#copyright ReportLab Inc. 2000
#see license.txt for license details
#history http://cvs.sourceforge.net/cgi-bin/cvsweb.cgi/reportlab/platypus/doctemplate.py?cvsroot=reportlab
#$Header: /tmp/reportlab/reportlab/platypus/doctemplate.py,v 1.52 2002/03/12 15:18:03 rgbecker Exp $
__version__=''' $Id: doctemplate.py,v 1.52 2002/03/12 15:18:03 rgbecker Exp $ '''
__doc__="""
This module contains the core structure of platypus.
Platypus constructs documents. Document styles are determined by DocumentTemplates.
Each DocumentTemplate contains one or more PageTemplates which defines the look of the
pages of the document.
Each PageTemplate has a procedure for drawing the "non-flowing" part of the page
(for example the header, footer, page number, fixed logo graphic, watermark, etcetera) and
a set of Frames which enclose the flowing part of the page (for example the paragraphs,
tables, or non-fixed diagrams of the text).
A document is built when a DocumentTemplate is fed a sequence of Flowables.
The action of the build consumes the flowables in order and places them onto
frames on pages as space allows. When a frame runs out of space the next frame
of the page is used. If no frame remains a new page is created. A new page
can also be created if a page break is forced.
The special invisible flowable NextPageTemplate can be used to specify
the page template for the next page (which by default is the one being used
for the current frame).
"""
from reportlab.platypus.flowables import *
from reportlab.platypus.paragraph import Paragraph
from reportlab.platypus.frames import Frame
from reportlab.rl_config import defaultPageSize, verbose
import reportlab.lib.sequencer
from types import *
import sys
def _doNothing(canvas, doc):
"Dummy callback for onPage"
pass
class IndexingFlowable(Flowable):
"""Abstract interface definition for flowables which might
hold references to other pages or themselves be targets
of cross-references. XRefStart, XRefDest, Table of Contents,
Indexes etc."""
def isIndexing(self):
return 1
def isSatisfied(self):
return 1
def notify(self, kind, stuff):
"""This will be called by the framework wherever 'stuff' happens.
'kind' will be a value that can be used to decide whether to
pay attention or not."""
pass
def beforeBuild(self):
"""Called by multiBuild before it starts; use this to clear
old contents"""
pass
def afterBuild(self):
"""Called after build ends but before isSatisfied"""
pass
class ActionFlowable(Flowable):
'''This Flowable is never drawn, it can be used for data driven controls
For example to change a page template (from one column to two, for example)
use NextPageTemplate which creates an ActionFlowable.
'''
def __init__(self,action=()):
if type(action) not in (ListType, TupleType):
action = (action,)
self.action = tuple(action)
def wrap(self, availWidth, availHeight):
'''Should never be called.'''
raise NotImplementedError
def draw(self):
'''Should never be called.'''
raise NotImplementedError
def apply(self,doc):
'''
This is called by the doc.build processing to allow the instance to
implement its behaviour
'''
action = self.action[0]
args = tuple(self.action[1:])
arn = 'handle_'+action
try:
apply(getattr(doc,arn), args)
except AttributeError, aerr:
if aerr.args[0]==arn:
raise NotImplementedError, "Can't handle ActionFlowable(%s)" % action
else:
raise
except "bogus":
t, v, None = sys.exc_info()
raise t, "%s\n handle_%s args=%s"%(v,action,args)
def __call__(self):
return self
class NextFrameFlowable(ActionFlowable):
def __init__(self,ix,resume=0):
ActionFlowable.__init__(self,('nextFrame',ix,resume))
class CurrentFrameFlowable(ActionFlowable):
def __init__(self,ix,resume=0):
ActionFlowable.__init__(self,('currentFrame',ix,resume))
class _FrameBreak(ActionFlowable):
'''
A special ActionFlowable that allows setting doc._nextFrameIndex
eg story.append(FrameBreak('mySpecialFrame'))
'''
def __call__(self,ix=None,resume=0):
r = self.__class__(self.action+(resume,))
r._ix = ix
return r
def apply(self,doc):
if getattr(self,'_ix',None): doc._nextFrameIndex = self._ix
ActionFlowable.apply(self,doc)
FrameBreak = _FrameBreak('frameEnd')
PageBegin = ActionFlowable('pageBegin')
class NextPageTemplate(ActionFlowable):
"""When you get to the next page, use the template specified (change to two column, for example) """
def __init__(self,pt):
ActionFlowable.__init__(self,('nextPageTemplate',pt))
class PageTemplate:
"""
essentially a list of Frames and an onPage routine to call at the start
of a page when this is selected. onPageEnd gets called at the end.
