"""
Displaying large NumPy arrays with TabularEditor

A demonstration of how the TabularEditor can be used to display (large) NumPy
arrays, in this case 100,000 random 3D points from a unit cube.

In addition to showing the coordinates of each point, it also displays the
index of each point in the array, as well as a red flag if the point lies within
0.25 of the center of the cube.
"""

#-- Imports --------------------------------------------------------------

from numpy import sqrt
from numpy.random import random
from traits.api import HasTraits, Property, Array
from traitsui.api import View, Item, TabularEditor, Font
from traitsui.tabular_adapter import TabularAdapter

#-- Tabular Adapter Definition -------------------------------------------


class ArrayAdapter(TabularAdapter):

    columns = [('i', 'index'), ('x', 0), ('y', 1), ('z', 2)]

    # Font fails with wx in OSX; see traitsui issue #13:
    # font        = Font('Courier 10')
    alignment = 'right'
    format = '%.4f'
    index_text = Property()
    index_image = Property()

    def _get_index_text(self):
        return str(self.row)

    def _get_index_image(self):
        x, y, z = self.item
        if sqrt((x - 0.5) ** 2 + (y - 0.5) ** 2 + (z - 0.5) ** 2) <= 0.25:
            return '@icons:red_ball'

        return None

#-- ShowArray Class Definition -------------------------------------------


class ShowArray(HasTraits):

    data = Array

    view = View(
        Item('data',
             show_label=False,
             style='readonly',
             editor=TabularEditor(adapter=ArrayAdapter())
             ),
        title='Array Viewer',
        width=0.3,
        height=0.8,
        resizable=True
    )

# Create the demo:
demo = ShowArray(data=random((100000, 3)))

# Run the demo (if invoked from the command line):
if __name__ == '__main__':
    demo.configure_traits()
