Added an example with a Group item

examples/plotGroups.py

@@ -0,0 +1,108 @@
+#!/usr/bin/env python
+# /*##########################################################################
+#
+# Copyright (c) 2016-2019 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.
+#
+# ###########################################################################*/
+"""
+Example to show the use of :class:`~silx.gui.items.group.Group`.
+"""
+
+__license__ = "MIT"
+
+import logging
+import numpy
+from silx.gui.plot import PlotWindow
+from silx.gui import qt
+from silx.gui.plot.items.group import Group
+from silx.gui.plot.items.curve import Curve
+
+
+logging.basicConfig()
+logger = logging.getLogger(__name__)
+
+
+class MyGroup(Group):
+
+    def __init__(self):
+        super(MyGroup, self).__init__()
+        self._cursor = 0
+        self._tick = 0
+
+    def update(self):
+        x = numpy.linspace(self._cursor, self._cursor + 100, 50)
+        y = numpy.random.poisson((numpy.sin(x / 100) + 1) * 100)
+        self._cursor += 100
+        self._tick += 1
+
+        curve = Curve()
+        curve.setColor("C0")
+        curve.setSymbol("")
+        curve.setLineStyle("-")
+        curve.setData(x, y, copy=False)
+        curve.setVisible(self._tick % 7 != 0)
+        self.addItem(curve)
+
+        if len(self.getItems()) > 10:
+            old = self.getItems()[0]
+            self.removeItem(old)
+
+
+def main(argv=None):
+    global app  # QApplication must be global to avoid seg fault on quit
+    app = qt.QApplication([])
+    sys.excepthook = qt.exceptionHandler
+
+    win = qt.QWidget()
+    win.setAttribute(qt.Qt.WA_DeleteOnClose)
+    layout = qt.QVBoxLayout(win)
+
+    plot = PlotWindow()
+    layout.addWidget(plot)
+
+    item = MyGroup()
+    plot.addItem(item)
+
+    def update():
+        item.update()
+        plot.resetZoom()
+
+    t = qt.QTimer()
+    t.timeout.connect(update)
+    t.start(1000)
+
+    show = qt.QPushButton()
+    show.setText("Show")
+    layout.addWidget(show)
+    show.clicked.connect(lambda: item.setVisible(True))
+
+    hide = qt.QPushButton()
+    hide.setText("Hide")
+    layout.addWidget(hide)
+    hide.clicked.connect(lambda: item.setVisible(False))
+
+    win.show()
+    return app.exec()
+
+
+if __name__ == "__main__":
+    import sys
+    sys.exit(main(argv=sys.argv[1:]))