patch 9.1.1857: Missing clipboard provider support

Problem:  Missing clipboard provider support
          (lilydjwg)
Solution: Add clipboard provider feature
          (Foxe Chen)

fixes: #12419
closes: #17998

Signed-off-by: Foxe Chen <chen.foxe@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

runtime/doc/builtin.txt

@@ -1,4 +1,4 @@
-*builtin.txt*	For Vim version 9.1.  Last change: 2025 Oct 13
+*builtin.txt*	For Vim version 9.1.  Last change: 2025 Oct 14
 
 
 		  VIM REFERENCE MANUAL	  by Bram Moolenaar
@@ -13061,6 +13061,7 @@ channel			Compiled with support for |channel| and |job|
 cindent			Compiled with 'cindent' support. (always true)
 clientserver		Compiled with remote invocation support |clientserver|.
 clipboard		Compiled with 'clipboard' support.
+clipboard_provider	Compiled with |clipboard-providers| support
 clipboard_working	Compiled with 'clipboard' support and it can be used.
 cmdline_compl		Compiled with |cmdline-completion| support.
 cmdline_hist		Compiled with |cmdline-history| support.

runtime/doc/eval.txt

@@ -1,4 +1,4 @@
-*eval.txt*	For Vim version 9.1.  Last change: 2025 Oct 12
+*eval.txt*	For Vim version 9.1.  Last change: 2025 Oct 14
 
 
 		  VIM REFERENCE MANUAL	  by Bram Moolenaar
@@ -38,6 +38,7 @@ a remark is given.
 12. The sandbox			|eval-sandbox|
 13. Textlock			|textlock|
 14. Vim script library		|vim-script-library|
+15. Clipboard providers		|clipboard-providers|
 
 Testing support is documented in |testing.txt|.
 Profiling is documented at |profiling|.
@@ -2251,6 +2252,11 @@ v:clipmethod	The current method of accessing the clipboard that is being
 					unavailable.
 		See 'clipmethod' for more details.
 
+					*v:clipproviders*
+v:clipproviders
+		A dictionary containing clipboard providers, see
+		|clipboard-providers| for more information.
+
 					*v:cmdarg* *cmdarg-variable*
 v:cmdarg	This variable is used for two purposes:
 		1. The extra arguments given to a file read/write command.
@@ -5263,5 +5269,133 @@ Usage: >vim
 	:call dist#vim9#Launch(<args>)
 	:Launch <app> <args>.
 <
+==============================================================================
+15. Clipboard providers					*clipboard-providers*
 
