From 4f55555ca92290e699930dbd199e3042160a98c3 Mon Sep 17 00:00:00 2001
From: Joshua Minor <github@pixelverse.org>
Date: Fri, 19 Nov 2021 01:05:26 -0800
Subject: [PATCH] Selection expands by word or line on double or triple click
 followed by drag.

---
 data/core/commands/doc.lua | 10 +++++-----
 data/core/docview.lua      | 24 +++++++++++++++++++++++-
 2 files changed, 28 insertions(+), 6 deletions(-)

diff --git a/data/core/commands/doc.lua b/data/core/commands/doc.lua
index ba3d1f0c..fe1fa3b1 100644
--- a/data/core/commands/doc.lua
+++ b/data/core/commands/doc.lua
@@ -82,13 +82,13 @@ local function split_cursor(direction)
   core.blink_reset()
 end
 
-local function set_cursor(x, y, type)
+local function set_cursor(x, y, snap_type)
   local line, col = dv():resolve_screen_position(x, y)
   doc():set_selection(line, col, line, col)
-  if type == "word" or type == "lines" then
-    command.perform("doc:select-" .. type)
+  if snap_type == "word" or snap_type == "lines" then
+    command.perform("doc:select-" .. snap_type)
   end
-  dv().mouse_selecting = { line, col }
+  dv().mouse_selecting = { line, col, snap_type }
   core.blink_reset()
 end
 
@@ -402,7 +402,7 @@ local commands = {
   ["doc:select-to-cursor"] = function(x, y, clicks) 
     local line1, col1 = select(3, doc():get_selection())
     local line2, col2 = dv():resolve_screen_position(x, y)
-    dv().mouse_selecting = { line1, col1 }
+    dv().mouse_selecting = { line1, col1, nil }
     doc():set_selection(line2, col2, line1, col1)
   end,
   
diff --git a/data/core/docview.lua b/data/core/docview.lua
index 07da1cef..60ef62bc 100644
--- a/data/core/docview.lua
+++ b/data/core/docview.lua
@@ -224,6 +224,7 @@ function DocView:scroll_to_make_visible(line, col)
   end
 end
 
+
 function DocView:on_mouse_moved(x, y, ...)
   DocView.super.on_mouse_moved(self, x, y, ...)
 
@@ -235,7 +236,7 @@ function DocView:on_mouse_moved(x, y, ...)
 
   if self.mouse_selecting then
     local l1, c1 = self:resolve_screen_position(x, y)
-    local l2, c2 = table.unpack(self.mouse_selecting)
+    local l2, c2, snap_type = table.unpack(self.mouse_selecting)
     if keymap.modkeys["ctrl"] then
       if l1 > l2 then l1, l2 = l2, l1 end
       self.doc.selections = { }
@@ -243,12 +244,33 @@ function DocView:on_mouse_moved(x, y, ...)
         self.doc:set_selections(i - l1 + 1, i, math.min(c1, #self.doc.lines[i]), i, math.min(c2, #self.doc.lines[i]))
       end
     else
+      if snap_type then
+        l1, c1, l2, c2 = self:mouse_selection(self.doc, snap_type, l1, c1, l2, c2)
+      end
       self.doc:set_selection(l1, c1, l2, c2)
     end
   end
 end
 
 
+function DocView:mouse_selection(doc, snap_type, line1, col1, line2, col2)
+  local swap = line2 < line1 or line2 == line1 and col2 <= col1
+  if swap then
+    line1, col1, line2, col2 = line2, col2, line1, col1
+  end
+  if snap_type == "word" then
+    line1, col1 = translate.start_of_word(doc, line1, col1)
+    line2, col2 = translate.end_of_word(doc, line2, col2)
+  elseif snap_type == "lines" then
+    col1, col2 = 1, math.huge
+  end
+  if swap then
+    return line2, col2, line1, col1
+  end
+  return line1, col1, line2, col2
+end
+
+
 function DocView:on_mouse_released(button)
   DocView.super.on_mouse_released(self, button)
   self.mouse_selecting = nil