[SHOT-3502] Prompt save changes on opening new file (#44)

* Add method to engine to check for unsaved changes by checking window title for '*' (no VRED API for this).
* Modify the workfiles reset scene operation hook to check for unsaved changes, and propmt the user to save or discard changes before continuing.
* Use the Workfiles2 File Save dialog when calling VRED engine to save a file, fallback to VRED's save dialog if Workfiles2 is not set up

engine.py

@@ -1,18 +1,22 @@
-# -*- coding: utf-8 -*-
-
-# Copyright (c) 2015 Shotgun Software Inc.
+# Copyright (c) 2020 Autodesk Inc.
 # CONFIDENTIAL AND PROPRIETARY
 #
 # This work is provided "AS IS" and subject to the Shotgun Pipeline Toolkit
 # Source Code License included in this distribution package. See LICENSE.
 # By accessing, using, copying or modifying this work you indicate your
 # agreement to the Shotgun Pipeline Toolkit Source Code License. All rights
-# not expressly granted therein are reserved by Shotgun Software Inc.
+# not expressly granted therein are reserved by Autodesk Inc.
+
 import logging
 import os
+import re
+
 import sgtk
 from tank_vendor import six
 
+import builtins
+
+builtins.vrFileIOService = vrFileIOService
 import vrController
 import vrFileDialog
 import vrFileIO
@@ -303,18 +307,44 @@ def show_panel(self, panel_id, title, bundle, widget_class, *args, **kwargs):
     #####################################################################################
     # VRED File IO
 
+    def has_unsaved_changes(self):
+        """
+        Return True if the current scene has unsaved changes, otherwise False.
+        The VRED API does not currently have an endpoint to check for unsaved changes,
+        so to determine whether or not there are changes, check if the VRED window title
+        contains a '*' character (this indicates that there are changes in the scene).
+        """
+
+        window_title_string = self._get_dialog_parent().windowTitle()
+        return re.findall(r"\*", window_title_string)
+
     def open_save_as_dialog(self):
         """
-        Opens a file dialog and lets the user choose a filename and then save the supplied
-        project to that path.
+        Open the tk-multi-workfiles2 app's file save dialog. Fallback to using VRED save
+        dialog UI if workfiles is not available.
         """
-        path = vrFileDialog.getSaveFileName(
-            caption="Save As",
-            filename="",
-            filter=["VRED Project Binary (*.vpb)"],
-        )
 
-        if path:
+        open_dialog_func = None
+        kwargs = {}
+        workfiles = self.apps.get("tk-multi-workfiles2", None)
+
+        if workfiles:
+            if hasattr(workfiles, "show_file_save_dlg"):
+                open_dialog_func = workfiles.show_file_save_dlg
+                kwargs["use_modal_dialog"] = True
+
+        if open_dialog_func:
+            open_dialog_func(**kwargs)
+
+        else:
+            # Fallback to using VRED's save dialog. Pass flag to not confirm overwrite, the
+            # save dialog will already ask this.
+            path = vrFileDialog.getSaveFileName(
+                caption="Save As",
+                filename=vrFileIOService.getFileName(),
+                filter=["VRED Project Binary (*.vpb)"],
+                confirmOverwrite=False,
+            )
             self.save_current_file(path, False)
 
     def save_current_file(self, file_path, set_render_path=True):
@@ -324,6 +354,14 @@ def save_current_file(self, file_path, set_render_path=True):
         :param file_path: the name of the project file.
         """
 
+        if not file_path:
+            self.logger.debug(
+                "{engine_name} no file path given for save -- aborting".format(
+                    engine_name=self.name
+                )
+            )
+            return
+
         self.logger.debug(
             "{engine_name} calling VRED save for file '{path}'".format(
                 engine_name=self.name, path=file_path

hooks/tk-multi-workfiles2/basic/scene_operation.py

@@ -1,4 +1,14 @@
+# Copyright (c) 2020 Autodesk, Inc.
+# CONFIDENTIAL AND PROPRIETARY
+#
+# This work is provided "AS IS" and subject to the Shotgun Pipeline Toolkit
+# Source Code License included in this distribution package. See LICENSE.
+# By accessing, using, copying or modifying this work you indicate your
+# agreement to the Shotgun Pipeline Toolkit Source Code License. All rights
+# not expressly granted therein are reserved by Autodesk, Inc.
+
 import sgtk
+from sgtk.platform.qt import QtCore, QtGui
 
 import vrController
 import vrFileIO
@@ -9,7 +19,7 @@
 
 class SceneOperation(HookClass):
     """
-    Hook called to perform an operation with the current file.
+    VRED scene operations for tk-multi-workfiles2
     """
 
     def execute(
@@ -42,7 +52,7 @@ def execute(
 
         :returns:               Depends on operation:
                                 'current_path' - Return the current scene file path as a String
-                                all others     - True
+                                all others     - True for success, else False
         """
 
         self.logger.debug(
@@ -51,6 +61,8 @@ def execute(
             )
         )
 
+        success = True
+
         if operation == "current_path":
             current_path = vrFileIO.getFileIOFilePath()
             return "" if current_path is None else current_path
@@ -74,6 +86,39 @@ def execute(
             self.parent.engine.save_current_file(file_path)
 
         elif operation == "reset":
-            vrController.newScene()
-
-        return True
+            # Do not let the user reset the scene until they have saved their changes,
+            # or explicitly said they do not want to save their changes. Override the
+            # cursor before opening any new dialogs, and restore once finished (the
+            # cursor is most likely to be "waiting" since we're in the reset operation).
+            restore_cursor = False
+            while self.parent.engine.has_unsaved_changes():
+                if not restore_cursor:
+                    restore_cursor = True
+                    QtGui.QApplication.setOverrideCursor(QtCore.Qt.ArrowCursor)
+
+                res = QtGui.QMessageBox.question(
+                    None,
+                    "Save your scene?",
+                    "Your scene has unsaved changes. Save before proceeding?",
+                    QtGui.QMessageBox.Yes
+                    | QtGui.QMessageBox.No
+                    | QtGui.QMessageBox.Cancel,
+                )
+
+                if res == QtGui.QMessageBox.Cancel:
+                    success = False
+                    break
+
+                if res == QtGui.QMessageBox.No:
+                    break
+
+                # The user has indicated they want to save changes before proceeding
+                self.parent.engine.open_save_as_dialog()
+
+            if restore_cursor:
+                QtGui.QApplication.restoreOverrideCursor()
+
+            if success:
+                vrController.newScene()
+
+        return success