New upstream version 0.10.1+dfsg

12 files changed, 392 insertions, 69 deletions

diff --git a/examples/compareImages.py b/examples/compareImages.py
index 94f68a0..623216a 100644
--- a/examples/compareImages.py
+++ b/examples/compareImages.py
@@ -30,19 +30,18 @@ import sys
 import logging
 import numpy
 import argparse
+import os
 
 import silx.io
 from silx.gui import qt
 import silx.test.utils
+from silx.io.url import DataUrl
 from silx.gui.plot.CompareImages import CompareImages
+from silx.gui.widgets.UrlSelectionTable import UrlSelectionTable
 
 _logger = logging.getLogger(__name__)
 
-try:
-    import fabio
-except ImportError:
-    _logger.debug("Backtrace", exc_info=True)
-    fabio = None
+import fabio
 
 try:
     import PIL
@@ -51,6 +50,70 @@ except ImportError:
     PIL = None
 
 
+class CompareImagesSelection(qt.QMainWindow):
+    def __init__(self, backend):
+        qt.QMainWindow.__init__(self, parent=None)
+        self._plot = CompareImages(parent=self, backend=backend)
+
+        self._selectionTable = UrlSelectionTable(parent=self)
+        self._dockWidgetMenu = qt.QDockWidget(parent=self)
+        self._dockWidgetMenu.layout().setContentsMargins(0, 0, 0, 0)
+        self._dockWidgetMenu.setFeatures(qt.QDockWidget.DockWidgetMovable)
+        self._dockWidgetMenu.setWidget(self._selectionTable)
+        self.addDockWidget(qt.Qt.LeftDockWidgetArea, self._dockWidgetMenu)
+
+        self.setCentralWidget(self._plot)
+
+        self._selectionTable.sigImageAChanged.connect(self._updateImageA)
+        self._selectionTable.sigImageBChanged.connect(self._updateImageB)
+
+    def setUrls(self, urls):
+        for url in urls:
+            self._selectionTable.addUrl(url)
+
+    def setFiles(self, files):
+        urls = list()
+        for _file in files:
+            if os.path.isfile(_file):
+                urls.append(DataUrl(file_path=_file, scheme=None))
+        urls.sort(key=lambda url: url.path())
+        window.setUrls(urls)
+        window._selectionTable.setSelection(url_img_a=urls[0].path(),
+                                            url_img_b=urls[1].path())
+
+    def clear(self):
+        self._plot.clear()
+        self._selectionTable.clear()
+
+    def _updateImageA(self, urlpath):
+        self._updateImage(urlpath, self._plot.setImage1)
+
+    def _updateImage(self, urlpath, fctptr):
+        def getData():
+            _url = silx.io.url.DataUrl(path=urlpath)
+            for scheme in ('silx', 'fabio'):
+                try:
+                    dataImg = silx.io.utils.get_data(
+                        silx.io.url.DataUrl(file_path=_url.file_path(),
+                                            data_slice=_url.data_slice(),
+                                            data_path=_url.data_path(),
+                                            scheme=scheme))
+                except:
+                    _logger.debug("Error while loading image with %s" % scheme,
+                                  exc_info=True)
+                else:
+                    # TODO: check is an image
+                    return dataImg
+            return None
+
+        data = getData()
+        if data is not None:
+            fctptr(data)
+
+    def _updateImageB(self, urlpath):
+        self._updateImage(urlpath, self._plot.setImage2)
+
+
 def createTestData():
     data = numpy.arange(100 * 100)
     data = (data % 100) / 5.0
@@ -68,14 +131,10 @@ def loadImage(filename):
     except Exception:
         _logger.debug("Error while loading image with silx.io", exc_info=True)
 
-    if fabio is None and PIL is None:
-        raise ImportError("fabio nor PIL are available")
-
-    if fabio is not None:
-        try:
-            return fabio.open(filename).data
-        except Exception:
-            _logger.debug("Error while loading image with fabio", exc_info=True)
+    try:
+        return fabio.open(filename).data
+    except Exception:
+        _logger.debug("Error while loading image with fabio", exc_info=True)
 
     if PIL is not None:
         try:
@@ -128,22 +187,25 @@ if __name__ == "__main__":
     if options.debug:
         logging.root.setLevel(logging.DEBUG)
 
