text: # -*- coding: utf-8 -*-
  """Top-level display functions for displaying object in different formats.
  
  Authors:
  
  * Brian Granger
  """
  
  #-----------------------------------------------------------------------------
  #       Copyright (C) 2013 The IPython Development Team
  #
  #  Distributed under the terms of the BSD License.  The full license is in
  #  the file COPYING, distributed as part of this software.
  #-----------------------------------------------------------------------------
  
  #-----------------------------------------------------------------------------
  # Imports
  #-----------------------------------------------------------------------------
  
  
  
  import os
  import struct
  
  from IPython.utils.py3compat import string_types, cast_bytes_py2, cast_unicode
  
  from .displaypub import publish_display_data
  
  #-----------------------------------------------------------------------------
  # utility functions
  #-----------------------------------------------------------------------------
  
  def _safe_exists(path):
      """Check path, but don't let exceptions raise"""
      try:
          return os.path.exists(path)
      except Exception:
          return False
  
  def _merge(d1, d2):
      """Like update, but merges sub-dicts instead of clobbering at the top level.
  
      Updates d1 in-place
      """
  
      if not isinstance(d2, dict) or not isinstance(d1, dict):
          return d2
      for key, value in list(d2.items()):
          d1[key] = _merge(d1.get(key), value)
      return d1
  
  def _display_mimetype(mimetype, objs, raw=False, metadata=None):
      """internal implementation of all display_foo methods
  
      Parameters
      ----------
      mimetype : str
          The mimetype to be published (e.g. 'image/png')
      objs : tuple of objects
          The Python objects to display, or if raw=True raw text data to
          display.
      raw : bool
          Are the data objects raw data or Python objects that need to be
          formatted before display? [default: False]
      metadata : dict (optional)
          Metadata to be associated with the specific mimetype output.
      """
      if metadata:
          metadata = {mimetype: metadata}
      if raw:
          # turn list of pngdata into list of { 'image/png': pngdata }
          objs = [ {mimetype: obj} for obj in objs ]
      display(*objs, raw=raw, metadata=metadata, include=[mimetype])
  
  #-----------------------------------------------------------------------------
  # Main functions
  #-----------------------------------------------------------------------------
  
  def display(*objs, **kwargs):
      """Display a Python object in all frontends.
  
      By default all representations will be computed and sent to the frontends.
      Frontends can decide which representation is used and how.
  
      Parameters
      ----------
      objs : tuple of objects
          The Python objects to display.
      raw : bool, optional
          Are the objects to be displayed already mimetype-keyed dicts of raw display data,
          or Python objects that need to be formatted before display? [default: False]
      include : list or tuple, optional
          A list of format type strings (MIME types) to include in the
          format data dict. If this is set *only* the format types included
          in this list will be computed.
      exclude : list or tuple, optional
          A list of format type strings (MIME types) to exclude in the format
          data dict. If this is set all format types will be computed,
          except for those included in this argument.
      metadata : dict, optional
          A dictionary of metadata to associate with the output.
          mime-type keys in this dictionary will be associated with the individual
          representation formats, if they exist.
      """
      raw = kwargs.get('raw', False)
      include = kwargs.get('include')
      exclude = kwargs.get('exclude')
      metadata = kwargs.get('metadata')
  
      from IPython.core.interactiveshell import InteractiveShell
  
      if raw:
          for obj in objs:
              publish_display_data('display', obj, metadata)
      else:
          format = InteractiveShell.instance().display_formatter.format
          for obj in objs:
              format_dict, md_dict = format(obj, include=include, exclude=exclude)
              if metadata:
                  # kwarg-specified metadata gets precedence
                  _merge(md_dict, metadata)
              publish_display_data('display', format_dict, md_dict)
  
  
  def display_pretty(*objs, **kwargs):
      """Display the pretty (default) representation of an object.
  
