Enh: Simplify controlling text of ImageInspectorOverlay

chaco/tools/image_inspector_tool.py

@@ -67,15 +67,15 @@ def normal_mouse_move(self, event):
                 if hasattr(plot, "_cached_mapped_image") and \
                        plot._cached_mapped_image is not None:
                     self.new_value = \
-                            dict(indices=ndx,
-                                 data_value=image_data.data[y_index, x_index],
-                                 color_value=plot._cached_mapped_image[y_index,
-                                                                       x_index])
+                        {"indices": ndx,
+                         "data_value": image_data.data[y_index, x_index],
+                         "color_value": plot._cached_mapped_image[y_index,
+                                                                  x_index]}
 
                 else:
                     self.new_value = \
-                        dict(indices=ndx,
-                             color_value=image_data.data[y_index, x_index])
+                        {"indices": ndx,
+                         "color_value": image_data.data[y_index, x_index]}
 
                 self.last_mouse_position = (event.x, event.y)
         return
@@ -100,10 +100,35 @@ class ImageInspectorOverlay(TextBoxOverlay):
     # tool's location, or whether it should be forced to be hidden or visible.
     visibility = Enum("auto", True, False)
 
+    # Private interface -------------------------------------------------------
+
+    def _build_text_from_event(self, event):
+        """ Create a formatted string to display from the mouse event data.
+        """
+        newstring = ""
+        if 'indices' in event:
+            newstring += '(%d, %d)' % event['indices']
+        if 'color_value' in event:
+            try:
+                newstring += "\n(%d, %d, %d)" % tuple(
+                    map(int, event['color_value'][:3]))
+            except IndexError:
+                # color value is an integer, for example if gray scale image
+                newstring += "\n%d" % event['color_value']
+
+        if 'data_value' in event:
+            newstring += "\n{}".format(event['data_value'])
+
+        return newstring
+
+    # Traits listeners --------------------------------------------------------
+
     def _image_inspector_changed(self, old, new):
         if old:
-            old.on_trait_event(self._new_value_updated, 'new_value', remove=True)
-            old.on_trait_change(self._tool_visible_changed, "visible", remove=True)
+            old.on_trait_event(self._new_value_updated, 'new_value',
+                               remove=True)
+            old.on_trait_change(self._tool_visible_changed, "visible",
+                                remove=True)
         if new:
             new.on_trait_event(self._new_value_updated, 'new_value')
             new.on_trait_change(self._tool_visible_changed, "visible")
@@ -123,16 +148,7 @@ def _new_value_updated(self, event):
         else:
             self.alternate_position = None
 
-        d = event
-        newstring = ""
-        if 'indices' in d:
-            newstring += '(%d, %d)' % d['indices'] + '\n'
-        if 'color_value' in d:
-            newstring += "(%d, %d, %d)" % tuple(map(int,d['color_value'][:3])) + "\n"
-        if 'data_value' in d:
-            newstring += str(d['data_value'])
-
-        self.text = newstring
+        self.text = self._build_text_from_event(event)
         self.component.request_redraw()
 
     def _visible_changed(self):

