No Linux Compose key

[Quoth]

The Compose Key doesn't work in the Calibre Editor. I have to open a text editor. But Ctrl C, X and V all work.
I use Compose commonly for – — … ° ′ and ″ (last two are prime and double prime for minutes or feet and seconds or inches (linear measure or fractions of degrees).

On earlier versions it did work in main HTML window, but that also is gone. AFAIK it's never worked in the Find/Search and Replace boxes. The characters work if copy/pasted from any Linux text editor.
I also use AltGr v, b, V and B for “ ” ‘ and ’ and for a while AltGr b or B opened something, but that was fixed by changing short cuts. I think all AltGr combos currently work.
I imagine it's QT because Viber uses QT and Compose key only sometimes works in it. Same on Calibre 5.44


Linux Mint 20.1 and Mate Desktop.
UK Extended Keyboard map.

[kovidgoyal]

Yes key handling is the province of Qt not calibre.

[Quoth]

It seems a long standing QT issue (4, 5, 6). It can be fixed by rebuilding from source, but the solution for recent Linux versions and desktops is below
Oddly some Compose key combos do work

The solution
In console make iBus default input method
im-config -n ibus

Edit the .XCompose in home, adding at start
include "/usr/share/X11/locale/en_US.UTF-8/Compose"
Enable show hidden and create if it doesn't exist

I use a UK Keyboard layout, but there is no en_<anything other than US> The /usr/share/X11/locale/en_US.UTF-8/Compose does seem to have all the default keys. Compose _a for ā Com oo for ° etc

All the common ones now like ° — – … ′ ″ work in Calibre, Viber and KATE (which I didn't realise only partly worked).
Obviously you have to Kill & restart Viber, or exit KATE, Calibre etc.

The AltGr keys are unaffected, eg þáŋçߧłŁ
My custom extra compose keys for Greek, prime and double prime:

include "/usr/share/X11/locale/en_US.UTF-8/Compose"
# GREEK CAPITAL LETTERS
<Multi_key> <G> <A> : "Α"    U0391    # GREEK CAPITAL LETTER ALPHA
<Multi_key> <G> <B> : "Β"    U0392    # GREEK CAPITAL LETTER BETA
<Multi_key> <G> <G> : "Γ"    U0393    # GREEK CAPITAL LETTER GAMMA
<Multi_key> <G> <D> : "Δ"    U0394    # GREEK CAPITAL LETTER DELTA
<Multi_key> <G> <E> : "Ε"    U0395    # GREEK CAPITAL LETTER EPSILON
<Multi_key> <G> <Z> : "Ζ"    U0396    # GREEK CAPITAL LETTER ZETA
<Multi_key> <G> <H> : "Η"    U0397    # GREEK CAPITAL LETTER ETA
<Multi_key> <G> <I> : "Ι"    U0399    # GREEK CAPITAL LETTER IOTA
<Multi_key> <G> <K> : "Κ"    U039A    # GREEK CAPITAL LETTER KAPPA
<Multi_key> <G> <L> : "Λ"    U039B    # GREEK CAPITAL LETTER LAMDA
<Multi_key> <G> <M> : "Μ"    U039C    # GREEK CAPITAL LETTER MU
<Multi_key> <G> <N> : "Ν"    U039D    # GREEK CAPITAL LETTER NU
<Multi_key> <G> <P> : "Π"    U03A0    # GREEK CAPITAL LETTER PI
<Multi_key> <G> <R> : "Ρ"    U03A1    # GREEK CAPITAL LETTER RHO
<Multi_key> <G> <S> : "Σ"    U03A3    # GREEK CAPITAL LETTER SIGMA
<Multi_key> <G> <T> : "Τ"    U03A4    # GREEK CAPITAL LETTER TAU
<Multi_key> <G> <U> : "Υ"    U03A5    # GREEK CAPITAL LETTER UPSILON
<Multi_key> <G> <F> : "Φ"    U03A6    # GREEK CAPITAL LETTER PHI
<Multi_key> <G> <X> : "Χ"    U03A7    # GREEK CAPITAL LETTER CHI
<Multi_key> <G> <O> : "Ω"    U03A9    # GREEK CAPITAL LETTER OMEGA