-    if options.testdata:
-        _logger.info("Generate test data")
-        data1, data2 = createTestData()
-    else:
-        if len(options.files) != 2:
-            raise Exception("Expected 2 images to compare them")
-        data1 = loadImage(options.files[0])
-        data2 = loadImage(options.files[1])
-
     if options.use_opengl_plot:
         backend = "gl"
     else:
         backend = "mpl"
 
     app = qt.QApplication([])
-    window = CompareImages(backend=backend)
-    window.setData(data1, data2)
+    if options.testdata or len(options.files) == 2:
+        if options.testdata:
+            _logger.info("Generate test data")
+            data1, data2 = createTestData()
+        else:
+            data1 = loadImage(options.files[0])
+            data2 = loadImage(options.files[1])
+        window = CompareImages(backend=backend)
+        window.setData(data1, data2)
+    else:
+        data = options.files
+        window = CompareImagesSelection(backend=backend)
+        window.setFiles(options.files)
+
     window.setVisible(True)
     app.exec_()
diff --git a/examples/customDataView.py b/examples/customDataView.py
index 6db5c3e..33662e8 100644
--- a/examples/customDataView.py
+++ b/examples/customDataView.py
@@ -2,7 +2,7 @@
 # coding: utf-8
 # /*##########################################################################
 #
-# Copyright (c) 2016-2017 European Synchrotron Radiation Facility
+# Copyright (c) 2016-2018 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
@@ -26,6 +26,7 @@
 """Qt data view example
 """
 
+import enum
 import logging
 import sys
 
@@ -36,7 +37,6 @@ _logger = logging.getLogger("customDataView")
 from silx.gui import qt
 from silx.gui.data.DataViewerFrame import DataViewerFrame
 from silx.gui.data.DataViews import DataView
-from silx.third_party import enum
 
 
 class Color(enum.Enum):
diff --git a/examples/dropZones.py b/examples/dropZones.py
new file mode 100644
index 0000000..d0d16b5
--- /dev/null
+++ b/examples/dropZones.py
@@ -0,0 +1,134 @@
+#!/usr/bin/env python
+# coding: utf-8
+# /*##########################################################################
+#
+# Copyright (c) 2016-2018 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.
+#
+# ###########################################################################*/
+"""
+Example of drop zone supporting application/x-silx-uri
+"""
+
+from __future__ import absolute_import
+
+__authors__ = ["V. Valls"]
+__license__ = "MIT"
+__date__ = "25/01/2019"
+
+import logging
+import silx.io
+from silx.gui import qt
+from silx.gui.plot.PlotWidget import PlotWidget
+
+_logger = logging.getLogger(__name__)
+logging.basicConfig(level=logging.DEBUG)
+
+
+class DropPlotWidget(PlotWidget):
+
+    def __init__(self, parent=None, backend=None):
+        PlotWidget.__init__(self, parent=parent, backend=backend)
+        self.setAcceptDrops(True)
+
+    def dragEnterEvent(self, event):
+        if event.mimeData().hasFormat("application/x-silx-uri"):
+            event.acceptProposedAction()
+
+    def dropEvent(self, event):
+        byteString = event.mimeData().data("application/x-silx-uri")
+        silxUrl = byteString.data().decode("utf-8")
+        with silx.io.open(silxUrl) as h5:
+            if silx.io.is_dataset(h5):
+                dataset = h5[...]
+            else:
+                _logger.error("Unsupported URI")
+                dataset = None
+
+        if dataset is not None:
+            if dataset.ndim == 1:
+                self.clear()
+                self.addCurve(y=dataset, x=range(dataset.size))
+                event.acceptProposedAction()
+            elif dataset.ndim == 2:
+                self.clear()
+                self.addImage(data=dataset)
+                event.acceptProposedAction()
+            else:
+                _logger.error("Unsupported dataset")
+
+
+class DropLabel(qt.QLabel):
+
+    def __init__(self, parent=None, backend=None):
+        qt.QLabel.__init__(self)
+        self.setAcceptDrops(True)
+        self.setText("Drop something here")
+
+    def dragEnterEvent(self, event):
+        if event.mimeData().hasFormat("application/x-silx-uri"):
+            event.acceptProposedAction()
+
+    def dropEvent(self, event):
+        byteString = event.mimeData().data("application/x-silx-uri")
+        silxUrl = byteString.data().decode("utf-8")
+        url = silx.io.url.DataUrl(silxUrl)
+        self.setText(url.path())
+
+        toolTipTemplate = ("<html><ul>"
+                           "<li><b>file_path</b>: {file_path}</li>"
+                           "<li><b>data_path</b>: {data_path}</li>"
+                           "<li><b>data_slice</b>: {data_slice}</li>"
+                           "<li><b>scheme</b>: {scheme}</li>"
+                           "</html>"
+                           "</ul></html>"
+                           )
+
+        toolTip = toolTipTemplate.format(
+            file_path=url.file_path(),
+            data_path=url.data_path(),
+            data_slice=url.data_slice(),
+            scheme=url.scheme())
+
+        self.setToolTip(toolTip)
+        event.acceptProposedAction()
+
+
+class DropExample(qt.QMainWindow):
+
+    def __init__(self, parent=None):
+        super(DropExample, self).__init__(parent)
+        centralWidget = qt.QWidget(self)
+        layout = qt.QVBoxLayout()
+        centralWidget.setLayout(layout)
+        layout.addWidget(DropPlotWidget(parent=self))
+        layout.addWidget(DropLabel(parent=self))
+        self.setCentralWidget(centralWidget)
+
+
+def main():
+    app = qt.QApplication([])
+    example = DropExample()
+    example.show()
+    app.exec_()
+
+
+if __name__ == "__main__":
+    main()
diff --git a/examples/fileDialog.py b/examples/fileDialog.py
index 9730b9a..82e6798 100644
--- a/examples/fileDialog.py
+++ b/examples/fileDialog.py
@@ -2,7 +2,7 @@
 # coding: utf-8
 # /*##########################################################################
 #
-# Copyright (c) 2016 European Synchrotron Radiation Facility
+# Copyright (c) 2016-2018 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
@@ -33,12 +33,12 @@ __authors__ = ["V. Valls"]
 __license__ = "MIT"
 __date__ = "14/02/2018"
 
