Source code for enable.primitives.line
# (C) Copyright 2005-2022 Enthought, Inc., Austin, TX
# 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
# is also available online at http://www.enthought.com/licenses/BSD.txt
#
# Thanks for using Enthought open source!
""" 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,
)