'''\
rendering HTML text with piddle
HTMLPiddler.py
jjk  02/02/00  001  first working version
jjk  02/03/00  002  some enhancements, renamed from piddleTaggedText.py
jjk  02/04/00  003  more enhancements, renamed from piddleHtmlWriter.py

Purpose:
    The HTMLPiddler class accepts an HTML string and a few layout constraints,
    and renders the HTML on a piddle canvas. This code is mainly a demonstration
    and proof-of-concept, and is not really intended for real work.
    
Usage:
    piddler = HTMLPiddler(html=aHtmlString, 
                              start=(startX, startY), 
                              xLimits=(leftMarginX, rightMarginX), 
                              font=aPiddleFontForDefault, 
                              color=aPiddleColorForDefault)
    piddler.renderOn(aPiddleCanvas)
    
    see also demo() functions at end of this file
    
Example:
    Just run this module as a python script (must have piddle installed)
    
Limitations:
    -only renders a subset of HTML (mostly text-related tags)
    -content between unsupported tags may not be rendered at all
    
Implementation:
    -derived largely on "demo07.py" from Jim Ahlstrom's WPY distribution (see credits)
    -uses the parser-formatter-writer model from the python standard library
    
Credits:
    PIDDLE
        author: Joe Strout <joe@strout.net>, et al
        download: http://www.strout.net/python/piddle/
        disclaimers: see __copyrite_jim__ below
    WPY
        author: Jim Ahlstrom <jim@interet.com>
        download: http://www.python.org/ftp/python/wpy/
        disclaimers: see __copyrite_jim__ below
    HTMLPiddler.py
        author: Jeff Kunce <kuncej@mail.conservation.state.mo.us>
        download: http://starship.python.net/crew/jjkunce/
        disclaimers: * NO WARRANTIES * USE AT YOUR OWN RISK *    
    
'''
from __future__ import print_function
import htmllib, formatter, string
from types import *
import piddle

TRACE=0

class HTMLPiddler:
    '''jjk  02/01/00'''
    
    def __init__(self, html='', start=(0,0), xLimits=(0,800), font=None, color=None): 
        '''instance initializer
        jjk  02/01/00'''
        self.html = html
        self.start = start
        self.xLimits = xLimits
        if not font: font = piddle.Font()
        self.font = font
        self.color = color

    def renderOn(self, aPiddleCanvas):
        '''draw the text with aPiddleCanvas
        jjk  02/01/00'''
        writer = _HtmlPiddleWriter(self, aPiddleCanvas)
        fmt = formatter.AbstractFormatter(writer)
        parser = _HtmlParser(fmt)
        parser.feed(self.html)
        parser.close()

class _HtmlParser(htmllib.HTMLParser):
    
    def anchor_bgn(self, href, name, type):
        htmllib.HTMLParser.anchor_bgn(self, href, name, type)
        self.formatter.writer.anchor_bgn(href, name, type)
    
    def anchor_end(self):
        htmllib.HTMLParser.anchor_end(self)
        self.formatter.writer.anchor_end()



class _HtmlPiddleWriter:
    
    FontSizeDict = {"h1":36, "h2":24, "h3":18, "h4":12, "h5":10, "h6":8}
    DefaultFontSize = 12
    
    def __init__(self, aHTMLPiddler, aPiddleCanvas):
        self.piddler = aHTMLPiddler	#view = view
        self.pc = aPiddleCanvas
        self.anchor = None
        self.lineHeight = 0
        self.atbreak = 0
        self.color = self.piddler.color
        self.defaultFont = self.font = self.piddler.font
        s = "W" * 20
        x = self.pc.stringWidth(s, self.font)
        y = self.pc.fontHeight(self.font)
        x = (x + 19) / 20	# Largest character size
        self.fsizex = x
        self.fsizey = self.oldLineHeight = y
        self.indentSize = x * 3
        self.lmargin, self.rmargin = self.piddler.xLimits
        self.x, self.y = self.piddler.start
        self.indent = self.lmargin + (x/3)
        
    def anchor_bgn(self, href, name, type):
        if href:
            self.oldcolor = self.color
            self.color = piddle.Color(0.0, 0.0, 200/255.0)
            self.anchor = (href, name, type)
            
    def anchor_end(self):
        if self.anchor:
            self.color = self.oldcolor
            self.anchor = None
            
