These are the default mappings of actions to the keyboard and mouse. All may be changed to your liking by copying the default a4.ini file to $HOME/.config/a4/a4.ini and making edits there.

Default terminal action mappings

mappings of keyboard combinations to terminal actions
click on element for action
click‑1 terminal window focus
C-click‑1 terminal window grouped focus
click‑3 terminal window zoom
wheel‑up terminal window scroll up 3 lines
wheel‑dn terminal window scroll dn 3 lines
S-wheel‑upterminal window scroll up ½ screen
S-wheel‑dnterminal window scroll dn ½ screen
C-wheel‑upterminal window scroll up 1 screen
C-wheel‑dnterminal window scroll dn 1 screen
click‑1 title bar minimize
click‑1 tag symbol set view
C-click‑1 tag symbol toggle view
click‑3 tag symbol set tag
C-click‑3 tag symbol toggle tag
click‑1 status text statusnext

All these actions begin by pressing Ctrl‑g (with one exception for scrollback mapping). In the a4.ini file, this is specified as C‑g

create_term
Create a new terminal window with create_term, C‑g+c. The position of all windows are automatically managed according to the current layout type. The layout type may be changed at any time, and the positioning is dynamically updated and managed.
minimize_tog, minimize_tog_mouse
A terminal window may be temporarily hidden using minimize_tog, C‑g+.. The title bars of all minimized windows are grouped on one line at the bottom of the screen. This can also be done using minimize_tog_mouse, click‑1 on a window's title bar.
focusn, focus_mouse
Focus the specified terminal window number. This action is mapped to each of the number keys, so C‑g+1 for window #1, etc. (C‑g+0 is the special case, see groupedfocus below.) This can also be done using focus_mouse, click‑1 in the terminal window area.

When mapping focusn in a4.ini, you can use the # character as a shortcut in the key combination and the action parameter to assign that combo/action pairing to digits 1-9. For the key combination, the last occurrence of # is replaced with the digit, and the same digit is passed as the action parameter. For example, C‑g # = focusn # is expanded out to C‑g 1 = focusn 1, C‑g 2 = focusn 2, ....

focusnext, focusprev, focusnextvis, focusprevvis, focusleft, focusdown, focusup, focusright
The focus movement keys generally follow vi's hjkl navigation keys pattern. focusnext C‑g+j and focusprev C‑g+k move the focus through all the terminal windows, in order. focusnextvis and focusprevvis do the same, but skip over all minimized windows (no default mappings). focusleft C‑g+H, focusdown C‑g+J, focusup C‑g+K, focusright C‑g+L, move the focus according to the coordinates of the windows.
focuslast
If you want to get back to the last terminal window you had focused, focuslast, C‑g+Tab takes you there.
groupedfocus, groupedfocus_mouse
Some or all of the terminal windows in view can grouped together in order to be able to type into all of them at the same time. Toggle the grouped focus of all of a view's windows with groupedfocus all, C‑g+0, or select individual windows to group together with groupedfocus, C‑g+). Individual windows can also be selected using groupedfocus_mouse, C‑click‑1 in the terminal window area.
zoom, zoom_mouse
zoom moves the selected terminal window to the top of the zoomed area, C‑g+Enter. If the selected window is already at the top of the zoomed area, it is instead swapped with the next window. This can also be done using zoom_mouse, click‑3 in the terminal window area.
scrollback
The scrollback action is used to scroll lines of a terminal up to the maximum defined in scroll_history. If the parameter passed to scrollback has a decimal point, it specifies the percentage of a screen of lines to scroll, e.g. 0.5 for half a screen of lines, otherwise it is the whole number of lines to scroll. Positive numbers scroll up and negative numbers scroll down. By default, S‑PageUp and S‑PageUp scroll up and down half a screen of lines at a time, and C‑g+PgUp and C‑g+PgUp scroll up and down a full screen of lines at a time. The mouse wheel is also mapped to scrolling actions, and this works on whichever terminal window the pointer is positioned over, not just the selected terminal. wheel‑up and wheel‑dn scroll 3 lines at a time, S‑wheel‑up and S‑wheel‑dn scroll half a screen of lines at a time, and C‑wheel‑up and C‑wheel‑dn scroll a full screen of lines at a time.
tag, tag_mouse, tag_tog, tag_tog_mouse
Each terminal window has a set of tags associated with it, initially set to whichever tags are being viewed when the window is created. Set the selected window (or group of windows) to have a single tag using tag followed by the tag number, 1-9, so C‑g+t+1 to give it only the first tag in the list, etc. This can also be done using tag_mouse, click‑3 on one of the tags on the left end of the status bar. Using a single tag on each window feels similar to the concept of workspaces. A terminal window can also have multiple tags selected. Toggle the tags for the selected window (or group of windows) on and off using tag_tog followed by the tag number, 1-9, so C‑g+T+1 to toggle the first tag in the list, etc. This can also be done this using tag_tog_mouse, C‑click‑3 on one of the tag indicators on the left end of the status bar.