# DOUBLES (additional stroke <Q>)
<Multi_key> <G> <Q> <T> : "Θ"    U0398    # GREEK CAPITAL LETTER THETA
<Multi_key> <G> <Q> <O> : "Ο"    U039F    # GREEK CAPITAL LETTER OMICRON
<Multi_key> <G> <Q> <X> : "Ξ"    U039E    # GREEK CAPITAL LETTER XI
<Multi_key> <G> <Q> <P> : "Ψ"    U03A8    # GREEK CAPITAL LETTER PSI

# greek small letters
<Multi_key> <g> <a> : "α"    U03B1    # GREEK SMALL LETTER ALPHA
<Multi_key> <g> <b> : "β"    U03B2    # GREEK SMALL LETTER BETA
<Multi_key> <g> <g> : "γ"    U03B3    # GREEK SMALL LETTER GAMMA
<Multi_key> <g> <d> : "δ"    U03B4    # GREEK SMALL LETTER DELTA
<Multi_key> <g> <e> : "ε"    U03B5    # GREEK SMALL LETTER EPSILON
<Multi_key> <g> <z> : "ζ"    U03B6    # GREEK SMALL LETTER ZETA
<Multi_key> <g> <h> : "η"    U03B7    # GREEK SMALL LETTER ETA
<Multi_key> <g> <i> : "ι"    U03B9    # GREEK SMALL LETTER IOTA
<Multi_key> <g> <k> : "κ"    U03BA    # GREEK SMALL LETTER KAPPA
<Multi_key> <g> <l> : "λ"    U03BB    # GREEK SMALL LETTER LAMDA
<Multi_key> <g> <m> : "μ"    U03BC    # GREEK SMALL LETTER MU
<Multi_key> <g> <n> : "ν"    U03BD    # GREEK SMALL LETTER NU
<Multi_key> <g> <p> : "π"    U03C0    # GREEK SMALL LETTER PI
<Multi_key> <g> <r> : "ρ"    U03C1    # GREEK SMALL LETTER RHO
<Multi_key> <g> <s> : "σ"    U03C3    # GREEK SMALL LETTER SIGMA
<Multi_key> <g> <t> : "τ"    U03C4    # GREEK SMALL LETTER TAU
<Multi_key> <g> <u> : "υ"    U03C5    # GREEK SMALL LETTER UPSILON
<Multi_key> <g> <f> : "φ"    U03C6    # GREEK SMALL LETTER PHI
<Multi_key> <g> <x> : "χ"    U03C7    # GREEK SMALL LETTER CHI
<Multi_key> <g> <o> : "ω"    U03C9    # GREEK SMALL LETTER OMEGA

# doubles (additional stroke <q>)
<Multi_key> <g> <q> <t> : "θ"    U03B8    # GREEK SMALL LETTER THETA
<Multi_key> <g> <q> <o> : "ο"    U03BF    # GREEK SMALL LETTER OMICRON
<Multi_key> <g> <q> <p> : "ψ"    U03C8    # GREEK SMALL LETTER PSI
<Multi_key> <g> <q> <s> : "ς"    U03C2    # GREEK SMALL LETTER FINAL SIGMA
<Multi_key> <g> <q> <x> : "ξ"    U03BE    # GREEK SMALL LETTER XI

# prime etc
<Multi_key> <0> <apostrophe> : "′"    U2032    # prime
<Multi_key> <0> <quotedbl> : "″"    U2033    # double prime

My .XCompose

[Quoth]

I use Caps Lock Key for Compose and Dual Shift, either Shift cancels for ALL CAPS.
I think Compose is an ancient UNIX/Solaris thing, though AltGr now makes many of the accented characters simpler.
You could add Cyrillic to .XCompose and there is a standard map layout for QWERTY.

There seems to be no need to put HTML entities for “”‘’°′″—…– etc when using UTF8 in ebooks. Conversion of epub2 to mobi and azw3 seems OK too. Non 7bit ASCII may not work well in either pdb format for PalmOS.

[lomkiri]

Originally Posted by Quoth

It seems a long standing QT issue (4, 5, 6). It can be fixed by rebuilding from source, but the solution for recent Linux versions and desktops is below

My compose key (left-win, here) works out of the box in all fields of the editor I've tested (main window, search-replace, file-name, search in preview), so it seems that it's not a Qt or calibre issue (I've tested …, —, œ, and some others). Maybe Qt doesn't like the Shift-Lock as a compose key?

I like your idea of linking L-Shift + R-Shift to Shift-Lock! What is your keymap to do so?

I think Compose is an ancient UNIX/Solaris thing, though AltGr now makes many of the accented characters simpler.

