Move drag blocking to Scroll (slab#2596)

Author: alecgibson

blots/scroll.js

@@ -15,6 +15,7 @@ class Scroll extends ScrollBlot {
     this.batch = false;
     this.optimize();
     this.enable();
+    this.domNode.addEventListener('dragstart', e => this.handleDragStart(e));
   }
 
   batchStart() {
@@ -63,6 +64,10 @@ class Scroll extends ScrollBlot {
     this.optimize();
   }
 
+  handleDragStart(event) {
+    event.preventDefault();
+  }
+
   insertAt(index, value, def) {
     if (index >= this.length()) {
       if (def == null || this.scroll.query(value, Scope.BLOCK) == null) {

core/quill.js

@@ -75,9 +75,6 @@ class Quill {
     this.container.innerHTML = '';
     instances.set(this.container, this);
     this.root = this.addContainer('ql-editor');
-    this.root.addEventListener('dragstart', e => {
-      e.preventDefault();
-    });
     this.root.classList.add('ql-blank');
     this.root.setAttribute('data-gramm', false);
     this.scrollingContainer = this.options.scrollingContainer || this.root;

test/unit/blots/scroll.js

@@ -39,6 +39,14 @@ describe('Scroll', function() {
     }, 1);
   });
 
+  it('prevent dragstart', function() {
+    const scroll = this.initialize(Scroll, '<p>Hello World!</p>');
+    const dragstart = new Event('dragstart');
+    spyOn(dragstart, 'preventDefault');
+    scroll.domNode.dispatchEvent(dragstart);
+    expect(dragstart.preventDefault).toHaveBeenCalled();
+  });
+
   describe('leaf()', function() {
     it('text', function() {
       const scroll = this.initialize(Scroll, '<p>Tests</p>');