Add primary selection support (#1729)

* Add support for primary selections

* Handle primary selection in `DocView`s

data/core/commands/doc.lua

@@ -93,6 +93,13 @@ local function cut_or_copy(delete)
   system.set_clipboard(full_text)
 end
 
+local function set_primary_selection(doc)
+  -- Doesn't work on Windows, so avoid spending time getting the text
+  if PLATFORM ~= "Windows" then
+    system.set_primary_selection(doc:get_selection_text())
+  end
+end
+
 local function split_cursor(dv, direction)
   local new_cursors = {}
   local dv_translate = direction < 0
@@ -297,6 +304,15 @@ local commands = {
     end
   end,
 
+  ["doc:paste-primary-selection"] = function(dv, x, y)
+    if type(x) == "number" and type(y) == "number" then
+      set_cursor(dv, x, y, "set")
+      -- Workaround to avoid that a middle mouse drag starts selecting
+      dv.mouse_selecting = nil
+    end
+    dv.doc:text_input(system.get_primary_selection() or "")
+  end,
+
   ["doc:newline"] = function(dv)
     for idx, line, col in dv.doc:get_selections(false, true) do
       local indent = dv.doc.lines[line]:match("^[\t ]*")
@@ -353,6 +369,7 @@ local commands = {
 
   ["doc:select-all"] = function(dv)
     dv.doc:set_selection(1, 1, math.huge, math.huge)
+    set_primary_selection(dv.doc)
     -- avoid triggering DocView:scroll_to_make_visible
     dv.last_line1 = 1
     dv.last_col1 = 1
@@ -365,6 +382,7 @@ local commands = {
       append_line_if_last_line(line2)
       dv.doc:set_selections(idx, line2 + 1, 1, line1, 1)
     end
+    set_primary_selection(dv.doc)
   end,
 
   ["doc:select-word"] = function(dv)
@@ -373,6 +391,7 @@ local commands = {
       local line2, col2 = translate.end_of_word(dv.doc, line1, col1)
       dv.doc:set_selections(idx, line2, col2, line1, col1)
     end
+    set_primary_selection(dv.doc)
   end,
 
   ["doc:join-lines"] = function(dv)
@@ -626,6 +645,7 @@ local commands = {
     local line2, col2 = dv:resolve_screen_position(x, y)
     dv.mouse_selecting = { line1, col1, nil }
     dv.doc:set_selection(line2, col2, line1, col1)
+    set_primary_selection(dv.doc)
   end,
 
   ["doc:create-cursor-previous-line"] = function(dv)
@@ -696,9 +716,16 @@ local translations = {
 }
 
 for name, obj in pairs(translations) do
-  commands["doc:move-to-" .. name] = function(dv) dv.doc:move_to(obj[name:gsub("-", "_")], dv) end
-  commands["doc:select-to-" .. name] = function(dv) dv.doc:select_to(obj[name:gsub("-", "_")], dv) end
-  commands["doc:delete-to-" .. name] = function(dv) dv.doc:delete_to(obj[name:gsub("-", "_")], dv) end
+  commands["doc:move-to-" .. name] = function(dv)
+    dv.doc:move_to(obj[name:gsub("-", "_")], dv)
+  end
+  commands["doc:select-to-" .. name] = function(dv)
+    dv.doc:select_to(obj[name:gsub("-", "_")], dv)
+    set_primary_selection(dv.doc)
+  end
+  commands["doc:delete-to-" .. name] = function(dv)
+    dv.doc:delete_to(obj[name:gsub("-", "_")], dv)
+  end
 end
 
 commands["doc:move-to-previous-char"] = function(dv)

data/core/keymap.lua

@@ -393,6 +393,7 @@ keymap.add_direct {
   ["1lclick"] = "doc:set-cursor",
   ["2lclick"] = { "doc:set-cursor-word", "emptyview:new-doc", "tabbar:new-doc" },
   ["3lclick"] = "doc:set-cursor-line",
+  ["mclick"] = "doc:paste-primary-selection",
   ["shift+left"] = "doc:select-to-previous-char",
   ["shift+right"] = "doc:select-to-next-char",
   ["shift+up"] = "doc:select-to-previous-line",

docs/api/system.lua

@@ -260,6 +260,18 @@ function system.get_clipboard() end
 ---@param text string
 function system.set_clipboard(text) end
 
+---
+---Retrieve the text currently stored in the primary selection.
+---
+---@return string
+function system.get_primary_selection() end
+
+---
+---Set the content of the primary selection.
+---
+---@param text string
+function system.set_primary_selection(text) end
+
 ---
 ---Get the process id of lite-xl itself.
 ---

src/api/system.c

@@ -897,6 +897,28 @@ static int f_set_clipboard(lua_State *L) {
 }
 
 
+static int f_get_primary_selection(lua_State *L) {
+#if SDL_VERSION_ATLEAST(2, 26, 0)
+  char *text = SDL_GetPrimarySelectionText();
+  if (!text) { return 0; }
+  lua_pushstring(L, text);
+  SDL_free(text);
+  return 1;
+#else
+  return 0;
+#endif
+}
+
+
+static int f_set_primary_selection(lua_State *L) {
+#if SDL_VERSION_ATLEAST(2, 26, 0)
+  const char *text = luaL_checkstring(L, 1);
+  SDL_SetPrimarySelectionText(text);
+#endif
+  return 0;
+}
+
+
 static int f_get_process_id(lua_State *L) {
 #ifdef _WIN32
   lua_pushinteger(L, GetCurrentProcessId());
@@ -1250,6 +1272,8 @@ static const luaL_Reg lib[] = {
   { "get_file_info",         f_get_file_info         },
   { "get_clipboard",         f_get_clipboard         },
   { "set_clipboard",         f_set_clipboard         },
+  { "get_primary_selection", f_get_primary_selection },
+  { "set_primary_selection", f_set_primary_selection },
   { "get_process_id",        f_get_process_id        },
   { "get_time",              f_get_time              },
   { "sleep",                 f_sleep                 },