wxWidgets/wxPython/wx/lib/fancytext.py

"""<font weight="bold" size="16">FancyText</font> -- <font style="italic" size="16">methods for rendering XML specified text</font>
<font family="swiss" size="12">
This module exports four main methods::
<font family="fixed" style="slant">
    def GetExtent(str, dc=None, enclose=True)
    def GetFullExtent(str, dc=None, enclose=True)
    def RenderToBitmap(str, background=None, enclose=True)
    def RenderToDC(str, dc, x, y, enclose=True)
</font>
In all cases, 'str' is an XML string. Note that start and end tags
are only required if *enclose* is set to False. In this case the 
text should be wrapped in FancyText tags.

In addition, the module exports one class::
<font family="fixed" style="slant">
    class StaticFancyText(self, window, id, text, background, ...)
</font>
This class works similar to StaticText except it interprets its text 
as FancyText.

The text can support<sup>superscripts</sup> and <sub>subscripts</sub>, text
in different <font size="20">sizes</font>, <font color="blue">colors</font>, <font style="italic">styles</font>, <font weight="bold">weights</font> and
<font family="script">families</font>. It also supports a limited set of symbols,
currently <times/>, <infinity/>, <angle/> as well as greek letters in both
upper case (<Alpha/><Beta/>...<Omega/>) and lower case (<alpha/><beta/>...<omega/>).

We can use doctest/guitest to display this string in all its marked up glory.
<font family="fixed">
>>> frame = wx.Frame(wx.NULL, -1, "FancyText demo", wx.DefaultPosition)
>>> sft = StaticFancyText(frame, -1, __doc__, wx.Brush("light grey", wx.SOLID))
>>> frame.SetClientSize(sft.GetSize())
>>> didit = frame.Show()
>>> from guitest import PauseTests; PauseTests()

</font></font>
The End"""
# Copyright 2001-2003 Timothy Hochberg
# Use as you see fit. No warantees, I cannot be help responsible, etc.
import copy
import math
import sys
import wx
import xml.parsers.expat

__all__ = "GetExtent", "GetFullExtent", "RenderToBitmap", "RenderToDC", "StaticFancyText"

if sys.platform == "win32":
    _greekEncoding = str(wx.FONTENCODING_CP1253)
else:
    _greekEncoding = str(wx.FONTENCODING_ISO8859_7)

_families = {"fixed" : wx.FIXED, "default" : wx.DEFAULT, "decorative" : wx.DECORATIVE, "roman" : wx.ROMAN,
                "script" : wx.SCRIPT, "swiss" : wx.SWISS, "modern" : wx.MODERN}
_styles = {"normal" : wx.NORMAL, "slant" : wx.SLANT, "italic" : wx.ITALIC}
_weights = {"normal" : wx.NORMAL, "light" : wx.LIGHT, "bold" : wx.BOLD}

# The next three classes: Renderer, SizeRenderer and DCRenderer are
# what you will need to override to extend the XML language. All of
# the font stuff as well as the subscript and superscript stuff are in 
# Renderer.

_greek_letters = ("alpha", "beta", "gamma", "delta", "epsilon",  "zeta",
                 "eta", "theta", "iota", "kappa", "lambda", "mu", "nu",
                 "xi", "omnikron", "pi", "rho", "altsigma", "sigma", "tau", "upsilon",
                 "phi", "chi", "psi", "omega")

def iround(number):
    return int(round(number))
    
def iceil(number):
    return int(math.ceil(number))

class Renderer:
    """Class for rendering XML marked up text.

    See the module docstring for a description of the markup.

    This class must be subclassed and the methods the methods that do
    the drawing overridden for a particular output device.

