How to use the chaco.tools.api.RangeSelectionOverlay function in chaco

def create_colorbar(colormap):
    colorbar = ColorBar(index_mapper=LinearMapper(range=colormap.range),
                        color_mapper=colormap,
                        orientation='v',
                        resizable='v',
                        width=30,
                        padding=20)
    colorbar.tools.append(RangeSelection(component=colorbar))
    colorbar.overlays.append(RangeSelectionOverlay(component=colorbar,
                                                   border_color="white",
                                                   alpha=0.8,
                                                   fill_color="lightgray"))
    return colorbar

# Create the colorbar, handing in the appropriate range and colormap
    colormap = my_plot.color_mapper
    colorbar = ColorBar(index_mapper=LinearMapper(range=colormap.range),
                        color_mapper=colormap,
                        plot=my_plot,
                        orientation='v',
                        resizable='v',
                        width=30,
                        padding=20)
    colorbar.padding_top = plot.padding_top
    colorbar.padding_bottom = plot.padding_bottom

    # create a range selection for the colorbar
    range_selection = RangeSelection(component=colorbar)
    colorbar.tools.append(range_selection)
    colorbar.overlays.append(RangeSelectionOverlay(component=colorbar,
                                                   border_color="white",
                                                   alpha=0.8,
                                                   fill_color="lightgray"))

    # we also want to the range selection to inform the cmap plot of
    # the selection, so set that up as well
    range_selection.listeners.append(my_plot)

    # Create a container to position the plot and the colorbar side-by-side
    container = HPlotContainer(use_backbuffer = True)
    container.add(plot)
    container.add(colorbar)
    container.bgcolor = "lightgray"

    #my_plot.set_value_selection((-1.3, 6.9))

colormap = self.my_plot.color_mapper
        self.colorbar = ColorBar(index_mapper=LinearMapper(range=colormap.range),
                            color_mapper=colormap,
                            plot=self.my_plot,
                            orientation='v',
                            resizable='v',
                            width=30,
                            padding=20)
            
        self.colorbar.padding_top = self.tplot.padding_top
        self.colorbar.padding_bottom = self.tplot.padding_bottom
        
        # create a range selection for the colorbar
        self.range_selection = RangeSelection(component=self.colorbar)
        self.colorbar.tools.append(self.range_selection)
        self.colorbar.overlays.append(RangeSelectionOverlay(component=self.colorbar,
                                                       border_color="white",
                                                       alpha=0.8,
                                                       fill_color="lightgray"))
    
        # we also want to the range selection to inform the cmap plot of
        # the selection, so set that up as well
        self.range_selection.listeners.append(self.my_plot)
    
        # Create a container to position the plot and the colorbar side-by-side
        container = HPlotContainer(use_backbuffer = True)
        container.add(self.tplot)
        container.add(self.colorbar)
        container.bgcolor = "white"
    
        return container

self.maintool = (fctool,None)
            fctool.on_trait_change(self._add_feature_point,'mouse_clicked')

        elif new == 'Range Select':
            pl.tools[0].drag_button = 'right'
            fplot = pl.plots['flux'][0]

            #TODO:clean up these hacky bugfix techniques if possible
            rstool = RangeSelectionBugfix(component=fplot,
                                          left_button_selects=True,
                                          enable_resize=False,
                                          mapper=self.plot.x_mapper)
            rstool.plot = fplot
            rstool.component = pl

            rsoverlay = RangeSelectionOverlay(component=fplot,
                                              mapper=self.plot.x_mapper)
            rsoverlay.plot = fplot
            rsoverlay.component = pl
            self.maintool = (rstool,rsoverlay)
            rstool.on_trait_change(self._add_feature_range,'selection_completed')

        elif new == 'Base Select':
            pl.tools[0].drag_button = 'right'
            slt = SingleLineTool(component=self.plot)
            slt.component = self.plot
            self.maintool = (slt,slt)
            slt.on_trait_change(self._add_feature_base,'finished')
        elif new == 'Click Delete':
            pl.tools[0].drag_button = 'right'
            fctool = FeatureClickTool(plot=self.plot)
            self.maintool = (fctool,None)