I totally disagree with this, compose key is an actual and useful feature, and is one of the magic of linux. If you were writing in a non-english language, you'll find a lot of useful char. accessible only with either compose key or Ctrl-u <unicode>, the former being much easier. In fact, I'm using it all the time.

[rjwse@aol.com]

I use compose key extensively on Ubuntu 22.04 with calibre 6.9 editor, but there are some keys not available in the compose key list. I make use of a combination of (1) sometimes compose key combos, (2) sometimes 'create/edit snippets', and (3) sometimes 'insert special characters'. For example, to make m-dash via compose key I put in right-ctrl with - - - and it converts to the extra-long dash on the fly. However, there is no compose key I can find for unbreakable hyphen, so I made a snippet of ctrl-j after a regular hyphen. In another example, I consider a double quote surrounding a single quote bad looking because it appears 'run-on' such as "' ... '" so I put a 'hair space" in between the two by means of 'sh ctrl-j " and the quotes have a small amount of space between and do not look run-on. Actually, by means of the calibre snippet feature you could make all of the compose key combos without using the compose key at all. The nicest feature of the snippets is that you can use any number of keys typed in as the trigger. It can be a single key followed by ctrl-j or any two or more followed by ctrl-j. System 76 just came out with a programmable keyboard with a 10-key, but it is $300. Best regards, Pop

[Quoth]

Originally Posted by lomkiri

Maybe Qt doesn't like the Shift-Lock as a compose key?

I like your idea of linking L-Shift + R-Shift to Shift-Lock! What is your keymap to do so?



I totally disagree with this, compose key is an actual and useful feature, and is one of the magic of linux. If you were writing in a non-english language, you'll find a lot of useful char. accessible only with either compose key or Ctrl-u <unicode>, the former being much easier. In fact, I'm using it all the time.

You misunderstand. Compose is wonderful, but predates AltGr (may not be on some USA or older Keyboards and = Ctrl RightAlt). Many accented characters (and dead key punctuation to accent a letter) are on AltGr, if using US International or UK or other non-Basic US Layouts:
¦¹¨³€½^{[]}\¸
@ẃé¶ŧýúíóþ¨~
áßðđŋħł´
|«»ç“”nµ,·

Dead keys to accent next letter usually show it hit twice.
¡½⅓¼⅜⅝⅞™±°¿˛
Á§ÐªŊĦ¦Ł˝ˇ
¦<>Ç‘’º×÷

The Control Center -> Keyboard -> Layouts -> Options on Linux Mint with Mate desktop sets
Disable Caps Lock Key (do first!)
Set Compose Key = Caps Lock
Caps Lock Function = Both Shifts to enable, one shift to disable.


The QT issue is known bug (on some configurations) on at least 4, 5 & 6. It doesn't matter what key is Compose. Solution:
In console make iBus default input method
im-config -n ibus

Edit the .XCompose in home, adding at start
include "/usr/share/X11/locale/en_US.UTF-8/Compose"
Enable show hidden and create if it doesn't exist

And OF COURSE my Left Win Key (many keyboards have no Right Win) is Hold down and press left mouse to drag a window, if no title bar available!
That on Mate/Mint Control Cebter is in Windows (Window Preferences -> Behaviour -> Movement Key

Compose is wonderful!
I did use MS Keyboard Layout Editor years ago in Windows XP to give it most of the Linux AltGr. Very pathetic, especially standard USA layout. Loads of people there speak Spanish. Many names with accents.

[lomkiri]

Originally Posted by Quoth

You misunderstand.

I did indeed...

That on Mate/Mint Control Cebter is in Windows (Window Preferences -> Behaviour -> Movement Key

Ok, thanks. I have no such setting in XFCE (but KDE has it), I'll simulate this behavior with xmodmap.

[Quoth]

I have XFCE and Cinnamon as alternate desktops. I once broke the Mate GUI and at least I figured how to switch to a Console/terminal fix via commands, but fixing a broken desktop from a GUI is simpler... Easier to look up Web unless you have more than one PC/Laptop/Tablet.
I've used various incarnations of Gnome, Ice Window Manager and KDE too. Nice to have choice. Mate with my own custom theme based on downloaded Win2003 & Win98 themes with Oxygen Icons is now my favourite. Four Place Bars for different purposes. Local program shortcuts on Left, Remote on Right. Menu & running on top. Status and dock icons & shutdown etc on bottom. Autohide.