derived classes can also implement beforeDrawPage and afterDrawPage if they want
"""
def __init__(self,id=None,frames=[],onPage=_doNothing, onPageEnd=_doNothing,
pagesize=defaultPageSize):
if type(frames) not in (ListType,TupleType): frames = [frames]
assert filter(lambda x: not isinstance(x,Frame), frames)==[], "frames argument error"
self.id = id
self.frames = frames
self.onPage = onPage
self.onPageEnd = onPageEnd
self.pagesize = pagesize
def beforeDrawPage(self,canv,doc):
"""Override this if you want additional functionality or prefer
a class based page routine. Called before any flowables for
this page are processed."""
pass
def checkPageSize(self,canv,doc):
'''This gets called by the template framework
If canv size != doc size then the canv size is set to
the template size or if that's not available to the
doc size.
'''
#### NEVER EVER EVER COMPARE FLOATS FOR EQUALITY
#RGB converting pagesizes to ints means we are accurate to one point
#RGB I suggest we should be aiming a little better
cp = None
dp = None
sp = None
if canv._pagesize: cp = map(int, canv._pagesize)
if self.pagesize: sp = map(int, self.pagesize)
if doc.pagesize: dp = map(int, doc.pagesize)
if cp!=sp:
if sp:
canv.setPageSize(self.pagesize)
elif cp!=dp:
canv.setPageSize(doc.pagesize)
def afterDrawPage(self, canv, doc):
"""This is called after the last flowable for the page has
been processed. You might use this if the page header or
footer needed knowledge of what flowables were drawn on
this page."""
pass
class BaseDocTemplate:
"""
First attempt at defining a document template class.
The basic idea is simple.
0) The document has a list of data associated with it
this data should derive from flowables. We'll have
special classes like PageBreak, FrameBreak to do things
like forcing a page end etc.
1) The document has one or more page templates.
2) Each page template has one or more frames.
3) The document class provides base methods for handling the
story events and some reasonable methods for getting the
story flowables into the frames.
4) The document instances can override the base handler routines.
Most of the methods for this class are not called directly by the user,
but in some advanced usages they may need to be overridden via subclassing.
EXCEPTION: doctemplate.build(...) must be called for most reasonable uses
since it builds a document using the page template.
Each document template builds exactly one document into a file specified
by the filename argument on initialization.
Possible keyword arguments for the initialization:
pageTemplates: A list of templates. Must be nonempty. Names
assigned to the templates are used for referring to them so no two used
templates should have the same name. For example you might want one template
for a title page, one for a section first page, one for a first page of
a chapter and two more for the interior of a chapter on odd and even pages.
If this argument is omitted then at least one pageTemplate should be provided
using the addPageTemplates method before the document is built.
showBoundary: if set draw a box around the frame boundaries.
leftMargin:
rightMargin:
topMargin:
bottomMargin: Margin sizes in points (default 1 inch)
These margins may be overridden by the pageTemplates. They are primarily of interest
for the SimpleDocumentTemplate subclass.
allowSplitting: If set flowables (eg, paragraphs) may be split across frames or pages
(default: 1)
title: Internal title for document (does not automatically display on any page)
author: Internal author for document (does not automatically display on any page)
"""
_initArgs = { 'pagesize':defaultPageSize,
'pageTemplates':[],
'showBoundary':0,
'leftMargin':inch,
'rightMargin':inch,
'topMargin':inch,
'bottomMargin':inch,
'allowSplitting':1,
'title':None,
'author':None,
'_pageBreakQuick':1}
_invalidInitArgs = ()
def __init__(self, filename, **kw):
"""create a document template bound to a filename (see class documentation for keyword arguments)"""
self.filename = filename
for k in self._initArgs.keys():
if not kw.has_key(k):
v = self._initArgs[k]
else:
if k in self._invalidInitArgs:
raise ValueError, "Invalid argument %s" % k
v = kw[k]
setattr(self,k,v)
#print "pagesize is", self.pagesize
p = self.pageTemplates
self.pageTemplates = []
self.addPageTemplates(p)
