How to get mouse position in a window with Python?

Question

I want to detect if the mouse is in certain area of the 3d View, so I can display a custom menu when it will be in the left top corner, over the view name ("User Persp" etc).

Answer 1

Here is a script from the blender wiki.

Go to the Invoke versus execute section for finding this code:

#----------------------------------------------------------
# File invoke.py
# from API documentation
#----------------------------------------------------------
 
import bpy
 
class SimpleMouseOperator(bpy.types.Operator):
    """ This operator shows the mouse location,
        this string is used for the tooltip and API docs
    """
    bl_idname = "wm.mouse_position"
    bl_label = "Mouse location"
 
    x: bpy.props.IntProperty()
    y: bpy.props.IntProperty()
 
    def execute(self, context):
        # rather then printing, use the report function,
        # this way the message appears in the header,
        self.report({'INFO'}, "Mouse coords are %d %d" % (self.x, self.y))
        return {'FINISHED'}
 
    def invoke(self, context, event):
        self.x = event.mouse_x
        self.y = event.mouse_y
        return self.execute(context)
 
#
#    Panel in tools region
#
class MousePanel(bpy.types.Panel):
    bl_label = "Mouse"
    bl_space_type = "VIEW_3D"
    bl_region_type = "TOOL_PROPS"
 
    def draw(self, context):
        self.layout.operator("wm.mouse_position")
 
#
#   Registration
#   Not really necessary to register the class, because this happens
#   automatically when the module is registered. OTOH, it does not hurt either.
bpy.utils.register_class(SimpleMouseOperator)
bpy.utils.register_module(__name__)
 
# Automatically display mouse position on startup
bpy.ops.wm.mouse_position('INVOKE_DEFAULT')
 
# Another test call, this time call execute() directly with pre-defined settings.
#bpy.ops.wm.mouse_position('EXEC_DEFAULT', x=20, y=66)

Now if you want to know the position of your 3D view, I made a quick research. With this you can find the area of your 3D View:

import bpy

for area in bpy.context.screen.areas:
    if area.type=='VIEW_3D':
        X= area.x
        Y= area.y
        WIDTH=area.width
        HEIGHT=area.height
        
        print(X,Y,WIDTH,HEIGHT)

Answer 2

You get the area and the region from the context argument (passed to the invoke / execute / poll method of the operator).

Use the operator's poll method to check for the right context. I.e:

@classmethod
def poll(cls, context):
    return context.area.type   == 'VIEW_3D' and \
           context.region.type == 'WINDOW'

Just want to add:

• The event class also provides the attributes mouse_region_x and mouse_region_y

• The view2d class provides methods to convert mouse coordinates from region coordinates to view coordinates

• The bpy_extras.view3d_utils module provides methods to deal with 3d-coordinates