Coverage for local/lib/python2.7/site-packages/sage/misc/viewer.py : 43%

r""" 

Determination of programs for viewing web pages, etc. 

The function :func:`default_viewer` defines reasonable defaults for 

these programs. To use something else, use ``viewer``. First 

import it:: 

sage: from sage.misc.viewer import viewer 

On OS X, PDFs are opened by default using the 'open' command, which 

runs whatever has been designated as the PDF viewer in the OS. To 

change this to use 'Adobe Reader':: 

sage: viewer.pdf_viewer('open -a /Applications/Adobe\ Reader.app') # not tested 

Similarly, you can set ``viewer.browser(...)``, ``viewer.dvi_viewer(...)``, 

and ``viewer.png_viewer(...)``. You can make this change permanent by adding 

lines like these to your :file:`SAGE_STARTUP_FILE` (which is 

:file:`$HOME/.sage/init.sage` by default):: 

from sage.misc.viewer import viewer 

viewer.pdf_viewer('open -a /Applications/Adobe\ Reader.app') 

Functions and classes 

--------------------- 

""" 

from sage.structure.sage_object import SageObject 

VIEWERS = ['browser', 'dvi_viewer', 'pdf_viewer', 'png_viewer'] 

def default_viewer(viewer=None): 

""" 

Set up default programs for opening web pages, PDFs, PNGs, and DVI files. 

INPUT: 

- ``viewer``: ``None`` or a string: one of 'browser', 'pdf', 'png', 

'dvi' -- return the name of the corresponding program. ``None`` 

is treated the same as 'browser'. 

EXAMPLES:: 

sage: from sage.misc.viewer import default_viewer 

sage: default_viewer(None) # random -- depends on OS, etc. 

'sage-open' 

sage: default_viewer('pdf') # random -- depends on OS, etc. 

'xdg-open' 

sage: default_viewer('jpg') 

Traceback (most recent call last): 

... 

ValueError: Unknown type of viewer: jpg. 

""" 

import os 

from sage.misc.sage_ostools import have_program 

if isinstance(viewer, str): 

viewer = viewer.lower() 

if 'BROWSER' in os.environ: 

BROWSER = os.environ['BROWSER'] 

DVI_VIEWER = BROWSER 

PDF_VIEWER = BROWSER 

PNG_VIEWER = BROWSER 

elif os.uname()[0] == 'Darwin': 

# Simple on OS X, since there is an open command that opens 

# anything, using the user's preferences. 

# sage-open -- a wrapper around OS X open that 

# turns off any of Sage's special library stuff. 

BROWSER = 'sage-open' 

DVI_VIEWER = BROWSER 

PDF_VIEWER = BROWSER 

PNG_VIEWER = BROWSER 

elif os.uname()[0][:6] == 'CYGWIN': 

# Windows is also easy, since it has a system for 

# determining what opens things. 

# Bobby Moreti provided the following. 

if not 'BROWSER' in os.environ: 

systemroot = os.environ['SYSTEMROOT'].replace(':','/').replace('\\','') 

systemroot = '/cygdrive/' + systemroot 

BROWSER = '%s/system32/rundll32.exe url.dll,FileProtocolHandler'%\ 

systemroot 

else: 

BROWSER = os.environ['BROWSER'] 

DVI_VIEWER = BROWSER 

PDF_VIEWER = BROWSER 

PNG_VIEWER = BROWSER 

elif have_program('xdg-open'): 

# On other OS'es try xdg-open if present. 

# See http://portland.freedesktop.org/xdg-utils-1.0. 

BROWSER = 'xdg-open' 

DVI_VIEWER = BROWSER 

PDF_VIEWER = BROWSER 

PNG_VIEWER = BROWSER 

else: 

# If all fails try to get something from the environment. 

try: 

BROWSER = os.environ['BROWSER'] 

except KeyError: 

BROWSER = 'less' # silly default; lets hope it doesn't come to this! 

for cmd in ['firefox', 'konqueror', 'mozilla', 'mozilla-firefox']: 

if have_program(cmd): 

BROWSER = cmd 

break 

DVI_VIEWER = BROWSER 

PDF_VIEWER = BROWSER 

PNG_VIEWER = BROWSER 

# Alternatives, if they are set in the environment or available. 

try: 