    # Start of methods required by the formatter
    
    def new_font(self, fontParams):
        if TRACE: print('nf',fontParams)
        # fontParams is None, or the tuple (size, i, b, tt)
        if not fontParams:
            fontParams = (None, None, None, None)
        size = fontParams[0]
        try:
            points = self.FontSizeDict[size]
        except KeyError:
            points = self.DefaultFontSize
        if fontParams[3]:
            face = "courier"    #"modern"
        elif type(size) is StringType and size[0] == "h":
            face = "helvetica"	#"swiss"
        else:
            face = "times"	#"roman"
        italic = fontParams[1]	# Italic indicator
        if italic==None:
            italic = 0
        bold = fontParams[2]	# Bold indicator
        if bold==None:
            bold = 0
        self.font = piddle.Font(points, bold, italic, face=face)
        x = self.pc.stringWidth('W'*20, self.font)
        self.fsizex = (x + 19) / 20	# Largest character size
        self.fsizey = self.pc.fontHeight(self.font)

    def new_margin(self, margin, level):
        self.send_line_break()
        self.indent = self.x = self.lmargin + self.indentSize * level
        
    def new_spacing(self, spacing):
        self.send_line_break()
        t = "new_spacing(%s)" % repr(spacing)
        self.OutputLine(t, 1)
        
    def new_styles(self, styles):
        self.send_line_break()
        t = "new_styles(%s)" % repr(styles)
        self.OutputLine(t, 1)
        
    def send_label_data(self, data):
        if data == "*":
            w = self.pc.stringWidth(data, self.font) / 3
            h = self.pc.fontHeight(self.font) / 3
            x = self.indent - w
            y = self.y - w 
            self.pc.drawRect(x, y, x-w, y-w)
        else:
            w = self.pc.stringWidth(data, self.font)
            h = self.pc.fontHeight(self.font)
            x = self.indent - w - self.fsizex / 3
            if x < 0:
                x = 0
            self.pc.drawString(data, x, self.y, self.font, self.color)
        
    def send_paragraph(self, blankline):
        self.send_line_break()
        self.y = self.y + self.oldLineHeight * blankline
            
    def send_line_break(self):
        if self.lineHeight:
            self.y = self.y + self.lineHeight
            self.oldLineHeight = self.lineHeight
            self.lineHeight = 0
        self.x = self.indent
        self.atbreak = 0
        if TRACE: raw_input('lb')
            
    def send_hor_rule(self):
        self.send_line_break()
        self.y = self.y + self.oldLineHeight
        border = self.fsizex
        self.pc.drawLine(border, self.y, self.rmargin-border, self.y, piddle.Color(0.0, 0.0, 200/255.0))
        self.y = self.y + self.oldLineHeight
        
    def send_literal_data(self, data):
        if not data:
            return
        lines = string.splitfields(data, '\n')
        text = string.expandtabs(lines[0])
        for l in lines[1:]:
            self.OutputLine(text, 1)
            text = string.expandtabs(l)
        self.OutputLine(text, 0)
        self.atbreak = 0
        
    def send_flowing_data(self, data):
        if not data:
            return
        atbreak = self.atbreak or data[0] in string.whitespace
        text = ""
        pixels = chars = 0
        for word in string.split(data):
            bword = " " + word	# blank + word
            length = len(bword)
            # The current line is "text" and its size is
            #    "pixels" pixels plus "chars" characters.
            if not atbreak:
                text = word
                chars = chars + length - 1
            elif self.x + pixels + (chars + length) * self.fsizex < self.rmargin:
                # Word fits easily on current line.
                text = text + bword
                chars = chars + length
            else:
                w = self.pc.stringWidth(text+bword, self.font)
                h = self.pc.fontHeight(self.font)
                if TRACE: print('sfd T:', text+bword)
                if TRACE: print('sfd',self.x,w,self.x+w,self.rmargin)
                if self.x + w < self.rmargin:
                    # Word fits.
                    text = text + bword
                    pixels = w
                    chars = 0
                else:
                    # Word does not fit.  Output current line.
                    self.OutputLine(text, 1)
                    text = word
                    chars = length - 1
                    pixels = 0
            atbreak = 1
        self.OutputLine(text, 0)
        self.atbreak = data[-1] in string.whitespace
        
    def OutputLine(self, text, linebreak = 0):
        if text:
            if TRACE: print('olt:',text)
            if TRACE: print('olf:',self.font.size, self.font.bold, self.font.italic, self.font.underline, self.font.face)
            self.pc.drawString(text, self.x, self.y, self.font, self.color)
            #if self.anchor:
            #    o.anchor = self.anchor
            self.lineHeight = max(self.lineHeight, self.pc.fontHeight(self.font))
            self.x = self.x + self.pc.stringWidth(text, self.font)
        if linebreak:
            self.send_line_break()


__copyrite_jim__ = '''\
Copyright 1994, 1995 by James C. Ahlstrom, Stirling NJ, USA.
Comments and complaints to jim@interet.com

                        All Rights Reserved

Permission to use, copy, modify, and distribute this software and its 
documentation for any purpose and without fee is hereby granted, 
provided that the above copyright notice appear in all copies and that
both that copyright notice and this permission notice appear in 
supporting documentation.

