Adding multi display support

Author: m1ket

manifest.json

@@ -1,7 +1,7 @@
 {
   "manifest_version": 3,
   "name": "Centralizer",
-  "version": "1.1",
+  "version": "1.3",
   "description": "Move and resize your window to be central in your monitor",
   "icons": {
     "16": "images/icon.png",

scripts/background.js

@@ -4,12 +4,12 @@ function centralize() {
         function(currentWindow) {
             chrome.system.display.getInfo(function(info) {
                 if (info && info.length > 0) {
-                    const display = info[0];
+                    const display = getClosestDisplayForWindowPosition(info, currentWindow);
                     const displayWidth = display.workArea.width;
                     const displayHeight = display.workArea.height;
 
                     const toBeWidth = Math.round((displayWidth / 4) * 3);
-                    const leftPos = Math.round((displayWidth - toBeWidth) / 2);
+                    const leftPos = display.workArea.left + Math.round((displayWidth - toBeWidth) / 2);
 
                     const toBeHeight = displayHeight - 20;
                     const topPos = display.workArea.top + 10;
@@ -29,6 +29,32 @@ function centralize() {
     );
 }
 
+function getClosestDisplayForWindowPosition(displays, window) {
+    if (displays.length == 1) {
+        return displays[0];
+    } 
+
+    const windowPosition = { x: window.top, y: window.left };
+
+    let points = [];
+
+    for (let i = 0; i < displays.length; i++) {
+        points.push({ 
+            x: displays[i].workArea.top, 
+            y: displays[i].workArea.left,
+            display: displays[i]
+        });
+    }
+
+    closest = points.reduce((a, b) => distance(a, windowPosition) < distance(b, windowPosition) ? a : b);
+
+    return closest.display;
+}
+
+function distance(p, point) {
+    return Math.sqrt(Math.pow(point.x - p.x, 2) + Math.pow(point.y - p.y, 2))
+}
+
 chrome.commands.onCommand.addListener((command) => {
     if (command === "centralize") {
         centralize();