    """
    defaultSize = None
    defaultFamily = wx.DEFAULT
    defaultStyle = wx.NORMAL
    defaultWeight = wx.NORMAL
    defaultEncoding = None
    defaultColor = "black"

    def __init__(self, dc=None, x=0, y=None):
        if dc == None:
            dc = wx.MemoryDC()
        self.dc = dc
        self.offsets = [0]
        self.fonts = [{}]
        self.width = self.height = 0
        self.x = x
        self.minY = self.maxY = self._y = y
        if Renderer.defaultSize is None:
            Renderer.defaultSize = wx.NORMAL_FONT.GetPointSize()
        if Renderer.defaultEncoding is None:
            Renderer.defaultEncoding = wx.Font_GetDefaultEncoding()
        
    def getY(self):
        if self._y is None:
            self.minY = self.maxY = self._y = self.dc.GetTextExtent("M")[1]
        return self._y
    def setY(self, value):
        self._y = y
    y = property(getY, setY)
        
    def startElement(self, name, attrs):
        method = "start_" + name
        if not hasattr(self, method):
            raise ValueError("XML tag '%s' not supported" % name)
        getattr(self, method)(attrs)

    def endElement(self, name):
        methname = "end_" + name
        if hasattr(self, methname):
            getattr(self, methname)()
        elif hasattr(self, "start_" + name):
            pass
        else:
            raise ValueError("XML tag '%s' not supported" % methname)
        
    def characterData(self, data):
        self.dc.SetFont(self.getCurrentFont())
        for i, chunk in enumerate(data.split('\n')):
            if i:
                self.x = 0
                self.y = self.mayY = self.maxY + self.dc.GetTextExtent("M")[1]
            if chunk:
                width, height, descent, extl = self.dc.GetFullTextExtent(chunk)
                self.renderCharacterData(data, iround(self.x), iround(self.y + self.offsets[-1] - height + descent))
            else:
                width = height = descent = extl = 0
            self.updateDims(width, height, descent, extl)

    def updateDims(self, width, height, descent, externalLeading):
        self.x += width
        self.width = max(self.x, self.width)
        self.minY = min(self.minY, self.y+self.offsets[-1]-height+descent)
        self.maxY = max(self.maxY, self.y+self.offsets[-1]+descent)
        self.height = self.maxY - self.minY

    def start_FancyText(self, attrs):
        pass
    start_wxFancyText = start_FancyText # For backward compatibility

    def start_font(self, attrs):
        for key, value in attrs.items():
            if key == "size":
                value = int(value)
            elif key == "family":
                value = _families[value]
            elif key == "style":
                value = _styles[value]
            elif key == "weight":
                value = _weights[value]
            elif key == "encoding":
                value = int(value)
            elif key == "color":
                pass
            else:
                raise ValueError("unknown font attribute '%s'" % key)
            attrs[key] = value
        font = copy.copy(self.fonts[-1])
        font.update(attrs)
        self.fonts.append(font)

    def end_font(self):
        self.fonts.pop()

    def start_sub(self, attrs):
        if attrs.keys():
            raise ValueError("<sub> does not take attributes")
        font = self.getCurrentFont()
        self.offsets.append(self.offsets[-1] + self.dc.GetFullTextExtent("M", font)[1]*0.5)
        self.start_font({"size" : font.GetPointSize() * 0.8})

    def end_sub(self):
        self.fonts.pop()
        self.offsets.pop()

    def start_sup(self, attrs):
        if attrs.keys():
            raise ValueError("<sup> does not take attributes")
        font = self.getCurrentFont()
        self.offsets.append(self.offsets[-1] - self.dc.GetFullTextExtent("M", font)[1]*0.3)
        self.start_font({"size" : font.GetPointSize() * 0.8})

    def end_sup(self):
        self.fonts.pop()
        self.offsets.pop()        

    def getCurrentFont(self):
        font = self.fonts[-1]
        return wx.TheFontList.FindOrCreateFont(font.get("size", self.defaultSize),
                             font.get("family", self.defaultFamily),
                             font.get("style", self.defaultStyle),
                             font.get("weight", self.defaultWeight),
                             encoding = font.get("encoding", self.defaultEncoding))