      Parameters
      ----------
      objs : tuple of objects
          The Python objects to display, or if raw=True raw text data to
          display.
      raw : bool
          Are the data objects raw data or Python objects that need to be
          formatted before display? [default: False]
      metadata : dict (optional)
          Metadata to be associated with the specific mimetype output.
      """
      _display_mimetype('text/plain', objs, **kwargs)
  
  
  def display_html(*objs, **kwargs):
      """Display the HTML representation of an object.
  
      Parameters
      ----------
      objs : tuple of objects
          The Python objects to display, or if raw=True raw HTML data to
          display.
      raw : bool
          Are the data objects raw data or Python objects that need to be
          formatted before display? [default: False]
      metadata : dict (optional)
          Metadata to be associated with the specific mimetype output.
      """
      _display_mimetype('text/html', objs, **kwargs)
  
  
  def display_svg(*objs, **kwargs):
      """Display the SVG representation of an object.
  
      Parameters
      ----------
      objs : tuple of objects
          The Python objects to display, or if raw=True raw svg data to
          display.
      raw : bool
          Are the data objects raw data or Python objects that need to be
          formatted before display? [default: False]
      metadata : dict (optional)
          Metadata to be associated with the specific mimetype output.
      """
      _display_mimetype('image/svg+xml', objs, **kwargs)
  
  
  def display_png(*objs, **kwargs):
      """Display the PNG representation of an object.
  
      Parameters
      ----------
      objs : tuple of objects
          The Python objects to display, or if raw=True raw png data to
          display.
      raw : bool
          Are the data objects raw data or Python objects that need to be
          formatted before display? [default: False]
      metadata : dict (optional)
          Metadata to be associated with the specific mimetype output.
      """
      _display_mimetype('image/png', objs, **kwargs)
  
  
  def display_jpeg(*objs, **kwargs):
      """Display the JPEG representation of an object.
  
      Parameters
      ----------
      objs : tuple of objects
          The Python objects to display, or if raw=True raw JPEG data to
          display.
      raw : bool
          Are the data objects raw data or Python objects that need to be
          formatted before display? [default: False]
      metadata : dict (optional)
          Metadata to be associated with the specific mimetype output.
      """
      _display_mimetype('image/jpeg', objs, **kwargs)
  
  
  def display_latex(*objs, **kwargs):
      """Display the LaTeX representation of an object.
  
      Parameters
      ----------
      objs : tuple of objects
          The Python objects to display, or if raw=True raw latex data to
          display.
      raw : bool
          Are the data objects raw data or Python objects that need to be
          formatted before display? [default: False]
      metadata : dict (optional)
          Metadata to be associated with the specific mimetype output.
      """
      _display_mimetype('text/latex', objs, **kwargs)
  
  
  def display_json(*objs, **kwargs):
      """Display the JSON representation of an object.
  
      Note that not many frontends support displaying JSON.
  
      Parameters
      ----------
      objs : tuple of objects
          The Python objects to display, or if raw=True raw json data to
          display.
      raw : bool
          Are the data objects raw data or Python objects that need to be
          formatted before display? [default: False]
      metadata : dict (optional)
          Metadata to be associated with the specific mimetype output.
      """
      _display_mimetype('application/json', objs, **kwargs)
  
  
  def display_javascript(*objs, **kwargs):
      """Display the Javascript representation of an object.
  
      Parameters
      ----------
      objs : tuple of objects
          The Python objects to display, or if raw=True raw javascript data to
          display.
      raw : bool
          Are the data objects raw data or Python objects that need to be
          formatted before display? [default: False]
      metadata : dict (optional)
          Metadata to be associated with the specific mimetype output.
      """
      _display_mimetype('application/javascript', objs, **kwargs)
  
  #-----------------------------------------------------------------------------
  # Smart classes
  #-----------------------------------------------------------------------------
  
  
  class DisplayObject(object):
      """An object that wraps data to be displayed."""
  
      _read_flags = 'r'
  
      def __init__(self, data=None, url=None, filename=None):
          """Create a display object given raw data.
  