chaco/tools/tests/test_image_inspector.py

@@ -0,0 +1,209 @@
+""" Tests for the ImageInspectorTool and ImageInspectorOverlay tools.
+"""
+
+from unittest import TestCase
+import numpy as np
+from numpy.testing import assert_array_equal
+
+from chaco.api import ArrayPlotData, Plot
+from chaco.tools.api import ImageInspectorTool, ImageInspectorOverlay
+from enable.testing import EnableTestAssistant
+from traits.testing.unittest_tools import UnittestTools
+
+
+def create_image_plot(img_values, **kwargs):
+    data = ArrayPlotData(img=img_values)
+    plot = Plot(data)
+    plot.img_plot("img", **kwargs)
+    return plot
+
+
+class CustomImageInspectorOverlay(ImageInspectorOverlay):
+    def _build_text_from_event(self, event):
+        return 'Position: ({}, {})'.format(*event['indices'])
+
+
+class BaseImageInspectorTool(EnableTestAssistant, UnittestTools):
+    def setUp(self):
+        # Control the pixel size of the plot to know where the tiles are:
+        self.plot.bounds = [100, 100]
+        self.plot._window = self.create_mock_window()
+        renderer = self.plot.plots["plot0"][0]
+        self.tool = ImageInspectorTool(component=renderer)
+        self.overlay = ImageInspectorOverlay(component=renderer,
+                                             image_inspector=self.tool)
+        self.overlay2 = CustomImageInspectorOverlay(component=renderer,
+                                                    image_inspector=self.tool)
+        self.plot.active_tool = self.tool
+        self.plot.do_layout()
+
+        self.insp_event = None
+
+    def test_mouse_move_records_last_position(self):
+        tool = self.tool
+
+        self.assertEqual(tool.last_mouse_position, ())
+
+        self.mouse_move(tool, 0, 0)
+        self.assertEqual(tool.last_mouse_position, (0, 0))
+
+        self.mouse_move(tool, 10, 10)
+        self.assertEqual(tool.last_mouse_position, (10, 10))
+
+        self.mouse_leave(tool, 1000, 1000)
+        self.assertEqual(tool.last_mouse_position, (10, 10))
+
+    def test_mouse_move_custom_overlay(self):
+        tool = self.tool
+
+        # Add a listener to catch the emitted event:
+        tool.on_trait_change(self.store_inspector_event, "new_value")
+        try:
+            self.assertIsNone(self.insp_event)
+
+            with self.assertTraitChanges(tool, "new_value", 1):
+                with self.assertTraitChanges(self.overlay2, "text", 1):
+                    self.mouse_move(tool, 0, 0)
+
+            self.assertEqual(self.overlay2.text, 'Position: (0, 0)')
+        finally:
+            tool.on_trait_change(self.store_inspector_event, "new_value",
+                                 remove=True)
+
+    # Helper methods ----------------------------------------------------------
+
+    def store_inspector_event(self, event):
+        self.insp_event = event
+
+
+class TestImageInspectorToolGray(BaseImageInspectorTool, TestCase):
+    """ Tests for the ImageInspector tool with a gray scale image
+    """
+
+    def setUp(self):
+        values = np.arange(4).reshape(2, 2)
+        self.plot = create_image_plot(values)
+        super(TestImageInspectorToolGray, self).setUp()
+
+    def test_mouse_move_collect_image_info(self):
+        tool = self.tool
+
+        # Add a listener to catch the emitted event:
+        tool.on_trait_change(self.store_inspector_event, "new_value")
+        try:
+            self.assertIsNone(self.insp_event)
+
+            with self.assertTraitChanges(tool, "new_value", 1):
+                with self.assertTraitChanges(self.overlay, "text", 1):
+                    self.mouse_move(tool, 0, 0)
+                    self.assertEqual(self.insp_event["color_value"], 0)
+                    self.assertEqual(self.insp_event["indices"], (0, 0))
+
+                    self.assertEqual(self.overlay.text, '(0, 0)\n0')
+
+            with self.assertTraitChanges(tool, "new_value", 1):
+                with self.assertTraitChanges(self.overlay, "text", 1):
+                    # Move within the same tile:
+                    self.mouse_move(tool, 90, 0)
+                    self.assertEqual(self.insp_event["color_value"], 1)
+                    self.assertEqual(self.insp_event["indices"], (1, 0))
+
+                    self.assertEqual(self.overlay.text, '(1, 0)\n1')
+
+            with self.assertTraitChanges(tool, "new_value", 1):
+                with self.assertTraitDoesNotChange(self.overlay, "text"):
+                    # Move within the same tile:
+                    self.mouse_move(tool, 91, 0)
+                    self.assertEqual(self.insp_event["color_value"], 1)
+                    self.assertEqual(self.insp_event["indices"], (1, 0))
+
+            with self.assertTraitChanges(tool, "new_value", 1):