JAMES C. AHLSTROM DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS
SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
FITNESS, IN NO EVENT SHALL HE BE LIABLE FOR ANY SPECIAL, INDIRECT
OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

'''


DEMO_HTML = '''Here's some starting text - should be rendered in
default font and color, and should start at specified start coordinates.
<BR><BR>
<H2>HTMLPiddler.py</H2>
<H3>Rendering HTML with Piddle</H3>

<P>The <b>HTMLPiddler</b> class accepts an HTML string and a few layout constraints,
and renders the HTML on a piddle canvas
<P>An Example:
<PRE>
    piddler = HTMLPiddler(html=aHtmlString, 
                              start=(startX, startY), 
                              xLimits=(leftMarginX, rightMarginX), 
                              font=aPiddleFontForDefault, 
                              color=aPiddleColorForDefault)
    piddler.renderOn(aPiddleCanvas)
</PRE>

<P>Limitations
<UL>
    <LI>only renders a subset of HTML (mostly text-related tags)
    <LI>content between unsupported tags may not be rendered at all
</UL>
    
<P><b>HTMLPiddler</b> is derived largely on "demo07.py" from the 
<A HREF="http://www.python.org/ftp/python/wpy/">WPY distribution</A>
by <A HREF="mailto:jim@interet.com">Jim Ahlstrom</A>

<P><i><b>HTMLPiddler.py</b> is mainly a demonstration/proof-of-concept, and
is not really intended for real work.</i>
<BR>
<BR><A HREF="mailto:kuncej@mail.conservation.state.mo.us">Jeff Kunce</A>
<BR><A HREF="http://starship.python.net/crew/jjkunce/">
    http://starship.python.net/crew/jjkunce/</A>
'''

def demoPDF(html):
    import piddlePDF
    pc = piddlePDF.PDFCanvas((750,1000),'HTMLPiddler.pdf')
    pc.drawLine(100,100,250,150, color=piddle.green)
    pc.drawRect(100,100,650,900, edgeColor=piddle.pink)
    ptt = HTMLPiddler(html, (250,150), (100,650))
    ptt.renderOn(pc)
    pc.save()

def demoPIL(html):
    print('be patient, this is a little slow...')
    import piddlePIL
    pc = piddlePIL.PILCanvas((800,600), 'HTMLPiddler')
    pc.drawLine(0,0,100,80, color=piddle.green)
    pc.drawRect(50,50,750,550, edgeColor=piddle.pink)
    ptt = HTMLPiddler(html, (100,80), (50,750))
    ptt.renderOn(pc)
    pc.save(format='tif')

def demoTK(html):
    import piddleTK
    pc = piddleTK.TKCanvas((800,600))
    pc.drawLine(0,0,50,50, color=piddle.green)
    pc.drawRect(10,10,590,790, edgeColor=piddle.pink)
    ptt = HTMLPiddler(html, (50,50), (10,790))
    pc.flush()
    ptt.renderOn(pc)
    
def demoWX(html):
    import piddleWX
    pc = piddleWX.WXCanvas((800,600))
    pc.drawLine(0,0,50,50, color=piddle.green)
    pc.drawRect(10,10,590,790, edgeColor=piddle.pink)
    ptt = HTMLPiddler(html, (50,50), (10,790))
    pc.flush()
    ptt.renderOn(pc)
    
def demo(html=DEMO_HTML):
    
    while 1:
        print('Demo of HTMLPiddler.py')
        print('   1. piddlePDF')
        print('   2. piddlePIL')
        #print('   3. piddleTK')
        #print('   4. piddleWX')
        print('   0. EXIT')
        sel = raw_input('Enter Selection Number: ')
        try: sel = string.atoi(string.strip(sel))
        except: sel = -1
        if (sel==0): break
        elif (sel==1): demoPDF(html)
        elif (sel==2): demoPIL(html)
        elif (sel==3): demoTK(html)
        elif (sel==4): demoWX(html)

if __name__=='__main__':
    import pdb
    demo()
