From d9ac5546ddde3add1619b00061eccccb7f75429d Mon Sep 17 00:00:00 2001
From: Dariusz L <dl122@wp.pl>
Date: Sat, 21 Jun 2025 00:25:09 +0200
Subject: [PATCH] Keep Proportion with shift

---
 js/Canvas.js | 25 ++++++++++++++++++++++++-
 1 file changed, 24 insertions(+), 1 deletion(-)

diff --git a/js/Canvas.js b/js/Canvas.js
index d276bbe..67d4eaf 100644
--- a/js/Canvas.js
+++ b/js/Canvas.js
@@ -560,7 +560,7 @@ export class Canvas {
 
     startCanvasMove(worldCoords) {
         this.interaction.mode = 'movingCanvas';
-        this.interaction.dragStart = { ...worldCoords };
+        this.interaction.dragStart = {...worldCoords};
         const initialX = this.snapToGrid(worldCoords.x - this.width / 2);
         const initialY = this.snapToGrid(worldCoords.y - this.height / 2);
 
@@ -701,6 +701,29 @@ export class Canvas {
         let newWidth = vecX * cos + vecY * sin;
         let newHeight = vecY * cos - vecX * sin;
 
+        if (isShiftPressed) {
+            const originalAspectRatio = o.width / o.height;
+            if (handle.length === 2) {
+
+                const potentialWidth = Math.abs(newWidth);
+                const potentialHeight = Math.abs(newHeight);
+
+                if (potentialWidth / originalAspectRatio > potentialHeight) {
+                    newHeight = newWidth / originalAspectRatio;
+                } else {
+                    newWidth = newHeight * originalAspectRatio;
+                }
+            } else {
+
+                if (signX !== 0) {
+                    newHeight = newWidth / originalAspectRatio;
+                } else {
+                    newWidth = newHeight * originalAspectRatio;
+                }
+            }
+        }
+
+
         let signX = handle.includes('e') ? 1 : (handle.includes('w') ? -1 : 0);
         let signY = handle.includes('s') ? 1 : (handle.includes('n') ? -1 : 0);