Cura/plugins/SupportEraser/SupportEraser.py

from UM.Tool import Tool
from PyQt5.QtCore import Qt, QUrl
from UM.Application import Application
from UM.Event import Event
from UM.Mesh.MeshBuilder import MeshBuilder
from UM.Operations.AddSceneNodeOperation import AddSceneNodeOperation
from UM.Settings.SettingInstance import SettingInstance
from cura.Scene.CuraSceneNode import CuraSceneNode
from cura.Scene.SliceableObjectDecorator import SliceableObjectDecorator
from cura.Scene.BuildPlateDecorator import BuildPlateDecorator
from cura.Settings.SettingOverrideDecorator import SettingOverrideDecorator

import os
import os.path

class SupportEraser(Tool):
    def __init__(self):
        super().__init__()
        self._shortcut_key = Qt.Key_G
        self._controller = Application.getInstance().getController()

    def event(self, event):
        super().event(event)

        if event.type == Event.ToolActivateEvent:

            # Load the remover mesh:
            self._createEraserMesh()

            # After we load the mesh, deactivate the tool again:
            self.getController().setActiveTool(None)

    def _createEraserMesh(self):
        # Selection.clear()

        node = CuraSceneNode()

        node.setName("Eraser")
        node.setSelectable(True)
        mesh = MeshBuilder()
        mesh.addCube(10,10,10)
        node.setMeshData(mesh.build())

        active_build_plate = Application.getInstance().getBuildPlateModel().activeBuildPlate

        node.addDecorator(SettingOverrideDecorator())
        node.addDecorator(BuildPlateDecorator(active_build_plate))
        node.addDecorator(SliceableObjectDecorator())

        stack = node.callDecoration("getStack") #Don't try to get the active extruder since it may be None anyway.
        if not stack:
            node.addDecorator(SettingOverrideDecorator())
            stack = node.callDecoration("getStack")

        print(stack)
        settings = stack.getTop()

        if not (settings.getInstance("anti_overhang_mesh") and settings.getProperty("anti_overhang_mesh", "value")):
            definition = stack.getSettingDefinition("anti_overhang_mesh")
            new_instance = SettingInstance(definition, settings)
            new_instance.setProperty("value", True)
            new_instance.resetState()  # Ensure that the state is not seen as a user state.
            settings.addInstance(new_instance)

        scene = self._controller.getScene()
        op = AddSceneNodeOperation(node, scene.getRoot())
        op.push()
        Application.getInstance().getController().getScene().sceneChanged.emit(node)