Merge e3d9388 into 3e52ecb

chaco/tools/better_zoom.py

@@ -2,7 +2,7 @@
 
 from chaco.grid_mapper import GridMapper
 from enable.api import BaseTool, KeySpec
-from traits.api import Enum, Float, Instance, Bool, HasTraits, List
+from traits.api import Enum, Float, Instance, Bool, List, Tuple
 
 from tool_history_mixin import ToolHistoryMixin
 from tool_states import ZoomState, PanState, GroupedToolState, ToolState
@@ -56,6 +56,9 @@ class BetterZoom(BaseTool, ToolHistoryMixin):
     # The amount to zoom in by. The zoom out will be inversely proportional
     zoom_factor = Float(2.0)
 
+    #: the position to zoom on (usually the mouse location)
+    position = Tuple(Float, Float)
+
     # The zoom factor on each axis
     _index_factor = Float(1.0)
     _value_factor = Float(1.0)
@@ -358,3 +361,11 @@ def _reset_state_pressed(self):
         for state in self._history[::-1]:
             state.revert(self)
         self._history = []
+
+    #--------------------------------------------------------------------------
+    #  Traits defaults
+    #--------------------------------------------------------------------------
+
+    def _position_default(self):
+        # center of the component is a sensible default
+        return self._center_screen()

chaco/tools/tests/better_zoom_test_case.py

@@ -0,0 +1,37 @@
+import unittest
+
+import numpy
+
+from chaco.api import create_line_plot
+from chaco.tools.api import BetterZoom
+from enable.testing import EnableTestAssistant
+from traits.testing.api import UnittestTools
+
+class TestBetterZoomTool(EnableTestAssistant, UnittestTools, unittest.TestCase):
+    """ Tests for the TraversePolyLine enable tool """
+
+    def setUp(self):
+        values = numpy.arange(10)
+        self.plot = create_line_plot((values, values))
+        self.plot.bounds = [100, 100]
+        self.plot._window = self.create_mock_window()
+        self.tool = BetterZoom(component=self.plot)
+        self.plot.active_tool = self.tool
+        self.plot.do_layout()
+
+    def tearDown(self):
+        del self.tool
+        del self.plot
+
+    def test_default_position(self):
+        tool = self.tool
+
+        # this doesn't throw an exception
+        self.send_key(tool, '+')
+
+        self.assertEqual(tool.position, (50, 50))
+
+        # expected behaviour for a normal zoom in operation
+        self.assertNotEqual(tool._index_factor, 1.0)
+        self.assertNotEqual(tool._value_factor, 1.0)
+        self.assertEqual(len(tool._history), 2)