+import enum
 import logging
 from silx.gui import qt
 from silx.gui.dialog.ImageFileDialog import ImageFileDialog
 from silx.gui.dialog.DataFileDialog import DataFileDialog
 import silx.io
-from silx.third_party import enum
 
 
 logging.basicConfig(level=logging.DEBUG)
diff --git a/examples/hdf5widget.py b/examples/hdf5widget.py
index bf92d4e..c344bec 100755
--- a/examples/hdf5widget.py
+++ b/examples/hdf5widget.py
@@ -33,7 +33,9 @@
 import logging
 import sys
 import tempfile
+
 import numpy
+import six
 
 logging.basicConfig()
 _logger = logging.getLogger("hdf5widget")
@@ -50,15 +52,12 @@ import h5py
 
 import silx.gui.hdf5
 import silx.utils.html
-from silx.third_party import six
 from silx.gui import qt
 from silx.gui.data.DataViewerFrame import DataViewerFrame
 from silx.gui.widgets.ThreadPoolPushButton import ThreadPoolPushButton
 
-try:
-    import fabio
-except ImportError:
-    fabio = None
+import fabio
+
 
 _file_cache = {}
 
@@ -713,26 +712,25 @@ class Hdf5TreeViewExample(qt.QMainWindow):
 
         content.layout().addStretch(1)
 
-        if fabio is not None:
-            content = qt.QGroupBox("Create EDF", panel)
-            content.setLayout(qt.QVBoxLayout())
-            panel.layout().addWidget(content)
+        content = qt.QGroupBox("Create EDF", panel)
+        content.setLayout(qt.QVBoxLayout())
+        panel.layout().addWidget(content)
 
-            combo = qt.QComboBox()
-            combo.addItem("Containing all types", get_edf_with_all_types)
-            combo.addItem("Containing 100000 datasets", get_edf_with_100000_frames)
-            combo.activated.connect(self.__edfComboChanged)
-            content.layout().addWidget(combo)
+        combo = qt.QComboBox()
+        combo.addItem("Containing all types", get_edf_with_all_types)
+        combo.addItem("Containing 100000 datasets", get_edf_with_100000_frames)
+        combo.activated.connect(self.__edfComboChanged)
+        content.layout().addWidget(combo)
 
