#see license.txt for license details

__doc__="""

"""

_geomAttr=('x1', 'y1', 'width', 'height', 'leftPadding', 'bottomPadding', 'rightPadding', 'topPadding')

_FUZZ=1e-6 # to avoid numerical difficulties we use this as an error band

from reportlab import rl_config

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):

        self.id = id

        #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

        # 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

        # 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

    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"""

        y = self._y

        p = self._y1p

        s = 0

        if not self._atTop:

            s =flowable.getSpaceBefore()

            if self._oASpace:

                h = self._prevASpace

                if h>s: s = 0

                else: s = s - h

        h = y - p - s

        if h>0:

            flowable.canv = canv #so they can use stringWidth etc

            w, h = flowable.wrap(self._getAvailableWidth(), h)

            del flowable.canv

        else:

            return 0

        h = h + s

        y = y - h

        if y < p-_FUZZ:

            if not rl_config.allowTableBoundsErrors and ((h>self._aH or w>self._aW) and not trySplit):

                raise "LayoutError", "Flowable %s (%sx%s points) too large for frame (%sx%s points)." % (

                    flowable.__class__, w,h, self._getAvailableWidth(),self._aH)

            return 0

        else:

            #now we can draw it, and update the current point.

            flowable.drawOn(canv, self._x + self._leftExtraIndent, y, _sW=self._getAvailableWidth()-w)

            s = flowable.getSpaceAfter()

            y = 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

        #print 'asked table to split.  _aW = %0.2f, y-p-s=%0.2f' % (self._aW, y-p-s)

        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.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