Glassy GNOME

A gnome-shell extension to enable window transparency.

Usage

Copy the extension to the extension folder manually

Put glassygnome@emiapwil to the extension folder (Mine is ~/.local/share/gnome-shell/extensions).

Build from source

Clone this repository and run make.

The extension will be compiled and put to folder ~/.local/share/gnome-shell/extensions. You might have to replace the EXTENSION_DIR with the path to the GNOME extensions on your own system.

Download from extensions.gnome.org

The extension has been uploaded to extensions.gnome.org. You can download the extension there.

Window Filters

The window filters are tuples in the following format: (patterns, active_opacity, inactive_opacity, step).

There are two default filters that come with the extension: one is matched against Terminal and the other is wildcard .*.

Since there is no GUI to manage the filters at the moment, people can use gsettings to modify them. For example, the following code inserts a new rule for Firefox:

gsettings --schemadir ~/.local/share/gnome-shell/extensions/glassygnome@emiapwil/schemas \
          set org.gnome.shell.extensions.glassy-gnome filters \
	      "[
              (['Terminal'], byte 0x50, byte 0x32, byte 0x0a),
	          (['Firefox'], byte 0x5f, byte 0x50, byte 0x0a),
	          (['.*'], byte 0x5f, byte 0x50, byte 0x05)
          ]"

If you are not certain what the regex should look like, it is possible to use xwininfo to see all names of the windows. Or you can use the looking glass tool, which is quite useful.

The valid range of active_opacity/inactive_opacity/step are 0~~100 (0x00~~0x64). If a given value is larger than 100, it will be treated as 100.

Shortcuts to manipulate the opacity of the active window

Currently I use <Super>0/<Super>9/<Super>8 to increase/decrease/reset the opacity of the active window.

There are five shortcuts available for glassy-gnome. Except the three mentioned above, you can also toggle both the global and per-window glassy effect. The key bindings for these two shortcuts, however, are not set when you first install the extension. You can use the following command to set up the shortcuts:

gsettings --schemadir ~/.local/share/gnome-shell/extensions/glassygnome@emiapwil/schemas \
          set org.gnome.shell.extensions.glassy-gnome toggle-glassy-global-key "['<Super>6']"

gsettings --schemadir ~/.local/share/gnome-shell/extensions/glassygnome@emiapwil/schemas \
          set org.gnome.shell.extensions.glassy-gnome toggle-glassy-window-key "['<Super>7']"

You can also replace toggle-glassy-global-key to inc-opacity-key/dec-opacity-key/reset-opacity-key to set up your own key bindings for increasing/decreasing/resetting the opacity for the active window.

It is worth pointing out that the changes will not be recorded after the window is closed. I might consider adding this as a future feature.

Auto start

The default value of auto-start is true. It SHOULD be possible to change the value to false but again I haven't tested it yet.

Indicator in the status bar

An indicator is put in the status bar with a single letter "G" and the style class "glassygnome-indicator". The opacity of the letter is identical to the opacity of the active window.

Toggle the Indicator

This feature is included since version 11 and is tested on GNOME 3.18.

People may find the indicator useless and want to disable it. You can do so by typing the following command:

gsettings --schemadir ~/.local/share/gnome-shell/extensions/glassygnome@emiapwil/schemas \
          set org.gnome.shell.extensions.glassy-gnome hide-indicator true

You can also re-enable the indicator:

gsettings --schemadir ~/.local/share/gnome-shell/extensions/glassygnome@emiapwil/schemas \
          set org.gnome.shell.extensions.glassy-gnome hide-indicator false

Known Bugs

Extra key strokes on fully opaque/transparent windows

If I hit Super+0 for a fully opaque window, say, three times, I need to hit Super+9 four times until the window starts becoming transparent.

See Issue 1.

Thanks @krlmlr for pointing out the bug.

Not functioning properly with always-on-top windows

If a window is sticked to the top (by enabling "always on top"), the opacity of the normal windows in the same workspace will not change when they loss/obtain the focus.

See Issue 2.

Thanks @ipaq3870 for providing the solution.

Increase the opacity for special windows

Some special windows require more opacity, for example, the menus and tool bars for the browser. An option named the mix-ratio is introduced which will be used to compute the "mixed" opacity for certain windows. See [Issue 4][issue 4] for details. The option is a byte, ranging from 0 to 255.

The opacity is computed as (slightly different from the implementation but should be enough to demonstrate how it works):

ratio = mix_ratio * 100 / 256
new_opacity = (original_opacity * (100 - ratio) + OPAQUE * ratio) / 100

Generally speaking, the opacity increases as the mix-ratio grows. A mix-ratio of 255 means the window will be completely opaque. The default value is 0 because of my personal favor, you can use the following command to set the mix-ratio:

gsettings --schemadir ~/.local/share/gnome-shell/extensions/glassygnome@emiapwil/schemas \
          set org.gnome.shell.extensions.glassy-gnome mix-ratio 128

Thanks @ipaq3870 for pointing out the bug and providing the basic solution.

The opacity for new window is not correct

The opacity of a new window is always 255 (fully opaque). It is (probably) caused because glassy sets the opacity before the window is prepared to respond to events.

See Issue 6.

Features in the Future

A GUI for settings
A CLI tool for settings
(DONE) Use the settings schema instead of a configuration file
(DONE) Shortcut bindings
(DONE) Dynamic/Customized opacity

References

This post is an excellent guide to how to use schemas to store the configurations.

mgafner / glassy-gnome