From 68ad7b4fcf12bd3d1b19f4eea40882ce981ccce4 Mon Sep 17 00:00:00 2001
From: Infi-power <75531788+Infi-power@users.noreply.github.com>
Date: Fri, 24 Nov 2023 08:40:29 +0000
Subject: [PATCH] Rework touchscreen `insert` command and add `delete` command
 (#40)

Co-authored-by: OgelGames <olliverdc28@gmail.com>
---
 docs/touchscreen.md | 15 ++++++++++++---
 touchscreen.lua     | 25 +++++++++++++++++++------
 2 files changed, 31 insertions(+), 9 deletions(-)

diff --git a/docs/touchscreen.md b/docs/touchscreen.md
index 4bd5697..1bb05bc 100644
--- a/docs/touchscreen.md
+++ b/docs/touchscreen.md
@@ -34,7 +34,7 @@ digiline_send("touchscreen", {
 })
 ```
 
-**`insert`** - Adds an element at a specific index.
+**`insert`** - Adds an element at a specific index. The index can be any positive number.
 
 ```lua
 digiline_send("touchscreen", {
@@ -63,7 +63,7 @@ digiline_send("touchscreen", {
 })
 ```
 
-**`remove`** - Removes an element.
+**`remove`** - Removes an element, shifting elements to fill the space.
 
 ```lua
 digiline_send("touchscreen", {
@@ -72,7 +72,16 @@ digiline_send("touchscreen", {
 })
 ```
 
-**`clear`** - Removes all elements, but keeps settings.
+**`delete`** - Removes an element without changing element indexes.
+
+```lua
+digiline_send("touchscreen", {
+	command = "delete",
+	index = 1,
+})
+```
+
+**`clear`** - Removes all elements.
 
 ```lua
 digiline_send("touchscreen", {
diff --git a/touchscreen.lua b/touchscreen.lua
index 15311d4..2335339 100644
--- a/touchscreen.lua
+++ b/touchscreen.lua
@@ -73,11 +73,7 @@ local function process_command(meta, data, msg)
 		local index = tonumber(msg.index)
 		if element and index and index > 0 then
 			local str = create_element_string(element, msg)
-			if index > #data then
-				table.insert(data, str)
-			else
-				table.insert(data, index, str)
-			end
+			table.insert(data, index, str)
 		end
 
 	elseif cmd == "replace" then
@@ -101,6 +97,12 @@ local function process_command(meta, data, msg)
 			table.remove(data, index)
 		end
 
+	elseif cmd == "delete" then
+		local index = tonumber(msg.index)
+		if index and data[index] then
+			data[index] = nil
+		end
+
 	elseif cmd == "set" then
 		if msg.locked ~= nil then
 			meta:set_int("locked", msg.locked == false and 0 or 1)
@@ -161,7 +163,18 @@ local function create_formspec(meta, data)
 	if focus then
 		fs = fs.."set_focus["..focus.."]"
 	end
-	return fs..table.concat(data)
+	local data_size = 0
+	for i in pairs(data) do
+		if i > data_size then
+			data_size = i
+		end
+	end
+	for i=1, data_size do
+		if data[i] then
+			fs = fs..data[i]
+		end
+	end
+	return fs
 end
 
 local function update_formspec(pos, meta, data)