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# pyglet
# Copyright (c) 2006-2008 Alex Holkner
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# $Id: $

'''Text formatting, layout and display.

This module provides classes for loading styled documents from text files,
HTML files and a pyglet-specific markup format.  Documents can be styled with
multiple fonts, colours, styles, text sizes, margins, paragraph alignments,
and so on.  

Using the layout classes, documents can be laid out on a single line or
word-wrapped to fit a rectangle.  A layout can then be efficiently drawn in
a window or updated incrementally (for example, to support interactive text
editing).

The label classes provide a simple interface for the common case where an
application simply needs to display some text in a window.

A plain text label can be created with::

    label = pyglet.text.Label('Hello, world', 
                              font_name='Times New Roman', 
                              font_size=36,
                              x=10, y=10)

Alternatively, a styled text label using HTML can be created with::

    label = pyglet.text.HTMLLabel('<b>Hello</b>, <i>world</i>',
                                  x=10, y=10)

Either label can then be drawn at any time with::

    label.draw()

For details on the subset of HTML supported, see `pyglet.text.formats.html`.

Refer to the Programming Guide for advanced usage of the document and layout
classes, including interactive editing, embedding objects within documents and
creating scrollable layouts.

:since: pyglet 1.1
'''

__docformat__ = 'restructuredtext'
__version__ = '$Id: $'

import os.path

import pyglet
from pyglet.text import layout, document, caret

class DocumentDecodeException(Exception):
    '''An error occured decoding document text.'''
    pass

class DocumentDecoder(object):
    '''Abstract document decoder.
    '''

    def decode(self, text, location=None):
        '''Decode document text.
        
        :Parameters:
            `text` : str
                Text to decode
            `location` : `Location`
                Location to use as base path for additional resources
                referenced within the document (for example, HTML images).

        :rtype: `AbstractDocument`
        '''
        raise NotImplementedError('abstract')

def get_decoder(filename, mimetype=None):
    '''Get a document decoder for the given filename and MIME type.

    If `mimetype` is omitted it is guessed from the filename extension.

    The following MIME types are supported:

    ``text/plain``
        Plain text
    ``text/html``
        HTML 4 Transitional
    ``text/vnd.pyglet-attributed``
        Attributed text; see `pyglet.text.formats.attributed`

    `DocumentDecodeException` is raised if another MIME type is given.

    :Parameters:
        `filename` : str
            Filename to guess the MIME type from.  If a MIME type is given,
            the filename is ignored.
        `mimetype` : str
            MIME type to lookup, or ``None`` to guess the type from the
            filename.

    :rtype: `DocumentDecoder`
    '''
    if mimetype is None:
        _, ext = os.path.splitext(filename)
        if ext.lower() in ('.htm', '.html', '.xhtml'):
            mimetype = 'text/html'
        else:
            mimetype = 'text/plain'

    if mimetype == 'text/plain':
        from pyglet.text.formats import plaintext
        return plaintext.PlainTextDecoder()
    elif mimetype == 'text/html':
        from pyglet.text.formats import html
        return html.HTMLDecoder()
    elif mimetype == 'text/vnd.pyglet-attributed':
        from pyglet.text.formats import attributed
        return attributed.AttributedTextDecoder()
    else:
        raise DocumentDecodeException('Unknown format "%s"' % mimetype)
    
def load(filename, file=None, mimetype=None):
    '''Load a document from a file.

    :Parameters:
        `filename` : str
            Filename of document to load.
        `file` : file-like object
            File object containing encoded data.  If omitted, `filename` is
            loaded from disk.
        `mimetype` : str
            MIME type of the document.  If omitted, the filename extension is
            used to guess a MIME type.  See `get_decoder` for a list of
            supported MIME types.

    :rtype: `AbstractDocument`
    '''
    decoder = get_decoder(filename, mimetype)
    if file is None:
        file = open(filename)
    location = pyglet.resource.FileLocation(os.path.dirname(filename))
    return decoder.decode(file.read(), location)

def decode_html(text, location=None):
    '''Create a document directly from some HTML formatted text.

    :Parameters:
        `text` : str
            HTML data to decode.
        `location` : str
            Location giving the base path for additional resources
            referenced from the document (e.g., images).

    :rtype: `FormattedDocument`
    '''
    decoder = get_decoder(None, 'text/html')
    return decoder.decode(text, location)

def decode_attributed(text):
    '''Create a document directly from some attributed text.

