pidTK.py

""" 
A Tkinter based backend for piddle. 
  
Perry A. Stoll 
  
Created: February 15, 1999 
  
Requires PIL for rotated string support.

Known Problems: 
     - Doesn't handle the interactive commands yet.
     - PIL based canvas inherits lack of underlining strings from piddlePIL
     
You can find the latest version of this file:
    via http://piddle.sourceforge.net
""" 
# we depend on PIL for rotated strings so watch for changes in PIL

import Tkinter, tkFont
tk = Tkinter
import sping.pid
import string
  
__version__ = "0.3" 
__date__    = "April 8, 1999" 
__author__  = "Perry Stoll,  perry.stoll@mail.com " 

# fixups by chris lee, cwlee@artsci.wustl.edu
# $Id$
# - added drawImage scaling support
# - shifted baseline y parameter in drawString to work around font metric
#         shift due to Tkinter's Canvas text_item object
# - fixed argument names so that argument keywords agreed with piddle.py (passes discipline.py)
#
#
# ToDo: for TKCanvas
#         make sure that fontHeight() is returnng appropriate measure.  Where is this info?
#     
# $Log: pidTK.py,v $
# Revision 1.1  2002/07/12 18:34:47  glandrum
# added
#
# Revision 1.6  2000/11/03 00:56:57  clee
# fixed sizing error in TKCanvas
#
# Revision 1.5  2000/11/03 00:25:37  clee
# removed reference to "BaseTKCanvas" (should just use TKCanvas as default)
#
# Revision 1.4  2000/10/29 19:35:31  clee
# eliminated BaseTKCanvas in favor of straightforward "TKCanvas" name
#
# Revision 1.3  2000/10/29 01:57:41  clee
# - added scrollbar support to both TKCanvas and TKCanvasPIL
# - added getTKCanvas() access method to TKCanvasPIL
#
# Revision 1.2  2000/10/15 00:47:17  clee
# commit before continuing after getting pil to work as package
#
# Revision 1.1.1.1  2000/09/27 03:53:15  clee
# Simple Platform Independent Graphics
#
# Revision 1.6  2000/04/06 01:55:34  pmagwene
# - TKCanvas now uses multiple inheritance from Tkinter.Canvas and piddle.Canvas
# 	* for the most part works much like a normal Tkinter.Canvas object
# - TKCanvas draws rotated strings using PIL image, other objects using normal Tk calls
# - Minor fixes to FontManager and TKCanvas so can specify root window other than Tk()
# - Removed Quit/Clear buttons from default canvas
#
# Revision 1.5  2000/03/12 07:07:42  clee
# sync with 1_x
#
# Revision 1.4  2000/02/26 23:12:42  clee
# turn off compression by default on piddlePDF
# add doc string to new pil-based piddleTK
#
# Revision 1.3  2000/02/26 21:23:19  clee
# update that makes PIL based TKCanvas the default Canvas for TK.
# Updated piddletest.py.  Also, added clear() methdo to piddlePIL's
# canvas it clears to "white" is this correct behavior?  Not well
# specified in current documents.
#

class FontManager:
    __alt_faces = { "serif": "Times",
                    "sansserif": "Helvetica",
                    "monospaced": "Courier"}
    def __init__(self, master):
        self.master = master
        self.font_cache = {}

    # the main interface
    def stringWidth(self, s, font):
        tkfont = self.piddleToTkFont(font)
        return tkfont.measure(s)

    def fontHeight(self, font):
        tkfont = self.piddleToTkFont(font)
        return self._tkfontHeight(tkfont) 
    
    def fontAscent(self, font):
        tkfont = self.piddleToTkFont(font)
        return self._tkfontAscent(tkfont)

    def fontDescent(self, font):
        tkfont = self.piddleToTkFont(font)
        return self._tkfontDescent(tkfont)

    def getTkFontString(self, font):
        """Return a string suitable to pass as the -font option to
        to a Tk widget based on the piddle-style FONT"""
        tkfont = self.piddleToTkFont(font)
        # XXX: should just return the internal tk font name?
        # return str(tkfont)
        return ('-family %(family)s -size %(size)s '
                '-weight %(weight)s -slant %(slant)s '
                '-underline %(underline)s' % tkfont.config())
    

    def getTkFontName(self, font):
        """Return a the name associated with the piddle-style FONT"""
        tkfont = self.piddleToTkFont(font)
        return str(tkfont)

    def piddleToTkFont(self, font): 
        """Return a tkFont instance based on the pid-style FONT"""
        if font is None: 
            return ''