# facility to assist multi-build and cross-referencing.
# various hooks can put things into here - key is what
# you want, value is a page number. This can then be
# passed to indexing flowables.
self._pageRefs = {}
self._indexingFlowables = []
#callback facility
self._onPage = None
self._calc()
self.afterInit()
def _calc(self):
self._rightMargin = self.pagesize[0] - self.rightMargin
self._topMargin = self.pagesize[1] - self.topMargin
self.width = self._rightMargin - self.leftMargin
self.height = self._topMargin - self.bottomMargin
def setPageCallBack(self, func):
'Progress monitor - func(pageNo) called on each new page'
self._onPage = func
def clean_hanging(self):
'handle internal postponed actions'
while len(self._hanging):
self.handle_flowable(self._hanging)
def addPageTemplates(self,pageTemplates):
'add one or a sequence of pageTemplates'
if type(pageTemplates) not in (ListType,TupleType):
pageTemplates = [pageTemplates]
#this test below fails due to inconsistent imports!
#assert filter(lambda x: not isinstance(x,PageTemplate), pageTemplates)==[], "pageTemplates argument error"
for t in pageTemplates:
self.pageTemplates.append(t)
def handle_documentBegin(self):
'''implement actions at beginning of document'''
self._hanging = [PageBegin]
self.pageTemplate = self.pageTemplates[0]
self.page = 0
self.beforeDocument()
def handle_pageBegin(self):
'''Perform actions required at beginning of page.
shouldn't normally be called directly'''
self.page = self.page + 1
self.pageTemplate.beforeDrawPage(self.canv,self)
self.pageTemplate.checkPageSize(self.canv,self)
self.pageTemplate.onPage(self.canv,self)
for f in self.pageTemplate.frames: f._reset()
self.beforePage()
if hasattr(self,'_nextFrameIndex'):
del self._nextFrameIndex
self.frame = self.pageTemplate.frames[0]
self.handle_frameBegin()
def handle_pageEnd(self):
''' show the current page
check the next page template
hang a page begin
'''
self.pageTemplate.afterDrawPage(self.canv, self)
self.pageTemplate.onPageEnd(self.canv, self)
self.afterPage()
self.canv.showPage()
if hasattr(self,'_nextPageTemplateIndex'):
self.pageTemplate = self.pageTemplates[self._nextPageTemplateIndex]
del self._nextPageTemplateIndex
self._hanging.append(PageBegin)
def handle_pageBreak(self):
'''some might choose not to end all the frames'''
if self._pageBreakQuick:
self.handle_pageEnd()
else:
n = len(self._hanging)
while len(self._hanging)==n:
self.handle_frameEnd()
def handle_frameBegin(self,resume=0):
'''What to do at the beginning of a frame'''
f = self.frame
if f._atTop:
if self.showBoundary or self.frame.showBoundary:
self.frame.drawBoundary(self.canv)
def handle_frameEnd(self,resume=0):
''' Handles the semantics of the end of a frame. This includes the selection of
the next frame or if this is the last frame then invoke pageEnd.
