11 files changed, 40 insertions, 16 deletions
diff --git a/core/locale.conf b/core/locale.conf
index e461f12f..b5792cb4 100644
--- a/core/locale.conf
+++ b/core/locale.conf
@@ -166,7 +166,6 @@ Delete Word = D_elete Word
 Select All = Select _All
 Match Brace = _Match Brace
 Complete Word = Complete _Word
-Highlight Word = _Highlight Word
 Toggle Block Comment = Toggle _Block Comment
 Transpose Characters = T_ranspose Characters
 Join Lines = _Join Lines
diff --git a/core/locales/locale.ar.conf b/core/locales/locale.ar.conf
index d1cf7408..08dde3c0 100644
--- a/core/locales/locale.ar.conf
+++ b/core/locales/locale.ar.conf
@@ -166,7 +166,6 @@ Delete Word = اح_ذف كلمة
 Select All = ا_ختيار الكل
 Match Brace = __طابق القوس
 Complete Word = كمّل ال_كلمة
-Highlight Word = _ظلّل الكلمة
 Toggle Block Comment = _بدِّل التعليق
 Transpose Characters = ا_سحب الحرف
 Join Lines = ا_دمج الأسطر
diff --git a/core/locales/locale.de.conf b/core/locales/locale.de.conf
index d94cfe3c..9ddee348 100644
--- a/core/locales/locale.de.conf
+++ b/core/locales/locale.de.conf
@@ -166,7 +166,6 @@ Delete Word = Wort löschen
 Select All = A_lles auswählen
 Match Brace = Zugehörige Klammer
 Complete Word = Wort vervollständigen
-Highlight Word = Wort hervorheben
 Toggle Block Comment = Kommentar umschalten
 Transpose Characters = Zeichen vertauschen
 Join Lines = Zeilen verbinden
diff --git a/core/locales/locale.es.conf b/core/locales/locale.es.conf
index 299a517b..3a6f8dd6 100644
--- a/core/locales/locale.es.conf
+++ b/core/locales/locale.es.conf
@@ -166,7 +166,6 @@ Delete Word = _Borrar palabra
 Select All = Seleccionar _todo
 Match Brace = _Saltar a paréntesis coincidente
 Complete Word = C_ompletar palabra
-Highlight Word = Res_altar palabra
 Toggle Block Comment = Activar/Desactivar co_mentario de bloque
 Transpose Characters = _Intercambiar caracteres
 Join Lines = U_nir líneas
diff --git a/core/locales/locale.fr.conf b/core/locales/locale.fr.conf
index 4468e16b..c2b45231 100644
--- a/core/locales/locale.fr.conf
+++ b/core/locales/locale.fr.conf
@@ -167,7 +167,6 @@ Delete Word = Supprim_er le mot
 Select All = _Tout sélectionner
 Match Brace = _Aller à la parenthèse correspondante
 Complete Word = Compléter le _mot
-Highlight Word = Sur_ligner le mot
 Toggle Block Comment = Commenter/_Décommenter
 Transpose Characters = In_verser deux caractères
 Join Lines = _Joindre les lignes
diff --git a/core/locales/locale.it.conf b/core/locales/locale.it.conf
index dcd1dc64..03c394a4 100644
--- a/core/locales/locale.it.conf
+++ b/core/locales/locale.it.conf
@@ -166,7 +166,6 @@ Delete Word = E_limina la parola
 Select All = Sele_ziona tutto
 Match Brace = _Parentesi corrispondente
 Complete Word = C_ompleta la parola
-Highlight Word = E_videnzia la parola
 Toggle Block Comment = Co_mmenta/Scommenta
 Transpose Characters = I_nverti due caratteri
 Join Lines = Con_giungi le linee
diff --git a/core/locales/locale.pl.conf b/core/locales/locale.pl.conf
index 351d3637..506aea78 100644
--- a/core/locales/locale.pl.conf
+++ b/core/locales/locale.pl.conf
@@ -167,7 +167,6 @@ Delete Word = Usuń wy_raz
 Select All = Z_aznacz wszystko
 Match Brace = Dopasuj nawias_y
 Complete Word = D_okończ wyraz
-Highlight Word = Podświe_tl wyraz
 Toggle Block Comment = Włącz/wyłącz komentarz _blokowy
 Transpose Characters = Tran_sponuj znaki
 Join Lines = Połącz w_iersze
diff --git a/core/locales/locale.ru.conf b/core/locales/locale.ru.conf
index 50eec40c..ec8e8999 100644
--- a/core/locales/locale.ru.conf
+++ b/core/locales/locale.ru.conf
@@ -166,7 +166,6 @@ Delete Word = Уда_лить слово
 Select All = Выделить вс_ё
 Match Brace = _Парные скобки
 Complete Word = Автозавершение сл_ова
-Highlight Word = Под_светить слово
 Toggle Block Comment = Изменить комментирование _блока
 Transpose Characters = Пе_реставить символы
 Join Lines = _Объединить строки
diff --git a/core/locales/locale.sv.conf b/core/locales/locale.sv.conf
index 1b3d3196..2b74dbb6 100644
--- a/core/locales/locale.sv.conf
+++ b/core/locales/locale.sv.conf
@@ -166,7 +166,6 @@ Delete Word = Ta _bort ord
 Select All = Markera _allt
 Match Brace = Matcha _parentes
 Complete Word = Komplettera _ord
-Highlight Word = _Framhäv ord
 Toggle Block Comment = Kommentera
 Transpose Characters = Transponera t_ecken
 Join Lines = _Slå ihop rader
diff --git a/core/locales/locale.zh.conf b/core/locales/locale.zh.conf
index 99cf57c5..2745bf92 100644
--- a/core/locales/locale.zh.conf
+++ b/core/locales/locale.zh.conf
@@ -166,7 +166,6 @@ Delete Word = 删除单词(_E)
 Select All = 全选(_A)
 Match Brace = 匹配括号(_M)
 Complete Word = 补全单词(_W)
-Highlight Word = 高亮单词(_H)
 Toggle Block Comment = 设置区块注释(_B)
 Transpose Characters = 颠倒字符(_R)
 Join Lines = 合并行(_J)
diff --git a/core/ui.lua b/core/ui.lua
index ee0042b3..5ee4fbd1 100644
--- a/core/ui.lua
+++ b/core/ui.lua
@@ -33,9 +33,17 @@ local ui = ui
 --   with a group of [`ui.print()`]() and [`ui._print()`]() function calls.
 --   The default value is `false`, and focuses buffers when messages are printed
 --   to them.
+-- @field highlight_words (bool)
+--   Whether or not to automatically highlight all instances of the selected
+--   word.
+--   The default value is `true` except in the terminal version.
+-- @field INDIC_HIGHLIGHT (number)
+--   The word highlight indicator number.
 module('ui')]]
 