        #default 12 pt, "Times", non-bold, non-italic
        size = 12
        family = "Times"
        weight = "normal"
        slant = "roman"
        underline = "false"

        if font.face:
            # check if the user specified a generic face type
            # like serif or monospaced. check is case-insenstive.
            f = string.lower(font.face)
            if self.__alt_faces.has_key(f):
                family = self.__alt_faces[f]
            else:
                family = font.face
            
        size = font.size or 12
        
        if font.bold:
            weight = "bold"
        if font.italic:
            slant = "italic"
        if font.underline:
            underline = 'true'

        # ugh... is there a better way to do this?
        key = (family,size,weight,slant,underline)

        # check if we've already seen this font.
        if self.font_cache.has_key(key):
            # yep, don't bother creating a new one. just fetch it.
            font = self.font_cache[key]
        else:
            # nope, let's create a new tk font.
            # this way we will return info about the actual font
            # selected by Tk, which may be different than what we ask
            # for if it's not availible.
            font = tkFont.Font(self.master, family=family, size=size, weight=weight,
                               slant=slant,underline=underline)
            self.font_cache[(family,size,weight,slant,underline)] = font
        
        return font

    def _tkfontAscent(self, tkfont):
        return tkfont.metrics("ascent")

    def _tkfontDescent(self, tkfont):
        return tkfont.metrics("descent")


class TKCanvas(tk.Canvas, sping.pid.Canvas): 

    __TRANSPARENT = ''                  # transparent for Tk color
    def __init__(self, size=(300,300), name="sping.TK",
                 master = None,
                 scrollingViewPortSize=None,  # a 2-tuple to define the size of the viewport 
                 **kw):
        """This canvas allows you to add a tk.Canvas with a sping API for drawing.
        To add scrollbars, the simpliest method is to set the 'scrollingViewPortSize'
        equal to a tuple that describes the width and height of the visible porition
        of the canvas on screen.  This sets scrollregion=(0,0, size[0], size[1]).
        Then you can add scrollbars as you would any tk.Canvas.

        Note, because this is a subclass of tk.Canvas, you can use the normal keywords
        to specify a tk.Canvas with scrollbars, however, you should then be careful to
        set the "scrollregion" option to the same size as the 'size' passed to __init__.
        Tkinter's scrollregion option essentially makes 'size' ignored.  """
        
        sping.pid.Canvas.__init__(self, size=size, name=size)
        if scrollingViewPortSize:   # turn on ability to scroll
            kw["scrollregion"] = (0, 0, size[0], size[1])
            kw["height"] = scrollingViewPortSize[0]
            kw["width"] =  scrollingViewPortSize[1]
        else:
            kw["width"]= size[0]
            kw["height"]= size[1]

        apply(tk.Canvas.__init__, (self, master), kw) # use kw to pass other tk.Canvas options
        self.config(background="white")
        self.width, self.height = size
        
        self._font_manager = FontManager(self)
        self._configure()
        self._item_ids = []
        self._images = []
        
    def _configure(self):
        pass
          
    def _display(self): 
        self.flush()
        self.mainloop() 
  
    def _quit(self): 
        self.quit() 

    # Hmmm...the postscript generated by this causes my Ghostscript to barf... 
    def _to_ps_file(self, filename): 
        self.postscript(file=filename)

    def isInteractive(self):
        return 0

    def onOver(self, event):
        pass

    def onClick(self, event):
        pass

    def onKey(self, event):
        pass
    
    def flush(self): 
        tk.Canvas.update(self) 
  
    def clear(self): 
        map(self.delete,self._item_ids) 
        self._item_ids = [] 
        
    def _colorToTkColor(self, c): 
        return "#%02X%02X%02X" %( int(c.red*255), 
                                  int(c.green*255), 
                                  int(c.blue*255)) 
  
    def _getTkColor(self, color, defaultColor): 
        if color is None: 
            color = defaultColor 
        if color is sping.pid.transparent: 
            color = self.__TRANSPARENT
        else:
            color = self._colorToTkColor(color) 
        return color 
  
    def drawLine(self, x1, y1, x2, y2, color = None, width = None): 
        color = self._getTkColor(color, self.defaultLineColor) 
        if width is None: 
            width  = self.defaultLineWidth 
        new_item = self.create_line(x1,y1,x2,y2,
                                    fill=color, width=width) 
        self._item_ids.append(new_item) 
  