-            button = ThreadPoolPushButton(content, text="Create")
-            button.setCallable(combo.itemData(combo.currentIndex()))
-            button.succeeded.connect(self.__fileCreated)
-            content.layout().addWidget(button)
+        button = ThreadPoolPushButton(content, text="Create")
+        button.setCallable(combo.itemData(combo.currentIndex()))
+        button.succeeded.connect(self.__fileCreated)
+        content.layout().addWidget(button)
 
-            self.__edfCombo = combo
-            self.__createEdfButton = button
+        self.__edfCombo = combo
+        self.__createEdfButton = button
 
-            content.layout().addStretch(1)
+        content.layout().addStretch(1)
 
         option = qt.QGroupBox("Tree options", panel)
         option.setLayout(qt.QVBoxLayout())
diff --git a/examples/imageview.py b/examples/imageview.py
index 37d1857..71bde70 100755
--- a/examples/imageview.py
+++ b/examples/imageview.py
@@ -42,7 +42,7 @@ from __future__ import division
 
 __authors__ = ["T. Vincent"]
 __license__ = "MIT"
-__date__ = "18/10/2016"
+__date__ = "08/11/2018"
 
 import logging
 from silx.gui.plot.ImageView import ImageViewMainWindow
@@ -118,8 +118,7 @@ def main(argv=None):
 
     if args.log:  # Use log normalization by default
         colormap = mainWindow.getDefaultColormap()
-        colormap['normalization'] = 'log'
-        mainWindow.setColormap(colormap)
+        colormap.setNormalization(colormap.LOGARITHM)
 
     mainWindow.setImage(data,
                         origin=args.origin,
diff --git a/examples/plot3dSceneWindow.py b/examples/plot3dSceneWindow.py
index cf6f209..5e78aa6 100644
--- a/examples/plot3dSceneWindow.py
+++ b/examples/plot3dSceneWindow.py
@@ -57,7 +57,7 @@ from silx.gui.widgets.BoxLayoutDockWidget import BoxLayoutDockWidget
 SIZE = 1024
 
 # Create QApplication
-qapp = qt.QApplication([])
+qapp = qt.QApplication.instance() or qt.QApplication([])
 
 # Create a SceneWindow widget
 window = SceneWindow()
@@ -83,6 +83,7 @@ window.addDockWidget(qt.Qt.BottomDockWidgetArea, dock)
 img = numpy.random.random(3 * SIZE ** 2).reshape(SIZE, SIZE, 3)  # Dummy image
 
 imageRgba = sceneWidget.addImage(img)  # Add ImageRgba item to the scene
+imageRgba.setLabel('Random RGBA image')  # Set name displayed in parameter tree
 
 # Set imageRgba transform
 imageRgba.setTranslation(SIZE*.15, SIZE*.15, 0.)  # Translate the image
diff --git a/examples/plotInteractiveImageROI.py b/examples/plotInteractiveImageROI.py
index d45bdf5..e06db89 100644
--- a/examples/plotInteractiveImageROI.py
+++ b/examples/plotInteractiveImageROI.py
@@ -39,14 +39,14 @@ from silx.gui.plot import Plot2D
 from silx.gui.plot.tools.roi import RegionOfInterestManager
 from silx.gui.plot.tools.roi import RegionOfInterestTableWidget
 from silx.gui.plot.items.roi import RectangleROI
+from silx.gui.plot.items import LineMixIn, SymbolMixIn
 
 
 def dummy_image():
     """Create a dummy image"""
     x = numpy.linspace(-1.5, 1.5, 1024)
     xv, yv = numpy.meshgrid(x, x)
-    signal = numpy.exp(- (xv ** 2 / 0.15 ** 2
-                          + yv ** 2 / 0.25 ** 2))
+    signal = numpy.exp(- (xv ** 2 / 0.15 ** 2 + yv ** 2 / 0.25 ** 2))
     # add noise
     signal += 0.3 * numpy.random.random(size=signal.shape)
     return signal
@@ -54,8 +54,12 @@ def dummy_image():
 
 app = qt.QApplication([])  # Start QApplication
 
+backend = "matplotlib"
+if "--opengl" in sys.argv:
+    backend = "opengl"
+
 # Create the plot widget and add an image
-plot = Plot2D()
+plot = Plot2D(backend=backend)
 plot.getDefaultColormap().setName('viridis')
 plot.addImage(dummy_image())
 