    def getCurrentColor(self):
        font = self.fonts[-1]
        return wx.TheColourDatabase.FindColour(font.get("color", self.defaultColor))
        
    def getCurrentPen(self):
        return wx.ThePenList.FindOrCreatePen(self.getCurrentColor(), 1, wx.SOLID)
        
    def renderCharacterData(self, data, x, y):
        raise NotImplementedError()


def _addGreek():
    alpha = 0xE1
    Alpha = 0xC1
    def end(self):
        pass
    for i, name in enumerate(_greek_letters):
        def start(self, attrs, code=chr(alpha+i)):
            self.start_font({"encoding" : _greekEncoding})
            self.characterData(code)
            self.end_font()
        setattr(Renderer, "start_%s" % name, start)
        setattr(Renderer, "end_%s" % name, end)
        if name == "altsigma":
            continue # There is no capital for altsigma
        def start(self, attrs, code=chr(Alpha+i)):
            self.start_font({"encoding" : _greekEncoding})
            self.characterData(code)
            self.end_font()
        setattr(Renderer, "start_%s" % name.capitalize(), start)
        setattr(Renderer, "end_%s" % name.capitalize(), end)
_addGreek()    



class SizeRenderer(Renderer):
    """Processes text as if rendering it, but just computes the size."""
    
    def __init__(self, dc=None):
        Renderer.__init__(self, dc, 0, 0)
    
    def renderCharacterData(self, data, x, y):
        pass
        
    def start_angle(self, attrs):
        self.characterData("M")

    def start_infinity(self, attrs):
        width, height = self.dc.GetTextExtent("M")
        width = max(width, 10)
        height = max(height, width / 2)
        self.updateDims(width, height, 0, 0)

    def start_times(self, attrs):
        self.characterData("M")

    def start_in(self, attrs):
        self.characterData("M")

    def start_times(self, attrs):
        self.characterData("M")        

    
class DCRenderer(Renderer):
    """Renders text to a wxPython device context DC."""

    def renderCharacterData(self, data, x, y):
        self.dc.SetTextForeground(self.getCurrentColor())
        self.dc.DrawText(data, (x, y))

    def start_angle(self, attrs):
        self.dc.SetFont(self.getCurrentFont())
        self.dc.SetPen(self.getCurrentPen())
        width, height, descent, leading = self.dc.GetFullTextExtent("M")
        y = self.y + self.offsets[-1]
        self.dc.DrawLine((iround(self.x), iround(y)), (iround( self.x+width), iround(y))) 
        self.dc.DrawLine((iround(self.x), iround(y)), (iround(self.x+width), iround(y-width)))
        self.updateDims(width, height, descent, leading)
      

    def start_infinity(self, attrs):
        self.dc.SetFont(self.getCurrentFont())
        self.dc.SetPen(self.getCurrentPen())
        width, height, descent, leading = self.dc.GetFullTextExtent("M")
        width = max(width, 10)
        height = max(height, width / 2)
        self.dc.SetPen(wx.Pen(self.getCurrentColor(), max(1, width/10)))
        self.dc.SetBrush(wx.TRANSPARENT_BRUSH)
        y = self.y + self.offsets[-1]
        r = iround( 0.95 * width / 4)
        xc = (2*self.x + width) / 2
        yc = iround(y-1.5*r)
        self.dc.DrawCircle((xc - r, yc), r)
        self.dc.DrawCircle((xc + r, yc), r)
        self.updateDims(width, height, 0, 0)

    def start_times(self, attrs):
        self.dc.SetFont(self.getCurrentFont())
        self.dc.SetPen(self.getCurrentPen())
        width, height, descent, leading = self.dc.GetFullTextExtent("M")
        y = self.y + self.offsets[-1]
        width *= 0.8
        width = iround(width+.5)
        self.dc.SetPen(wx.Pen(self.getCurrentColor(), 1))
        self.dc.DrawLine((iround(self.x), iround(y-width)), (iround(self.x+width-1), iround(y-1)))
        self.dc.DrawLine((iround(self.x), iround(y-2)), (iround(self.x+width-1), iround(y-width-1)))
        self.updateDims(width, height, 0, 0)


