fix(tiling): Improve focus matching across displays

src/auto_tiler.ts

@@ -657,7 +657,7 @@ export class AutoTiler {
             return Err('ignoring focus');
         }
 
-        const prev = ext.prev_focused[0]
+        const prev = ext.previously_focused(win)
 
         if (!prev) {
             return Err('no window has been previously focused');

src/extension.ts

@@ -152,7 +152,7 @@ export class Ext extends Ecs.System<ExtEvent> {
     injections: Array<Injection> = new Array();
 
     /** The window that was focused before the last window */
-    prev_focused: [null | Entity, null | Entity] = [null, null];
+    private prev_focused: [null | Entity, null | Entity] = [null, null];
 
     tween_signals: Map<string, [SignalID, any]> = new Map();
 
@@ -1070,6 +1070,17 @@ export class Ext extends Ecs.System<ExtEvent> {
         }
     }
 
+    previously_focused(active: Window.ShellWindow): null | Ecs.Entity {
+        for (const id of [1, 0]) {
+            const prev = this.prev_focused[id]
+            if (prev && ! Ecs.entity_eq(active.entity, prev)) {
+                return prev;
+            }
+        }
+
+        return null
+    }
+
     movement_is_valid(win: Window.ShellWindow, movement: movement.Movement) {
         if ((movement & Movement.SHRINK) !== 0) {
             if ((movement & Movement.DOWN) !== 0) {