gp_toolbox/OP_material_move_to_layer.py

import bpy
from bpy.types import Operator
import mathutils
from mathutils import Vector, Matrix, geometry
from bpy_extras import view3d_utils
from . import utils

# def get_layer_list(self, context):
#     '''return (identifier, name, description) of enum content'''
#     if not context:
#         return [('None', 'None','None')]
#     if not context.object:
#         return [('None', 'None','None')]
#     return [(l.name, l.name, '') for l in context.object.data.layers] #  if l != context.object.data.layers.active

## in Class
# bl_property = "layers_enum"

# layers_enum : bpy.props.EnumProperty(
#     name="Send Material To Layer",
#     description="Send active material to layer",
#     items=get_layer_list,
#     options={'HIDDEN'},
#     )

class GPTB_OT_move_material_to_layer(Operator) :
    bl_idname = "gp.move_material_to_layer"
    bl_label = 'Move Material To Layer'
    bl_description = 'Move active material to an existing or new layer'
    bl_options = {"REGISTER", "UNDO", "INTERNAL"}

    layer_name : bpy.props.StringProperty(
        name='Layer Name', default='', options={'SKIP_SAVE'})
    
    copy : bpy.props.BoolProperty(
        name='Copy to layer', default=False, 
        description='Copy strokes to layer instead of moving',
        options={'SKIP_SAVE'})

    @classmethod
    def poll(cls, context):
        return context.object and context.object.type == 'GREASEPENCIL'

    def invoke(self, context, event):
        if self.layer_name:
            return self.execute(context)
        if not len(context.object.data.layers):
            self.report({'WARNING'}, 'No layers on current GP object')
            return {'CANCELLED'}

        mat = context.object.data.materials[context.object.active_material_index]
        self.mat_name = mat.name

        # wm.invoke_search_popup(self)
        return context.window_manager.invoke_props_dialog(self, width=250)

    def draw(self, context):
        layout = self.layout
        # layout.operator_context = "INVOKE_DEFAULT"
        layout.prop(self, 'copy', text='Copy Strokes')
        action_label = 'Copy' if self.copy else 'Move'
        layout.label(text=f'{action_label} material "{self.mat_name}" to layer:', icon='MATERIAL')
        
        col = layout.column()
        col.prop(self, 'layer_name', text='', icon='ADD')
        # if self.layer_name:
        #     col.label(text='Ok/Enter to create new layer', icon='INFO')
        
        col.separator()
        for l in reversed(context.object.data.layers):

            icon = 'GREASEPENCIL' if l == context.object.data.layers.active else 'BLANK1'
            row = col.row()
            row.alignment = 'LEFT'
            op = col.operator('gp.move_material_to_layer', text=l.name, icon=icon, emboss=False)
            op.layer_name = l.name
            op.copy = self.copy

    def execute(self, context):
        if not self.layer_name:
            print('Out')
            return {'CANCELLED'}

        ## Active + selection
        pool = [o for o in bpy.context.selected_objects if o.type == 'GREASEPENCIL']
        if not context.object in pool:
            pool.append(context.object)

        mat = context.object.data.materials[context.object.active_material_index]

        print(f'Moving strokes using material "{mat.name}" on {len(pool)} object(s)')
        # import time
        # t = time.time() # Dbg
        total = 0
        oct = 0

        for ob in pool:
            mat_index = next((i for i, ms in enumerate(ob.material_slots) if ms.material and ms.material == mat), None)
            if mat_index is None:
                print(f'/!\ {ob.name} has no Material {mat.name} in stack')
                continue

            gpl = ob.data.layers
            
            if not (target_layer := gpl.get(self.layer_name)):
                target_layer = gpl.new(self.layer_name) 

            ## List existing frames
            key_dict = {f.frame_number : f for f in target_layer.frames}

            ### Move Strokes to a new key (or existing key if comming for yet another layer)
            fct = 0
            sct = 0
            for layer in gpl:
                if layer == target_layer:
                    ## ! infinite loop if target layer is included
                    continue
                for fr in layer.frames:
                    ## skip if no stroke has active material
                    if not next((s for s in fr.drawing.strokes if s.material_index == mat_index), None):
                        continue
                    ## Get/Create a destination frame and keep a reference to it
                    if not (dest_key := key_dict.get(fr.frame_number)):
                        dest_key = target_layer.frames.new(fr.frame_number)
                        key_dict[dest_key.frame_number] = dest_key

                    print(f'{ob.name} : frame {fr.frame_number}')
                    ## Replicate strokes in dest_keys
                    stroke_to_delete = []
                    for s_idx, s in enumerate(fr.drawing.strokes):
                        if s.material_index == mat_index:
                            utils.copy_stroke_to_frame(s, dest_key)
                            stroke_to_delete.append(s_idx)

                        ## Debug
                        # if time.time() - t > 10:
                        #     print('TIMEOUT')
                        #     return {'CANCELLED'}

                    sct += len(stroke_to_delete)

                    ## Remove from source frame (fr)
                    if not self.copy:
                        # print('Removing frames') # Dbg
                        if stroke_to_delete:
                            fr.drawing.remove_strokes(indices=stroke_to_delete)

                    ## ? Remove frame if layer is empty ? -> probably not, otherwise will show previous frame
                    
                    fct += 1

        
            if fct:
                oct += 1
                print(f'{ob.name}: Moved {fct} frames -> {sct} Strokes') # Dbg
            
            total += fct
                
        report_type = 'INFO' if total else 'WARNING'
        if self.copy:
            self.report({report_type}, f'Copied {total} frames accross {oct} object(s)')
        else:
            self.report({report_type}, f'Moved {total} frames accross {oct} object(s)')
        return {'FINISHED'}


# def menu_duplicate_and_send_to_layer(self, context):
#     if context.space_data.ui_mode == 'GPENCIL':
#         self.layout.operator_context = 'INVOKE_REGION_WIN'
#         self.layout.operator('gp.duplicate_send_to_layer', text='Move Keys To Layer').delete_source = True
#         self.layout.operator('gp.duplicate_send_to_layer', text='Copy Keys To Layer')

classes = (
GPTB_OT_move_material_to_layer,
)

def register():
    for cls in classes:
        bpy.utils.register_class(cls)

def unregister():
    for cls in reversed(classes):
        bpy.utils.unregister_class(cls)