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# All rights reserved.
#
# This software is provided without warranty under the terms of the BSD
# license included in LICENSE.txt and may be redistributed only under
# the conditions described in the aforementioned license. The license
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""" Defines the DrawPointsTool class.
"""
# Major library imports
from numpy import array, float64, hstack

# Enthought library imports
from traits.api import Instance, Bool
from enable.api import BaseTool

# Chaco import
from chaco.array_data_source import ArrayDataSource


class DrawPointsTool(BaseTool):
    """A tool that draws points onto a rectangular plot as they are clicked."""

    #: A data source for the x-dimension of the drawn points.
    xdata = Instance(ArrayDataSource)
    #: A data source for the y-dimension of the drawn points.
    ydata = Instance(ArrayDataSource)
    #: Is this the active tool?
    activated = Bool(True)

    # It would be nice to set the pointer to a cross

    def __init__(self, **kwtraits):
        BaseTool.__init__(self, **kwtraits)
        self.xdata = self.component.value1
        self.ydata = self.component.value2

    def normal_left_down(self, event):
        """Handles the left mouse button being clicked when the tool is in the
        'normal' state.

        Maps the event position into data space, adds the point to the points
        for this tool, and redraws.
        """
        x, y = event.x, event.y
        data_x, data_y = self.component.map_data((x, y))
        self._append_data(self.xdata, data_x)
        self._append_data(self.ydata, data_y)
        self.component.request_redraw()

    def _activate(self):
        self.activated = True

    def _deactivate(self):
        self.activated = False

    def _append_data(self, datasource, data):
        olddata = array(datasource.get_data(), float64)
        newdata = hstack((olddata, data))
        datasource.set_data(newdata)