display_image.py

# SPDX-License-Identifier: GPL-2.0-or-later
"""
Display Active Image Node on Image Editor

When selecting an Image node, it will show it on the Image editor (if
there is any available). If you don't like this behavior, you can
disable it from the Amaranth Toolset panel on the Scene properties.
Coded by the awesome Sergey Sharybin. This feature only works on Blender
2.68 and newer. Select an Image Node in the Compositor or Cycles nodes
editor, there must be at least one image editor available.
"""

import bpy


KEYMAPS = list()

image_nodes = ("CompositorNodeRLayers",
               "CompositorNodeImage",
               "CompositorNodeViewer",
               "CompositorNodeComposite",
               "ShaderNodeTexImage",
               "ShaderNodeTexEnvironment",
               "GeometryNodeImageTexture")


class AMTH_NODE_OT_show_active_node_image(bpy.types.Operator):
    """Show active image node image in the image editor"""
    bl_idname = "node.show_active_node_image"
    bl_label = "Preview Image from Node"
    bl_options = {"UNDO"}

    @classmethod
    def poll(cls, context):
        return context.space_data == 'NODE_EDITOR' and context.active_node is not None

    def execute(self, context):
        return {'FINISHED'}

    def invoke(self, context, event):
        mlocx = event.mouse_region_x
        mlocy = event.mouse_region_y
        select_node = bpy.ops.node.select(location=(mlocx, mlocy), extend=False)

        if 'FINISHED' in select_node:  # Only run if we're clicking on a node
            get_addon = "amaranth" in context.preferences.addons.keys()
            if not get_addon:
                return {"CANCELLED"}

            preferences = context.preferences.addons["amaranth"].preferences
            if preferences.use_image_node_display:
                if context.active_node:
                    active_node = context.active_node

                    if active_node.bl_idname in image_nodes:
                        # Use largest image editor
                        area = None
                        area_size = 0
                        for a in context.screen.areas:
                            if a.type == "IMAGE_EDITOR":
                                size = a.width * a.height
                                if size > area_size:
                                    area_size = size
                                    area = a
                        if area:
                            for space in area.spaces:
                                if space.type == "IMAGE_EDITOR":
                                    if active_node.bl_idname == "CompositorNodeViewer":
                                        space.image = bpy.data.images[
                                            "Viewer Node"]
                                    elif active_node.bl_idname in ["CompositorNodeComposite", "CompositorNodeRLayers"]:
                                        space.image = bpy.data.images[
                                            "Render Result"]
                                    elif active_node.bl_idname == "GeometryNodeImageTexture":
                                        if active_node.inputs['Image'].is_linked:
                                            self.report({'INFO'}, "Previewing linked sockets is not supported yet")
                                            break
                                        if active_node.inputs['Image'].default_value:
                                            space.image = active_node.inputs['Image'].default_value
                                    elif active_node.image:
                                        space.image = active_node.image
                                    else:
                                        self.report({'INFO'}, "No image detected")
                                        break
                                break
                        else:
                            return {'CANCELLED'}

            return {"FINISHED"}
        else:
            return {"PASS_THROUGH"}


def register():
    bpy.utils.register_class(AMTH_NODE_OT_show_active_node_image)
    kc = bpy.context.window_manager.keyconfigs.addon
    km = kc.keymaps.new(name="Node Editor", space_type="NODE_EDITOR")
    kmi = km.keymap_items.new("node.show_active_node_image",
                              "LEFTMOUSE", "DOUBLE_CLICK")
    KEYMAPS.append((km, kmi))


def unregister():
    bpy.utils.unregister_class(AMTH_NODE_OT_show_active_node_image)
    for km, kmi in KEYMAPS:
        km.keymap_items.remove(kmi)
    KEYMAPS.clear()