DVI_VIEWER = os.environ['DVI_VIEWER'] 

except KeyError: 

for cmd in ['xdvi', 'kdvi']: 

if have_program(cmd): 

DVI_VIEWER = cmd 

break 

try: 

PDF_VIEWER = os.environ['PDF_VIEWER'] 

except KeyError: 

for cmd in ['acroread', 'xpdf']: 

if have_program(cmd): 

PDF_VIEWER = cmd 

break 

if viewer is None or viewer.startswith('browse'): 

return BROWSER 

elif viewer.startswith('dvi'): 

return DVI_VIEWER 

elif viewer.startswith('png'): 

return PNG_VIEWER 

elif viewer.startswith('pdf'): 

return PDF_VIEWER 

else: 

raise ValueError('Unknown type of viewer: {}.'.format(viewer)) 

# _viewer_prefs: a dictionary holding global preferences for viewers. 

_viewer_prefs = {} 

class Viewer(SageObject): 

""" 

Set defaults for various viewing applications: a web browser, a 

dvi viewer, a pdf viewer, and a png viewer. 

EXAMPLES:: 

sage: from sage.misc.viewer import viewer 

sage: old_browser = viewer.browser() # indirect doctest 

sage: viewer.browser('open -a /Applications/Firefox.app') 

sage: viewer.browser() 

'open -a /Applications/Firefox.app' 

sage: viewer.browser(old_browser) # restore old value 

""" 

def _set(self, app=None, TYPE='browser'): 

r""" 

Change the default viewer. Return the current setting if the 

argument ``app`` is ``None``. 

INPUT: 

- ``app`` -- ``None`` or a string, the program to use 

- ``TYPE`` -- a string, must be in the list ``VIEWERS`` defined in 

:module:`sage.misc.viewer`. Default 'browser'. 

EXAMPLES:: 

sage: from sage.misc.viewer import viewer 

sage: old_browser = viewer.browser() 

sage: viewer.browser('open -a /Applications/Firefox.app') # indirect doctest 

sage: viewer.browser() 

'open -a /Applications/Firefox.app' 

sage: viewer.browser(old_browser) # restore old value 

""" 

TYPE = TYPE.lower() 

if TYPE not in VIEWERS: 

raise ValueError('Unrecognized type of viewer: {}'.format(TYPE)) 

if app is None: 

try: 

return _viewer_prefs[TYPE] 

except KeyError: 

return default_viewer(TYPE) 

elif app == 'default': 

try: 

del _viewer_prefs[TYPE] 

except KeyError: 

pass 

else: 

_viewer_prefs[TYPE] = app 

def browser(self, app=None): 

r""" 

Change the default browser. Return the current setting if arg 

is ``None``, which is the default. 

INPUT: 

- ``app`` -- ``None`` or a string, the program to use 

EXAMPLES:: 

sage: from sage.misc.viewer import viewer 

sage: old_browser = viewer.browser() 

sage: viewer.browser('open -a /Applications/Firefox.app') # indirect doctest 

sage: viewer.browser() 

'open -a /Applications/Firefox.app' 

sage: viewer.browser(old_browser) # restore old value 

""" 

return self._set(app, TYPE='browser') 

def dvi_viewer(self, app=None): 

r""" 

Change the default dvi viewer. Return the current setting if arg 

is ``None``, which is the default. 

INPUT: 

- ``app`` -- ``None`` or a string, the program to use 

EXAMPLES:: 

sage: from sage.misc.viewer import viewer 

sage: old_dvi_app = viewer.dvi_viewer() 

sage: viewer.dvi_viewer('/usr/bin/xdvi') # indirect doctest 

sage: viewer.dvi_viewer() 

'/usr/bin/xdvi' 

sage: viewer.dvi_viewer(old_dvi_app) # restore old value 

""" 

return self._set(app, TYPE='dvi_viewer') 

def pdf_viewer(self, app=None): 

r""" 

Change the default pdf viewer. Return the current setting if arg 

is ``None``, which is the default. 

INPUT: 

- ``app`` -- ``None`` or a string, the program to use 

EXAMPLES:: 

sage: from sage.misc.viewer import viewer 

sage: old_pdf_app = viewer.pdf_viewer() 

sage: viewer.pdf_viewer('/usr/bin/pdfopen') # indirect doctest 

sage: viewer.pdf_viewer() 

'/usr/bin/pdfopen' 

sage: viewer.pdf_viewer(old_pdf_app) # restore old value 

""" 

return self._set(app, TYPE='pdf_viewer') 

def png_viewer(self, app=None): 

r""" 

Change the default png viewer. Return the current setting if arg 

is ``None``, which is the default. 