    See `pyglet.text.formats.attributed` for a description of attributed text.

    :Parameters:
        `text` : str
            Attributed text to decode.

    :rtype: `FormattedDocument`
    '''
    decoder = get_decoder(None, 'text/vnd.pyglet-attributed')
    return decoder.decode(text)

def decode_text(text):
    '''Create a document directly from some plain text.

    :Parameters:
        `text` : str
            Plain text to initialise the document with.

    :rtype: `UnformattedDocument`
    '''
    decoder = get_decoder(None, 'text/plain')
    return decoder.decode(text)

class DocumentLabel(layout.TextLayout):
    '''Base label class.

    A label is a layout that exposes convenience methods for manipulating the
    associated document.
    '''
    def __init__(self, document=None,
                 x=0, y=0, width=None, height=None,
                 anchor_x='left', anchor_y='baseline', 
                 multiline=False, dpi=None, batch=None, group=None):
        '''Create a label for a given document.

        :Parameters:
            `document` : `AbstractDocument`
                Document to attach to the layout.
            `x` : int
                X coordinate of the label.
            `y` : int
                Y coordinate of the label.
            `width` : int
                Width of the label in pixels, or None
            `height` : int
                Height of the label in pixels, or None
            `anchor_x` : str
                Anchor point of the X coordinate: one of ``"left"``,
                ``"center"`` or ``"right"``.
            `anchor_y` : str
                Anchor point of the Y coordinate: one of ``"bottom"``,
                ``"baseline"``, ``"center"`` or ``"top"``.
            `multiline` : bool
                If True, the label will be word-wrapped and accept newline
                characters.  You must also set the width of the label.
            `dpi` : float
                Resolution of the fonts in this layout.  Defaults to 96.
            `batch` : `Batch`
                Optional graphics batch to add the label to.
            `group` : `Group`
                Optional graphics group to use.

        '''
        super(DocumentLabel, self).__init__(document, 
                                            width=width, height=height, 
                                            multiline=multiline, 
                                            dpi=dpi, batch=batch, group=group)

        self._x = x
        self._y = y
        self._anchor_x = anchor_x
        self._anchor_y = anchor_y
        self._update()

    def _get_text(self):
        return self.document.text

    def _set_text(self, text):
        self.document.text = text

    text = property(_get_text, _set_text,
                    doc='''The text of the label.
                    
    :type: str
    ''')

    def _get_color(self):
        return self.document.get_style('color')

    def _set_color(self, color):
        self.document.set_style(0, len(self.document.text), 
                                {'color': color})

    color = property(_get_color, _set_color,
                     doc='''Text color.

    Color is a 4-tuple of RGBA components, each in range [0, 255].

    :type: (int, int, int, int)
    ''')

    def _get_font_name(self):
        return self.document.get_style('font_name')

    def _set_font_name(self, font_name):
        self.document.set_style(0, len(self.document.text), 
                                {'font_name': font_name})

    font_name = property(_get_font_name, _set_font_name,
                         doc='''Font family name.

    The font name, as passed to `pyglet.font.load`.  A list of names can
    optionally be given: the first matching font will be used.

    :type: str or list
    ''')

    def _get_font_size(self):
        return self.document.get_style('font_size')

    def _set_font_size(self, font_size):
        self.document.set_style(0, len(self.document.text), 
                                {'font_size': font_size})

    font_size = property(_get_font_size, _set_font_size,
                         doc='''Font size, in points.

    :type: float
    ''') 

    def _get_bold(self):
        return self.document.get_style('bold')

    def _set_bold(self, bold):
        self.document.set_style(0, len(self.document.text), 
                                {'bold': bold})

    bold = property(_get_bold, _set_bold,
                    doc='''Bold font style.

    :type: bool
    ''')

    def _get_italic(self):
        return self.document.get_style('italic')

    def _set_italic(self, italic):
        self.document.set_style(0, len(self.document.text), 
                                {'italic': italic})

    italic = property(_get_italic, _set_italic,
                      doc='''Italic font style.
                      
    :type: bool
    ''')

    def get_style(self, name):
        '''Get a document style value by name.

        If the document has more than one value of the named style,
        `pyglet.text.document.STYLE_INDETERMINATE` is returned.

        :Parameters:
            `name` : str
                Style name to query.  See documentation for
                `pyglet.text.layout` for known style names.

