custom draw for the 3dview header, when some condition is met, otherwise display the default.


import bpy
from bl_ui.space_view3d import VIEW3D_HT_header as ov3d


f = ov3d.draw


def preview_view_draw(self, context):
    if some_condition:
        custom_draw(self, context)
    else:
      # revert to default
       f(self, context)

def register():
    bpy.types.VIEW3D_HT_header.draw = preview_view_draw 


def unregister():
    bpy.types.VIEW3D_HT_header.draw = ov3d.draw
3

Thanks for that. Method 1 will do exactly what I am after. I will also keep the overide option in mind for future.