_openbrowser.py (original) (raw)

File: mergeall-android-scripts/_readme-items/PYDROID3-TKINTER/CODE/_openbrowser.py

Python 3.X code run in the Pydroid 3 app's IDE

"""

Open documents by URL in a browser or other viewer on Android.

UPDATE APRIL 21, 2019

The document-open story recently changed in the Pydroid 3 app:

Prior to its 3.0 release, its $BROWSER setting sufficed to enable webbrowser use on Android as described below.
As of 3.0, its DISPLAY setting makes webbrowser crash, and its $BROWSER setting disables local-file URLs in any event.

To open documents in both Pydroid 3's 2.2 and 3.0 releases, use os.system() and a hardcoded activity-manager command of the form ahead. This works as well as pre-3.0 webbrowser, and avoids environment changes of unknown consequence.

For full details, see: http://learning-python.com/ mergeall-android-scripts/_README.html#webbrowsermodule

ORIGINAL NOTES

The code below demos opening a file by URL in a browser (or other viewer) on Android, using both a manual activity-manager shell command, and Python's webbrowser module.

To support both schemes, Pydroid 3's 2.2 release predefines a template for the required command in $BROWSER like this:

am start --user 0 -a android.intent.action.VIEW -d %s

In the first scheme, this script launches a command-line string like the following with Python's os.system():

am start --user 0 -a android.intent.action.VIEW -d http://...

In the second scheme, the webbrowser module does similar, but automatically uses $BROWSER if set in the host platform's shell, calling subprocess.Popen() to spawn the same command line.

In both schemes, viewers run in parallel on Android, and a back tap returns to their spawner immediately (if still running).

Both schemes are picky about URLs: local requires a "file://" and rendering HTML files seems to require a remote "http://". webbrowser is cross platform, but has no advantage on Android.

CAVEATS

When pressed, Buttons may lose their background color, and stay depressed occasionally an some devices (known Pydroid 3 bugs).
These schemes rely on Android's default-apps model, which is not as general or inclusive as filename associations elsewhere.
"""

import os, webbrowser from tkinter import *

def openBrowser_System(url, trace=True): """ Open a viewer for a URL, with a spawned shell command. Don't use $BROWSER: it disables "file://" in Pydroid 3 3.0. """ #brw = os.environ['BROWSER'] brw = 'am start --user 0 -a android.intent.action.VIEW -d %s' cmd = brw % url os.system(cmd) if trace: print('opened by command:', repr(cmd), end='\n\n')

def openBrowser_Module(url, trace=True): """ Open a viewer for a URL, with Python's webbrowser module. All webbrowser.open() calls work in Pydroid 2.2, fail in 3.0. A first 3.0 exception seems to leave webbrowser unresponsive. """ try: webbrowser.open(url) # fails in Pydroid 3 3.0 per above except: print('FAILED module open:', repr(url)) print(sys.exc_info()[0], '\n', sys.exc_info()[1], end='\n\n') else: if trace: print('opened by module:', repr(url), end='\n\n')

def onBrowse(): """ Pick next URL and opener on wrap-around lists. The math opens all urls in each opener in turn: i.e., for x in openers, for y in urls, x(y). """ global nview url = urls[nview % len(urls)] opn = openers[(nview // len(urls)) % len(openers)] opn(url) nview += 1

openers = [ openBrowser_System, openBrowser_Module ]

urls = [ 'http://learning-python.com', 'http://www.python.org', 'http://www.tcl.tk', 'http://learning-python.com/programs.html', 'file:///sdcard/shared.txt', # until Android Q breaks? 'file://%s/local.txt' % os.getcwd(), # permission dependent 'file:///sdcard/nonesuch.txt' # test invalid files ]

make test files

nview = 0 open('local.txt', 'w').write('local dir') open('/sdcard/shared.txt', 'w').write('shared dir')

build and run gui

root = Tk() Button(root, text='Browse', width=18, height=10, font='arial 8 bold', # fails: bg='ivory' command=onBrowse).pack(expand=YES) root.mainloop()

delete test files

os.remove('local.txt') os.remove('/sdcard/shared.txt')