Source code for enable.primitives.line

# (C) Copyright 2005-2022 Enthought, Inc., Austin, TX
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# This software is provided without warranty under the terms of the BSD
# license included in LICENSE.txt and may be redistributed only under
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""" A line segment component. """

from numpy import array, resize

# Enthought library imports.
from kiva.api import FILL, FILL_STROKE, STROKE
from traits.api import Any, Event, Float, List, Bool

# Local imports.
from enable.api import border_size_trait, Component
from enable.colors import ColorTrait

[docs]class Line(Component): """A line segment component""" # Event fired when the points are no longer updating. # PZW: there seems to be a missing defn here; investigate. # An event to indicate that the point list has changed updated = Event # The color of the line. line_color = ColorTrait("black") # The dash pattern for the line. line_dash = Any # The width of the line. line_width = border_size_trait(1) # The points that make up this polygon. points = List # List of Tuples # The color of each vertex. vertex_color = ColorTrait("black") # The size of each vertex. vertex_size = Float(3.0) # Whether to draw the path closed, with a line back to the first point close_path = Bool(True) # ------------------------------------------------------------------------- # 'Line' interface # -------------------------------------------------------------------------
[docs] def reset(self): "Reset the polygon to the initial state" self.points = [] self.event_state = "normal" self.updated = self
# ------------------------------------------------------------------------- # 'Component' interface # ------------------------------------------------------------------------- def _draw_mainlayer(self, gc, view_bounds=None, mode="default"): "Draw this line in the specified graphics context" if len(self.points) > 1: with gc: # Set the drawing parameters. gc.set_stroke_color(self.line_color_) gc.set_line_dash(self.line_dash) gc.set_line_width(self.line_width) # Draw the path as lines. gc.begin_path() offset_points = [(x, y) for x, y in self.points] offset_points = resize( array(offset_points), (len(self.points), 2) ) gc.lines(offset_points) if self.close_path: gc.close_path() gc.draw_path(STROKE) if len(self.points) > 0: with gc: # Draw the vertices. self._draw_points(gc) # ------------------------------------------------------------------------- # Private interface # ------------------------------------------------------------------------- def _draw_points(self, gc): "Draw the points of the line" # Shortcut out if we would draw transparently. if self.vertex_color_[3] != 0: with gc: gc.set_fill_color(self.vertex_color_) gc.set_line_dash(None) offset_points = [(x, y) for x, y in self.points] offset_points = resize( array(offset_points), (len(self.points), 2) ) offset = self.vertex_size / 2.0 if hasattr(gc, "draw_path_at_points"): path = gc.get_empty_path() path.rect( -offset, -offset, self.vertex_size, self.vertex_size ) gc.draw_path_at_points(offset_points, path, FILL_STROKE) else: for x, y in offset_points: gc.draw_rect( ( x - offset, y - offset, self.vertex_size, self.vertex_size, ), FILL, )