New property useSingleNodeRotation for Konva.Transformer

CHANGELOG.md

@@ -3,6 +3,10 @@
 All notable changes to this project will be documented in this file.
 This project adheres to [Semantic Versioning](http://semver.org/).
 
+## 8.1.0
+
+- New property `useSingleNodeRotation` for `Konva.Transformer`.
+
 ## 8.0.4
 
 - Fix fill pattern updates on `fillPatternX` and `fillPatternY` changes.

src/Shape.ts

@@ -199,12 +199,12 @@ export class Shape<
 
   getContext() {
     Util.warn(
-      'shape.getContext() method is deprecated. Please don not use it.'
+      'shape.getContext() method is deprecated. Please do not use it.'
     );
     return this.getLayer().getContext();
   }
   getCanvas() {
-    Util.warn('shape.getCanvas() method is deprecated. Please don not use it.');
+    Util.warn('shape.getCanvas() method is deprecated. Please do not use it.');
     return this.getLayer().getCanvas();
   }
 

src/shapes/Transformer.ts

@@ -37,6 +37,8 @@ export interface TransformerConfig extends ContainerConfig {
   node?: Rect;
   ignoreStroke?: boolean;
   boundBoxFunc?: (oldBox: Box, newBox: Box) => Box;
+  useSingleNodeRotation?: boolean;
+  shouldOverdrawWholeArea?: boolean;
 }
 
 var EVENTS_NAME = 'tr-konva';
@@ -221,7 +223,8 @@ function getSnap(snaps: Array<number>, newRotationRad: number, tol: number) {
  * @param {Boolean} [config.flipEnabled] Can we flip/mirror shape on transform?. True by default
  * @param {Function} [config.boundBoxFunc] Bounding box function
  * @param {Function} [config.ignoreStroke] Should we ignore stroke size? Default is false
- *
+ * @param {Boolean} [config.useSingleNodeRotation] When just one node attached, should we use its rotation for transformer?
+ * @param {Boolean} [config.shouldOverdrawWholeArea] Should we fill whole transformer area with fake transparent shape to enable dragging from empty spaces?
  * @example
  * var transformer = new Konva.Transformer({
  *   nodes: [rectangle],
@@ -284,7 +287,7 @@ export class Transformer extends Group {
       this.detach();
     }
     this._nodes = nodes;
-    if (nodes.length === 1) {
+    if (nodes.length === 1 && this.useSingleNodeRotation()) {
       this.rotation(nodes[0].getAbsoluteRotation());
     } else {
       this.rotation(0);
@@ -295,8 +298,7 @@ export class Transformer extends Group {
         .join(' ');
 
       const onChange = () => {
-        //
-        if (this.nodes().length === 1) {
+        if (this.nodes().length === 1 && this.useSingleNodeRotation()) {
           this.rotation(this.nodes()[0].getAbsoluteRotation());
         }
 
@@ -1225,6 +1227,7 @@ export class Transformer extends Group {
   ignoreStroke: GetSet<boolean, this>;
   boundBoxFunc: GetSet<(oldBox: Box, newBox: Box) => Box, this>;
   shouldOverdrawWholeArea: GetSet<boolean, this>;
+  useSingleNodeRotation: GetSet<boolean, this>;
 }
 
 function validateAnchors(val) {
@@ -1629,8 +1632,39 @@ Factory.addGetterSetter(Transformer, 'nodes');
  */
 Factory.addGetterSetter(Transformer, 'boundBoxFunc');
 
+/**
+ * using this setting you can drag transformer group by dragging empty space between attached nodes
+ * shouldOverdrawWholeArea = true may temporary disable all events on attached nodes
+ * @name Konva.Transformer#shouldOverdrawWholeArea
+ * @method
+ * @param {Boolean} shouldOverdrawWholeArea
+ * @returns {Boolean}
+ * @example
+ * // get
+ * var shouldOverdrawWholeArea = transformer.shouldOverdrawWholeArea();
+ *
+ * // set
+ * transformer.shouldOverdrawWholeArea(true);
+ */
 Factory.addGetterSetter(Transformer, 'shouldOverdrawWholeArea', false);
 
+/**
+ * If you have just one attached node to Transformer it will set its initial rotation to the rotation of that node.
+ * In some cases you may need to set a different rotation.
+ * @name Konva.Transformer#useSingleNodeRotation
+ * @method
+ * @param {Boolean} useSingleNodeRotation
+ * @returns {Boolean}
+ * @example
+ * // set flag to false
+ * transformer.useSingleNodeRotation(false);
+ * // attach a shape
+ * transformer.nodes([shape]);
+ * transformer.rotation(45);
+ * transformer.update();
+ */
+ Factory.addGetterSetter(Transformer, 'useSingleNodeRotation', true);
+
 Factory.backCompat(Transformer, {
   lineEnabled: 'borderEnabled',
   rotateHandlerOffset: 'rotateAnchorOffset',

test/unit/Transformer-test.ts

@@ -36,7 +36,7 @@ function simulateMouseUp(tr: Transformer, pos = { x: 0, y: 0 }) {
   su(tr.getStage(), pos || { x: 1, y: 1 });
 }
 
-describe('Transformer', function () {
+describe.only('Transformer', function () {
   // ======================================================
   it('init transformer on simple rectangle', function () {
     var stage = addStage();
@@ -4620,4 +4620,35 @@ describe('Transformer', function () {
 
     assert.equal(textNode.getClientRect().width, 100);
   });
+
+  // ======================================================
+  it('init transformer on simple rectangle', function () {
+    var stage = addStage();
+    stage.rotation(45);
+
+    var layer = new Konva.Layer();
+    stage.add(layer);
+
+    var rect = new Konva.Rect({
+      x: 100,
+      y: 60,
+      draggable: true,
+      width: 100,
+      height: 100,
+      fill: 'yellow',
+      rotation: 45
+    });
+    layer.add(rect);
+
+    var tr = new Konva.Transformer({
+      useSingleNodeRotation: false,
+      nodes: [rect],
+    });
+    layer.add(tr);
+
+    layer.draw();
+    assert.equal(tr.getClassName(), 'Transformer');
+
+    assert.equal(tr.rotation(), 0);
+  });
 });