# Copyright 2018 The dm_control Authors.

#

# Licensed under the Apache License, Version 2.0 (the "License");

# you may not use this file except in compliance with the License.

# You may obtain a copy of the License at

#

# http://www.apache.org/licenses/LICENSE-2.0

#

# Unless required by applicable law or agreed to in writing, software

# distributed under the License is distributed on an "AS IS" BASIS,

# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

# See the License for the specific language governing permissions and

# limitations under the License.

# ============================================================================

"""Viewer's windowing systems."""

from dm_control import _render

# pylint: disable=g-import-not-at-top

# pylint: disable=invalid-name

RenderWindow = None

try:

from dm_control.viewer.gui import glfw_gui

RenderWindow = glfw_gui.GlfwWindow

except ImportError:

pass

if RenderWindow is None:

def ErrorRenderWindow(*args, **kwargs):

del args, kwargs

raise ImportError(

'Cannot create a window because no windowing system could be imported')

RenderWindow = ErrorRenderWindow

del _render