Fix CoordinateLineOverlay for Base2DPlots

CHANGES.txt

@@ -6,6 +6,9 @@ Chaco CHANGELOG
 What's new in Chaco 4.5.0
 -------------------------
 
+Fixes
+
+ * Fix CoordinateLineOverlay so that it works with Base2DPlots (PR#165).
 
 
 Release 4.4.1

chaco/overlays/coordinate_line_overlay.py

@@ -8,7 +8,7 @@
 
 from traits.api import Instance, Float, Array
 from enable.api import black_color_trait, LineStyle, Component
-from chaco.api import AbstractOverlay
+from chaco.api import AbstractOverlay, Base2DPlot
 
 
 class CoordinateLineOverlay(AbstractOverlay):
@@ -51,10 +51,16 @@ class CoordinateLineOverlay(AbstractOverlay):
     def overlay(self, component, gc, view_bounds, mode="normal"):
 
         comp = self.component
-        x_pts = comp.index_mapper.map_screen(self.index_data)
-        y_pts = comp.value_mapper.map_screen(self.value_data)
-        if comp.orientation == "v":
-            x_pts, y_pts = y_pts, x_pts
+        if isinstance(self.component, Base2DPlot):
+            x_mapper = comp.index_mapper._xmapper
+            y_mapper = comp.index_mapper._ymapper
+        else:
+            x_mapper = comp.index_mapper
+            y_mapper = comp.value_mapper
+            if comp.orientation == "v":
+                x_mapper, y_mapper = y_mapper, x_mapper
+        x_pts = x_mapper.map_screen(self.index_data)
+        y_pts = y_mapper.map_screen(self.value_data)
 
         with gc:
             # Set the line color and style parameters.

examples/demo/coordinate_line_image_overlay_demo.py

@@ -0,0 +1,129 @@
+"""
+Demonstration of the Chaco overlay CoordinateLineOverlay.
+
+A CoordinateLineOverlay is a Chaco overlay that draws "infinite"
+vertical and horizontal lines in a Chaco Plot.  In this demo,
+two instances of CoordinateLineOverlay are added to the overlays
+of a Plot containing a single line plot.
+
+Zoom out, pan around, and notice that the blue solid lines and
+the red dashed lines are always drawn all the way across the
+window.  They do not have end points.
+"""
+
+import numpy as np
+
+from traits.api import HasTraits, Instance, Array
+from traitsui.api import View, HGroup, UItem
+
+from enable.api import ComponentEditor
+
+from chaco.api import Plot, ArrayPlotData, jet
+from chaco.tools.api import PanTool, ZoomTool
+from chaco.overlays.coordinate_line_overlay import CoordinateLineOverlay
+
+
+class PlotExample(HasTraits):
+
+    # 1D arrays of coordinates where a line should be drawn.
+    x1 = Array(dtype=np.float64)
+    y1 = Array(dtype=np.float64)
+    x2 = Array(dtype=np.float64)
+    y2 = Array(dtype=np.float64)
+
+    image_plot = Instance(Plot)
+
+    image_plot_data = Instance(ArrayPlotData)
+
+    # These is used in `time_plot` to mark special times.
+    line_overlay1 = Instance(CoordinateLineOverlay)
+    line_overlay2 = Instance(CoordinateLineOverlay)
+
+    traits_view = \
+        View(
+            HGroup(
+                UItem('image_plot', editor=ComponentEditor(height=20)),
+            ),
+            title="Demo",
+            width=1000, height=640, resizable=True,
+        )
+
+    #------------------------------------------------------------------------
+    # Trait change handlers
+    #------------------------------------------------------------------------
+
+    def _x1_changed(self):
+        self.line_overlay1.index_data = self.x1
+
+    def _y1_changed(self):
+        self.line_overlay1.value_data = self.y1
+
+    def _x2_changed(self):
+        self.line_overlay2.index_data = self.x2
+
+    def _y2_changed(self):
+        self.line_overlay2.value_data = self.y2
+
+    #------------------------------------------------------------------------
+    # Trait defaults
+    #------------------------------------------------------------------------
+
+    def _x1_default(self):
+        return np.array([-np.pi, np.pi])
+
+    def _x2_default(self):
+        return np.array([np.pi/2.0])
+
+    def _y2_default(self):
+        return np.array([np.pi])
+
+    def _image_plot_data_default(self):
+        xbounds = (-2*np.pi, 2*np.pi, 600)
+        ybounds = (-1.5*np.pi, 1.5*np.pi, 300)
+        xs = np.linspace(*xbounds)
+        ys = np.linspace(*ybounds)
+        x, y = np.meshgrid(xs,ys)
+        z = np.sin(x)*y
+        data = ArrayPlotData(x=x, y=y, z=z)
+        return data
+
+    def _image_plot_default(self):
+        image_plot = Plot(self.image_plot_data)
+
+        renderer=image_plot.img_plot('z', xbounds=(-2*np.pi, 2*np.pi),
+                           ybounds=(-1.5*np.pi, 1.5*np.pi),
+                           colormap=jet)[0]
+
+        image_plot.index_axis.title = "Time"
+
+        image_plot.tools.append(PanTool(image_plot))
+
+        zoomtool = ZoomTool(image_plot, drag_button='right',
+                                                    always_on=True)
+        image_plot.overlays.append(zoomtool)
+
+        lines1 = CoordinateLineOverlay(component=renderer,
+                    index_data=self.x1,
+                    value_data=self.y1,
+                    color=(0.75, 0.25, 0.25, 0.75),
+                    line_style='dash', line_width=1)
+        renderer.underlays.append(lines1)
+        self.line_overlay1 = lines1
+
+        lines2 = CoordinateLineOverlay(component=image_plot,
+                    index_data=self.x2,
+                    value_data=self.y2,
+                    color=(0.2, 0.5, 1.0, 0.75),
+                    line_width=3)
+        image_plot.underlays.append(lines2)
+        self.line_overlay2 = lines2
+
+        return image_plot
+
+
+demo = PlotExample()
+
+
+if __name__ == "__main__":
+    ##demo.edit_traits()
+    demo.configure_traits()