From 07b8252c2216a4b62a3af0c1d4dccdc1b584bb27 Mon Sep 17 00:00:00 2001
From: Lorenzo Cogotti <lcg@doublefourteen.io>
Date: Thu, 25 Aug 2022 09:35:30 +0200
Subject: [PATCH] [input] Handle drawing text larger than the input box.

---
 input.lua | 25 ++++++++++++++++++++++---
 1 file changed, 22 insertions(+), 3 deletions(-)

diff --git a/input.lua b/input.lua
index 8d4cdad..053fcaf 100644
--- a/input.lua
+++ b/input.lua
@@ -27,6 +27,7 @@ function Input.new(args)
     self.cursor = math.max(1, math.min(utf8.len(self.text)+1,
                                        self.cursor or utf8.len(self.text)+1))
     self.candidate = { text = "", start = 0, length = 0 }
+    self.drawofs = 0
 
     return self
 end
@@ -136,10 +137,25 @@ function Input:draw()
         cursor_pos = font:getWidth(s)
     end
 
-    -- Compute drawing offset
+    -- Calculate initial text offset
+    local wm = math.max(w - 6, 0)  -- width minus margin
+    if cursor_pos - self.drawofs < 0 then
+        -- cursor left of input box
+        self.drawofs = cursor_pos
+    end
+    if cursor_pos - self.drawofs > wm then
+        -- cursor right of input box
+        self.drawofs = cursor_pos - wm
+    end
+    if tw - self.drawofs < wm and tw > wm then
+        -- text bigger than input box, but doesn't fill it
+        self.drawofs = tw - wm
+    end
+
+    -- Handle cursor movement within the box
     if self.px ~= nil then
         -- Mouse movement
-        local mx = self.px - self.x
+        local mx = self.px - self.x + self.drawofs
 
         self.cursor = utf8.len(self.text) + 1
         for c = 1,self.cursor do
@@ -153,16 +169,19 @@ function Input:draw()
         self.px,self.py = nil,nil
     end
 
+    -- Perform actual draw
     core.drawBox(x,y,w,h, self.color.normal, self.cornerRadius)
 
     -- Apply text margins
-    w = math.max(w - 6, 0)
     x = math.min(x + 3, x + w)
 
     -- Set scissors
     local sx, sy, sw, sh = love.graphics.getScissor()
     love.graphics.setScissor(x-1,y,w+2,h)
 
+    -- Move to focused text box region
+    x = x - self.drawofs
+
     -- Text
     love.graphics.setColor(self.color.normal.fg)
     love.graphics.setFont(font)