+When Vim is compiled with the |+clipboard_provider| feature, which requires
+the |+eval| feature, creating custom clipboards is possible.  These providers
+handle the "+" and "*" registers.  Note that on non-Unix or non-VMS systems,
+only the "*" register will be available for use.
+
+To add a provider, add a new entry to the |v:clipproviders| dictionary, in the
+format of: >
+	let v:clipproviders["name"] = {
+            \   "available": function("Available"),
+            \   "paste": {
+            \       '+': function("Paste"), " For the + register
+            \       '*': function("Paste"), " For the * register
+            \   },
+            \   "copy": {
+            \       '+': function("Copy"), " Same thing as above
+            \       '*': function("Copy"),
+            \   },
+            \ }
+
+The key is the provider name, which should be used in 'clipmethod', for
+example in the following example, you would add "name" to 'clipmethod' in
+order to use it. >
+	set clipmethod=name,wayland,x11,gui
+
+Each callback can either be a name of a function in a string, a |Funcref|, or
+a |lambda| expression.
+
+Note that these dictionary entries are optional, for example, if you don't
+care about the "copy" functions, then you can simply exclude them.  When Vim
+yanks/copies something, then simply nothing will be done.
+
+						*clipboard-provider-available*
+The "available" callback should return a string, which should contain which
+clipboard registers are available.  For example, if the "+" register is only
+available, then the function would return "+", or if both "+" and "*" are
+available, then return "+*".
+
+						*clipboard-provider-paste*
+The "paste" callback takes a first argument which is the register being put
+(string), and a second argument which is the type of access (string).  It
+should return either a tuple/list or string.  If a tuple/list is returned, it
+should have two elements:
+	- The register type conforming to |setreg()|.
+	- A list of strings
+If the register type is an empty string, then the type is automatically
+chosen, see |setreg()|.  If a string is returned, then it can either be "clear"
+or "previous".  "clear" makes Vim clear the register, and "previous" makes Vim
+use the previous register contents (or current depending on how you view it).
+
+The second argument, the access type, can either be "explicit" or "implicit".
+"explicit" means that the user is directly accessing the clipboard, such as
+putting text, or calling |getreg()|;  "implicit" means that the clipboard is
+being accessed indirectly, such when |:registers| is called, or when an
+unrelated operation causes Vim to access the clipboard.
+
+This is useful since some operations in Vim implicity access the clipboard
+indirectly.  For example, if when you want to create a provider for the OSC52
+command (accessing the clipboard via an escape code).  Many terminals show a
+confirmation if you want Vim to access the clipboard.  This can be very
+annoying with the terminal asking for permission everytime you do something
+that accesses the clipboard behind the scenes.  A good way to handle implicit
+access is to return "previous", which leaves the register contents unchanged.
+
+						*clipboard-provider-copy*
+The "copy" callback returns nothing, and takes the given arguments in order:
+	- The register being operated on
+	- The register type, conforming to |getregtype()|
+	- A list of strings to copy
+
+The provider can do whatever it wants with the given information.  This
+function is called on every request to change the clipboard register(s).
+
+						*clipboard-provider-textlock*
+In both the "paste" and "copy" callbacks, it is not allowed to change the
+buffer text, see |textlock|.
+
+						*clipboard-provider-example*
+Here is an example script that uses the clipboard provider feature through the
+OSC52 command: >vim
+
+	func Available()
+	  return "+"
+	endfunc
+	
+	func Paste(reg, type)
+	  " If implicit access, don't do anything
+	  if a:type == "implicit"
+	    return "previous"
+	  endif
+	
+	  augroup OSC
+	    autocmd!
+	    autocmd TermResponseAll osc ++once call feedkeys("\<F30>", '!')
+	  augroup END
+	
+	  " Send command
+	  call echoraw("\<Esc>]52;c;?\<Esc>\\")
+	
+	  " Wait until autocmd is triggered
+	  while getchar(-1) != "\<F30>"
+	  endwhile
+	
+	  autocmd! OSC
+	
+	  " Extract the base64 stuff
+	  let l:stuff = matchstr(v:termosc, '52;c;\zs[A-Za-z0-9+/=]\+')
+	
+	  return ("", blob2str(base64_decode(l:stuff)))
+	endfunc
+
+	func Copy(reg, type, lines)
+	  call echoraw("\<Esc>]52;c;" ..
+	    \ base64_encode(str2blob(a:lines)) .. "\<Esc>\\")
+	endfunc
+	let v:clipproviders["myosc"] = {
+	    \   "available": function("Available"),
+	    \   "paste": {
+	    \     '+': function("Paste"),
+	    \   },
+	    \   "copy": {
+	    \     '+': function("Copy"),
+	    \   },
+	    \ }
+	set clipmethod=myosc
+
+<
  vim:tw=78:ts=8:noet:ft=help:norl:

runtime/doc/options.txt

@@ -1919,10 +1919,15 @@ A jump table for the options with a short description can be found at |Q_op|.
 		x11		X11 selections
 		gui		GUI specific method
 		other		Some other method
+		*		Clipboard provider method
 
 	Note: "other" is used on systems without X11/Wayland, such as
 	MS-Windows or MacOS, when running Vim without the GUI.
 
+	Note that the name of the clipboard provider should be used when you
+	want to use a clipboard provider.  See |clipboard-providers| for more
+	information.
+
 	The option value is a list of comma separated items.  The list is
 	parsed left to right in order, and the first method that Vim
 	determines is available or is working is used as the actual method for

