Include context switching during regular File->Open operation

engine.py

@@ -191,6 +191,9 @@ def eventFilter(self, obj, event):
         # This needs to be present for apps as it will be used in
         # show_dialog when perforce asks for login info very early on.
         self.tk_3dsmax = self.import_module("tk_3dsmax")
+
+        # include callbacks to ensure context is correct
+        self.tk_3dsmax.tank_ensure_callbacks_registered(engine=self)
 
         # The "qss_watcher" setting causes us to monitor the engine's
         # style.qss file and re-apply it on the fly when it changes
@@ -585,6 +588,7 @@ def show_modal(self, title, bundle, widget_class, *args, **kwargs):
             return None
 
         status = QtGui.QDialog.DialogCode.Rejected
+        widget=None
 
         try:
             # Disable 'Shotgun' background menu while modals are there.
@@ -611,7 +615,8 @@ def show_modal(self, title, bundle, widget_class, *args, **kwargs):
             self.tk_3dsmax.MaxScript.enable_menu()
 
         # lastly, return the instantiated widget
-        return (status, widget)
+        if widget:
+            return (status, widget)
 
     def safe_dialog_exec(self, func):
         """

python/tk_3dsmax/__init__.py

@@ -8,5 +8,190 @@
 # agreement to the Shotgun Pipeline Toolkit Source Code License. All rights
 # not expressly granted therein are reserved by Shotgun Software Inc.
 
