Cycle through opening links with webbrowser module, xdg-open or --run…

… argument

Related to firecat53#51.

README.rst

@@ -46,6 +46,10 @@ Relative to urlview, urlscan has the following additional features:
 - Execute an arbitrary function (for example, copy URL to clipboard) instead of
   opening URL in a browser.
 
+- Use `l` to cycle through whether URLs are opened using the Python webbrowser
+  module (default), xdg-open (if installed) or opened by a function passed on
+  the command line with `--run`.
+
 - Configure colors and keybindings via ~/.config/urlscan/config.json. Generate
   default config file for editing by running `urlscan -g`. Cycle through
   available palettes with `p`.
@@ -106,11 +110,12 @@ context from around the URLs in the curses browser, and the '-d' flag removes
 duplicate URLs. Files can also be piped to urlscan using normal shell pipe
 mechanisms: `cat <something> | urlscan` or `urlscan < <something>`
 
-Instead of opening a web browser, the selected URL can be passed as the
-argument to a command using `--run <command>`. Alternatively, the URL can be
-piped to the command using `--run <command> --pipe`. Using --run with --pipe is
-preferred if the command supports it, as it is marginally more secure and
-tolerant of special characters in the URL.
+Instead of opening a web browser, the selected URL can be passed as the argument
+to a command using `--run "<command> {}"`. Note the use of `{}` in the command
+string to denote the selected URL. Alternatively, the URL can be piped to the
+command using `--run <command> --pipe`. Using --run with --pipe is preferred if
+the command supports it, as it is marginally more secure and tolerant of special
+characters in the URL.
 
 Theming
 -------
@@ -139,6 +144,7 @@ The follow actions are supported:
 - `context` -- show/hide context (default: `c`)
 - `down` -- cursor down (default: `j`)
 - `help_menu` -- show/hide help menu (default: `F1`)
+- `link_handler` -- cycle link handling (webbrowser, xdg-open or --run) (default: `l`)
 - `open_url` -- open selected URL (default: `space` or `enter`)
 - `palette` -- cycle through palettes (default: `p`)
 - `quit` -- quit (default: `q` or `Q`)

conf.py

@@ -0,0 +1,3 @@
+URLINTERNALPATTERN = r'[{}()@\w/\\\-%?!&.=:;+,#~]'
+URLTRAILINGPATTERN = r'[{}(@\w/\-%&=+#]'
+HTTPURLPATTERN = (r'(?:(https?|file|ftps?)://' + URLINTERNALPATTERN + r'*' + URLTRAILINGPATTERN + r')')

urlscan.1

@@ -1,6 +1,6 @@
 .\"                                      Hey, EMACS: -*- nroff -*-
 
-.TH URLSCAN 1 "April 4, 2019"
+.TH URLSCAN 1 "May 29, 2019"
 
 .SH NAME
 urlscan \- browse the URLs in an email message from a terminal
@@ -52,10 +52,15 @@ for color options and allowed values.
 
 \fB7.\fR \fBu\fR will unescape the highlighted URL if necessary.
 
-\fB8.\fR Run a command with the selected URL as the argument or pipe the selected
-  URL to a command using the \fB--run\fR and \fB--pipe\fR arguments.
+\fB8.\fR Run a command with the selected URL as the argument or pipe the
+selected URL to a command using the \fB--run\fR and \fB--pipe\fR arguments.
 
-\fB9.\fR \fBF1\fR shows the help menu.
+\fB9.\fR Use \fBl\fR to cycle through whether URLs are opened using the Python
+webbrowser module (default), xdg-open (if installed) or a function passed on the
+command line with \fB--run\fR. The \fB--run\fR function will respect the value
+of \fB--pipe\fR.
+
+\fB10.\fR \fBF1\fR shows the help menu.
 
 .SH OPTIONS
 .TP
@@ -78,9 +83,10 @@ Useful for scripting (implies \fB\-\-compact\fR).
 .TP
 .B \-r, \-\-run \<expression\>
 Execute \<expression\> in place of opening URL with a browser. Use {} in
-\<expression\> to substitute in the URL. Example:
+\<expression\> to substitute in the URL. Examples:
 
