From 9615ead41be09c447d6ca26ff52a545f8f31cbb9 Mon Sep 17 00:00:00 2001
From: ThaCuber <70547062+thacuber2a03@users.noreply.github.com>
Date: Wed, 29 Nov 2023 15:12:43 -0400
Subject: [PATCH] Text overwriting (#1495)

* added text overwriting

* rewrote `DocView:draw_caret` to not use the order of draws

* forgot to delete some old code in `DocView:draw_overlay`
also added a temporary solution to overwriting
and added the missing arguments in `DocView:draw_ime_decoration`
and fixed `DocView:draw_caret`

* accidentally broke the `draw_caret` call in `draw_overlay` in the process

* multiline

* fixed calling `Doc:get_char` as a function
that, in turn, crashed the editor because "can't index a number"

* move and rename some stuff

* remove unneeded extra check

I just had to change the `~=` to `<` in the second condition

* overwrite disregards pasting text

* disregard overwrite on selections; doc only removes selection

* Fixed error where `doc` was used, instead of `self`.

---------

Co-authored-by: ThaCuber <70547062+ThaCuber@users.noreply.github.com>
Co-authored-by: Adam Harrison <adamdharrison@gmail.com>
---
 data/core/commands/doc.lua |  5 +++
 data/core/doc/init.lua     | 87 +++++++++++++++++---------------------
 data/core/docview.lua      | 14 ++++--
 data/core/keymap.lua       |  1 +
 data/core/statusview.lua   | 13 ++++++
 5 files changed, 67 insertions(+), 53 deletions(-)

diff --git a/data/core/commands/doc.lua b/data/core/commands/doc.lua
index c698d2cc..3d4426c3 100644
--- a/data/core/commands/doc.lua
+++ b/data/core/commands/doc.lua
@@ -545,6 +545,11 @@ local commands = {
     dv.doc.crlf = not dv.doc.crlf
   end,
 
+  ["doc:toggle-overwrite"] = function(dv)
+    dv.doc.overwrite = not dv.doc.overwrite
+    core.blink_reset() -- to show the cursor has changed edit modes
+  end,
+
   ["doc:save-as"] = function(dv)
     local last_doc = core.last_active_view and core.last_active_view.doc
     local text
diff --git a/data/core/doc/init.lua b/data/core/doc/init.lua
index c3eeba87..3c0a30d7 100644
--- a/data/core/doc/init.lua
+++ b/data/core/doc/init.lua
@@ -1,5 +1,6 @@
 local Object = require "core.object"
 local Highlighter = require "core.doc.highlighter"
+local translate = require "core.doc.translate"
 local core = require "core"
 local syntax = require "core.syntax"
 local config = require "core.config"
@@ -29,7 +30,6 @@ function Doc:new(filename, abs_filename, new_file)
   end
 end
 
-
 function Doc:reset()
   self.lines = { "\n" }
   self.selections = { 1, 1, 1, 1 }
@@ -38,10 +38,10 @@ function Doc:reset()
   self.redo_stack = { idx = 1 }
   self.clean_change_id = 1
   self.highlighter = Highlighter(self)
+  self.overwrite = false
   self:reset_syntax()
 end
 
-
 function Doc:reset_syntax()
   local header = self:get_text(1, 1, self:position_offset(1, 1, 128))
   local path = self.abs_filename
@@ -56,16 +56,14 @@ function Doc:reset_syntax()
   end
 end
 
-
 function Doc:set_filename(filename, abs_filename)
   self.filename = filename
   self.abs_filename = abs_filename
   self:reset_syntax()
 end
 
-
 function Doc:load(filename)
-  local fp = assert( io.open(filename, "rb") )
+  local fp = assert(io.open(filename, "rb"))
   self:reset()
   self.lines = {}
   local i = 1
@@ -85,7 +83,6 @@ function Doc:load(filename)
   self:reset_syntax()
 end
 
