Persist complete monitor layouts

config/dot/hypr/monitors.lua

@@ -20,7 +20,10 @@
 local prefs = require("prefs")
 
 -- Per-output overrides written by Panama Settings, keyed by output name:
---   { ["DP-2"] = { mode = "3840x2160@60", scale = 2, transform = 0 } }
+--   { ["DP-2"] = {
+--       mode = "3840x2160@60", scale = 2, transform = 0,
+--       x = 0, y = 0, primary = true,
+--   } }
 --
 -- Only mode, scale, and transform are read. Colour management and bit depth
 -- stay here, because those are the settings with a documented reason attached
@@ -71,6 +74,26 @@ local function valid_transform(transform)
         and transform <= 3
 end
 
+local function valid_coordinate(value)
+    return type(value) == "number"
+        and value == value
+        and value == math.floor(value)
+        and value >= -100000
+        and value <= 100000
+end
+
+local function valid_position(entry)
+    return valid_coordinate(entry.x) and valid_coordinate(entry.y)
+end
+
+local function valid_primary(entry)
+    return type(entry.primary) == "boolean"
+end
+
+local function has_layout_fields(entry)
+    return entry.x ~= nil or entry.y ~= nil or entry.primary ~= nil
+end
+
 local function display_entry(output)
     if type(output) ~= "string" or output == ""
         or output:match("^[%w_.-]+$") == nil then
@@ -85,9 +108,23 @@ local function display_entry(output)
         or not valid_transform(entry.transform) then
         return nil
     end
+    -- Legacy records have none of the layout fields and keep automatic
+    -- placement. A partially written extended record is unsafe: accepting its
+    -- mode but guessing its position could overlap or strand another output.
+    if has_layout_fields(entry)
+        and (not valid_position(entry) or not valid_primary(entry)) then
+        return nil
+    end
     return entry
 end
 
+local function display_position(entry, fallback)
+    if entry ~= nil and has_layout_fields(entry) then
+        return string.format("%dx%d", entry.x, entry.y)
+    end
+    return fallback
+end
+
 local shipped_mode = "4500x3000@60"
 local shipped_scale = 1.5
 local shipped_transform = 0
@@ -96,7 +133,7 @@ local dp2 = display_entry("DP-2")
 hl.monitor({
     output   = "DP-2",
     mode     = dp2 and dp2.mode or shipped_mode,
-    position = "0x0",
+    position = display_position(dp2, "0x0"),
     scale    = dp2 and dp2.scale or shipped_scale,
     transform = dp2 and dp2.transform or shipped_transform,
 
@@ -119,7 +156,7 @@ for output, _ in pairs(displays) do
             hl.monitor({
                 output = output,
                 mode = entry.mode,
-                position = "auto",
+                position = display_position(entry, "auto"),
                 scale = entry.scale,
                 transform = entry.transform,
             })