INPUT: 

- ``app`` -- ``None`` or a string, the program to use 

EXAMPLES:: 

sage: from sage.misc.viewer import viewer 

sage: old_png_app = viewer.png_viewer() 

sage: viewer.png_viewer('display') # indirect doctest 

sage: viewer.png_viewer() 

'display' 

sage: viewer.png_viewer(old_png_app) # restore old value 

""" 

return self._set(app, TYPE='png_viewer') 

def __call__(self, x=None): 

""" 

Return the current setting for a viewer program. 

INPUT: 

- ``x`` -- string 

If ``x`` is ``None`` or starts with 'browse', then return the 

current browser app. If ``x`` starts with 'dvi', return the 

current dvi viewer, and similarly if ``x`` starts with 'png' 

or 'pdf'. 

EXAMPLES:: 

sage: from sage.misc.viewer import viewer 

sage: viewer('pdf') # random -- depends on OS, etc. 

'mozilla' 

sage: viewer('browser') == viewer() 

True 

""" 

if isinstance(x, str): 

x = x.lower() 

if x is None or x.startswith('browse'): 

return self.browser() 

elif x.startswith('dvi'): 

return self.dvi_viewer() 

elif x.startswith('png'): 

return self.png_viewer() 

elif x.startswith('pdf'): 

return self.pdf_viewer() 

viewer = Viewer() 

def browser(): 

""" 

Return the program used to open a web page. By default, the 

program used depends on the platform and other factors, like 

settings of certain environment variables. To use a different 

program, call ``viewer.browser('PROG')``, where 'PROG' is the 

desired program. 

This will start with 'sage-native-execute', which sets the 

environment appropriately. 

EXAMPLES:: 

sage: from sage.misc.viewer import browser 

sage: browser() # random -- depends on OS, etc. 

'sage-native-execute sage-open' 

sage: browser().startswith('sage-native-execute') 

True 

""" 

return "sage-native-execute " + viewer.browser() 

def dvi_viewer(): 

""" 

Return the program used to display a dvi file. By default, the 

program used depends on the platform and other factors, like 

settings of certain environment variables. To use a different 

program, call ``viewer.dvi_viewer('PROG')``, where 'PROG' is the 

desired program. 

This will start with 'sage-native-execute', which sets the 

environment appropriately. 

EXAMPLES:: 

sage: from sage.misc.viewer import dvi_viewer 

sage: dvi_viewer() # random -- depends on OS, etc. 

'sage-native-execute sage-open' 

sage: dvi_viewer().startswith('sage-native-execute') 

True 

""" 

viewer() 

return "sage-native-execute " + viewer.dvi_viewer() 

def pdf_viewer(): 

""" 

Return the program used to display a pdf file. By default, the 

program used depends on the platform and other factors, like 

settings of certain environment variables. To use a different 

program, call ``viewer.pdf_viewer('PROG')``, where 'PROG' is the 

desired program. 

This will start with 'sage-native-execute', which sets the 

environment appropriately. 

EXAMPLES:: 

sage: from sage.misc.viewer import pdf_viewer, viewer 

sage: old_pdf_app = viewer.pdf_viewer() 

sage: viewer.pdf_viewer('acroread') 

sage: pdf_viewer() 

'sage-native-execute acroread' 

sage: viewer.pdf_viewer('old_pdf_app') 

""" 

viewer() 

return "sage-native-execute " + viewer.pdf_viewer() 

def png_viewer(): 

""" 

Return the program used to display a png file. By default, the 

program used depends on the platform and other factors, like 

settings of certain environment variables. To use a different 

program, call ``viewer.png_viewer('PROG')``, where 'PROG' is the 

desired program. 

This will start with 'sage-native-execute', which sets the 

environment appropriately. 

EXAMPLES:: 

sage: from sage.misc.viewer import png_viewer 

sage: png_viewer() # random -- depends on OS, etc. 

'sage-native-execute xdg-open' 

sage: png_viewer().startswith('sage-native-execute') 

True 

""" 

viewer() 

return "sage-native-execute " + viewer.png_viewer()