Added a Chaco example.

Author: Jonathan Rocher

Chaco/zoom_overlay.py

@@ -0,0 +1,89 @@
+"""
+The main executable file for the zoom_plot demo.
+Right-click and drag on the upper plot to select a region to view in detail
+in the lower plot.  The selected region can be moved around by dragging,
+or resized by clicking on one of its edges and dragging.
+"""
+# Standard library imports
+import os
+# Major library imports
+from numpy import amin, amax, arange, searchsorted, sin, pi, linspace
+from enthought.enable.example_support import DemoFrame, demo_main
+# Enthought imports
+from enthought.enable.api import Component, ComponentEditor, Window
+from enthought.traits.api import HasTraits, Instance
+from enthought.traits.ui.api import Item, Group, View
+from enthought.util.resource import find_resource
+# Chaco imports
+from enthought.chaco.api import SimplePlotFrame, VPlotContainer
+from enthought.chaco.tools.api import RangeSelection
+# Relative imports
+from grid_plot_factory import create_gridded_line_plot
+from zoom_overlay import ZoomOverlay
+     
+sample_path = os.path.join('examples','data','sample.wav')
+alt_path = os.path.join('..','data','sample.wav')
+fname = find_resource('Chaco', sample_path, alt_path=alt_path,
+    return_path=True)
+numpts = 3000
+def read_music_data():
+    from wav_to_numeric import wav_to_numeric
+    index, data = wav_to_numeric(fname)
+    return index[:numpts], data[:numpts]
+def create_zoomed_plot():
+    try:
+        x,y = read_music_data()
+    except:
+        x = linspace(-10*pi, 10*pi, numpts)
+        y = sin(x)
+    main_plot = create_gridded_line_plot(x,y)
+    zoom_plot = create_gridded_line_plot(x,y)
+    outer_container = VPlotContainer(padding=30,
+                                     fill_padding=True,
+                                     spacing=50,
+                                     stack_order='top_to_bottom',
+                                     bgcolor='lightgray',
+                                     use_backbuffer=True)
+    outer_container.add(main_plot)
+    outer_container.add(zoom_plot)
+   
+    main_plot.controller = RangeSelection(main_plot)
+   
+    zoom_overlay = ZoomOverlay(source=main_plot, destination=zoom_plot)
+    outer_container.overlays.append(zoom_overlay)
+    return outer_container
+#===============================================================================
+# Attributes to use for the plot view.
+size = (800, 600)
+title = fname
+       
+#===============================================================================
+# # Demo class that is used by the demo.py application.
+#===============================================================================
+class Demo(HasTraits):
+    plot = Instance(Component)
+   
+    traits_view = View(
+                    Group(
+                        Item('plot', editor=ComponentEditor(size=size), 
+                             show_label=False),
+                        orientation = "vertical"),
+                    resizable=True, title=title,
+                    width=size[0], height=size[1]
+                    )
+   
+    def _plot_default(self):
+         return create_zoomed_plot()
+   
+demo = Demo()
+#===============================================================================
+# Stand-alone frame to display the plot.
+#===============================================================================
+class PlotFrame(DemoFrame):
+    def _create_window(self):
+        # Return a window containing our plots
+        return Window(self, -1, component=create_zoomed_plot())
+   
+if __name__ == "__main__":
+    demo_main(PlotFrame, size=size, title=title)
+#--EOF---