@@ -69,6 +73,12 @@ def updateAddedRegionOfInterest(roi):
     """Called for each added region of interest: set the name"""
     if roi.getLabel() == '':
         roi.setLabel('ROI %d' % len(roiManager.getRois()))
+    if isinstance(roi, LineMixIn):
+        roi.setLineWidth(2)
+        roi.setLineStyle('--')
+    if isinstance(roi, SymbolMixIn):
+        roi.setSymbol('o')
+        roi.setSymbolSize(5)
 
 
 roiManager.sigRoiAdded.connect(updateAddedRegionOfInterest)
@@ -99,6 +109,7 @@ widget.setLayout(layout)
 layout.addWidget(roiToolbar)
 layout.addWidget(roiTable)
 
+
 def roiDockVisibilityChanged(visible):
     """Handle change of visibility of the roi dock widget
 
@@ -107,6 +118,7 @@ def roiDockVisibilityChanged(visible):
     if not visible:
         roiManager.stop()
 
+
 dock = qt.QDockWidget('Image ROI')
 dock.setWidget(widget)
 dock.visibilityChanged.connect(roiDockVisibilityChanged)
diff --git a/examples/plotStats.py b/examples/plotStats.py
index fff7585..f7474ec 100644
--- a/examples/plotStats.py
+++ b/examples/plotStats.py
@@ -2,7 +2,7 @@
 # coding: utf-8
 # /*##########################################################################
 #
-# Copyright (c) 2016-2018 European Synchrotron Radiation Facility
+# 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
@@ -43,6 +43,7 @@ __date__ = "24/07/2018"
 
 
 from silx.gui import qt
+from silx.gui.colors import Colormap
 from silx.gui.plot import Plot1D
 from silx.gui.plot.stats.stats import StatBase
 import numpy
@@ -102,6 +103,7 @@ def main():
     plot.addScatter(x=[0, 2, 5, 5, 12, 20],
                     y=[2, 3, 4, 20, 15, 6],
                     value=[5, 6, 7, 10, 90, 20],
+                    colormap=Colormap('viridis'),
                     legend='myScatter')
 
     stats = [
diff --git a/examples/printPreview.py b/examples/printPreview.py
index 7567adb..6de8209 100755
--- a/examples/printPreview.py
+++ b/examples/printPreview.py
@@ -42,22 +42,38 @@ from silx.gui import qt
 from silx.gui.plot import PlotWidget
 from silx.gui.plot import PrintPreviewToolButton
 
+
+class MyPrintPreviewButton(PrintPreviewToolButton.PrintPreviewToolButton):
+    """This class illustrates how to subclass PrintPreviewToolButton
+    to add a title and a comment."""
+    def getTitle(self):
+        return "Widget 1's plot"
+
+    def getCommentAndPosition(self):
+        legends = self.getPlot().getAllCurves(just_legend=True)
+        comment = "Curves displayed in widget 1:\n\t"
+        if legends:
+            comment += ", ".join(legends)
+        else:
+            comment += "none"
+        return comment, "CENTER"
+
+
 app = qt.QApplication([])
 
 x = numpy.arange(1000)
 
-# first widget has a standalone print preview action
+# first widget has a standalone preview action with custom title and comment
 pw1 = PlotWidget()
 pw1.setWindowTitle("Widget 1 with standalone print preview")
 toolbar1 = qt.QToolBar(pw1)
-toolbutton1 = PrintPreviewToolButton.PrintPreviewToolButton(parent=toolbar1,
-                                                            plot=pw1)
+toolbutton1 = MyPrintPreviewButton(parent=toolbar1, plot=pw1)
 pw1.addToolBar(toolbar1)
 toolbar1.addWidget(toolbutton1)
 pw1.show()
 pw1.addCurve(x, numpy.tan(x * 2 * numpy.pi / 1000))
 