-
 function Doc:reload()
   if self.filename then
     local sel = { self:get_selection() }
@@ -95,7 +92,6 @@ function Doc:reload()
   end
 end
 
-
 function Doc:save(filename, abs_filename)
   if not filename then
     assert(self.filename, "no filename set to default to")
@@ -104,7 +100,7 @@ function Doc:save(filename, abs_filename)
   else
     assert(self.filename or abs_filename, "calling save on unnamed doc without absolute path")
   end
-  local fp = assert( io.open(filename, "wb") )
+  local fp = assert(io.open(filename, "wb"))
   for _, line in ipairs(self.lines) do
     if self.crlf then line = line:gsub("\n", "\r\n") end
     fp:write(line)
@@ -115,12 +111,10 @@ function Doc:save(filename, abs_filename)
   self:clean()
 end
 
-
 function Doc:get_name()
   return self.filename or "unsaved"
 end
 
-
 function Doc:is_dirty()
   if self.new_file then
     if self.filename then return true end
@@ -130,20 +124,17 @@ function Doc:is_dirty()
   end
 end
 
-
 function Doc:clean()
   self.clean_change_id = self:get_change_id()
 end
 
-
 function Doc:get_indent_info()
   if not self.indent_info then return config.tab_type, config.indent_size, false end
   return self.indent_info.type or config.tab_type,
-         self.indent_info.size or config.indent_size,
-         self.indent_info.confirmed
+      self.indent_info.size or config.indent_size,
+      self.indent_info.confirmed
 end
 
-
 function Doc:get_change_id()
   return self.undo_stack.idx
 end
@@ -167,13 +158,14 @@ function Doc:get_selection(sort)
   return line1, col1, line2, col2, swap
 end
 
-
 ---Get the selection specified by `idx`
 ---@param idx integer @the index of the selection to retrieve
 ---@param sort? boolean @whether to sort the selection returned
 ---@return integer,integer,integer,integer,boolean? @line1, col1, line2, col2, was the selection sorted
 function Doc:get_selection_idx(idx, sort)
-  local line1, col1, line2, col2 = self.selections[idx*4-3], self.selections[idx*4-2], self.selections[idx*4-1], self.selections[idx*4]
+  local line1, col1, line2, col2 = self.selections[idx * 4 - 3], self.selections[idx * 4 - 2],
+      self.selections[idx * 4 - 1],
+      self.selections[idx * 4]
   if line1 and sort then
     return sort_positions(line1, col1, line2, col2)
   else
@@ -217,7 +209,7 @@ function Doc:set_selections(idx, line1, col1, line2, col2, swap, rm)
   if swap then line1, col1, line2, col2 = line2, col2, line1, col1 end
   line1, col1 = self:sanitize_position(line1, col1)
   line2, col2 = self:sanitize_position(line2 or line1, col2 or col1)
-  common.splice(self.selections, (idx - 1)*4 + 1, rm == nil and 4 or rm, { line1, col1, line2, col2 })
+  common.splice(self.selections, (idx - 1) * 4 + 1, rm == nil and 4 or rm, { line1, col1, line2, col2 })
 end
 
 function Doc:add_selection(line1, col1, line2, col2, swap)
@@ -233,7 +225,6 @@ function Doc:add_selection(line1, col1, line2, col2, swap)
   self.last_selection = target
 end
 
-
 function Doc:remove_selection(idx)
   if self.last_selection >= idx then
     self.last_selection = self.last_selection - 1
@@ -241,7 +232,6 @@ function Doc:remove_selection(idx)
   common.splice(self.selections, (idx - 1) * 4 + 1, 4)
 end
 