'''
if hasattr(self,'_nextFrameIndex'):
frame = self.pageTemplate.frames[self._nextFrameIndex]
del self._nextFrameIndex
self.handle_frameBegin(resume)
elif hasattr(self.frame,'lastFrame') or self.frame is self.pageTemplate.frames[-1]:
self.handle_pageEnd()
self.frame = None
else:
f = self.frame
self.frame = self.pageTemplate.frames[self.pageTemplate.frames.index(f) + 1]
self.handle_frameBegin()
def handle_nextPageTemplate(self,pt):
'''On endPage chenge to the page template with name or index pt'''
if type(pt) is StringType:
for t in self.pageTemplates:
if t.id == pt:
self._nextPageTemplateIndex = self.pageTemplates.index(t)
return
raise ValueError, "can't find template('%s')"%pt
elif type(pt) is IntType:
self._nextPageTemplateIndex = pt
else:
raise TypeError, "argument pt should be string or integer"
def handle_nextFrame(self,fx):
'''On endFrame chenge to the frame with name or index fx'''
if type(fx) is StringType:
for f in self.pageTemplate.frames:
if f.id == fx:
self._nextFrameIndex = self.pageTemplate.frames.index(f)
return
raise ValueError, "can't find frame('%s')"%fx
elif type(fx) is IntType:
self._nextFrameIndex = fx
else:
raise TypeError, "argument fx should be string or integer"
def handle_currentFrame(self,fx):
'''chenge to the frame with name or index fx'''
if type(fx) is StringType:
for f in self.pageTemplate.frames:
if f.id == fx:
self._nextFrameIndex = self.pageTemplate.frames.index(f)
return
raise ValueError, "can't find frame('%s')"%fx
elif type(fx) is IntType:
self._nextFrameIndex = fx
else:
raise TypeError, "argument fx should be string or integer"
def handle_breakBefore(self, flowables):
'''preprocessing step to allow pageBreakBefore and frameBreakBefore attributes'''
first = flowables[0]
# if we insert a page break before, we'll process that, see it again,
# and go in an infinite loop. So we need to set a flag on the object
# saying 'skip me'. This should be unset on the next pass
if hasattr(first, '_skipMeNextTime'):
delattr(first, '_skipMeNextTime')
return
# this could all be made much quicker by putting the attributes
# in to the flowables with a defult value of 0
if hasattr(first,'pageBreakBefore') and first.pageBreakBefore == 1:
first._skipMeNextTime = 1
first.insert(0, PageBreak())
return
if hasattr(first,'style') and hasattr(first.style, 'pageBreakBefore') and first.style.pageBreakBefore == 1:
first._skipMeNextTime = 1
flowables.insert(0, PageBreak())
return
if hasattr(first,'frameBreakBefore') and first.frameBreakBefore == 1:
first._skipMeNextTime = 1
flowables.insert(0, FrameBreak())
return
if hasattr(first,'style') and hasattr(first.style, 'frameBreakBefore') and first.style.frameBreakBefore == 1:
first._skipMeNextTime = 1
flowables.insert(0, FrameBreak())
return
def handle_keepWithNext(self, flowables):
"implements keepWithNext"
i = 0
n = len(flowables)
while i<n and flowables[i].getKeepWithNext(): i = i + 1
if i:
i = i + 1
K = KeepTogether(flowables[:i])
for f in K._flowables:
f.keepWithNext = 0
del flowables[:i]
flowables.insert(0,K)
def handle_flowable(self,flowables):
'''try to handle one flowable from the front of list flowables.'''
#allow document a chance to look at, modify or ignore
#the object(s) about to be processed
self.filterFlowables(flowables)
self.handle_breakBefore(flowables)
self.handle_keepWithNext(flowables)
f = flowables[0]
del flowables[0]
if f is None:
return
if isinstance(f,PageBreak):
self.handle_pageBreak()
self.afterFlowable(f)
elif isinstance(f,ActionFlowable):
f.apply(self)
self.afterFlowable(f)
else:
#try to fit it then draw it
if self.frame.add(f, self.canv, trySplit=self.allowSplitting):
self.afterFlowable(f)
else:
#if isinstance(f, KeepTogether): print 'could not add it to frame'
if self.allowSplitting:
# see if this is a splittable thing
S = self.frame.split(f,self.canv)
n = len(S)
else:
n = 0
#if isinstance(f, KeepTogether): print 'n=%d' % n
if n:
if self.frame.add(S[0], self.canv, trySplit=0):
self.afterFlowable(S[0])
else:
print 'n = %d' % n
raise "LayoutError", "splitting error on page %d in\n%s" % (self.page,f.identity(30))
del S[0]
for f in xrange(n-1):
flowables.insert(f,S[f]) # put split flowables back on the list
else:
# this must be cleared when they are finally drawn!
## if hasattr(f,'postponed'):
if hasattr(f,'_postponed'):
message = "Flowable %s too large on page %d" % (f.identity(30), self.page)
#show us, it might be handy
#HACK = it seems within tables we sometimes
#get an empty paragraph that won't fit and this
#causes it to fall over. FIXME FIXME FIXME
raise "LayoutError", message
## f.postponed = 1
f._postponed = 1
flowables.insert(0,f) # put the flowable back
self.handle_frameEnd()
#these are provided so that deriving classes can refer to them
_handle_documentBegin = handle_documentBegin
_handle_pageBegin = handle_pageBegin
_handle_pageEnd = handle_pageEnd
_handle_frameBegin = handle_frameBegin
_handle_frameEnd = handle_frameEnd
_handle_flowable = handle_flowable
_handle_nextPageTemplate = handle_nextPageTemplate
_handle_currentFrame = handle_currentFrame
_handle_nextFrame = handle_nextFrame
def _startBuild(self, filename=None, canvasmaker=canvas.Canvas):
self._calc()
self.canv = canvasmaker(filename or self.filename,pagesize=self.pagesize)
if self._onPage:
self.canv.setPageCallBack(self._onPage)
self.handle_documentBegin()
def _endBuild(self):
if self._hanging!=[] and self._hanging[-1] is PageBegin:
del self._hanging[-1]
self.clean_hanging()
else:
self.clean_hanging()
self.handle_pageBreak()
if getattr(self,'_doSave',1): self.canv.save()
if self._onPage: self.canv.setPageCallBack(None)
def build(self, flowables, filename=None, canvasmaker=canvas.Canvas):
"""Build the document from a list of flowables.
If the filename argument is provided then that filename is used
rather than the one provided upon initialization.
If the canvasmaker argument is provided then it will be used
instead of the default. For example a slideshow might use
an alternate canvas which places 6 slides on a page (by
doing translations, scalings and redefining the page break
operations).
"""
#assert filter(lambda x: not isinstance(x,Flowable), flowables)==[], "flowables argument error"
self._startBuild(filename,canvasmaker)
while len(flowables):
self.clean_hanging()
self.handle_flowable(flowables)
self._endBuild()
def _allSatisfied(self):
"""Called by multi-build - are all cross-references resolved?"""
allHappy = 1
for f in self._indexingFlowables:
if not f.isSatisfied():
allHappy = 0
break
return allHappy
def notify(self, kind, stuff):
""""Forward to any listeners"""
for l in self._indexingFlowables:
l.notify(kind, stuff)
def pageRef(self, label):
"""hook to register a page number"""
if verbose: print "pageRef called with label '%s' on page %d" % (
label, self.page)
self._pageRefs[label] = self.page
def multiBuild(self, story,
filename=None,
canvasmaker=canvas.Canvas,
maxPasses = 10):
"""Makes multiple passes until all indexing flowables
are happy."""
self._indexingFlowables = []
#scan the story and keep a copy
for thing in story:
if thing.isIndexing():
self._indexingFlowables.append(thing)
#print 'scanned story, found these indexing flowables:\n'
#print self._indexingFlowables
passes = 0
while 1:
passes = passes + 1
if verbose: print 'building pass '+str(passes) + '...',
for fl in self._indexingFlowables:
fl.beforeBuild()
# work with a copy of the story, since it is consumed
tempStory = story[:]
self.build(tempStory, filename, canvasmaker)
#self.notify('debug',None)
#clean up so multi-build does not go wrong - the frame
#packer might have tacked an attribute onto some
#paragraphs
for elem in story:
## if hasattr(elem, 'postponed'):
## del elem.postponed
if hasattr(elem, '_postponed'):
del elem._postponed
for fl in self._indexingFlowables:
fl.afterBuild()
happy = self._allSatisfied()
if happy:
## print 'OK'
break
## else:
## print 'failed'
if passes > maxPasses:
raise IndexError, "Index entries not resolved after %d passes" % maxPasses
if verbose: print 'saved'
#these are pure virtuals override in derived classes
#NB these get called at suitable places by the base class
#so if you derive and override the handle_xxx methods
#it's up to you to ensure that they maintain the needed consistency
def afterInit(self):
"""This is called after initialisation of the base class."""
pass
def beforeDocument(self):
"""This is called before any processing is
done on the document."""
pass
def beforePage(self):
"""This is called at the beginning of page
processing, and immediately before the
beforeDrawPage method of the current page
template."""
pass
def afterPage(self):
"""This is called after page processing, and
immediately after the afterDrawPage method
of the current page template."""
pass
def filterFlowables(self,flowables):
'''called to filter flowables at the start of the main handle_flowable method.