     $ urlscan --run 'echo {} | xclip -i' file.txt
+    $ urlscan --run 'tmux set buffer {}'
 .TP
 .B \-p, \-\-pipe
 Pipe the selected URL to the command specified by `--run`. This is preferred
@@ -137,6 +143,8 @@ The follow actions are supported:
 .TP
 \fBhelp_menu\fR \-\- show/hide help menu (Default: \fBF1\fR)
 .TP
+\fBlink_handler\fR \-\- cycle link handling (webbrowser, xdg-open or custom) (Default: \fBl\fR)
+.TP
 \fBopen_url\fR \-\- open selected URL (Default: \fBspace\fR or \fBenter\fR)
 .TP
 \fBpalette\fR \-\- cycle through palettes (Default: \fBp\fR)

urlscan/urlchoose.py

@@ -24,7 +24,7 @@
 from os.path import dirname, exists, expanduser
 import re
 import shlex
-from subprocess import Popen, PIPE
+from subprocess import call, Popen, PIPE, DEVNULL
 import sys
 from threading import Thread
 from time import sleep
@@ -114,6 +114,7 @@ def __init__(self, extractedurls, compact=False, nohelp=False, dedupe=False,
                      'j': self._down,
                      'k': self._up,
                      'P': self._clipboard_pri,
+                     'l': self._link_handler,
                      'p': self._palette,
                      'Q': self._quit,
                      'q': self._quit,
@@ -168,6 +169,11 @@ def __init__(self, extractedurls, compact=False, nohelp=False, dedupe=False,
                     pass
         except FileNotFoundError:
             pass
+        try:
+            call(['xdg-open'], stdout=DEVNULL)
+            self.xdg = True
+        except OSError:
+            self.xdg = False
         self.shorten = shorten
         self.compact = compact
         self.run = run
@@ -194,10 +200,16 @@ def __init__(self, extractedurls, compact=False, nohelp=False, dedupe=False,
         self.items_org = grp_list(self.items)
         listbox = urwid.ListBox(self.items)
         self.header = (":: F1 - help/keybindings :: "
-                       ":: q - quit :: "
-                       "/ - search :: ")
+                       "q - quit :: "
+                       "/ - search :: "
+                       "URL opening mode - {}")
+        self.link_open_modes = ["Web Browser", "Xdg-Open"] if self.xdg is True else ["Web Browser"]
+        if self.run:
+            self.link_open_modes.insert(0, self.run)
+        self.nohelp = nohelp
         if nohelp is False:
-            self.headerwid = urwid.AttrMap(urwid.Text(self.header), 'header')
+            self.headerwid = urwid.AttrMap(urwid.Text(
+                self.header.format(self.link_open_modes[0])), 'header')
         else:
             self.headerwid = None
         self.top = urwid.Frame(listbox, self.headerwid)
@@ -299,7 +311,8 @@ def _quit(self):
 
     def _open_url(self):
         """<Enter> or <space>"""
-        load_text = "Loading URL..." if not self.run else "Executing: {}".format(self.run)
+        load_text = "Loading URL..." if self.link_open_modes[0] != self.run \
+                else "Executing: {}".format(self.run)
         if os.environ.get('BROWSER') not in ['elinks', 'links', 'w3m', 'lynx']:
             self._footer_start_thread(load_text, 5)
 
@@ -322,6 +335,7 @@ def _help_menu(self):
                     "context -- show/hide context\n"
                     "down -- cursor down\n"
                     "help_menu -- show/hide help menu\n"
+                    "link_handler -- cycle through xdg-open, webbrowser and user-defined function\n"
                     "open_url -- open selected URL\n"
                     "palette -- cycle through palettes\n"
                     "quit -- quit\n"
@@ -596,6 +610,18 @@ def draw_screen(self, size):
     def _get_search(self):
         return lambda: self.search, lambda: self.enter
 
+    def _link_handler(self):
+        """Function to cycle through opening links via webbrowser module,
+        xdg-open or custom expression passed with --run.
+
+        """
+        mode = self.link_open_modes.pop()
+        self.link_open_modes.insert(0, mode)
+        if self.nohelp is False:
+            self.headerwid = urwid.AttrMap(urwid.Text(
+                self.header.format(self.link_open_modes[0])), 'header')
+            self.top.header = self.headerwid
+
     def mkbrowseto(self, url):
         """Create the urwid callback function to open the web browser or call
         another function with the URL.
@@ -621,9 +647,12 @@ def browse(*args):
                 if self._get_search()[1]() is True:
                     self.search = False
                     self.enter = False
-            elif not self.run:
+            elif self.link_open_modes[0] == "Web Browser":
                 webbrowser.open(url)
-            elif self.run and self.pipe:
+            elif self.link_open_modes[0] == "Xdg-Open":
+                run = 'xdg-open "{}"'.format(url)
+                process = Popen(shlex.split(run), stdout=PIPE, stdin=PIPE)
+            elif self.link_open_modes[0] == self.run and self.pipe:
                 process = Popen(shlex.split(self.run), stdout=PIPE, stdin=PIPE)
                 process.communicate(input=url.encode(sys.getdefaultencoding()))
             else: