Writing flow: fix vertical arrow keys not moving

packages/dom/README.md

@@ -192,7 +192,7 @@ Check whether the selection is horizontally at the edge of the container.
 
 _Parameters_
 
--   _container_ `Element`: Focusable element.
+-   _container_ `HTMLElement`: Focusable element.
 -   _isReverse_ `boolean`: Set to true to check left, false for right.
 
 _Returns_
@@ -269,7 +269,7 @@ Check whether the selection is vertically at the edge of the container.
 
 _Parameters_
 
--   _container_ `Element`: Focusable element.
+-   _container_ `HTMLElement`: Focusable element.
 -   _isReverse_ `boolean`: Set to true to check top, false for bottom.
 
 _Returns_

packages/dom/src/dom/is-edge.js

@@ -8,15 +8,16 @@ import isSelectionForward from './is-selection-forward';
 import hiddenCaretRangeFromPoint from './hidden-caret-range-from-point';
 import { assertIsDefined } from '../utils/assert-is-defined';
 import isInputOrTextArea from './is-input-or-text-area';
+import { scrollIfNoRange } from './scroll-if-no-range';
 
 /**
  * Check whether the selection is at the edge of the container. Checks for
  * horizontal position by default. Set `onlyVertical` to true to check only
  * vertically.
  *
- * @param {Element} container            Focusable element.
- * @param {boolean} isReverse            Set to true to check left, false to check right.
- * @param {boolean} [onlyVertical=false] Set to true to check only vertical position.
+ * @param {HTMLElement} container            Focusable element.
+ * @param {boolean}     isReverse            Set to true to check left, false to check right.
+ * @param {boolean}     [onlyVertical=false] Set to true to check only vertical position.
  *
  * @return {boolean} True if at the edge, false if not.
  */
@@ -96,11 +97,8 @@ export default function isEdge( container, isReverse, onlyVertical = false ) {
 	// pixels. `getComputedStyle` may return a value with different units.
 	const x = isReverseDir ? containerRect.left + 1 : containerRect.right - 1;
 	const y = isReverse ? containerRect.top + 1 : containerRect.bottom - 1;
-	const testRange = hiddenCaretRangeFromPoint(
-		ownerDocument,
-		x,
-		y,
-		/** @type {HTMLElement} */ ( container )
+	const testRange = scrollIfNoRange( container, isReverse, () =>
+		hiddenCaretRangeFromPoint( ownerDocument, x, y, container )
 	);
 
 	if ( ! testRange ) {

packages/dom/src/dom/is-horizontal-edge.js

@@ -6,8 +6,8 @@ import isEdge from './is-edge';
 /**
  * Check whether the selection is horizontally at the edge of the container.
  *
- * @param {Element} container Focusable element.
- * @param {boolean} isReverse Set to true to check left, false for right.
+ * @param {HTMLElement} container Focusable element.
+ * @param {boolean}     isReverse Set to true to check left, false for right.
  *
  * @return {boolean} True if at the horizontal edge, false if not.
  */

packages/dom/src/dom/is-vertical-edge.js

@@ -6,8 +6,8 @@ import isEdge from './is-edge';
 /**
  * Check whether the selection is vertically at the edge of the container.
  *
- * @param {Element} container Focusable element.
- * @param {boolean} isReverse Set to true to check top, false for bottom.
+ * @param {HTMLElement} container Focusable element.
+ * @param {boolean}     isReverse Set to true to check top, false for bottom.
  *
  * @return {boolean} True if at the vertical edge, false if not.
  */

packages/dom/src/dom/place-caret-at-edge.js

@@ -5,6 +5,7 @@ import hiddenCaretRangeFromPoint from './hidden-caret-range-from-point';
 import { assertIsDefined } from '../utils/assert-is-defined';
 import isInputOrTextArea from './is-input-or-text-area';
 import isRTL from './is-rtl';
+import { scrollIfNoRange } from './scroll-if-no-range';
 
 /**
  * Gets the range to place.
@@ -70,26 +71,11 @@ export default function placeCaretAtEdge( container, isReverse, x ) {
 		return;
 	}
 
-	let range = getRange( container, isReverse, x );
+	const range = scrollIfNoRange( container, isReverse, () =>
+		getRange( container, isReverse, x )
+	);
 
-	// If no range range can be created or it is outside the container, the
-	// element may be out of view.
-	if (
-		! range ||
-		! range.startContainer ||
-		! container.contains( range.startContainer )
-	) {
-		container.scrollIntoView( isReverse );
-		range = range = getRange( container, isReverse, x );
-
-		if (
-			! range ||
-			! range.startContainer ||
-			! container.contains( range.startContainer )
-		) {
-			return;
-		}
-	}
+	if ( ! range ) return;
 
 	const { ownerDocument } = container;
 	const { defaultView } = ownerDocument;

packages/dom/src/dom/scroll-if-no-range.js

@@ -0,0 +1,34 @@
+/**
+ * If no range range can be created or it is outside the container, the element
+ * may be out of view, so scroll it into view and try again.
+ *
+ * @param {HTMLElement} container  The container to scroll.
+ * @param {boolean}     alignToTop True to align to top, false to bottom.
+ * @param {Function}    callback   The callback to create the range.
+ *
+ * @return {?Range} The range returned by the callback.
+ */
+export function scrollIfNoRange( container, alignToTop, callback ) {
+	let range = callback();
+
+	// If no range range can be created or it is outside the container, the
+	// element may be out of view.
+	if (
+		! range ||
+		! range.startContainer ||
+		! container.contains( range.startContainer )
+	) {
+		container.scrollIntoView( alignToTop );
+		range = callback();
+
+		if (
+			! range ||
+			! range.startContainer ||
+			! container.contains( range.startContainer )
+		) {
+			return null;
+		}
+	}
+
+	return range;
+}