move anchors around

static/javascript/resize_photo_dialouge.js

@@ -58,11 +58,14 @@ document.body.addEventListener("mouseup", () => {
 // handle anchors
 resize_anchors = document.getElementsByClassName("resize_anchor");
 var handleBeingHeld = [false, false, false, false];
+var startX, startY;
 for (var i = 0; i < resize_anchors.length; i++) {
   const index = i;
   resize_anchors[index].addEventListener("mousedown", (e) => {
     e.stopPropagation();
     handleBeingHeld[index] = true;
+    startX = currentX;
+    startY = currentY;
   });
 
   document.body.addEventListener("mouseup", () => {
@@ -77,7 +80,12 @@ document.body.addEventListener("mousemove", () => {
   for (var i = 0; i < handleBeingHeld.length; i++) {
     if (!handleBeingHeld[i]) continue;
 
-    resize_anchors[i].style.setProperty("--x-offset", "100px");
-    resize_anchors[i].style.setProperty("--y-offset", "100px");
+    newX = startX - currentX;
+    newY = currentY - startY;
+
+    moveAmount = max(min(newX, newY), 0);
+
+    resize_anchors[i].style.setProperty("--x-offset", moveAmount + "px");
+    resize_anchors[i].style.setProperty("--y-offset", moveAmount + "px");
   }
 });