Pop-Up Browser Windows

Midori [4], a lightweight web browser, has been available with the Raspberry Pi desktop for many years. One of Midori's advantages is that it can be easily launched as a pop-up window without affecting your main browser settings.

To install Midori on a Debian/Raspian/Ubuntu system enter:

sudo apt install midori

Midori can be run as a pop-up window by using the web application -a command-line option.

Listing 4 shows a one-line Bash statement that creates a tray icon that can launch four different Midori browser windows (Figure 5).

yad --notification --image="emblem-web" \
 --command="midori -a https://news.google.com/"   \
 --menu="Facebook! midori -a https://mbasic.facebook.com \
        | Linux! midori -a https://www.linux-magazine.com \
        | Weather! midori -a https://www.theweathernetwork.com \
        | Quit ! killall yad"  \
 --text="My Fav Web Pages"

Figure 5: You can also create a tray icon that will launch Midori browser windows for your favorite web pages.

Toggling

YAD supports the ability to dynamically change a tray item's icon, command, menuing, and tooltip. To do this you need to enable listen mode (--listen) and then redirect the standard I/O (stdio) – file 1 as shown in Listing 5 – to a named pipe. After completion, a YAD tray item can be manipulated from the main script, an external script, or manually from a terminal.

01 #!/bin/bash
02 #
03 # tray_toggle.sh - toggle system tray items
04 #                - create a named pipe for inputs
05 #
06 mytraypipe="/tmp/tray1.pipe"
07
08 # Make the named pipe (if it doesn't exist)
09 if ! test -e "$mytraypipe"; then
10   mkfifo $mytraypipe
11 fi
12
13 # redirect the stdio (file 1) to the named pipe
14 exec 1<> $mytraypipe
15
16 # create the notification icon
17 yad --notification                  \
18     --listen                        \
19     --image="emblem-colors-grey"  \              \
20     --text="My Tray Test"   \
21     --command="yad --text='Test Tray App' " <&1
22
23 # Every 10 seconds toggle the tray features with fake weather
24 while :
25 do
26   sleep 10
27   echo "action:yad --text='Rain until morning'" > $mytraypipe
28   sleep 1
29   echo "icon:stock_weather-showers" >> $mytraypipe
30   sleep 1
31   echo "tooltip:Rain until morning" >> $mytraypipe
32   sleep 10
33   echo "action:yad --text='Sunny for 2 days'" > $mytraypipe
34   sleep 1
35   echo "icon:stock_weather-sunny" >> $mytraypipe
36   sleep 1
37   echo "tooltip:Sunny for 2 days" >> $mytraypipe
38 done

Listing 5 shows a standalone script that creates a system tray item that can toggle some of its tray features (e.g., icon, tooltip, or command) every 10 seconds.

The first step in Listing 5 sets up a named pipe (lines 6 and 9-11). The named pipe is a file that is used to pass command arguments to YAD. Next, redirect stdio (file 1) to the named pipe (line 14) and then have YAD get its input from the redirected file 1 (line 21).

A while loop cycles every 10 seconds (line 24-26). Custom YAD command arguments are written/redirected to the named pipe with echo statements (e.g., line 27). Adding sleep statements helps ensure that YAD doesn't miss a command before a new command is written.

Listing 5 uses static weather data (Figure 6). A future step would be to periodically scan for actual weather data. If you're interested in using Bash to scrape the web [5], take a look at the Lynx [6] command-line browser. With one line of Bash, you can use Lynx to cleanly extract the contents of a web page; then, with a piped grep command, you can parse out the desired data.

Figure 6: You can toggle the system tray icon, tooltip, or command with YAD.

It should be noted that the YAD menus can also be dynamically changed. In Listing 5, to add a new menu item or change a menu item, the code would look something like:

echo "action:menu= \
  menu_title1 ! menu_command1 | \
  menu_title2 ! menu_command2" \
   > $mytraypipe

Summary

Coding errors are a fact of life, so I found the command:

killall yad ; killall bash

to be quite useful, especially when I was playing with YAD in listening mode.

It's pretty amazing that with just one or a couple of lines of Bash script you can pull together all your favorite apps and web pages into a common system tray icon.