#Copyright ReportLab Europe Ltd. 2000-2004 #see license.txt for license details #history http://www.reportlab.co.uk/cgi-bin/viewcvs.cgi/public/reportlab/trunk/reportlab/platypus/frames.py __version__=''' $Id: frames.py 2852 2006-05-08 15:04:15Z rgbecker $ ''' __doc__=""" """ import logging logger = logging.getLogger('reportlab.platypus') _geomAttr=('x1', 'y1', 'width', 'height', 'leftPadding', 'bottomPadding', 'rightPadding', 'topPadding') from reportlab import rl_config _FUZZ=rl_config._FUZZ class Frame: ''' A Frame is a piece of space in a document that is filled by the "flowables" in the story. For example in a book like document most pages have the text paragraphs in one or two frames. For generality a page might have several frames (for example for 3 column text or for text that wraps around a graphic). After creation a Frame is not usually manipulated directly by the applications program -- it is used internally by the platypus modules. Here is a diagramatid abstraction for the definitional part of a Frame width x2,y2 +---------------------------------+ | l top padding r | h | e +-------------------------+ i | e | f | | g | i | t | | h | g | | | t | h | p | | | t | a | | p | | d | | a | | | | d | | +-------------------------+ | | bottom padding | +---------------------------------+ (x1,y1) <-- lower left corner NOTE!! Frames are stateful objects. No single frame should be used in two documents at the same time (especially in the presence of multithreading. ''' def __init__(self, x1, y1, width,height, leftPadding=6, bottomPadding=6, rightPadding=6, topPadding=6, id=None, showBoundary=0, overlapAttachedSpace=None,_debug=None): self.id = id self._debug = _debug #these say where it goes on the page self.__dict__['_x1'] = x1 self.__dict__['_y1'] = y1 self.__dict__['_width'] = width self.__dict__['_height'] = height #these create some padding. self.__dict__['_leftPadding'] = leftPadding self.__dict__['_bottomPadding'] = bottomPadding self.__dict__['_rightPadding'] = rightPadding self.__dict__['_topPadding'] = topPadding # if we want a boundary to be shown self.showBoundary = showBoundary if overlapAttachedSpace is None: overlapAttachedSpace = rl_config.overlapAttachedSpace self._oASpace = overlapAttachedSpace self._geom() self._reset() def __getattr__(self,a): if a in _geomAttr: return self.__dict__['_'+a] raise AttributeError, a def __setattr__(self,a,v): if a in _geomAttr: self.__dict__['_'+a] = v self._geom() else: self.__dict__[a] = v def _geom(self): self._x2 = self._x1 + self._width self._y2 = self._y1 + self._height #efficiency self._y1p = self._y1 + self._bottomPadding #work out the available space self._aW = self._x2 - self._x1 - self._leftPadding - self._rightPadding self._aH = self._y2 - self._y1p - self._topPadding def _reset(self): #drawing starts at top left self._x = self._x1 + self._leftPadding self._y = self._y2 - self._topPadding self._atTop = 1 self._prevASpace = 0 # these two should NOT be set on a frame. # they are used when Indenter flowables want # to adjust edges e.g. to do nested lists self._leftExtraIndent = 0.0 self._rightExtraIndent = 0.0 def _getAvailableWidth(self): return self._aW - self._leftExtraIndent - self._rightExtraIndent def _add(self, flowable, canv, trySplit=0): """ Draws the flowable at the current position. Returns 1 if successful, 0 if it would not fit. Raises a LayoutError if the object is too wide, or if it is too high for a totally empty frame, to avoid infinite loops""" if getattr(flowable,'frameAction',None): flowable.frameAction(self) return 1 y = self._y p = self._y1p s = 0 aW = self._getAvailableWidth() if not self._atTop: s =flowable.getSpaceBefore() if self._oASpace: s = max(s-self._prevASpace,0) h = y - p - s if h>0: flowable._frame = self flowable.canv = canv #so they can use stringWidth etc w, h = flowable.wrap(aW, h) del flowable.canv, flowable._frame else: return 0 h += s y -= h if y < p-_FUZZ: if not rl_config.allowTableBoundsErrors and ((h>self._aH or w>aW) and not trySplit): raise "LayoutError", "Flowable %s (%sx%s points) too large for frame (%sx%s points)." % ( flowable.__class__, w,h, aW,self._aH) return 0 else: #now we can draw it, and update the current point. flowable._frame = self flowable.drawOn(canv, self._x + self._leftExtraIndent, y, _sW=aW-w) if self._debug: logger.debug('drew %s' % flowable.identity()) del flowable._frame s = flowable.getSpaceAfter() y -= s if self._oASpace: self._prevASpace = s if y!=self._y: self._atTop = 0 self._y = y return 1 add = _add def split(self,flowable,canv): '''Ask the flowable to split using up the available space.''' y = self._y p = self._y1p s = 0 if not self._atTop: s = flowable.getSpaceBefore() flowable.canv = canv #some flowables might need this r = flowable.split(self._aW, y-p-s) del flowable.canv return r def drawBoundary(self,canv): "draw the frame boundary as a rectangle (primarily for debugging)." from reportlab.lib.colors import Color, CMYKColor, toColor sb = self.showBoundary isColor = type(sb) in (type(''),type(()),type([])) or isinstance(sb,Color) if isColor: sb = toColor(sb,self) if sb is self: isColor = 0 else: canv.saveState() canv.setStrokeColor(sb) canv.rect( self._x1, self._y1, self._x2 - self._x1, self._y2 - self._y1 ) if isColor: canv.restoreState() def addFromList(self, drawlist, canv): """Consumes objects from the front of the list until the frame is full. If it cannot fit one object, raises an exception.""" if self._debug: logger.debug("enter Frame.addFromlist() for frame %s" % self.id) if self.showBoundary: self.drawBoundary(canv) while len(drawlist) > 0: head = drawlist[0] if self.add(head,canv,trySplit=0): del drawlist[0] else: #leave it in the list for later break