runtime/doc/tags

@@ -1411,6 +1411,7 @@ $quote	eval.txt	/*$quote*
 +cindent	various.txt	/*+cindent*
 +clientserver	various.txt	/*+clientserver*
 +clipboard	various.txt	/*+clipboard*
++clipboard_provider	various.txt	/*+clipboard_provider*
 +clipboard_working	various.txt	/*+clipboard_working*
 +cmd	editing.txt	/*+cmd*
 +cmdline_compl	various.txt	/*+cmdline_compl*
@@ -6691,6 +6692,12 @@ clipboard-autoselectml	options.txt	/*clipboard-autoselectml*
 clipboard-autoselectplus	options.txt	/*clipboard-autoselectplus*
 clipboard-exclude	options.txt	/*clipboard-exclude*
 clipboard-html	options.txt	/*clipboard-html*
+clipboard-provider-available	eval.txt	/*clipboard-provider-available*
+clipboard-provider-copy	eval.txt	/*clipboard-provider-copy*
+clipboard-provider-example	eval.txt	/*clipboard-provider-example*
+clipboard-provider-paste	eval.txt	/*clipboard-provider-paste*
+clipboard-provider-textlock	eval.txt	/*clipboard-provider-textlock*
+clipboard-providers	eval.txt	/*clipboard-providers*
 clipboard-unnamed	options.txt	/*clipboard-unnamed*
 clipboard-unnamedplus	options.txt	/*clipboard-unnamedplus*
 clojure-indent	indent.txt	/*clojure-indent*
@@ -11254,6 +11261,7 @@ v:char	eval.txt	/*v:char*
 v:charconvert_from	eval.txt	/*v:charconvert_from*
 v:charconvert_to	eval.txt	/*v:charconvert_to*
 v:clipmethod	eval.txt	/*v:clipmethod*
+v:clipproviders	eval.txt	/*v:clipproviders*
 v:cmdarg	eval.txt	/*v:cmdarg*
 v:cmdbang	eval.txt	/*v:cmdbang*
 v:collate	eval.txt	/*v:collate*

runtime/doc/various.txt

@@ -1,4 +1,4 @@
-*various.txt*   For Vim version 9.1.  Last change: 2025 Oct 12
+*various.txt*   For Vim version 9.1.  Last change: 2025 Oct 14
 
 
 		  VIM REFERENCE MANUAL    by Bram Moolenaar
@@ -378,6 +378,7 @@ m  *+channel*		inter process communication |channel|
 T  *+cindent*		'cindent', C indenting; Always enabled
 N  *+clientserver*	Unix and Win32: Remote invocation |clientserver|
    *+clipboard*		|clipboard| support compiled-in
+N  *+clipboard_provider*  |clipboard-providers| support compiled-in
    *+clipboard_working*	|clipboard| support compiled-in and working
 T  *+cmdline_compl*	command line completion |cmdline-completion|
 T  *+cmdline_hist*	command line history |cmdline-history|
@@ -807,7 +808,10 @@ K			Run a program to lookup the keyword under the
 :clip[reset]		Attempts to choose a new method for accessing the
 			clipboard, using the 'clipmethod' option.  This is
 			useful when the current method has become unavailable,
-			and you want to try using another method.
+			and you want to try using another method.  If the
+			|+clipboard_provider| feature is being used, this
+			command should be called after the availability of one
+			of the clipboard registers changes.
 			{only available when compiled with the |+clipboard|
 			feature}
 

runtime/doc/version9.txt

@@ -1,4 +1,4 @@
-*version9.txt*  For Vim version 9.1.  Last change: 2025 Oct 12
+*version9.txt*  For Vim version 9.1.  Last change: 2025 Oct 14
 
 
 		  VIM REFERENCE MANUAL    by Bram Moolenaar
@@ -41653,6 +41653,8 @@ Other new features ~
 
 - |items()| function now supports Blob.
 
+- |clipboard-providers| support.
+
 							*changed-9.2*
 Changed~
 -------
@@ -41900,13 +41902,29 @@ Options: ~
 			compositor
 
 Vim Variables: ~
+|v:clipmethod|		The current 'clipmethod'.
+|v:clipproviders|	A dictionary containing clipboard providers
+			information.
+|v:stacktrace|		The most recent caught exception.
+|v:t_enumvalue|		Value of |enumvalue|.
+|v:t_enum|		Value of |enum| type.
+|v:t_tuple|		Value of |Tuple| type.
 |v:termda1|		The escape sequence returned for the primary device
 			attribute query (DA1).
+|v:termosc|		The most recent received OSC response.
+|v:wayland_display|	The name of the Wayland display Vim is connected to.
 
 Vim Arguments: ~
 |-Y|			Do not connect to the |wayland| compositor.
 |--clientserver|	Specify backend for clientserver functionality.
 
+Configure Switches: ~
+--with-wayland			Enable the |wayland| feature.
+--enable-wayland-focus-steal	Enable the |wayland-focus-steal| feature.
+--enable-socketserver		Enable the |socketserver-clientserver|
+				feature.
+--enable-clipboard-provider	Enable the |clipboard-providers| feature.
+
 
 ==============================================================================
 INCOMPATIBLE CHANGES					*incompatible-9.2*