make popup windows dynamic

[schlegelp]

Show additional options only upon changing dropdown/ticking a box. See this example using check():

import bpy


def main(context):
    for ob in context.scene.objects:
        print(ob)
        
class SimplePanel(bpy.types.Panel):
    """Creates Import Menu in Properties -> Scene """
    bl_label = "Test"
    bl_space_type = "PROPERTIES"
    bl_region_type = "WINDOW"
    bl_context = "scene"

    def draw(self, context):
        layout = self.layout
        
        row = layout.row(align=True)
        row.alignment = 'EXPAND'
        row.operator("object.simple_operator", text = "Run", icon ='VISIBLE_IPO_ON')

class SimpleOperator(bpy.types.Operator):
    """Tooltip"""
    bl_idname = "object.simple_operator"
    bl_label = "Simple Object Operator"
    bl_options = {'REGISTER', 'UNDO'}

    val1 = bpy.props.BoolProperty()
    val2 = bpy.props.BoolProperty()
    val3 = bpy.props.BoolProperty()

    @classmethod
    def poll(cls, context):
        """If this returns False, operator is greyed-out."""
        return context.selected_objects != []
    
    def check(self, context):
        """While this returns True, draw() is called continuously."""
        return True

    def execute(self, context):
        main(context)
        return {'FINISHED'}
    
    def draw(self, context):
        layout = self.layout
        layout.prop(self, "val1")
        
        if self.val1:
            box = layout.box()
            box.prop(self, "val2")
            box.prop(self, "val3")
            
    def invoke(self, context, event):
        return context.window_manager.invoke_props_dialog(self, width = 800)


def register():
    bpy.utils.register_class(SimpleOperator)
    bpy.utils.register_class(SimplePanel)


def unregister():
    bpy.utils.unregister_class(SimpleOperator)
    bpy.utils.unregister_class(SimplePanel)


if __name__ == "__main__":
    register()