Upon return if flowables[0] has been set to None it is discarded and the main
method returns.
'''
pass
def afterFlowable(self, flowable):
'''called after a flowable has been rendered'''
pass
class SimpleDocTemplate(BaseDocTemplate):
"""A special case document template that will handle many simple documents.
See documentation for BaseDocTemplate. No pageTemplates are required
for this special case. A page templates are inferred from the
margin information and the onFirstPage, onLaterPages arguments to the build method.
A document which has all pages with the same look except for the first
page may can be built using this special approach.
"""
_invalidInitArgs = ('pageTemplates',)
def handle_pageBegin(self):
'''override base method to add a change of page template after the firstpage.
'''
self._handle_pageBegin()
self._handle_nextPageTemplate('Later')
def build(self,flowables,onFirstPage=_doNothing, onLaterPages=_doNothing):
"""build the document using the flowables. Annotate the first page using the onFirstPage
function and later pages using the onLaterPages function. The onXXX pages should follow
the signature
def myOnFirstPage(canvas, document):
# do annotations and modify the document
...
The functions can do things like draw logos, page numbers,
footers, etcetera. They can use external variables to vary
the look (for example providing page numbering or section names).
"""
self._calc() #in case we changed margins sizes etc
frameT = Frame(self.leftMargin, self.bottomMargin, self.width, self.height, id='normal')
self.addPageTemplates([PageTemplate(id='First',frames=frameT, onPage=onFirstPage,pagesize=self.pagesize),
PageTemplate(id='Later',frames=frameT, onPage=onLaterPages,pagesize=self.pagesize)])
if onFirstPage is _doNothing and hasattr(self,'onFirstPage'):
self.pageTemplates[0].beforeDrawPage = self.onFirstPage
if onLaterPages is _doNothing and hasattr(self,'onLaterPages'):
self.pageTemplates[1].beforeDrawPage = self.onLaterPages
BaseDocTemplate.build(self,flowables)
##########################################################
##
## testing
##
##########################################################
def randomText():
#this may or may not be appropriate in your company
from random import randint, choice
RANDOMWORDS = ['strategic','direction','proactive',
'reengineering','forecast','resources',
'forward-thinking','profit','growth','doubletalk',
'venture capital','IPO']
sentences = 5
output = ""
for sentenceno in range(randint(1,5)):
output = output + 'Blah'
for wordno in range(randint(10,25)):
if randint(0,4)==0:
word = choice(RANDOMWORDS)
else:
word = 'blah'
output = output + ' ' +word
output = output+'.'
return output
if __name__ == '__main__':
def myFirstPage(canvas, doc):
canvas.saveState()
canvas.setStrokeColor(red)
canvas.setLineWidth(5)
canvas.line(66,72,66,PAGE_HEIGHT-72)
canvas.setFont('Times-Bold',24)
canvas.drawString(108, PAGE_HEIGHT-108, "TABLE OF CONTENTS DEMO")
canvas.setFont('Times-Roman',12)
canvas.drawString(4 * inch, 0.75 * inch, "First Page")
canvas.restoreState()
def myLaterPages(canvas, doc):
canvas.saveState()
canvas.setStrokeColor(red)
canvas.setLineWidth(5)
canvas.line(66,72,66,PAGE_HEIGHT-72)
canvas.setFont('Times-Roman',12)
canvas.drawString(4 * inch, 0.75 * inch, "Page %d" % doc.page)
canvas.restoreState()
def run():
objects_to_draw = []
from reportlab.lib.styles import ParagraphStyle
#from paragraph import Paragraph
from doctemplate import SimpleDocTemplate
#need a style
normal = ParagraphStyle('normal')
normal.firstLineIndent = 18
normal.spaceBefore = 6
import random
for i in range(15):
height = 0.5 + (2*random.random())
box = XBox(6 * inch, height * inch, 'Box Number %d' % i)
objects_to_draw.append(box)
para = Paragraph(randomText(), normal)
objects_to_draw.append(para)
SimpleDocTemplate('doctemplate.pdf').build(objects_to_draw,
onFirstPage=myFirstPage,onLaterPages=myLaterPages)
run()