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Loads and saves RGB images from disk
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- Left-drag pans the plot.
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- Mousewheel up and down zooms the plot in and out.
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- Pressing "z" brings up the Zoom Box, and you can click-drag a rectangular
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region to zoom. If you use a sequence of zoom boxes, pressing alt-left-arrow
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and alt-right-arrow moves you forwards and backwards through the "zoom
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# Standard library imports
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# Major library imports
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# Enthought library imports
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from traits.util.resource import find_resource
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from traits.api import File, HasTraits, Instance
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from traitsui.api import Handler, Item, View
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import Action, CloseAction, Menu, MenuBar, OKCancelButtons, Separator
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import ArrayPlotData, ImageData, Plot, PlotGraphicsContext
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from enable.component_editor import ComponentEditor
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from chaco.tools.api import PanTool, ZoomTool
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#-------------------------------------------------------------------------------
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#-------------------------------------------------------------------------------
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class DemoView(HasTraits):
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### Public Traits ##########################################################
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# A Plot Data object to hold our image data
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pd = Instance(ArrayPlotData, ())
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# A Plot object to plot our image data
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### Private Traits #########################################################
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# File name to load image from
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resource_path = os.path.join('examples','basic','capitol.jpg')
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alt_path = 'capitol.jpg'
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image_path = find_resource('Chaco', resource_path, alt_path=alt_path,
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_load_file = File(image_path)
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# File name to save image to
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### Traits Views ###########################################################
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# This view is for a file dialog to select the 'load' filename
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load_file_view = View(
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buttons=OKCancelButtons,
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kind='livemodal', # NB must use livemodal, plot objects don't copy well
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# This view is for a file dialog to select the 'save' filename
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save_file_view = View(
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buttons=OKCancelButtons,
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kind='livemodal', # NB must use livemodal, plot objects don't copy well
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#---------------------------------------------------------------------------
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# Public 'DemoView' interface
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#---------------------------------------------------------------------------
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def __init__(self, *args, **kwargs):
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super(DemoView, self).__init__(*args, **kwargs)
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# Create the plot object, set some options, and add some tools
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plot = self.plot = Plot(self.pd, default_origin="top left")
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plot.x_axis.orientation = "top"
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plot.tools.append(PanTool(plot))
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zoom = ZoomTool(component=plot, tool_mode="box", always_on=False)
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plot.overlays.append(zoom)
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# Load the default image
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# Plot the image plot with this image
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self.plot.img_plot("imagedata")
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def default_traits_view(self):
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""" Returns the default view to use for this class.
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# NOTE: I moved the view to this method so we can declare a handler
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# for the view. Alternatively, we could move the DemoController class
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# to the top and declare view=Instance(HasTraits) instead.
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editor=ComponentEditor(),
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Menu(Action(name="Save Plot", action="save"), # see Controller for
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Action(name="Load Plot", action="load"), # these callbacks
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handler=DemoController
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#---------------------------------------------------------------------------
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# Private 'DemoView' interface
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#---------------------------------------------------------------------------
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# Create a graphics context of the right size
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win_size = self.plot.outer_bounds
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plot_gc = PlotGraphicsContext(win_size)
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# Have the plot component into it
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plot_gc.render_component(self.plot)
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# Save out to the user supplied filename
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plot_gc.save(self._save_file)
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# Load the image with the user supplied filename
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image = ImageData.fromfile(self._load_file)
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# Update the plot data. NB we must extract _date from the image
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# for the time being, until ImageData is made more friendly
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self.pd.set_data("imagedata", image._data)
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# Set the title and redraw
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self.plot.title = os.path.basename(self._load_file)
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self.plot.request_redraw()
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# If loading fails, simply do nothing
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#-------------------------------------------------------------------------------
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# Class 'DemoController'
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#-------------------------------------------------------------------------------
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class DemoController(Handler):
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# The HasTraits object we are a controller for
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view = Instance(DemoView)
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#---------------------------------------------------------------------------
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# Public 'DemoController' interface
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#---------------------------------------------------------------------------
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def init(self, info):
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""" Initializes the controls of a user interface.
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Overridden here to assign the 'view' trait.
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self.view = info.object
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def save(self, ui_info):
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Callback for the 'Save Image' menu option.
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ui = self.view.edit_traits(view='save_file_view')
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if ui.result == True:
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def load(self, ui_info):
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Callback for the 'Load Image' menu option.
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ui = self.view.edit_traits(view='load_file_view')
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if ui.result == True:
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#===============================================================================
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# # popup object that is used by the demo.py application.
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#===============================================================================
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# Note: we declare a 'popup' rather than a 'demo' since the menubar doesn't seem
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# to show up in a 'panel' mode.
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#-------------------------------------------------------------------------------
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#-------------------------------------------------------------------------------
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view.configure_traits()
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#-------------------------------------------------------------------------------
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if __name__ == "__main__":
added
removed
examples/demo/basic/image_from_file.py
