Unreal中使用Pyside2

摘要

Unreal Engine这几次更新后, 强化了Python(DCC之王)的使用.

在Editor使用情况下, 用PySide2 写UI远远比原生的SlateUI好用太多…

但是Unreal创建Qt窗口时, 会导致窗口无法前台, 一闪而过, 使用以下方法,可以快速附加Qt窗口到Unreal.

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Easy To Copy!

# coding=utf-8
# Script created by MineClever


import re as re
import unreal as unreal
import os as os

################################
# Build Ui for tool.
################################
# UI Part
from functools import partial
import PySide2 as PySide2
from PySide2 import QtWidgets, QtUiTools, QtWidgets, QtCore
####################################

class UnrealPyUiLoaderBase (QtWidgets.QWidget):
    """
    Create a default tool window. Base Class
    """
    # store ref to window to prevent garbage collection
    window = None

    def __init__(self, parent=None, ui_file_name=""):
        """
        Import UI and connect components
        """
        super().__init__(parent)

        # load the created UI widget
        current_file_dir = current_file_dir = os.path.dirname(__file__)
        ui_file_path = os.path.join(current_file_dir, ui_file_name).replace("\\", "/")
        # NOTE: path to .ui file
        ui_file_object = QtCore.QFile(ui_file_path)
        if not ui_file_object.open(QtCore.QIODevice.ReadOnly):
            raise Exception("Can not load ui file {}".format(ui_file_path))

        qt_ui_loader = QtUiTools.QUiLoader()
        loaded_ui_window = qt_ui_loader.load(ui_file_object)  # type: QtWidgets.QWidget
        self.widget = loaded_ui_window
        # attach the widget to the instance of this class (aka self)
        self.widget.setParent(self)
        self._modifyUi()

    def findButton(self, name, clicked_callback=None):
        # type: (str, ...) -> QtWidgets.QPushButton | None
        if self.widget == None : return None
        btn = self.widget.findChild(QtWidgets.QPushButton, name) # type: QtWidgets.QPushButton
        if clicked_callback and btn:
            btn.clicked.connect(clicked_callback)
        return btn

    def findTextEdit(self, name):
        if self.widget == None: return None
        txt_edit = self.widget.findChild(QtWidgets.QTextEdit, name) # type: QtWidgets.QTextEdit
        return txt_edit

    def _modifyUi(self):
        """Modify current widget load from ui file"""
        pass

    def resizeEvent(self, event):
        """
        Called on automatically generated resize event
        """
        self.widget.resize(self.width(), self.height())

    def closewindow(self):
        """
        Close the window.
        """
        self.destroy()


class QtUiStartHelper():
    u"""
    Always calling "start_qt_app()" firstly. Then init this class with a widget.

    ---
    Example:
    ---

    QtUiStartHelper.start_qt_app()

    qt_ui_widget = UnrealMeshTexExportUiLoader(ui_file_name = "unreal_tool_ui_path.ui")
    unreal_qt_ui_helper = QtUiStartHelper(qt_ui_widget)
    unreal_qt_ui_helper.windowTitleName = u"Unreal Tool Name " + unreal_qt_ui_helper.version
__file__
    unreal_qt_ui_helper.build_unreal_window()

    """

    @staticmethod
    def _registerUnrealQtAppWindow():
        unreal_app = QtWidgets.QApplication([])
        tick_handle = unreal.register_slate_post_tick_callback(
            lambda delta: QtWidgets.QApplication.sendPostedEvents())
        __QtAppQuit__ = partial(unreal.unregister_slate_post_tick_callback, tick_handle)
        unreal_app.aboutToQuit.connect(__QtAppQuit__)

    @staticmethod
    def startQtApp():
        unreal_app = QtWidgets.QApplication.instance()
        if not unreal_app:
            QtUiStartHelper._registerUnrealQtAppWindow()


    def __init__ (self, widget):
        # type: (QtWidgets.QWidget) -> None
        if not isinstance(widget, QtWidgets.QWidget):
            raise
        self._widget = widget
        self.version = "0.0.1"
        self.windowObjName = "UnrealLevelUsdExport"
        self.windowTitleName = u"{win_name} {ver}".format(win_name = self.windowObjName, ver=self.version)
        if widget.windowTitle():
            self.windowTitleName = widget.windowTitle()


    def _bindWidgetToUnreal(self):
        # NOTE: must show firstly, then bind to unreal, or would not parent into unreal main window...
        widget = self._widget
        widget.setObjectName(self.windowObjName)
        widget.setWindowTitle(self.windowTitleName)
        widget.show()
        win_id = widget.winId()
        unreal.parent_external_window_to_slate(win_id)


    def buildUnrealWindow (self):

        # Id any current instances of tool and destroy
        all_qt_windows = QtWidgets.QApplication.topLevelWidgets() # type: list[QtWidgets.QWidget]
        for qt_win in all_qt_windows:
            if self.windowObjName in qt_win.objectName():  # update this name to match name below
                qt_win.deleteLater()
                qt_win.close()
                qt_win.destroy()

        self._bindWidgetToUnreal()


class UnrealDemoPyUiLoader(UnrealPyUiLoaderBase):
    """
    Create tool window.
    """

    def __init__(self, parent=None, ui_file_name=""):
        self.file_dir_path = unreal.Paths.project_saved_dir()
        super().__init__(parent, ui_file_name)

    ################################
    # Your code goes here.
    ################################

    def _modifyUi(self):
        # -----------------------------------------
        # find interactive elements of UI
        self.btn_run = self.findButton("Btn_run", clicked_callback=self.openFileDialog)
        self.txt_edit_export_file_dir_path = self.findTextEdit("Text_FilePath")


    @QtCore.Slot()
    def openFileDialog(self):
        """
        open get file path window
        """
        chosen_dir_path = QtWidgets.QFileDialog.getExistingDirectory(
            self,
            options =QtWidgets.QFileDialog.ShowDirsOnly,
            caption=u"Choose Export Folder",
            dir=unreal.Paths.project_saved_dir())
        if not chosen_dir_path: return

        # NOTE: update UI and dir path
        self.file_dir_path = chosen_dir_path
        if self.txt_edit_export_file_dir_path:
            self.txt_edit_export_file_dir_path.setText(chosen_dir_path)


if __name__ == "__main__":
    QtUiStartHelper.startQtApp()

    qt_ui_widget = UnrealDemoPyUiLoader(ui_file_name="demo_ui_file.ui")
    unreal_qt_ui_helper = QtUiStartHelper(qt_ui_widget)

    unreal_qt_ui_helper.buildUnrealWindow()