Merge pull request #15916 from atom/as-jr-stop-dragging-when-interact…

…ing-with-keyboard

Stop dragging only when user interacts with keyboard

spec/text-editor-component-spec.js

@@ -4422,7 +4422,7 @@ describe('TextEditorComponent', () => {
       expect(dragEvents).toEqual([])
     })
 
-    it('calls `didStopDragging` if the buffer changes while dragging', async () => {
+    it('calls `didStopDragging` if the user interacts with the keyboard while dragging', async () => {
       const {component, editor} = buildComponent()
 
       let dragging = false
@@ -4435,8 +4435,14 @@ describe('TextEditorComponent', () => {
       await getNextAnimationFramePromise()
       expect(dragging).toBe(true)
 
-      editor.delete()
+      // Buffer changes don't cause dragging to be stopped.
+      editor.insertText('X')
+      expect(dragging).toBe(true)
+
+      // Keyboard interaction prevents users from dragging further.
+      component.didKeydown({code: 'KeyX'})
       expect(dragging).toBe(false)
+
       window.dispatchEvent(new MouseEvent('mousemove'))
       await getNextAnimationFramePromise()
       expect(dragging).toBe(false)

src/text-editor-component.js

@@ -1638,6 +1638,11 @@ class TextEditorComponent {
   // keypress, meaning we're *holding* the _same_ key we intially pressed.
   // Got that?
   didKeydown (event) {
+    // Stop dragging when user interacts with the keyboard. This prevents
+    // unwanted selections in the case edits are performed while selecting text
+    // at the same time.
+    if (this.stopDragging) this.stopDragging()
+
     if (this.lastKeydownBeforeKeypress != null) {
       if (this.lastKeydownBeforeKeypress.code === event.code) {
         this.accentedCharacterMenuIsOpen = true
@@ -1862,7 +1867,6 @@ class TextEditorComponent {
   handleMouseDragUntilMouseUp ({didDrag, didStopDragging}) {
     let dragging = false
     let lastMousemoveEvent
-    let bufferWillChangeDisposable
 
     const animationFrameLoop = () => {
       window.requestAnimationFrame(() => {
@@ -1882,9 +1886,9 @@ class TextEditorComponent {
     }
 
     function didMouseUp () {
+      this.stopDragging = null
       window.removeEventListener('mousemove', didMouseMove)
       window.removeEventListener('mouseup', didMouseUp, {capture: true})
-      bufferWillChangeDisposable.dispose()
       if (dragging) {
         dragging = false
         didStopDragging()
@@ -1893,10 +1897,7 @@ class TextEditorComponent {
 
     window.addEventListener('mousemove', didMouseMove)
     window.addEventListener('mouseup', didMouseUp, {capture: true})
-    // Simulate a mouse-up event if the buffer is about to change. This prevents
-    // unwanted selections when users perform edits while holding the left mouse
-    // button at the same time.
-    bufferWillChangeDisposable = this.props.model.getBuffer().onWillChange(didMouseUp)
+    this.stopDragging = didMouseUp
   }
 
   autoscrollOnMouseDrag ({clientX, clientY}, verticalOnly = false) {