def create_colorbar(colormap):
    colorbar = ColorBar(index_mapper=LinearMapper(range=colormap.range),
                        color_mapper=colormap,
                        orientation='v',
                        resizable='v',
                        width=30,
                        padding=20)
    colorbar.grid_visible = False
    colorbar._axis.tick_visible = False
    colorbar.tools.append(RangeSelection(component=colorbar))
    colorbar.overlays.append(RangeSelectionOverlay(component=colorbar,
                                                   border_color="white",
                                                   alpha=0.8,
                                                   fill_color="lightgray"))
    return colorbar

selection_type="range")
        cmap_renderer.overlays.append(selection)
        if self.thresh is not None:
            cmap_renderer.color_data.metadata['selections']=self.thresh
            cmap_renderer.color_data.metadata_changed={'selections':self.thresh}
        # Create the colorbar, handing in the appropriate range and colormap
        colormap=scatplot.color_mapper
        colorbar = ColorBar(index_mapper=LinearMapper(range=DataRange1D(low = 0.0,
                                       high = 1.0)),
                        orientation='v',
                        resizable='v',
                        width=30,
                        padding=20)
        colorbar_selection=RangeSelection(component=colorbar)
        colorbar.tools.append(colorbar_selection)
        ovr=colorbar.overlays.append(RangeSelectionOverlay(component=colorbar,
                                                   border_color="white",
                                                   alpha=0.8,
                                                   fill_color="lightgray",
                                                   metadata_name='selections'))
        #ipshell('colorbar, colorbar_selection and ovr available:')
        self.cbar_selection=colorbar_selection
        self.cmap_renderer=cmap_renderer
        colorbar.plot = cmap_renderer
        colorbar.padding_top = scatplot.padding_top
        colorbar.padding_bottom = scatplot.padding_bottom
        self.colorbar=colorbar
        return colorbar

color_mapper=colormap,
                            plot=self.my_plot,
                            orientation='v',
                            resizable='v',
                            width=30,
                            padding=20)
            
        self.colorbar.padding_top = self.tplot.padding_top
        self.colorbar.padding_bottom = self.tplot.padding_bottom
        
        # TODO: the range selection gives a Segmentation Fault,
        # but why, the matrix_viewer.py example works just fine!
        # create a range selection for the colorbar
        self.range_selection = RangeSelection(component=self.colorbar)
        self.colorbar.tools.append(self.range_selection)
        self.colorbar.overlays.append(RangeSelectionOverlay(component=self.colorbar,
                                                       border_color="white",
                                                       alpha=0.8,
                                                       fill_color="lightgray"))
    
        # we also want to the range selection to inform the cmap plot of
        # the selection, so set that up as well
        #self.range_selection.listeners.append(self.my_plot)
    
        # Create a container to position the plot and the colorbar side-by-side
        container = HPlotContainer(use_backbuffer = True)
        container.add(self.tplot)
        container.add(self.colorbar)
        container.bgcolor = "white"
    
        # my_plot.set_value_selection((-1.3, 6.9))

inds=range(len(self.df.index))
        idx=ArrayDataSource(inds)
        vals=ArrayDataSource(df.index.values)
        
        index_range = DataRange1D(idx)        
        val_range=DataRange1D(vals)
        imap=LinearMapper(range=index_range)#,stretch_data=self.index_mapper.stretch_data)     
        vmap=LinearMapper(range=val_range)
     #   mycomp.index_range.refresh()
        
        mycomp.index_mapper=imap        
        mycomp.value_mapper=vmap
        
        self.rangeselect=RangeSelection(mycomp, axis=self.selection_axis)
        self.plot.active_tool = self.rangeselect
        self.plot.overlays.append(RangeSelectionOverlay(component=mycomp)) 
        self.rangeselect.on_trait_change(self.on_selection_changed, "selection")