    # NYI: curve with fill 
    #def drawCurve(self, x1, y1, x2, y2, x3, y3, x4, y4, 
    #              edgeColor=None, edgeWidth=None, fillColor=None, closed=0): 
    # 

    def stringWidth(self, s, font=None):
        return self._font_manager.stringWidth(s, font or self.defaultFont)
    
    def fontAscent(self, font=None):
        return self._font_manager.fontAscent(font or self.defaultFont)

    def fontDescent(self, font=None):
        return self._font_manager.fontDescent(font or self.defaultFont)

    def drawString(self, s, x, y, font=None, color=None, angle=None):
        if angle:
            try:
                self._drawRotatedString(s,x,y,font,color,angle)
                return
            except ImportError:
                print("PIL not available. Using unrotated strings.")
        # fudge factor for TK on linux (at least)
        # strings are being drawn using create_text in canvas
        y = y - self.fontHeight(font) * .28 # empirical
        #y = y - self.fontDescent(font)
    
        color = self._getTkColor(color, self.defaultLineColor)
        font  = self._font_manager.getTkFontString(font or self.defaultFont) 
        new_item = self.create_text(x, y, text=s, 
                                    font=font, fill=color, 
                                    anchor=Tkinter.W) 
        self._item_ids.append(new_item)

    def _drawRotatedString(self, s, x,y, font=None, color=None, angle=0):
        # we depend on PIL for rotated strings so watch for changes in PIL
        try:
            import sping.PIL.pidPIL
            from PIL import Image, ImageTk
            pp = sping.PIL.pidPIL
        except ImportError:
            raise ImportError("Rotated strings only possible with PIL support")

        pilCan = pp.PILCanvas(size=(self.width,self.height))
        pilCan.defaultFont = self.defaultFont
        pilCan.defaultLineColor = self.defaultLineColor
        
        if '\n' in s or '\r' in s:
            self.drawMultiLineString(s, x,y, font, color, angle)
            return
        if not font: font = pilCan.defaultFont
  
        if not color:
            color = self.defaultLineColor
        if color == sping.pid.transparent: return

        # draw into an offscreen Image
        tempsize = pilCan.stringWidth(s, font) * 1.2
        tempimg = Image.new('RGB',(tempsize,tempsize), (0,0,0))
        txtimg = Image.new('RGB',(tempsize,tempsize), (255,255,255))

        from PIL import ImageDraw
        temppen = ImageDraw.ImageDraw(tempimg)
        temppen.setink( (255,255,255) )
        pilfont = pp._pilFont(font)

        if not pilfont: raise ValueError,"Bad font: %s"%font

        temppen.setfont( pilfont )
        pos = [4, int(tempsize/2 - pilCan.fontAscent(font)) - pilCan.fontDescent(font)]
        temppen.text( pos, s )
        pos[1] = int(tempsize/2)
        
        # rotate
        if angle:
                from math import pi, sin, cos
                tempimg = tempimg.rotate( angle, Image.BILINEAR )
                temppen = ImageDraw.ImageDraw(tempimg)
                radians = -angle * pi/180.0
                r = tempsize/2 - pos[0]
                pos[0] = int(tempsize/2 - r * cos(radians))
                pos[1] = int(pos[1] - r * sin(radians))
                
        ###temppen.rectangle( (pos[0],pos[1],pos[0]+2,pos[1]+2) ) # PATCH for debugging
        # colorize, and copy it in
        mask = tempimg.convert('L').point(lambda c:c)
        temppen.setink( (color.red*255, color.green*255, color.blue*255) )
        temppen.setfill(1)
        temppen.rectangle( (0,0,tempsize,tempsize) )

        txtimg.paste( tempimg, (0,0), mask)
        
        ##Based on code posted by John Michelson in the PIL SIG
        transp = txtimg.convert("RGBA")
        source = transp.split()
        R, G, B, A = 0, 1, 2, 3
        mask = transp.point(lambda i: i < 255 and 255) # use white as transparent
        source[A].paste(mask)
        transp = Image.merge(transp.mode, source)  # build a new multiband image

        self.drawImage(transp, x-pos[0], y-pos[1])


  
    def drawRect(self, x1, y1, x2, y2, edgeColor=None, 
                 edgeWidth=None, fillColor=None): 
        fillColor = self._getTkColor(fillColor, self.defaultFillColor) 
        edgeColor = self._getTkColor(edgeColor, self.defaultLineColor) 
        if edgeWidth is None: 
            edgeWidth  = self.defaultLineWidth 
        new_item = self.create_rectangle(x1,y1,x2,y2, 
                                        fill=fillColor, 
                                        width=edgeWidth, 
                                        outline=edgeColor) 
        self._item_ids.append(new_item) 
          
