gp_interpolate/ui.py

import bpy

class GP_PT_interpolate(bpy.types.Panel):
    bl_label = "Interpolate"
    bl_category = "Gpencil"
    bl_space_type = 'VIEW_3D'
    bl_region_type = 'UI'

    # @classmethod
    # def poll(cls, context):
    #     return context.object

    def draw(self, context):
        settings = bpy.context.scene.gp_interpo_settings

        layout = self.layout
        layout.use_property_split = True
        col = layout.column(align=False)

        ## Interpolation buttons
        if settings.mode == 'FRAME':
            prev_icon, next_icon = 'FRAME_PREV', 'FRAME_NEXT'
        else:
            prev_icon, next_icon = 'PREV_KEYFRAME', 'NEXT_KEYFRAME'

        prev_text = next_text = ''
        scn = context.scene
        if settings.use_animation:
            prev_icon, next_icon = 'PLAY_REVERSE', 'PLAY'
            ## Show animation range:
            prev_text = f'{scn.frame_preview_start if scn.use_preview_range else scn.frame_start} < {scn.frame_current}'
            next_text = f'{scn.frame_current} > {scn.frame_preview_end if scn.use_preview_range else scn.frame_end}'


        row = col.row(align=True)
        row.scale_x = 3
        row.operator("gp.interpolate_stroke", text=prev_text, icon=prev_icon).next = False
        row.operator("gp.interpolate_stroke", text=next_text, icon=next_icon).next = True

        col.prop(settings, 'use_animation', text='Animation')
        col.prop(settings, 'method', text='Method')

        if settings.method == 'BONE':
            col = layout.column(align=True)
            col.prop_search(settings, 'target_rig', context.scene, 'objects', text='Rig')
            if settings.target_rig:
                # col.prop_search(ob.rig_picker, 'name', settings.target_rig.pose, 'bones', text='Bone')
                col.prop_search(settings, 'target_bone', settings.target_rig.pose, 'bones', text='Bone')
                col.prop(settings, 'use_bone_rotation', text='Use Bone Rotation')

        elif settings.method == 'GEOMETRY':
            col.prop(settings, 'search_range')
            col.prop(settings, 'remove_occluded')
        
        elif settings.method == 'OBJECT':
            col.prop(settings, 'target_object', text='Object')

        col.separator()
        col = layout.column(align=True)
        row = col.row(align=True)
        row.prop(settings, 'mode', expand=True)

        if settings.mode == 'FRAME':
            col.prop(settings, 'padding')

        if settings.mode == 'RIGKEY':
            col.prop(settings, 'target_collection', text='Collection')
        ## Parent still full WIP
        # col = layout.column()
        # col.label(text='Layer Parent')
        # col.operator('gp.parent_layer', text='Direct Parent').direct_parent = True
        # col.operator('gp.parent_layer', text='Empty Parent').direct_parent = False

        if context.scene.gp_interpo_settings.method in ('GEOMETRY', 'OBJECT'):
            col.separator()
            row = col.row(align=True)
            row.operator('gp.debug_geometry_interpolation_targets', text='Debug points')
            row.operator('gp.debug_geometry_interpolation_targets', text='', icon='X').clear = True

classes = (
    GP_PT_interpolate,
)

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

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