Using <font> (font tag) within pys60 Text widget (See related posts)

The Text widget allow rich text. However, it's quite
difficult to use. You need to set each attribute
(font, style, highlight, color) of the widget
before adding more text with differert style.

So, I make a function that make it a bit easier.
The font tag (<font></font>) is used (borrowed from HTML).
Attributes allowed are
- color ( #RRGGBB or 0xRRGGBB or color name)
- face ( both font and size eg. albi17b )
- style ( bold, italic, underline or strikethrough )
(styles can be combined using comma)
- highlight ( standard, rounded, shadow)
- hcolor ( highlight color )

from appuifw import *

def process_color(color):
    color_name = {
        'red': 0xff0000, 'green': 0x008000, 'blue':0x0000ff,       
        'black': 0,      'white':0xffffff,      'yellow': 0xffff00
        }
    if color.startswith('#'):   # HTML format #000000
        return int(color[1:], 16)
    if color.startswith('0x'):  # pys60 format 0x000000
        return int(color, 16)
    return color_name[color]

def set_ml(t, s):
    stack = []
    t.clear()
    t.font = 'normal'
    i = 0
    while i < len(s):
        if s.startswith('<', i):  # tag end or tag begin
            j = s.find('>', i) + 1
            if s[i:i+7] == '</font>' or s[i:i+3] == '</>':
                t.color, t.font, t.style, t.highlight_color = stack.pop()
            else:
                stack.append([t.color, t.font, t.style, t.highlight_color])
                to_style = 0
                for attr_val in s[i:j-1].split(' '):
                    if '=' in attr_val:
                        attr, val = attr_val.split('=')
                        if attr == 'color':
                            t.color = process_color(val)
                        elif attr == 'face':
                            t.font = unicode(val)
                        elif attr == 'hcolor':
                            t.highlight_color = process_color(val)
                        elif attr == 'style':   # style and highlight go together
                            to_style |= eval('|'.join(['STYLE_' + st.upper() for st in val.split(',')]))
                        elif attr == 'highlight':
                            to_style |= eval("HIGHLIGHT_" + val.upper())
                if to_style:
                    t.style = to_style
        else:    # normal text
            j = s.find('<', i)
            if j == -1: j = len(s)
            text = u'' + s[i:j].replace('&lt;', '<')
            t.add(text)
        i = j      # go next chunk

Now you can use it easily

>>> t = app.body   # use the default Text widget that start pys60
>>> set_ml(t, '<font color=red>Hello</font> <font style=bold>World</font>.')
>>>  # a stylish 'Hello World' is displayed

Notice:
- Quotation marks are not used to specify attribute values.
- A </> shorthand can be used for </font>
- <font> can be nested.