-
 function Doc:set_selection(line1, col1, line2, col2, swap)
   self.selections = {}
   self:set_selections(1, line1, col1, line2, col2, swap)
@@ -252,24 +242,24 @@ function Doc:merge_cursors(idx)
   for i = (idx or (#self.selections - 3)), (idx or 5), -4 do
     for j = 1, i - 4, 4 do
       if self.selections[i] == self.selections[j] and
-        self.selections[i+1] == self.selections[j+1] then
-          common.splice(self.selections, i, 4)
-          if self.last_selection >= (i+3)/4 then
-            self.last_selection = self.last_selection - 1
-          end
-          break
+          self.selections[i + 1] == self.selections[j + 1] then
+        common.splice(self.selections, i, 4)
+        if self.last_selection >= (i + 3) / 4 then
+          self.last_selection = self.last_selection - 1
+        end
+        break
       end
     end
   end
 end
 
 local function selection_iterator(invariant, idx)
-  local target = invariant[3] and (idx*4 - 7) or (idx*4 + 1)
+  local target = invariant[3] and (idx * 4 - 7) or (idx * 4 + 1)
   if target > #invariant[1] or target <= 0 or (type(invariant[3]) == "number" and invariant[3] ~= idx - 1) then return end
   if invariant[2] then
-    return idx+(invariant[3] and -1 or 1), sort_positions(table.unpack(invariant[1], target, target+4))
+    return idx + (invariant[3] and -1 or 1), sort_positions(table.unpack(invariant[1], target, target + 4))
   else
-    return idx+(invariant[3] and -1 or 1), table.unpack(invariant[1], target, target+4)
+    return idx + (invariant[3] and -1 or 1), table.unpack(invariant[1], target, target + 4)
   end
 end
 
@@ -277,8 +267,9 @@ end
 -- If a number, runs for exactly that iteration.
 function Doc:get_selections(sort_intra, idx_reverse)
   return selection_iterator, { self.selections, sort_intra, idx_reverse },
-    idx_reverse == true and ((#self.selections / 4) + 1) or ((idx_reverse or -1)+1)
+      idx_reverse == true and ((#self.selections / 4) + 1) or ((idx_reverse or -1) + 1)
 end
+
 -- End of cursor seciton.
 
 function Doc:sanitize_position(line, col)
@@ -291,7 +282,6 @@ function Doc:sanitize_position(line, col)
   return line, common.clamp(col, 1, #self.lines[line])
 end
 
-
 local function position_offset_func(self, line, col, fn, ...)
   line, col = self:sanitize_position(line, col)
   return fn(self, line, col, ...)
@@ -330,7 +320,6 @@ function Doc:position_offset(line, col, ...)
   end
 end
 
-
 function Doc:get_text(line1, col1, line2, col2)
   line1, col1 = self:sanitize_position(line1, col1)
   line2, col2 = self:sanitize_position(line2, col2)
@@ -346,13 +335,11 @@ function Doc:get_text(line1, col1, line2, col2)
   return table.concat(lines)
 end
 
-
 function Doc:get_char(line, col)
   line, col = self:sanitize_position(line, col)
   return self.lines[line]:sub(col, col)
 end
 
-
 local function push_undo(undo_stack, time, type, ...)
   undo_stack[undo_stack.idx] = { type = type, time = time, ... }
   undo_stack[undo_stack.idx - config.max_undos] = nil
@@ -413,7 +400,8 @@ function Doc:raw_insert(line, col, text, undo_stack, time)
     if cline1 < line then break end
     local line_addition = (line < cline1 or col < ccol1) and #lines - 1 or 0
     local column_addition = line == cline1 and ccol1 > col and len or 0
-    self:set_selections(idx, cline1 + line_addition, ccol1 + column_addition, cline2 + line_addition, ccol2 + column_addition)
+    self:set_selections(idx, cline1 + line_addition, ccol1 + column_addition, cline2 + line_addition,
+      ccol2 + column_addition)
   end
 
   -- push undo
@@ -426,7 +414,6 @@ function Doc:raw_insert(line, col, text, undo_stack, time)
   self:sanitize_selection()
 end
 
