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+# coding: utf-8
+# /*##########################################################################
+#
+# Copyright (c) 2017-2018 European Synchrotron Radiation Facility
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+# THE SOFTWARE.
+#
+# ###########################################################################*/
+"""This script illustrates the update of a :class:`~silx.gui.plot.Plot2D`
+widget from a thread.
+
+The problem is that plot and GUI methods should be called from the main thread.
+To safely update the plot from another thread, one need to execute the update
+asynchronously in the main thread.
+In this example, this is achieved with
+:func:`~silx.gui.utils.concurrent.submitToQtMainThread`.
+
+In this example a thread calls submitToQtMainThread to update the image
+of a plot.
+
+Update from 1d to 2d example by Hans Fangohr, European XFEL GmbH, 26 Feb 2018.
+"""
+
+__authors__ = ["T. Vincent"]
+__license__ = "MIT"
+__date__ = "05/09/2017"
+
+
+import threading
+import time
+
+import numpy
+
+from silx.gui import qt
+from silx.gui.utils import concurrent
+from silx.gui.plot import Plot2D
+
+
+Nx = 150
+Ny = 50
+
+
+class UpdateThread(threading.Thread):
+ """Thread updating the image of a :class:`~sil.gui.plot.Plot2D`
+
+ :param plot2d: The Plot2D to update."""
+
+ def __init__(self, plot2d):
+ self.plot2d = plot2d
+ self.running = False
+ self.future_result = None
+ super(UpdateThread, self).__init__()
+
+ def start(self):
+ """Start the update thread"""
+ self.running = True
+ super(UpdateThread, self).start()
+
+ def run(self, pos={'x0': 0, 'y0': 0}):
+ """Method implementing thread loop that updates the plot
+
+ It produces an image every 10 ms or so, and
+ either updates the plot or skip the image
+ """
+ while self.running:
+ time.sleep(0.01)
+
+ # Create image
+ # width of peak
+ sigma_x = 0.15
+ sigma_y = 0.25
+ # x and y positions
+ x = numpy.linspace(-1.5, 1.5, Nx)
+ y = numpy.linspace(-1.0, 1.0, Ny)
+ xv, yv = numpy.meshgrid(x, y)
+ signal = numpy.exp(- ((xv - pos['x0']) ** 2 / sigma_x ** 2
+ + (yv - pos['y0']) ** 2 / sigma_y ** 2))
+ # add noise
+ signal += 0.3 * numpy.random.random(size=signal.shape)
+ # random walk of center of peak ('drift')
+ pos['x0'] += 0.05 * (numpy.random.random() - 0.5)
+ pos['y0'] += 0.05 * (numpy.random.random() - 0.5)
+
+ # If previous frame was not added to the plot yet, skip this one
+ if self.future_result is None or self.future_result.done():
+ # plot the data asynchronously, and
+ # keep a reference to the `future` object
+ self.future_result = concurrent.submitToQtMainThread(
+ self.plot2d.addImage, signal, resetzoom=False)
+
+ def stop(self):
+ """Stop the update thread"""
+ self.running = False
+ self.join(2)
+
+
+def main():
+ global app
+ app = qt.QApplication([])
+
+ # Create a Plot2D, set its limits and display it
+ plot2d = Plot2D()
+ plot2d.setLimits(0, Nx, 0, Ny)
+ plot2d.getDefaultColormap().setVRange(0., 1.5)
+ plot2d.show()
+
+ # Create the thread that calls submitToQtMainThread
+ updateThread = UpdateThread(plot2d)
+ updateThread.start() # Start updating the plot
+
+ app.exec_()
+
+ updateThread.stop() # Stop updating the plot
+
+
+if __name__ == '__main__':
+ main()