def RenderToRenderer(str, renderer, enclose=True):
    try:
        if enclose:
            str = '<?xml version="1.0"?><FancyText>%s</FancyText>' % str
        p = xml.parsers.expat.ParserCreate()
        p.returns_unicode = 0
        p.StartElementHandler = renderer.startElement
        p.EndElementHandler = renderer.endElement
        p.CharacterDataHandler = renderer.characterData
        p.Parse(str, 1)
    except xml.parsers.expat.error, err:
        raise ValueError('error parsing text text "%s": %s' % (str, err)) 


# Public interface


def GetExtent(str, dc=None, enclose=True):
    "Return the extent of str"
    renderer = SizeRenderer(dc)
    RenderToRenderer(str, renderer, enclose)
    return iceil(renderer.width), iceil(renderer.height) # XXX round up


def GetFullExtent(str, dc=None, enclose=True):
    renderer = SizeRenderer(dc)
    RenderToRenderer(str, renderer, enclose)
    return iceil(renderer.width), iceil(renderer.height), -iceil(renderer.minY) # XXX round up


def RenderToBitmap(str, background=None, enclose=1):
    "Return str rendered on a minumum size bitmap"
    dc = wx.MemoryDC()
    width, height, dy = GetFullExtent(str, dc, enclose)
    bmp = wx.EmptyBitmap(width, height)
    dc.SelectObject(bmp)
    if background is None:
        dc.SetBackground(wx.WHITE_BRUSH)
    else:
        dc.SetBackground(background) 
    dc.Clear()
    renderer = DCRenderer(dc, y=dy)
    dc.BeginDrawing()
    RenderToRenderer(str, renderer, enclose)
    dc.EndDrawing()
    dc.SelectObject(wx.NullBitmap)
    if background is None:
        img = wx.ImageFromBitmap(bmp)
        bg = dc.GetBackground().GetColour()
        img.SetMaskColour(bg.Red(), bg.Green(), bg.Blue())
        bmp = img.ConvertToBitmap()
    return bmp


def RenderToDC(str, dc, x, y, enclose=1):
    "Render str onto a wxDC at (x,y)"
    width, height, dy = GetFullExtent(str, dc)
    renderer = DCRenderer(dc, x, y+dy)
    RenderToRenderer(str, renderer, enclose)
    
    
class StaticFancyText(wx.StaticBitmap):
    def __init__(self, window, id, text, *args, **kargs):
        args = list(args)
        kargs.setdefault('name', 'staticFancyText')
        if 'background' in kargs:
            background = kargs.pop('background')
        elif args:
            background = args.pop(0)
        else:
            background = wx.Brush(window.GetBackgroundColour(), wx.SOLID)
        
        bmp = RenderToBitmap(text, background)
        wx.StaticBitmap.__init__(self, window, id, bmp, *args, **kargs)


# Old names for backward compatibiliry
getExtent = GetExtent
renderToBitmap = RenderToBitmap
renderToDC = RenderToDC


# Test Driver

def test():
    app = wx.PyApp()
    box = wx.BoxSizer(wx.VERTICAL)
    frame = wx.Frame(wx.NULL, -1, "FancyText demo", wx.DefaultPosition)
    frame.SetBackgroundColour("light grey")
    sft = StaticFancyText(frame, -1, __doc__)
    box.Add(sft, 1, wx.EXPAND)
    frame.SetSizer(box)
    frame.SetAutoLayout(True)
    box.Fit(frame)
    box.SetSizeHints(frame)
    frame.Show()
    app.MainLoop()

if __name__ == "__main__":    
    test()