-
 function Doc:raw_remove(line1, col1, line2, col2, undo_stack, time)
   -- push undo
   local text = self:get_text(line1, col1, line2, col2)
@@ -485,7 +472,6 @@ function Doc:raw_remove(line1, col1, line2, col2, undo_stack, time)
   self:sanitize_selection()
 end
 
-
 function Doc:insert(line, col, text)
   self.redo_stack = { idx = 1 }
   -- Reset the clean id when we're pushing something new before it
@@ -497,7 +483,6 @@ function Doc:insert(line, col, text)
   self:on_text_change("insert")
 end
 
-
 function Doc:remove(line1, col1, line2, col2)
   self.redo_stack = { idx = 1 }
   line1, col1 = self:sanitize_position(line1, col1)
@@ -507,28 +492,34 @@ function Doc:remove(line1, col1, line2, col2)
   self:on_text_change("remove")
 end
 
-
 function Doc:undo()
   pop_undo(self, self.undo_stack, self.redo_stack, false)
 end
 
-
 function Doc:redo()
   pop_undo(self, self.redo_stack, self.undo_stack, false)
 end
 
-
 function Doc:text_input(text, idx)
   for sidx, line1, col1, line2, col2 in self:get_selections(true, idx or true) do
+    local had_selection = false
     if line1 ~= line2 or col1 ~= col2 then
       self:delete_to_cursor(sidx)
+      had_selection = true
     end
+
+    if self.overwrite
+    and not had_selection
+    and col1 < #self.lines[line1]
+    and text:ulen() == 1 then
+      self:remove(line1, col1, translate.next_char(self, line1, col1))
+    end
+
     self:insert(line1, col1, text)
     self:move_to_cursor(sidx, #text)
   end
 end
 
-
 function Doc:ime_text_editing(text, start, length, idx)
   for sidx, line1, col1, line2, col2 in self:get_selections(true, idx or true) do
     if line1 ~= line2 or col1 ~= col2 then
@@ -539,7 +530,6 @@ function Doc:ime_text_editing(text, start, length, idx)
   end
 end
 
-
 function Doc:replace_cursor(idx, line1, col1, line2, col2, fn)
   local old_text = self:get_text(line1, col1, line2, col2)
   local new_text, res = fn(old_text)
@@ -555,7 +545,7 @@ function Doc:replace_cursor(idx, line1, col1, line2, col2, fn)
 end
 
 function Doc:replace(fn)
-  local has_selection, results = false, { }
+  local has_selection, results = false, {}
   for idx, line1, col1, line2, col2 in self:get_selections(true) do
     if line1 ~= line2 or col1 ~= col2 then
       results[idx] = self:replace_cursor(idx, line1, col1, line2, col2, fn)
@@ -569,7 +559,6 @@ function Doc:replace(fn)
   return results
 end
 
-
 function Doc:delete_to_cursor(idx, ...)
   for sidx, line1, col1, line2, col2 in self:get_selections(true, idx) do
     if line1 ~= line2 or col1 ~= col2 then
@@ -583,6 +572,7 @@ function Doc:delete_to_cursor(idx, ...)
   end
   self:merge_cursors(idx)
 end
+
 function Doc:delete_to(...) return self:delete_to_cursor(nil, ...) end
 
 function Doc:move_to_cursor(idx, ...)
@@ -591,8 +581,8 @@ function Doc:move_to_cursor(idx, ...)
   end
   self:merge_cursors(idx)
 end
-function Doc:move_to(...) return self:move_to_cursor(nil, ...) end
 
+function Doc:move_to(...) return self:move_to_cursor(nil, ...) end
 
 function Doc:select_to_cursor(idx, ...)
   for sidx, line, col, line2, col2 in self:get_selections(false, idx) do
@@ -601,8 +591,8 @@ function Doc:select_to_cursor(idx, ...)
   end
   self:merge_cursors(idx)
 end
-function Doc:select_to(...) return self:select_to_cursor(nil, ...) end
 