    # NYI: 
    #def drawRoundRect(self, x1,y1, x2,y2, rx=5, ry=5, 
    #                  edgeColor=None, edgeWidth=None, fillColor=None): 
  
  
    def drawEllipse(self, x1,y1, x2,y2, 
                    edgeColor=None, edgeWidth=None, fillColor=None): 
        fillColor = self._getTkColor(fillColor, self.defaultFillColor) 
        edgeColor = self._getTkColor(edgeColor, self.defaultLineColor) 
        if edgeWidth is None: 
            edgeWidth  = self.defaultLineWidth 
        new_item = self.create_oval(x1, y1, x2, y2, 
                                    fill=fillColor, 
                                    outline=edgeColor,
                                    width=edgeWidth)
        
        self._item_ids.append(new_item) 
  
    def drawArc(self, x1, y1, x2, y2, startAng=0, extent=360, 
                edgeColor=None, edgeWidth=None, fillColor=None): 
        fillColor = self._getTkColor(fillColor, self.defaultFillColor) 
        edgeColor = self._getTkColor(edgeColor, self.defaultLineColor) 
        if edgeWidth is None: 
            edgeWidth  = self.defaultLineWidth 
        new_item = self.create_arc( x1, y1, x2, y2, 
                                     start=startAng, 
                                     extent=extent, 
                                     fill=fillColor, 
                                     width=edgeWidth,
                                     outline=edgeColor) 
        self._item_ids.append(new_item) 
  
    def drawPolygon(self, pointlist, 
                    edgeColor=None, edgeWidth=None, fillColor=None, closed=0): 
        fillColor = self._getTkColor(fillColor, self.defaultFillColor) 
        edgeColor = self._getTkColor(edgeColor, self.defaultLineColor) 
        if edgeWidth is None: 
            edgeWidth  = self.defaultLineWidth 
        if closed:
            # draw a closed shape
            new_item = self.create_polygon( pointlist, 
                                            fill=fillColor, 
                                            width=edgeWidth,
                                            outline=edgeColor)
        else:
            if fillColor == self.__TRANSPARENT:
                # draw open-ended set of lines
                d = { 'fill':edgeColor, 'width': edgeWidth}
                new_item = apply(self.create_line, pointlist, d)
            else:
                # open filled shape.
                # draw it twice:
                #    once as a polygon with no edge outline with the fill color
                #    and once as an open set of lines of the appropriate color
                new_item = self.create_polygon( pointlist, 
                                                fill=fillColor, 
                                                outline=self.__TRANSPARENT)
                
                self._item_ids.append(new_item)
                
                d = { 'fill':edgeColor, 'width': edgeWidth}
                new_item = apply(self.create_line, pointlist, d)
                                                   
        self._item_ids.append(new_item) 
  
    
    #def drawFigure(self, partList, 
    #               edgeColor=None, edgeWidth=None, fillColor=None):
    # use default implementation
          
    def drawImage(self, image, x1, y1, x2=None,y2=None):

        try:
            from PIL import ImageTk
        except ImportError:
            raise NotImplementedError('drawImage - require the ImageTk module')

        w,h = image.size
        if not x2 :
            x2 = w + x1
        if not y2 :
            y2 = h + y1

        if (w != x2-x1) or (h != y2-y1) :  # need to scale image
            myimage = image.resize((x2-x1,y2-y1))
        else:
            myimage = image
            
        # unless I keep a copy of this PhotoImage, it seems to be garbage collected
        # and the image is removed from the display after this function. weird
        itk = ImageTk.PhotoImage(myimage, master=self)
        new_item = self.create_image(x1, y1, image=itk, anchor=Tkinter.NW)
        self._item_ids.append(new_item) 
        self._images.append(itk)



try :
    import sping.PIL

    class TKCanvasPIL(sping.PIL.PILCanvas):

        """This canvas maintains a PILCanvas as its backbuffer.  Drawing calls
        are made to the backbuffer and flush() sends the image to the screen
        using TKCanvas.  
           You can also save what is displayed to a file in any of the formats
        supported by PIL"""
        
        def  __init__(self, size=(300,300), name='TKCanvas',  master = None, **kw) :
            sping.PIL.PILCanvas.__init__(self, size=size, name=name)
            self._tkcanvas = apply(TKCanvas, (size, name, master), kw)

        def flush(self) :
            sping.PIL.PILCanvas.flush(self) # call inherited one first
            self._tkcanvas.drawImage(self._image, 0,0)  # self._image should be a PIL image
            self._tkcanvas.flush()

        def getTKCanvas(self):
            return self._tkcanvas

except ImportError:
    raise ImportError, "TKCanvasPIL requires sping  PIL Canvas, PIL may not be installed"