-# next two plots share a common print preview
+# next two plots share a common standard print preview
 pw2 = PlotWidget()
 pw2.setWindowTitle("Widget 2 with shared print preview")
 toolbar2 = qt.QToolBar(pw2)
diff --git a/examples/syncPlotLocation.py b/examples/syncPlotLocation.py
new file mode 100644
index 0000000..55332bc
--- /dev/null
+++ b/examples/syncPlotLocation.py
@@ -0,0 +1,105 @@
+#!/usr/bin/env python
+# coding: utf-8
+# /*##########################################################################
+#
+# Copyright (c) 2016-2017 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 is an example to illustrate how to use axis synchronization
+tool.
+"""
+
+from silx.gui import qt
+from silx.gui.plot import Plot2D
+import numpy
+import silx.test.utils
+from silx.gui.plot.utils.axis import SyncAxes
+from silx.gui.colors import Colormap
+
+
+class SyncPlot(qt.QMainWindow):
+
+    def __init__(self):
+        qt.QMainWindow.__init__(self)
+        self.setWindowTitle("Plot with synchronized axes")
+        widget = qt.QWidget(self)
+        self.setCentralWidget(widget)
+
+        layout = qt.QGridLayout()
+        widget.setLayout(layout)
+
+        backend = "gl"
+        plots = []
+
+        data = numpy.arange(100 * 100)
+        data = (data % 100) / 5.0
+        data = numpy.sin(data)
+        data.shape = 100, 100
+
+        colormaps = ["gray", "red", "green", "blue"]
+        for i in range(2 * 2):
+            plot = Plot2D(parent=widget, backend=backend)
+            plot.setInteractiveMode('pan')
+            plot.setDefaultColormap(Colormap(colormaps[i]))
+            noisyData = silx.test.utils.add_gaussian_noise(data, mean=i / 10.0)
+            plot.addImage(noisyData)
+            plots.append(plot)
+
+        xAxis = [p.getXAxis() for p in plots]
+        yAxis = [p.getYAxis() for p in plots]
+
+        self.constraint1 = SyncAxes(xAxis,
+                                    syncLimits=False,
+                                    syncScale=True,
+                                    syncDirection=True,
+                                    syncCenter=True,
+                                    syncZoom=True)
+        self.constraint2 = SyncAxes(yAxis,
+                                    syncLimits=False,
+                                    syncScale=True,
+                                    syncDirection=True,
+                                    syncCenter=True,
+                                    syncZoom=True)
+
+        for i, plot in enumerate(plots):
+            if i % 2 == 0:
+                plot.setFixedWidth(400)
+            else:
+                plot.setFixedWidth(500)
+            if i // 2 == 0:
+                plot.setFixedHeight(400)
+            else:
+                plot.setFixedHeight(500)
+            layout.addWidget(plot, i // 2, i % 2)
+
+    def createCenteredLabel(self, text):
+        label = qt.QLabel(self)
+        label.setAlignment(qt.Qt.AlignCenter)
+        label.setText(text)
+        return label
+
+
+if __name__ == "__main__":
+    app = qt.QApplication([])
+    window = SyncPlot()
+    window.setAttribute(qt.Qt.WA_DeleteOnClose, True)
+    window.setVisible(True)
+    app.exec_()
diff --git a/examples/viewer3DVolume.py b/examples/viewer3DVolume.py
index d030fba..4de04f6 100644
--- a/examples/viewer3DVolume.py
+++ b/examples/viewer3DVolume.py
@@ -52,13 +52,7 @@ logging.basicConfig()
 
 _logger = logging.getLogger(__name__)
 
-
-try:
-    import h5py
-except ImportError:
-    _logger.warning('h5py is not installed: HDF5 not supported')
-    h5py = None
-
+import h5py
 
 def load(filename):
     """Load 3D scalar field from file.
@@ -72,7 +66,7 @@ def load(filename):
     if not os.path.isfile(filename.split('::')[0]):
         raise IOError('No input file: %s' % filename)
 
-    if h5py is not None and h5py.is_hdf5(filename.split('::')[0]):
+    if h5py.is_hdf5(filename.split('::')[0]):
         if '::' not in filename:
             raise ValueError(
                 'HDF5 path not provided: Use <filename>::<path> format')