          When this object is returned by an expression or passed to the
          display function, it will result in the data being displayed
          in the frontend. The MIME type of the data should match the
          subclasses used, so the Png subclass should be used for 'image/png'
          data. If the data is a URL, the data will first be downloaded
          and then displayed. If
  
          Parameters
          ----------
          data : unicode, str or bytes
              The raw data or a URL or file to load the data from
          url : unicode
              A URL to download the data from.
          filename : unicode
              Path to a local file to load the data from.
          """
          if data is not None and isinstance(data, string_types):
              if data.startswith('http') and url is None:
                  url = data
                  filename = None
                  data = None
              elif _safe_exists(data) and filename is None:
                  url = None
                  filename = data
                  data = None
  
          self.data = data
          self.url = url
          self.filename = None if filename is None else str(filename)
  
          self.reload()
  
      def reload(self):
          """Reload the raw data from file or URL."""
          if self.filename is not None:
              with open(self.filename, self._read_flags) as f:
                  self.data = f.read()
          elif self.url is not None:
              try:
                  import urllib.request, urllib.error, urllib.parse
                  response = urllib.request.urlopen(self.url)
                  self.data = response.read()
                  # extract encoding from header, if there is one:
                  encoding = None
                  for sub in response.headers['content-type'].split(';'):
                      sub = sub.strip()
                      if sub.startswith('charset'):
                          encoding = sub.split('=')[-1].strip()
                          break
                  # decode data, if an encoding was specified
                  if encoding:
                      self.data = self.data.decode(encoding, 'replace')
              except:
                  self.data = None
  
  class Pretty(DisplayObject):
  
      def _repr_pretty_(self):
          return self.data
  
  
  class HTML(DisplayObject):
  
      def _repr_html_(self):
          return self.data
  
      def __html__(self):
          """
          This method exists to inform other HTML-using modules (e.g. Markupsafe,
          htmltag, etc) that this object is HTML and does not need things like
          special characters (<>&) escaped.
          """
          return self._repr_html_()
  
  
  class Math(DisplayObject):
  
      def _repr_latex_(self):
          s = self.data.strip('$')
          return "$$%s$$" % s
  
  
  class Latex(DisplayObject):
  
      def _repr_latex_(self):
          return self.data
  
  
  class SVG(DisplayObject):
  
      # wrap data in a property, which extracts the <svg> tag, discarding
      # document headers
      _data = None
  
      @property
      def data(self):
          return self._data
  
      @data.setter
      def data(self, svg):
          if svg is None:
              self._data = None
              return
          # parse into dom object
          from xml.dom import minidom
          svg = cast_bytes_py2(svg)
          x = minidom.parseString(svg)
          # get svg tag (should be 1)
          found_svg = x.getElementsByTagName('svg')
          if found_svg:
              svg = found_svg[0].toxml()
          else:
              # fallback on the input, trust the user
              # but this is probably an error.
              pass
          svg = cast_unicode(svg)
          self._data = svg
  
      def _repr_svg_(self):
          return self.data
  
  
  class JSON(DisplayObject):
  
      def _repr_json_(self):
          return self.data
  
  css_t = """$("head").append($("<link/>").attr({
    rel:  "stylesheet",
    type: "text/css",
    href: "%s"
  }));
  """
  
  lib_t1 = """$.getScript("%s", function () {
  """
  lib_t2 = """});
  """
  
  class Javascript(DisplayObject):
  
      def __init__(self, data=None, url=None, filename=None, lib=None, css=None):
          """Create a Javascript display object given raw data.
  
          When this object is returned by an expression or passed to the
          display function, it will result in the data being displayed
          in the frontend. If the data is a URL, the data will first be
          downloaded and then displayed.
  
          In the Notebook, the containing element will be available as `element`,
          and jQuery will be available.  The output area starts hidden, so if
          the js appends content to `element` that should be visible, then
          it must call `container.show()` to unhide the area.
  
