From 159ef14fb9e198bb0066ea14e6b980f065de63dd Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Picca=20Fr=C3=A9d=C3=A9ric-Emmanuel?=
 <picca@synchrotron-soleil.fr>
Date: Tue, 31 Jul 2018 16:22:25 +0200
Subject: New upstream version 0.8.0+dfsg

---
 examples/plotUpdateImageFromThread.py | 133 ++++++++++++++++++++++++++++++++++
 1 file changed, 133 insertions(+)
 create mode 100644 examples/plotUpdateImageFromThread.py

(limited to 'examples/plotUpdateImageFromThread.py')

diff --git a/examples/plotUpdateImageFromThread.py b/examples/plotUpdateImageFromThread.py
new file mode 100644
index 0000000..5850263
--- /dev/null
+++ b/examples/plotUpdateImageFromThread.py
@@ -0,0 +1,133 @@
+# 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()
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