+function Doc:select_to(...) return self:select_to_cursor(nil, ...) end
 
 function Doc:get_indent_string()
   local indent_type, indent_size = self:get_indent_info()
@@ -625,7 +615,7 @@ function Doc:get_line_indent(line, rnd_up)
     local indent = e and line:sub(1, e):gsub("\t", soft_tab) or ""
     local number = #indent / #soft_tab
     return e, indent:sub(1,
-      (rnd_up and math.ceil(number) or math.floor(number))*#soft_tab)
+      (rnd_up and math.ceil(number) or math.floor(number)) * #soft_tab)
   end
 end
 
@@ -674,5 +664,4 @@ function Doc:on_close()
   core.log_quiet("Closed doc \"%s\"", self:get_name())
 end
 
-
 return Doc
diff --git a/data/core/docview.lua b/data/core/docview.lua
index e2da6dfc..c2502040 100644
--- a/data/core/docview.lua
+++ b/data/core/docview.lua
@@ -460,9 +460,14 @@ function DocView:draw_line_text(line, x, y)
   return self:get_line_height()
 end
 
-function DocView:draw_caret(x, y)
-    local lh = self:get_line_height()
+function DocView:draw_caret(x, y, line, col)
+  local lh = self:get_line_height()
+  if self.doc.overwrite then
+    local w = self:get_font():get_width(self.doc:get_char(line, col))
+    renderer.draw_rect(x, y + lh, w, style.caret_width * 2, style.caret)
+  else
     renderer.draw_rect(x, y, style.caret_width, lh, style.caret)
+  end
 end
 
 function DocView:draw_line_body(line, x, y)
@@ -542,7 +547,7 @@ function DocView:draw_ime_decoration(line1, col1, line2, col2)
     line_size = style.caret_width
     renderer.draw_rect(x + math.min(x1, x2), y + lh - line_size, math.abs(x1 - x2), line_size, style.caret)
   end
-  self:draw_caret(x + x1, y)
+  self:draw_caret(x + x1, y, line1, col)
 end
 
 
@@ -559,7 +564,8 @@ function DocView:draw_overlay()
         else
           if config.disable_blink
           or (core.blink_timer - core.blink_start) % T < T / 2 then
-            self:draw_caret(self:get_line_screen_position(line1, col1))
+            local x, y = self:get_line_screen_position(line1, col1)
+            self:draw_caret(x, y, line1, col1)
           end
         end
       end
diff --git a/data/core/keymap.lua b/data/core/keymap.lua
index 74e270d2..9f19cfb7 100644
--- a/data/core/keymap.lua
+++ b/data/core/keymap.lua
@@ -341,6 +341,7 @@ keymap.add_direct {
   ["ctrl+x"] = "doc:cut",
   ["ctrl+c"] = "doc:copy",
   ["ctrl+v"] = "doc:paste",
+  ["insert"] = "doc:toggle-overwrite",
   ["ctrl+insert"] = "doc:copy",
   ["shift+insert"] = "doc:paste",
   ["escape"] = { "command:escape", "doc:select-none", "dialog:select-no" },
diff --git a/data/core/statusview.lua b/data/core/statusview.lua
index 3ef40d82..74124768 100644
--- a/data/core/statusview.lua
+++ b/data/core/statusview.lua
@@ -319,6 +319,19 @@ function StatusView:register_docview_items()
     end,
     command = "doc:toggle-line-ending"
   })
+
+  self:add_item {
+    predicate = predicate_docview,
+    name = "doc:overwrite-mode",
+    alignment = StatusView.Item.RIGHT,
+    get_item = function()
+      return {
+        style.text, core.active_view.doc.overwrite and "OVR" or "INS"
+      }
+    end,
+    command = "doc:toggle-overwrite",
+    separator = StatusView.separator2
+  }
 end