        :rtype: object
        '''
        return self.document.get_style_range(name, 0, len(self.document.text))

    def set_style(self, name, value):
        '''Set a document style value by name over the whole document.

        :Parameters:
            `name` : str
                Name of the style to set.  See documentation for
                `pyglet.text.layout` for known style names.
            `value` : object
                Value of the style.

        '''
        self.document.set_style(0, len(self.document.text), {name: value})

class Label(DocumentLabel):
    '''Plain text label.
    '''
    def __init__(self, text='', 
                 font_name=None, font_size=None, bold=False, italic=False,
                 color=(255, 255, 255, 255),
                 x=0, y=0, width=None, height=None, 
                 anchor_x='left', anchor_y='baseline',
                 halign='left',
                 multiline=False, dpi=None, batch=None, group=None):
        '''Create a plain text label.

        :Parameters:
            `text` : str
                Text to display.
            `font_name` : str or list
                Font family name(s).  If more than one name is given, the
                first matching name is used.
            `font_size` : float
                Font size, in points.
            `bold` : bool
                Bold font style.
            `italic` : bool
                Italic font style.
            `color` : (int, int, int, int)
                Font colour, as RGBA components in range [0, 255].
            `x` : int
                X coordinate of the label.
            `y` : int
                Y coordinate of the label.
            `width` : int
                Width of the label in pixels, or None
            `height` : int
                Height of the label in pixels, or None
            `anchor_x` : str
                Anchor point of the X coordinate: one of ``"left"``,
                ``"center"`` or ``"right"``.
            `anchor_y` : str
                Anchor point of the Y coordinate: one of ``"bottom"``,
                ``"baseline"``, ``"center"`` or ``"top"``.
            `halign` : str
                Horizontal alignment of text on a line, only applies if
                a width is supplied. One of ``"left"``, ``"center"``
                or ``"right"``.
            `multiline` : bool
                If True, the label will be word-wrapped and accept newline
                characters.  You must also set the width of the label.
            `dpi` : float
                Resolution of the fonts in this layout.  Defaults to 96.
            `batch` : `Batch`
                Optional graphics batch to add the label to.
            `group` : `Group`
                Optional graphics group to use.

        '''
        document = decode_text(text)
        super(Label, self).__init__(document, x, y, width, height, 
                                    anchor_x, anchor_y,
                                    multiline, dpi, batch, group)

        self.document.set_style(0, len(self.document.text), {
            'font_name': font_name,
            'font_size': font_size,
            'bold': bold,
            'italic': italic,
            'color': color,
            'halign': halign,
        })

class HTMLLabel(DocumentLabel):
    '''HTML formatted text label.
    
    A subset of HTML 4.01 is supported.  See `pyglet.text.formats.html` for
    details.
    '''
    def __init__(self, text='', location=None, 
                 x=0, y=0, width=None, height=None,
                 anchor_x='left', anchor_y='baseline',
                 multiline=False, dpi=None, batch=None, group=None):
        '''Create a label with an HTML string.

        :Parameters:
            `text` : str
                HTML formatted text to display.
            `location` : `Location`
                Location object for loading images referred to in the
                document.  By default, the working directory is used.
            `x` : int
                X coordinate of the label.
            `y` : int
                Y coordinate of the label.
            `width` : int
                Width of the label in pixels, or None
            `height` : int
                Height of the label in pixels, or None
            `anchor_x` : str
                Anchor point of the X coordinate: one of ``"left"``,
                ``"center"`` or ``"right"``.
            `anchor_y` : str
                Anchor point of the Y coordinate: one of ``"bottom"``,
                ``"baseline"``, ``"center"`` or ``"top"``.
            `multiline` : bool
                If True, the label will be word-wrapped and render paragraph
                and line breaks.  You must also set the width of the label.
            `dpi` : float
                Resolution of the fonts in this layout.  Defaults to 96.
            `batch` : `Batch`
                Optional graphics batch to add the label to.
            `group` : `Group`
                Optional graphics group to use.

        ''' 
        self._text = text
        self._location = location
        document = decode_html(text, location)
        super(HTMLLabel, self).__init__(document, x, y, width, height, 
                                        anchor_x, anchor_y,
                                        multiline, dpi, batch, group)

    def _set_text(self, text):
        self._text = text
        self.document = decode_html(text, self._location)

    def _get_text(self):
        return self._text

    text = property(_get_text, _set_text, 
                    doc='''HTML formatted text of the label.

    :type: str
    ''')
