Add method to toggle visibility of Node.

src/Node.ts

@@ -1043,6 +1043,15 @@ export abstract class Node<Config extends NodeConfig = NodeConfig> {
     this.visible(false);
     return this;
   }
+  /**
+   * toggle visibility of node.
+   * @method
+   * @name Konva.Node#toggleVisibility
+   * @returns {Konva.Node}
+   */
+  toggleVisibility() {
+    return this.isVisible() ? this.hide() : this.show();
+  }
   getZIndex() {
     return this.index || 0;
   }

test/unit/Node-test.ts

@@ -943,6 +943,14 @@ describe('Node', function () {
     layer2.show();
     assert.equal(layer2.isVisible(), true);
     assert.equal(layer2.canvas._canvas.style.display, 'block');
+
+    layer2.toggleVisibility();
+    assert.equal(layer2.isVisible(), false);
+    assert.equal(layer2.canvas._canvas.style.display, 'none');
+
+    layer2.toggleVisibility();
+    assert.equal(layer2.isVisible(), true);
+    assert.equal(layer2.canvas._canvas.style.display, 'block');
   });
 
   // ======================================================
@@ -2271,6 +2279,16 @@ describe('Node', function () {
     layer.draw();
 
     assert.equal(circle.isVisible(), true);
+
+    circle.toggleVisibility();
+    layer.draw();
+
+    assert.equal(circle.isVisible(), false);
+
+    circle.toggleVisibility();
+    layer.draw();
+
+    assert.equal(circle.isVisible(), true);
   });
 
   // ======================================================