Merge pull request #1966 from konvajs/copilot/fix-ef4e67b7-060b-4fef-9892-75e9feada698

Fix Transformer back shape draggable behavior with non-draggable nodes

src/shapes/Transformer.ts

@@ -86,6 +86,7 @@ const TRANSFORM_CHANGE_STR = [
   'offsetYChange',
   'transformsEnabledChange',
   'strokeWidthChange',
+  'draggableChange',
 ];
 
 const ANGLES = {
@@ -616,7 +617,6 @@ export class Transformer extends Group {
       name: 'back',
       width: 0,
       height: 0,
-      draggable: true,
       sceneFunc(ctx, shape) {
         const tr = shape.getParent() as Transformer;
         const padding = tr.padding();
@@ -1257,6 +1257,7 @@ export class Transformer extends Group {
       stroke: this.borderStroke(),
       strokeWidth: this.borderStrokeWidth(),
       dash: this.borderDash(),
+      draggable: this.nodes().some((node) => node.draggable()),
       x: 0,
       y: 0,
     });

test/unit/Transformer-test.ts

@@ -5193,4 +5193,204 @@ describe('Transformer', function () {
       y: 60,
     });
   });
+
+  it('should not be draggable via back area when all attached nodes are non-draggable', function () {
+    var stage = addStage();
+    var layer = new Konva.Layer();
+    stage.add(layer);
+
+    var rect = new Konva.Rect({
+      x: 50,
+      y: 50,
+      draggable: false,
+      width: 50,
+      height: 50,
+      fill: 'yellow',
+    });
+    layer.add(rect);
+
+    var tr = new Konva.Transformer({
+      nodes: [rect],
+      shouldOverdrawWholeArea: true,
+    });
+    layer.add(tr);
+    layer.draw();
+
+    var back = tr.findOne('.back');
+    assert.notEqual(back, null, 'Back shape should exist');
+    assert.equal(
+      back!.draggable(),
+      false,
+      'Back should not be draggable when node is not draggable'
+    );
+
+    // Try to drag via back area - should not move
+    var initialX = rect.x();
+    var initialY = rect.y();
+
+    simulateMouseDown(tr, {
+      x: 75, // center of the rect/back area
+      y: 75,
+    });
+    sm(stage, {
+      x: 85,
+      y: 85,
+    });
+    su(stage, {
+      x: 85,
+      y: 85,
+    });
+
+    assert.equal(
+      rect.x(),
+      initialX,
+      'Rect should not move when dragging back area of non-draggable node'
+    );
+    assert.equal(
+      rect.y(),
+      initialY,
+      'Rect should not move when dragging back area of non-draggable node'
+    );
+  });
+
+  it('should be draggable via back area when at least one attached node is draggable', function () {
+    var stage = addStage();
+    var layer = new Konva.Layer();
+    stage.add(layer);
+
+    var rect1 = new Konva.Rect({
+      x: 50,
+      y: 50,
+      draggable: false,
+      width: 50,
+      height: 50,
+      fill: 'yellow',
+    });
+    layer.add(rect1);
+
+    var rect2 = new Konva.Rect({
+      x: 100,
+      y: 100,
+      draggable: true,
+      width: 50,
+      height: 50,
+      fill: 'red',
+    });
+    layer.add(rect2);
+
+    var tr = new Konva.Transformer({
+      nodes: [rect1, rect2],
+      shouldOverdrawWholeArea: true,
+    });
+    layer.add(tr);
+    layer.draw();
+
+    var back = tr.findOne('.back');
+    assert.notEqual(back, null, 'Back shape should exist');
+    assert.equal(
+      back!.draggable(),
+      true,
+      'Back should be draggable when at least one node is draggable'
+    );
+  });
+
+  it('should update back draggable when node draggable property changes', function () {
+    var stage = addStage();
+    var layer = new Konva.Layer();
+    stage.add(layer);
+
+    var rect = new Konva.Rect({
+      x: 50,
+      y: 50,
+      draggable: true,
+      width: 50,
+      height: 50,
+      fill: 'yellow',
+    });
+    layer.add(rect);
+
+    var tr = new Konva.Transformer({
+      nodes: [rect],
+      shouldOverdrawWholeArea: true,
+    });
+    layer.add(tr);
+    layer.draw();
+
+    var back = tr.findOne('.back');
+    assert.notEqual(back, null, 'Back shape should exist');
+    assert.equal(back!.draggable(), true, 'Back should initially be draggable');
+
+    // Change node to non-draggable
+    rect.draggable(false);
+    assert.equal(
+      back!.draggable(),
+      false,
+      'Back should become non-draggable when node becomes non-draggable'
+    );
+
+    // Change back to draggable
+    rect.draggable(true);
+    assert.equal(
+      back!.draggable(),
+      true,
+      'Back should become draggable when node becomes draggable'
+    );
+  });
+
+  it('should handle mixed draggable states correctly', function () {
+    var stage = addStage();
+    var layer = new Konva.Layer();
+    stage.add(layer);
+
+    var rect1 = new Konva.Rect({
+      x: 50,
+      y: 50,
+      draggable: true,
+      width: 50,
+      height: 50,
+      fill: 'yellow',
+    });
+    layer.add(rect1);
+
+    var rect2 = new Konva.Rect({
+      x: 100,
+      y: 100,
+      draggable: false,
+      width: 50,
+      height: 50,
+      fill: 'red',
+    });
+    layer.add(rect2);
+
+    var tr = new Konva.Transformer({
+      nodes: [rect1, rect2],
+      shouldOverdrawWholeArea: true,
+    });
+    layer.add(tr);
+    layer.draw();
+
+    var back = tr.findOne('.back');
+    assert.notEqual(back, null, 'Back shape should exist');
+    assert.equal(
+      back!.draggable(),
+      true,
+      'Back should be draggable when at least one node is draggable'
+    );
+
+    // Make both non-draggable
+    rect1.draggable(false);
+    assert.equal(
+      back!.draggable(),
+      false,
+      'Back should be non-draggable when all nodes are non-draggable'
+    );
+
+    // Make one draggable again
+    rect2.draggable(true);
+    assert.equal(
+      back!.draggable(),
+      true,
+      'Back should be draggable when at least one node is draggable'
+    );
+  });
 });