Current File : //lib/python3/dist-packages/reportlab/pdfgen/pathobject.py
#Copyright ReportLab Europe Ltd. 2000-2017
#see license.txt for license details
#history https://hg.reportlab.com/hg-public/reportlab/log/tip/src/reportlab/pdfgen/pathobject.py
__version__='3.3.0'
__doc__="""
PDFPathObject is an efficient way to draw paths on a Canvas. Do not
instantiate directly, obtain one from the Canvas instead.
Progress Reports:
8.83, 2000-01-13, gmcm: created from pdfgen.py
"""
from reportlab.pdfgen import pdfgeom
from reportlab.lib.rl_accel import fp_str
class PDFPathObject:
"""Represents a graphic path. There are certain 'modes' to PDF
drawing, and making a separate object to expose Path operations
ensures they are completed with no run-time overhead. Ask
the Canvas for a PDFPath with getNewPathObject(); moveto/lineto/
curveto wherever you want; add whole shapes; and then add it back
into the canvas with one of the relevant operators.
Path objects are probably not long, so we pack onto one line
the code argument allows a canvas to get the operations appended directly so
avoiding the final getCode
"""
def __init__(self,code=None):
self._code = (code,[])[code is None]
self._code_append = self._init_code_append
def _init_code_append(self,c):
assert c.endswith(' m') or c.endswith(' re'), 'path must start with a moveto or rect'
code_append = self._code.append
code_append('n')
code_append(c)
self._code_append = code_append
def getCode(self):
"pack onto one line; used internally"
return ' '.join(self._code)
def moveTo(self, x, y):
self._code_append('%s m' % fp_str(x,y))
def lineTo(self, x, y):
self._code_append('%s l' % fp_str(x,y))
def curveTo(self, x1, y1, x2, y2, x3, y3):
self._code_append('%s c' % fp_str(x1, y1, x2, y2, x3, y3))
def arc(self, x1,y1, x2,y2, startAng=0, extent=90):
"""Contributed to piddlePDF by Robert Kern, 28/7/99.
Draw a partial ellipse inscribed within the rectangle x1,y1,x2,y2,
starting at startAng degrees and covering extent degrees. Angles
start with 0 to the right (+x) and increase counter-clockwise.
These should have x1<x2 and y1<y2.
The algorithm is an elliptical generalization of the formulae in
Jim Fitzsimmon's TeX tutorial <URL: http://www.tinaja.com/bezarc1.pdf>."""
self._curves(pdfgeom.bezierArc(x1,y1, x2,y2, startAng, extent))
def arcTo(self, x1,y1, x2,y2, startAng=0, extent=90):
"""Like arc, but draws a line from the current point to
the start if the start is not the current point."""
self._curves(pdfgeom.bezierArc(x1,y1, x2,y2, startAng, extent),'lineTo')
def rect(self, x, y, width, height):
"""Adds a rectangle to the path"""
self._code_append('%s re' % fp_str((x, y, width, height)))
def ellipse(self, x, y, width, height):
"""adds an ellipse to the path"""
self._curves(pdfgeom.bezierArc(x, y, x + width,y + height, 0, 360))
def _curves(self,curves,initial='moveTo'):
getattr(self,initial)(*curves[0][:2])
for curve in curves:
self.curveTo(*curve[2:])
def circle(self, x_cen, y_cen, r):
"""adds a circle to the path"""
x1 = x_cen - r
y1 = y_cen - r
width = height = 2*r
self.ellipse(x1, y1, width, height)
def roundRect(self, x, y, width, height, radius):
"""Draws a rectangle with rounded corners. The corners are
approximately quadrants of a circle, with the given radius."""
#use a precomputed set of factors for the bezier approximation
#to a circle. There are six relevant points on the x axis and y axis.
#sketch them and it should all make sense!
m = 0.4472 #radius multiplier
xhi = x,x+width
xlo, xhi = min(xhi), max(xhi)
yhi = y,y+height
ylo, yhi = min(yhi), max(yhi)
if isinstance(radius,(list,tuple)):
r = [max(0,r) for r in radius]
if len(r)<4: r += (4-len(r))*[0]
self.moveTo(xlo + r[2], ylo) #start at bottom left
self.lineTo(xhi - r[3], ylo) #bottom row
if r[3]>0:
t = m*r[3]
self.curveTo(xhi - t, ylo, xhi, ylo + t, xhi, ylo + r[3]) #bottom right
self.lineTo(xhi, yhi - r[1]) #right edge
if r[1]>0:
t = m*r[1]
self.curveTo(xhi, yhi - t, xhi - t, yhi, xhi - r[1], yhi) #top right
self.lineTo(xlo + r[0], yhi) #top row
if r[0]>0:
t = m*r[0]
self.curveTo(xlo + t, yhi, xlo, yhi - t, xlo, yhi - r[0]) #top left
self.lineTo(xlo, ylo + r[2]) #left edge
if r[2]>0:
t = m*r[2]
self.curveTo(xlo, ylo + t, xlo + t, ylo, xlo + r[2], ylo) #bottom left
# 4 radii top left top right bittom left bottom right
else:
t = m * radius
self.moveTo(xlo + radius, ylo)
self.lineTo(xhi - radius, ylo) #bottom row
self.curveTo(xhi - t, ylo, xhi, ylo + t, xhi, ylo + radius) #bottom right
self.lineTo(xhi, yhi - radius) #right edge
self.curveTo(xhi, yhi - t, xhi - t, yhi, xhi - radius, yhi) #top right
self.lineTo(xlo + radius, yhi) #top row
self.curveTo(xlo + t, yhi, xlo, yhi - t, xlo, yhi - radius) #top left
self.lineTo(xlo, ylo + radius) #left edge
self.curveTo(xlo, ylo + t, xlo + t, ylo, xlo + radius, ylo) #bottom left
self.close()
def close(self):
"draws a line back to where it started"
self._code_append('h')
Mini Shell