          Parameters
          ----------
          data : unicode, str or bytes
              The Javascript source code or a URL to download it from.
          url : unicode
              A URL to download the data from.
          filename : unicode
              Path to a local file to load the data from.
          lib : list or str
              A sequence of Javascript library URLs to load asynchronously before
              running the source code. The full URLs of the libraries should
              be given. A single Javascript library URL can also be given as a
              string.
          css: : list or str
              A sequence of css files to load before running the source code.
              The full URLs of the css files should be given. A single css URL
              can also be given as a string.
          """
          if isinstance(lib, str):
              lib = [lib]
          elif lib is None:
              lib = []
          if isinstance(css, str):
              css = [css]
          elif css is None:
              css = []
          if not isinstance(lib, (list,tuple)):
              raise TypeError('expected sequence, got: %r' % lib)
          if not isinstance(css, (list,tuple)):
              raise TypeError('expected sequence, got: %r' % css)
          self.lib = lib
          self.css = css
          super(Javascript, self).__init__(data=data, url=url, filename=filename)
  
      def _repr_javascript_(self):
          r = ''
          for c in self.css:
              r += css_t % c
          for l in self.lib:
              r += lib_t1 % l
          r += self.data
          r += lib_t2*len(self.lib)
          return r
  
  # constants for identifying png/jpeg data
  _PNG = b'\x89PNG\r\n\x1a\n'
  _JPEG = b'\xff\xd8'
  
  def _pngxy(data):
      """read the (width, height) from a PNG header"""
      ihdr = data.index(b'IHDR')
      # next 8 bytes are width/height
      w4h4 = data[ihdr+4:ihdr+12]
      return struct.unpack('>ii', w4h4)
  
  def _jpegxy(data):
      """read the (width, height) from a JPEG header"""
      # adapted from http://www.64lines.com/jpeg-width-height
      
      idx = 4
      while True:
          block_size = struct.unpack('>H', data[idx:idx+2])[0]
          idx = idx + block_size
          if data[idx:idx+2] == b'\xFF\xC0':
              # found Start of Frame
              iSOF = idx
              break
          else:
              # read another block
              idx += 2
  
      h, w = struct.unpack('>HH', data[iSOF+5:iSOF+9])
      return w, h
  
  class Image(DisplayObject):
  
      _read_flags = 'rb'
      _FMT_JPEG = 'jpeg'
      _FMT_PNG = 'png'
      _ACCEPTABLE_EMBEDDINGS = [_FMT_JPEG, _FMT_PNG]
  
      def __init__(self, data=None, url=None, filename=None, format='png', embed=None, width=None, height=None, retina=False):
          """Create a display an PNG/JPEG image given raw data.
  
          When this object is returned by an expression or passed to the
          display function, it will result in the image being displayed
          in the frontend.
  
          Parameters
          ----------
          data : unicode, str or bytes
              The raw image data or a URL or filename to load the data from.
              This always results in embedded image data.
          url : unicode
              A URL to download the data from. If you specify `url=`,
              the image data will not be embedded unless you also specify `embed=True`.
          filename : unicode
              Path to a local file to load the data from.
              Images from a file are always embedded.
          format : unicode
              The format of the image data (png/jpeg/jpg). If a filename or URL is given
              for format will be inferred from the filename extension.
          embed : bool
              Should the image data be embedded using a data URI (True) or be
              loaded using an <img> tag. Set this to True if you want the image
              to be viewable later with no internet connection in the notebook.
  
              Default is `True`, unless the keyword argument `url` is set, then
              default value is `False`.
  
              Note that QtConsole is not able to display images if `embed` is set to `False`
          width : int
              Width to which to constrain the image in html
          height : int
              Height to which to constrain the image in html
          retina : bool
              Automatically set the width and height to half of the measured
              width and height.
              This only works for embedded images because it reads the width/height
              from image data.
              For non-embedded images, you can just set the desired display width
              and height directly.
  
          Examples
          --------
          # embedded image data, works in qtconsole and notebook
          # when passed positionally, the first arg can be any of raw image data,
          # a URL, or a filename from which to load image data.
          # The result is always embedding image data for inline images.
          Image('http://www.google.fr/images/srpr/logo3w.png')
          Image('/path/to/image.jpg')
          Image(b'RAW_PNG_DATA...')
  