+import sgtk #@UnresolvedImport
+import os
+from traceback import format_exc
+
 from .menu_generation import MenuGenerator
 from .maxscript import MaxScript
+from .warning_dialog import WarningDialog
+
+import MaxPlus, pymxs #@UnresolvedImport
+
+logger = sgtk.LogManager.get_logger(__name__)
+
+g_tank_callbacks_registered = False
+
+def PostOpenProcess(*args, **kwargs):
+    """
+    Callback that fires every time a script is loaded.
+    """
+    try:
+        logger.debug("SGTK Callback: script loaded")
+        # If we have opened a file then we should check if automatic 
+        # context switching is enabled and change if possible
+        engine = sgtk.platform.current_engine()
+        file_name = _session_path()
+        logger.debug("Currently running engine: %s" % (engine,))
+        logger.debug("File name to load: '%s'" % (file_name,))
+
+        #if we already have a context and it matches the path, dont do anything else
+        curr_ctx = None
+        if engine:
+            curr_ctx = engine.context
+            new_ctx = engine.sgtk.context_from_path(file_name, curr_ctx)
+            if curr_ctx==new_ctx:
+                logger.debug("Shotgun reports context is already correct, not attempting to reset")
+                return
+
+        if file_name and engine is not None:
+            logger.debug("Will attempt to execute tank_from_path('%s')" % (file_name,))
+            try:
+                # todo: do we need to create a new tk object, instead should we just 
+                # check that the context gets created correctly?
+                tk = sgtk.sgtk_from_path(file_name)
+                logger.debug("Instance '%s'is associated with '%s'" % (tk, file_name))
+            except sgtk.TankError as e:
+                error=format_exc().replace('\n', '<br />')
+                errorMessage="No tk instance associated with '%s':<br /><br /> %s<br /><br />%s" % (file_name, e, error)
+                friendlyMessage='<b>Could not determine a Shotgun Entitiy for '+os.path.basename(file_name)+",</b><br />"
+                friendlyMessage+='Please ensure you are in a Shotgun-aware instance of 3dsMax with the correct project and try again.'
+                logger.debug(errorMessage)
+                engine.show_modal('Error Initializing Shotgun', 
+										engine,
+										WarningDialog,
+										message=friendlyMessage,
+										details=errorMessage)
+
+                #TODO: replace with command that just remove tools requiring specific context (ie Publish)
+                #but leave tools that can direct a user back to the correct context (ie Workfiles)
+                engine._remove_shotgun_menu()
+                return
+
+            # try to get current ctx and inherit its values if possible
+            curr_ctx = None
+            if sgtk.platform.current_engine():
+                curr_ctx = sgtk.platform.current_engine().context
+
+            logger.debug("")
+            new_ctx = tk.context_from_path(file_name, curr_ctx)
+            logger.debug("Current context: %r" % (curr_ctx,))
+            logger.debug("New context: %r" % (new_ctx,))
+            # Now switch to the context appropriate for the file
+            engine.change_context(new_ctx)
+
+        elif file_name and engine is None:
+
+            #NOTE that this is untested, as I was unable to determine when this sitatuation would be true
+
+            # we have no engine, this maybe because the integration disabled itself, 
+            # due to a non Toolkit file being opened, prior to this new file. We must 
+            # create a sgtk instance from the script path.
+            logger.debug("3dsmax file is already loaded but no tk engine running.")
+            logger.debug("Will attempt to execute tank_from_path('%s')" % (file_name,))
+            try:
+                tk = sgtk.sgtk_from_path(file_name)
+                logger.debug("Instance '%s'is associated with '%s'" % (tk, file_name))
+            except sgtk.TankError as e:
+                error=format_exc().replace('\n', '<br />')
+                errorMessage="No tk instance associated with '%s':<br /><br /> %s<br /><br />%s" % (file_name, e, error)
+                friendlyMessage='<b>Could not determine a Shotgun Entitiy for '+os.path.basename(file_name)+",</b><br />"
+                friendlyMessage+='Please ensure you are in a Shotgun-aware instance of 3dsMax with the correct project and try again.'
+                logger.debug(errorMessage)
+                engine.show_modal('Error Initializing Shotgun', 
+										engine,
+										WarningDialog,
+										message=friendlyMessage,
+										details=errorMessage)
+
+                engine._remove_shotgun_menu()
+                return
+
+            new_ctx = tk.context_from_path(file_name)
+            logger.debug("New context: %r" % (new_ctx,))
+            # Now switch to the context appropriate for the file
+            engine.change_context(new_ctx)
+
+    except Exception:
+        error=format_exc()
+        logger.exception("An exception was raised during addOnScriptLoad callback.")
+        friendlyMessage='An unknown error occured attempting to initialize the Shotgun engine.'
+        logger.debug(error)
+        engine.show_modal('Error Initializing Shotgun', 
+										engine,
+										WarningDialog,
+										message=friendlyMessage,
+										details=error)
+        return
+
+def tank_ensure_callbacks_registered(engine=None):
+    """
+    Make sure that we have callbacks tracking context state changes.
+    The OnScriptLoad callback really only comes into play when you're opening a file or creating a new script, when
+    there is no current script open in your Nuke session. If there is a script currently open then this will spawn a
+    new Nuke instance and the callback won't be called.
+    """
+
+    global g_tank_callbacks_registered
+
+    logger.debug("Setting up 3dsMax Context Switching callbacks")
+
+    # we'll assume context switching is allowed for now
+    #if engine.get_setting("automatic_context_switch"):
+    if not g_tank_callbacks_registered:
+        logger.debug("SGTK Registering onLoad callback")
+        MaxPlus.NotificationManager.Register(MaxPlus.NotificationCodes.FilePostOpen, PostOpenProcess)
+        g_tank_callbacks_registered = True
+    #else:
+        # we have an engine but the automatic context switching has been disabled, we should ensure the callbacks
+        # are removed.
+    #    if g_tank_callbacks_registered:
+            #remove here
+    #        g_tank_callbacks_registered = False
+
+def _session_path():
+    """
+    Return the path to the current session
+    :return:
+    """
+    if pymxs.runtime.maxFilePath and pymxs.runtime.maxFileName:
+        return os.path.join(pymxs.runtime.maxFilePath, pymxs.runtime.maxFileName)
+    else:
+        return None
+
+def __engine_refresh(new_context):
+    """
+    Checks if the 3dsmax engine should be created or just have the context changed.
+    If an engine is already started then we just need to change context, 
+    else we need to start the engine.
+    """
+
+    engine_name = 'tk-3dsmax'
+
+    curr_engine = sgtk.platform.current_engine()
+    if curr_engine:
+        # If we already have an engine, we can just tell it to change contexts
+        curr_engine.change_context(new_context)
+    else:
+        # try to create new engine
+        try:
+            logger.debug(
+                "Starting new engine: %s, %s, %s" % (
+                    engine_name, 
+                    new_context.sgtk, 
+                    new_context
+                )
+            )
+            sgtk.platform.start_engine(engine_name, new_context.sgtk, new_context)
+
+        except sgtk.TankEngineInitError as e:
+            # context was not sufficient! - disable tank!
+            logger.exception("Engine could not be started.")
+            #TODO: replace with command that just remove tools requiring specific context (ie Publish)
+            #but leave tools that can direct a user back to the correct context (ie Workfiles)
+
+            #engine._remove_shotgun_menu()
+
+
+
+

python/tk_3dsmax/warning_dialog.py

@@ -0,0 +1,32 @@
+'''
+
+simple dialog to raise warnings to user
+
+'''
+
+from sgtk.platform.qt import QtGui, QtCore #@UnresolvedImport
+
+#if we have an engine, we can simply use this class
+class WarningDialog(QtGui.QWidget):
+
+	def __init__(self, message, details=None, *args, **kwargs):
+
+		super(WarningDialog, self).__init__(*args, **kwargs)
+
+		self.setObjectName("SGTK_WARNING_DIALOG")
+
+		self._label = QtGui.QLabel("<h3>"+message+"</h3>")
+		self._label.setTextFormat(QtCore.Qt.RichText)
+		self._text = QtGui.QTextEdit()
+		self._text.setReadOnly(True)
+		#self._text.setLineWrapMode(QtGui.QTextEdit.NoWrap)
+		self._text.setText(str(details))
+
+		self._layout = QtGui.QVBoxLayout(self)
+		self._layout.addWidget(self._label)
+		self._layout.addWidget(self._text)
+
+#if we don't have an engine, we'll need to do some of the legwork ourselves
+def showWarningDialog(message, details=None):
+
+	parent=QtGui.QApplication.activeWindow()