When mapping tag and tag_tog in a4.ini, you can use the # character as a shortcut in the key combination and the action parameter to assign that combo/action pairing to digits 1-9. For the key combination, the last occurrence of # is replaced with the digit, and the same digit is passed as the action parameter. For example, C‑g t # = tag # is expanded out to C‑g t 1 = tag 1, C‑g t 2 = tag 2, ....

view, view_mouse, view_tog, view_tog_mouse
A4 displays all of the terminal windows that have one of the selected tags, as indicated on the left end of the status bar. The windows are always dynamically arranged according to the selected layout. Select to view the windows of just one tag by using view followed by the tag number, 1-9, so C‑g+v+1 to view all windows with the first tag in the list, etc. This can also be done this using view_mouse, click‑1 on one of the tag indicators on the left end of the status bar. Toggle additional tags on and off using view_tog_mouse followed by the tag number, 1-9, so C‑g+V+1 to toggle the first tag in the list, etc. This can also be done this using view_tog_mouse, C‑click‑1 on one of the tag indicators on the left end of the status bar.

When mapping view and view_tog in a4.ini, you can use the # character as a shortcut in the key combination and the action parameter to assign that combo/action pairing to digits 1-9. For the key combination, the last occurrence of # is replaced with the digit, and the same digit is passed as the action parameter. For example, C‑g v # = view # is expanded out to C‑g v 1 = view 1, C‑g v 2 = view 2, .... Likewise, to map function keys to view, C‑g F# = view # is expanded out to C‑g F1 = view 1, C‑g F2 = view 2, ....

viewprevtag
If you want to get back to the previous view you were using, viewprevtag, C‑g+v+Tab takes you there.
readonly_tog
Terminal windows can be set as read-only so that you do not accidentally type into it. The title bar of windows set as read-only have a different appearance so that they can be identified. Toggle read-only status using readonly_tog, C‑g+*.
statusbarvis, statusbarpos
The application status bar can be toggled on and off using statusbarvis, C‑g+s, and can be toggled top and bottom using stausbarpos, C‑g+S.
statusnext
The status bar text is updated after statusbar_interval seconds have elapsed. If more than one statusbar_cmd statements are defined then they will be cycled through in order. The next command can be forced to run immediately using statusnext, click‑1 on the status text on the right end of the status bar.
redraw
If you need to force a screen refresh, use redraw, C‑l. The redraw action redraws then entire a4 application, and then sends a Ctrl-L to the selected terminal window, if there is one.
destroy_term
It is best to exit a terminal normally, but if you cannot you can use destroy_term to force closed the selected terminal window. In order to avoid accidental use, this action requires pressing x twice, so C‑g+x+x.
quit_a4
When you exit the last terminal open in a4, the application will also close. If necessary, you can use quit_a4 to force the a4 to close immediately. In order to avoid accidental use, this action requires pressing q twice, so C‑g+q+q

Default layout arrangement mappings

mappings of keyboard combinations to layout arrangements
click on element for action
click‑1 layout symbol next layout
click‑3 layout symbol previous layout
<no default mapping> last layout
C-click‑1 layout symbol add 1 to zoomnum
C-click‑3 layout symbol remove 1 from zoomnum
M-C-click‑1 layout symbol increase zoomsize by 10%
M-C-click‑3 layout symbol reduce zoomsize by 10%
click‑1 frame line fullscreen layout

All these actions begin by pressing Ctrl‑a. In the a4.ini file, this is specified as C‑a

setlayout
Set the dynamic layout of the terminal windows in a4 using setlayout. (The eight available layouts are described at a4.) You can select a specific layout, or you can cycle through each of the layouts in order using C‑a+Space to go forward and C‑a+C‑Space to go backward. In addition, you can cycle through the layouts using click‑1 on the layout symbol in the status bar to go forward, and click‑3 to go backward.
key combo layout
C‑a+f fullscreen
C‑a+g grid
C‑a+h zoom_left
C‑a+j zoom_bottom
C‑a+k zoom_top
C‑a+l zoom_right
C‑a+c columns
C‑a+r rows
C‑a+Space next layout
C‑a+C‑Space prev layout
setlastlayout
Go back to the previously set layout using setlastlayout, C‑a+Tab. This can also be assigned to a mouse action, but is not mapped by default.
setzoomnum, setzoomsize
Change the number of terminal windows in the zoom area using setzoomnum, C‑a+i to add 1 window and C‑a+d to remove 1. Change the percentage of the screen taken up by the zoom area using setzoomsize, C‑a+I to increase it by 10% and C‑a+D to reduce it by 10%. In addition, you can perform these same changes using the mouse on the layout symbol, C‑click‑1 and C‑click‑3 for zoomnum and M‑C‑click‑1 and M‑C‑click‑3 for zoomsize.

Miscellaneous actions

keysequence
Arbitrary strings can be sent to a terminal using the keysequence action. There are three typical uses for this action.

Mapping terminal input sequences
The underlying terminal typically implements a virtual terminal standard mapping, such as VT100 or xterm, but some terminal applications require a different standard, such as VT220 (for example Home = keysequence \e[1~). A4 includes a vt220.ini override file that can be included to set VT220 sequences. See Terminal input sequences for more details.
Startup actions
If you want to do something in a terminal by default when you start a4, such as change directory, you can put the command into a keysequence action to have it typed out (for exammple startup = cd projects\n). See below for the backslash escape sequences for special characters, such as \n for new line.
Mapping commonly used strings to keyboard combinations to save time typing
C-g Space = keysequence Hello, World!

A set of backslash character escape sequences are available for use in keysequences

\a  0x07  alert (bell)
\b  0x08  backspace
\e  0x1B  an escape character
\f  0x0C  form feed
\n  0x0A  newline
\r  0x0D  carriage return
\t  0x09  horizontal tab
\v  0x0B  vertical tab
\\  0x5C  backslash

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