          # Specifying Image(url=...) does not embed the image data,
          # it only generates `<img>` tag with a link to the source.
          # This will not work in the qtconsole or offline.
          Image(url='http://www.google.fr/images/srpr/logo3w.png')
  
          """
          if filename is not None:
              ext = self._find_ext(filename)
          elif url is not None:
              ext = self._find_ext(url)
          elif data is None:
              raise ValueError("No image data found. Expecting filename, url, or data.")
          elif isinstance(data, string_types) and (
              data.startswith('http') or _safe_exists(data)
          ):
              ext = self._find_ext(data)
          else:
              ext = None
  
          if ext is not None:
              format = ext.lower()
              if ext == 'jpg' or ext == 'jpeg':
                  format = self._FMT_JPEG
              if ext == 'png':
                  format = self._FMT_PNG
          elif isinstance(data, bytes) and format == 'png':
              # infer image type from image data header,
              # only if format might not have been specified.
              if data[:2] == _JPEG:
                  format = 'jpeg'
  
          self.format = str(format).lower()
          self.embed = embed if embed is not None else (url is None)
  
          if self.embed and self.format not in self._ACCEPTABLE_EMBEDDINGS:
              raise ValueError("Cannot embed the '%s' image format" % (self.format))
          self.width = width
          self.height = height
          self.retina = retina
          super(Image, self).__init__(data=data, url=url, filename=filename)
          
          if retina:
              self._retina_shape()
      
      def _retina_shape(self):
          """load pixel-doubled width and height from image data"""
          if not self.embed:
              return
          if self.format == 'png':
              w, h = _pngxy(self.data)
          elif self.format == 'jpeg':
              w, h = _jpegxy(self.data)
          else:
              # retina only supports png
              return
          self.width = w // 2
          self.height = h // 2
  
      def reload(self):
          """Reload the raw data from file or URL."""
          if self.embed:
              super(Image,self).reload()
              if self.retina:
                  self._retina_shape()
  
      def _repr_html_(self):
          if not self.embed:
              width = height = ''
              if self.width:
                  width = ' width="%d"' % self.width
              if self.height:
                  height = ' height="%d"' % self.height
              return '<img src="%s"%s%s/>' % (self.url, width, height)
  
      def _data_and_metadata(self):
          """shortcut for returning metadata with shape information, if defined"""
          md = {}
          if self.width:
              md['width'] = self.width
          if self.height:
              md['height'] = self.height
          if md:
              return self.data, md
          else:
              return self.data
  
      def _repr_png_(self):
          if self.embed and self.format == 'png':
              return self._data_and_metadata()
  
      def _repr_jpeg_(self):
          if self.embed and (self.format == 'jpeg' or self.format == 'jpg'):
              return self._data_and_metadata()
  
      def _find_ext(self, s):
          return str(s.split('.')[-1].lower())
  
  
  def clear_output(stdout=True, stderr=True, other=True):
      """Clear the output of the current cell receiving output.
  
      Optionally, each of stdout/stderr or other non-stream data (e.g. anything
      produced by display()) can be excluded from the clear event.
  
      By default, everything is cleared.
  
      Parameters
      ----------
      stdout : bool [default: True]
          Whether to clear stdout.
      stderr : bool [default: True]
          Whether to clear stderr.
      other : bool [default: True]
          Whether to clear everything else that is not stdout/stderr
          (e.g. figures,images,HTML, any result of display()).
      """
      from IPython.core.interactiveshell import InteractiveShell
      if InteractiveShell.initialized():
          InteractiveShell.instance().display_pub.clear_output(
              stdout=stdout, stderr=stderr, other=other,
          )
      else:
          from IPython.utils import io
          if stdout:
              print('\033[2K\r', file=io.stdout, end='')
              io.stdout.flush()
          if stderr:
              print('\033[2K\r', file=io.stderr, end='')
              io.stderr.flush()
  
  