def paint(edge):
'''Draw lobj, an AggLine, as a simple line with text labels along its length.'''
startx, starty, endx, endy, dx, dy = _adj_coords(edge)
#construct the points
pts = util.mkpoints([(startx, starty), (endx, endy)])
#get style data from edge stylesheet
sheet = edge.stylesheet
stroke = sheet.stroke_color
text_color = sheet.text_color
font = sheet.text_fontdesc
#draw the line
GooCanvas.CanvasPolyline(end_arrow=edge.end_arrow, start_arrow=edge.start_arrow, points=pts, parent=edge, arrow_length=9, arrow_tip_length=7, arrow_width=7, line_width=edge.width/2, stroke_color_rgba=stroke)
#draw a label above the center of the line
center = edge.get_xyr()
text_color = edge.stylesheet.text_color
font = edge.stylesheet.text_fontdesc
#the label field is a dict of three labels, each a list of [weight,text]
label = edge.label
origin = edge.origin.label
dest = edge.dest.label
cx = center['x']
cy = center['y']
deg = degrees(atan(dy/dx))
#Pick which perpendicular based on dx to keep it "above" the line (bottoms
#of letters always face the line).
nx = -dy if dx < 0 else dy
ny = dx if dx < 0 else -dx
#multiply for distance from the line, and adj to eminate from the center coords
topx = nx*3 + cx
topy = ny*3 + cy
botx = -nx*3 + cx
boty = -ny*3 + cy
#make the label
parts = []
if label['to']: parts.append(' '.join((origin, label['to'][1], dest)))
if label['from']: parts.append(' '.join((dest, label['from'][1], origin)))
toptext = "; ".join(parts)
bottext = 'Both '+label['bidir'][1] if label['bidir'] else '';
toplbl = GooCanvas.CanvasText(parent=edge, text=toptext, alignment="center", fill_color_rgba=text_color, font_desc=font, anchor=GooCanvas.CanvasAnchorType.SOUTH, x=topx, y=topy)
botlbl = GooCanvas.CanvasText(parent=edge, text=bottext, alignment="center", fill_color_rgba=text_color, font_desc=font, anchor=GooCanvas.CanvasAnchorType.NORTH, x=botx, y=boty)
#rotate the label appropriately
toplbl.rotate(deg, topx, topy)
botlbl.rotate(deg, botx, boty)
def show_selected(edge):
'''Draw a highlight outline around the edge.'''
startx, starty, endx, endy, dx, dy = _adj_coords(edge)
#construct the points
pts = util.mkpoints([(startx, starty), (endx, endy)])
sheet = edge.stylesheet
stroke = sheet.sel_color
width = edge.width/2 + sheet.sel_width*2
arrow_len = 10*(edge.width/2)/width
arrow_tip_len = 7*(edge.width/2)/width
arrow_width = 9*(edge.width/2)/width
#draw the line
highlight = GooCanvas.CanvasPolyline(end_arrow=edge.end_arrow, start_arrow=edge.start_arrow, arrow_length=arrow_len, arrow_tip_length=arrow_tip_len, arrow_width=arrow_width, points=pts, parent=edge, line_width=width, stroke_color_rgba=stroke)
highlight.lower(edge.get_child(0))
return highlight