+                with self.assertTraitChanges(self.overlay, "text", 1):
+                    # Move to another value in the image:
+                    self.mouse_move(tool, 0, 90)
+                    self.assertEqual(self.insp_event["color_value"], 2)
+                    self.assertEqual(self.insp_event["indices"], (0, 1))
+
+                    self.assertEqual(self.overlay.text, '(0, 1)\n2')
+
+            with self.assertTraitChanges(tool, "new_value", 1):
+                with self.assertTraitChanges(self.overlay, "text", 1):
+                    # Move within the same tile:
+                    self.mouse_move(tool, 90, 90)
+                    self.assertEqual(self.insp_event["color_value"], 3)
+                    self.assertEqual(self.insp_event["indices"], (1, 1))
+
+                    self.assertEqual(self.overlay.text, '(1, 1)\n3')
+
+        finally:
+            tool.on_trait_change(self.store_inspector_event, "new_value",
+                                 remove=True)
+
+
+class TestImageInspectorToolRGB(BaseImageInspectorTool, TestCase):
+    """ Tests for the ImageInspector tool with an RGB image.
+    """
+
+    def setUp(self):
+        values = np.arange(12).reshape(2, 2, 3)
+        self.plot = create_image_plot(values)
+        super(TestImageInspectorToolRGB, self).setUp()
+
+    def test_mouse_move_collect_image_info(self):
+        tool = self.tool
+
+        # Add a listener to catch the emitted event:
+        tool.on_trait_change(self.store_inspector_event, "new_value")
+        try:
+            self.assertIsNone(self.insp_event)
+
+            with self.assertTraitChanges(tool, "new_value", 1):
+                with self.assertTraitChanges(self.overlay, "text", 1):
+                    self.mouse_move(tool, 0, 0)
+                    assert_array_equal(self.insp_event["color_value"],
+                                       np.array([0, 1, 2]))
+                    self.assertEqual(self.insp_event["indices"], (0, 0))
+
+                    self.assertEqual(self.overlay.text, '(0, 0)\n(0, 1, 2)')
+
+            with self.assertTraitChanges(tool, "new_value", 1):
+                with self.assertTraitChanges(self.overlay, "text", 1):
+                    # Move within the same tile:
+                    self.mouse_move(tool, 90, 0)
+                    assert_array_equal(self.insp_event["color_value"],
+                                       np.array([3, 4, 5]))
+                    self.assertEqual(self.insp_event["indices"], (1, 0))
+
+                    self.assertEqual(self.overlay.text, '(1, 0)\n(3, 4, 5)')
+
+            with self.assertTraitChanges(tool, "new_value", 1):
+                with self.assertTraitDoesNotChange(self.overlay, "text"):
+                    # Move within the same tile:
+                    self.mouse_move(tool, 91, 0)
+                    assert_array_equal(self.insp_event["color_value"],
+                                       np.array([3, 4, 5]))
+                    self.assertEqual(self.insp_event["indices"], (1, 0))
+
+            with self.assertTraitChanges(tool, "new_value", 1):
+                with self.assertTraitChanges(self.overlay, "text", 1):
+                    # Move to another value in the image:
+                    self.mouse_move(tool, 0, 90)
+                    assert_array_equal(self.insp_event["color_value"],
+                                       np.array([6, 7, 8]))
+                    self.assertEqual(self.insp_event["indices"], (0, 1))
+
+                    self.assertEqual(self.overlay.text, '(0, 1)\n(6, 7, 8)')
+
+            with self.assertTraitChanges(tool, "new_value", 1):
+                with self.assertTraitChanges(self.overlay, "text", 1):
+                    # Move within the same tile:
+                    self.mouse_move(tool, 90, 90)
+                    assert_array_equal(self.insp_event["color_value"],
+                                       np.array([9, 10, 11]))
+                    self.assertEqual(self.insp_event["indices"], (1, 1))
+
+                    self.assertEqual(self.overlay.text, '(1, 1)\n(9, 10, 11)')
+
+        finally:
+            tool.on_trait_change(self.store_inspector_event, "new_value",
+                                 remove=True)

examples/demo/basic/image_inspector.py

@@ -57,7 +57,7 @@ def _create_plot_component():# Create a scalar field to colormap
     plot.tools.append(PanTool(plot))
     zoom = ZoomTool(component=plot, tool_mode="box", always_on=False)
     plot.overlays.append(zoom)
-    imgtool = ImageInspectorTool(img_plot)
+    imgtool = ImageInspectorTool(component=img_plot)
     img_plot.tools.append(imgtool)
     overlay = ImageInspectorOverlay(component=img_plot, image_inspector=imgtool,
                                     bgcolor="white", border_visible=True)