 ui.silent_print = false
+ui.highlight_words = not CURSES
+ui.INDIC_HIGHLIGHT = _SCINTILLA.next_indic_number()
 
 -- Helper function for printing messages to buffers.
 -- @see ui._print
@@ -179,10 +187,12 @@ ui.dialogs = setmetatable({}, {__index = function(_, k)
   end
 end})
 
+local events, events_connect = events, events.connect
+
 local buffers_zorder = {}
 
 -- Adds new buffers to the z-order list.
-events.connect(events.BUFFER_NEW, function()
+events_connect(events.BUFFER_NEW, function()
   if buffer ~= ui.command_entry then table.insert(buffers_zorder, 1, buffer) end
 end)
 
@@ -198,13 +208,13 @@ local function update_zorder()
   end
   table.insert(buffers_zorder, 1, buffer)
 end
-events.connect(events.BUFFER_AFTER_SWITCH, update_zorder)
-events.connect(events.VIEW_AFTER_SWITCH, update_zorder)
+events_connect(events.BUFFER_AFTER_SWITCH, update_zorder)
+events_connect(events.VIEW_AFTER_SWITCH, update_zorder)
 
 -- Saves and restores buffer zorder data during a reset.
-events.connect(
+events_connect(
   events.RESET_BEFORE, function(persist) persist.ui_zorder = buffers_zorder end)
-events.connect(
+events_connect(
   events.RESET_AFTER, function(persist) buffers_zorder = persist.ui_zorder end)
 
 ---
@@ -281,7 +291,31 @@ function ui.goto_file(filename, split, preferred_view, sloppy)
   io.open_file(filename)
 end
 
-local events, events_connect = events, events.connect
+-- Clears highlighted word indicators.
+local function clear_highlighted_words()
+  buffer.indicator_current = ui.INDIC_HIGHLIGHT
+  buffer:indicator_clear_range(1, buffer.length)
+end
+events_connect(events.KEYPRESS, function(code)
+  if keys.KEYSYMS[code] == 'esc' then clear_highlighted_words() end
+end, 1)
+
+-- Highlight all instances of the selected word.
+events_connect(events.UPDATE_UI, function(updated)
+  if updated and updated & buffer.UPDATE_SELECTION > 0 and
+     ui.highlight_words and not buffer.selection_empty and
+     buffer:is_range_word(buffer.selection_start, buffer.selection_end) then
+    clear_highlighted_words()
+    local word = buffer:text_range(buffer.selection_start, buffer.selection_end)
+    buffer.search_flags = buffer.FIND_MATCHCASE | buffer.FIND_WHOLEWORD
+    buffer:target_whole_document()
+    while buffer:search_in_target(word) ~= -1 do
+      buffer:indicator_fill_range(
+        buffer.target_start, buffer.target_end - buffer.target_start)
+      buffer:set_target_range(buffer.target_end, buffer.length + 1)
+    end
+  end
+end)
 
 -- Ensure title, statusbar, etc. are updated for new views.
 events_connect(events.VIEW_NEW, function() events.emit(events.UPDATE_UI, 3) end)