xref: /vim-8.2.3635/runtime/doc/textprop.txt (revision 94688b8a)
1*textprop.txt*  For Vim version 8.1.  Last change: 2019 Jan 08
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4		  VIM REFERENCE MANUAL    by Bram Moolenaar
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7Displaying text with properties attached.		*text-properties*
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9THIS IS UNDER DEVELOPMENT - ANYTHING MAY STILL CHANGE  *E967*
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11What is not working yet:
12- Adjusting column/length when inserting text
13- Text properties spanning more than one line
14- prop_find()
15- callbacks when text properties are outdated
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17
181. Introduction			|text-prop-intro|
192. Functions			|text-prop-functions|
203. When text changes		|text-prop-changes|
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22
23{Vi does not have text properties}
24{not able to use text properties when the |+textprop| feature was
25disabled at compile time}
26
27==============================================================================
281. Introduction						*text-prop-intro*
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30Text properties can be attached to text in a buffer.  They will move with the
31text: If lines are deleted or inserted the properties move with the text they
32are attached to.  Also when inserting/deleting text in the line before the
33text property.  And when inserting/deleting text inside the text property, it
34will increase/decrease in size.
35
36The main use for text properties is to highlight text.  This can be seen as a
37replacement for syntax highlighting.  Instead of defining patterns to match
38the text, the highlighting is set by a script, possibly using the output of an
39external parser.  This only needs to be done once, not every time when
40redrawing the screen, thus can be much faster, after the initial cost of
41attaching the text properties.
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43Text properties can also be used for other purposes to identify text.  For
44example, add a text property on a function name, so that a search can be
45defined to jump to the next/previous function.
46
47A text property is attached at a specific line and column, and has a specified
48length.  The property can span multiple lines.
49
50A text property has these fields:
51	"id"		a number to be used as desired
52	"type"		the name of a property type
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54
55Property Types ~
56							*E971*
57A text property normally has the name of a property type, which defines
58how to highlight the text.  The property type can have these entries:
59	"highlight"	name of the highlight group to use
60	"priority"	when properties overlap, the one with the highest
61			priority will be used.
62	"start_incl"	when TRUE inserts at the start position will be
63			included in the text property
64	"end_incl"    	when TRUE inserts at the end position will be
65			included in the text property
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67
68Example ~
69
70Suppose line 11 in a buffer has this text (excluding the indent):
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72	The number 123 is smaller than 4567.
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74To highlight the numbers in this text: >
75	call prop_type_add('number', {'highlight': 'Constant'})
76	call prop_add(11, 12, {'length': 3, 'type': 'number'})
77	call prop_add(11, 32, {'length': 4, 'type': 'number'})
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79Try inserting or deleting lines above the text, you will see that the text
80properties stick to the text, thus the line number is adjusted as needed.
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82Setting "start_incl" and "end_incl" is useful when white space surrounds the
83text, e.g. for a function name.  Using false is useful when the text starts
84and/or ends with a specific character, such as the quote surrounding a string.
85
86	func FuncName(arg) ~
87	     ^^^^^^^^        property with start_incl and end_incl set
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89	var = "text"; ~
90	      ^^^^^^	     property with start_incl and end_incl not set
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92Nevertheless, when text is inserted or deleted the text may need to be parsed
93and the text properties updated.  But this can be done asynchronously.
94
95==============================================================================
962. Functions						*text-prop-functions*
97
98Manipulating text property types:
99
100prop_type_add({name}, {props})		define a new property type
101prop_type_change({name}, {props})	change an existing property type
102prop_type_delete({name} [, {props}])	delete a property type
103prop_type_get([{name} [, {props}])	get property type values
104prop_type_list([{props}])		get list of property types
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106
107Manipulating text properties:
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109prop_add({lnum}, {col}, {props})  	add a text property
110prop_clear({lnum} [, {lnum-end} [, {bufnr}]])
111					remove all text properties
112prop_find({props} [, {direction}])	search for a text property
113prop_list({lnum} [, {props})  		text properties in {lnum}
114prop_remove({props} [, {lnum} [, {lnum-end}]])
115					remove a text property
116
117==============================================================================
1183. When text changes				*text-prop-changes*
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120Vim will do its best to keep the text properties on the text where it was
121attached.  When inserting or deleting text the properties after the change
122will move accordingly.
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124When text is deleted and a text property no longer includes any text, it is
125deleted.  However, a text property that was defined as zero-width will remain,
126unless the whole line is deleted.
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128When using replace mode, the text properties stay on the same character
129positions, even though the characters themselves change.
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131
132When text property columns are not updated ~
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134- When setting the line with |setline()| or through an interface, such as Lua,
135  Tcl or Python.
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138 vim:tw=78:ts=8:noet:ft=help:norl:
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