From d9e3c24218908f4408da13cdfb4a33d0e0fab251 Mon Sep 17 00:00:00 2001
From: tellthemachines <isabel@tellthemachines.com>
Date: Tue, 26 May 2020 10:25:40 +1000
Subject: [PATCH] Prototype move blocks between levels with keyboard

---
 .../developers/data/data-core-block-editor.md | 20 ++++++
 .../src/components/block-actions/index.js     |  9 ++-
 .../src/components/block-list/breadcrumb.js   | 16 ++++-
 .../src/components/block-list/style.scss      | 26 +++++++
 .../src/components/writing-flow/index.js      | 72 +++++++++++++++++--
 packages/block-editor/src/store/actions.js    | 12 ++++
 packages/block-editor/src/store/reducer.js    | 19 +++++
 packages/block-editor/src/store/selectors.js  | 11 +++
 8 files changed, 176 insertions(+), 9 deletions(-)

diff --git a/docs/designers-developers/developers/data/data-core-block-editor.md b/docs/designers-developers/developers/data/data-core-block-editor.md
index 23e48402fb1cb..6ff6c95e15453 100644
--- a/docs/designers-developers/developers/data/data-core-block-editor.md
+++ b/docs/designers-developers/developers/data/data-core-block-editor.md
@@ -758,6 +758,18 @@ _Returns_
 
 -   `?boolean`: Whether the insertion point is visible or not.
 
+<a name="isBlockMovingMode" href="#isBlockMovingMode">#</a> **isBlockMovingMode**
+
+Returns whether block moving mode is enabled.
+
+_Parameters_
+
+-   _state_ `Object`: Editor state.
+
+_Returns_
+
+-   `string`: Client Id of moving block.
+
 <a name="isBlockMultiSelected" href="#isBlockMultiSelected">#</a> **isBlockMultiSelected**
 
 Returns true if the client ID occurs within the block multi-selection, or
@@ -1255,6 +1267,14 @@ _Parameters_
 
 -   _clientId_ `string`: Block client ID.
 
+<a name="setBlockMovingMode" href="#setBlockMovingMode">#</a> **setBlockMovingMode**
+
+Generators that triggers an action used to enable or disable the block moving mode.
+
+_Parameters_
+
+-   _isBlockMovingMode_ `string`: Enable/Disable block moving mode.
+
 <a name="setHasControlledInnerBlocks" href="#setHasControlledInnerBlocks">#</a> **setHasControlledInnerBlocks**
 
 Returns an action object that sets whether the block has controlled innerblocks.
diff --git a/packages/block-editor/src/components/block-actions/index.js b/packages/block-editor/src/components/block-actions/index.js
index 9b890ee5c4ed7..e71e86e5d3069 100644
--- a/packages/block-editor/src/components/block-actions/index.js
+++ b/packages/block-editor/src/components/block-actions/index.js
@@ -19,6 +19,7 @@ function BlockActions( {
 	onGroup,
 	onInsertAfter,
 	onInsertBefore,
+	onMoveTo,
 	onRemove,
 	onUngroup,
 	blocks,
@@ -31,6 +32,7 @@ function BlockActions( {
 		onGroup,
 		onInsertAfter,
 		onInsertBefore,
+		onMoveTo,
 		onRemove,
 		onUngroup,
 		blocks,
@@ -73,13 +75,14 @@ export default compose( [
 	} ),
 	withDispatch( ( dispatch, props, { select } ) => {
 		const { clientIds, blocks } = props;
-
 		const {
 			removeBlocks,
 			replaceBlocks,
 			duplicateBlocks,
 			insertAfterBlock,
 			insertBeforeBlock,
+			setBlockMovingMode,
+			setNavigationMode,
 		} = dispatch( 'core/block-editor' );
 
 		return {
@@ -95,6 +98,10 @@ export default compose( [
 			onInsertAfter() {
 				insertAfterBlock( last( castArray( clientIds ) ) );
 			},
+			onMoveTo() {
+				setNavigationMode( true );
+				setBlockMovingMode( clientIds[ 0 ] );
+			},
 			onGroup() {
 				if ( ! blocks.length ) {
 					return;
diff --git a/packages/block-editor/src/components/block-list/breadcrumb.js b/packages/block-editor/src/components/block-list/breadcrumb.js
index 2151725040c46..a837d43a8e769 100644
--- a/packages/block-editor/src/components/block-list/breadcrumb.js
+++ b/packages/block-editor/src/components/block-list/breadcrumb.js
@@ -1,3 +1,8 @@
+/**
+ * External dependencies
+ */
+import classnames from 'classnames';
+
 /**
  * WordPress dependencies
  */
@@ -36,16 +41,17 @@ function BlockBreadcrumb( {
 			const {
 				__unstableGetBlockWithoutInnerBlocks,
 				getBlockIndex,
+				isBlockMovingMode,
 			} = select( 'core/block-editor' );
 			const index = getBlockIndex( clientId, rootClientId );
 			const { name, attributes } = __unstableGetBlockWithoutInnerBlocks(
 				clientId
 			);
-			return { index, name, attributes };
+			return { index, name, attributes, isBlockMovingMode };
 		},
 		[ clientId, rootClientId ]
 	);
-	const { index, name, attributes } = selected;
+	const { index, name, attributes, isBlockMovingMode } = selected;
 	const { setNavigationMode, removeBlock } = useDispatch(
 		'core/block-editor'
 	);
@@ -73,8 +79,12 @@ function BlockBreadcrumb( {
 		moverDirection
 	);
 
+	const classNames = classnames( 'block-editor-block-list__breadcrumb', {
+		'is-navigate-mode': !! isBlockMovingMode(),
+	} );
+
 	return (
-		<div className="block-editor-block-list__breadcrumb" { ...props }>
+		<div className={ classNames } { ...props }>
 			<Button
 				ref={ ref }
 				onClick={ () => setNavigationMode( false ) }
diff --git a/packages/block-editor/src/components/block-list/style.scss b/packages/block-editor/src/components/block-list/style.scss
index 0b3dfa5e23241..9f6fbba1fffb9 100644
--- a/packages/block-editor/src/components/block-list/style.scss
+++ b/packages/block-editor/src/components/block-list/style.scss
@@ -161,8 +161,34 @@
 			}
 		}
 	}
+
+
+	.is-navigate-mode.is-block-moving-mode & .block-editor-block-list__block.is-selected {
+		&::before {
+			content: "";
+			position: absolute;
+			z-index: 0;
+			pointer-events: none;
+			transition:
+				border-color 0.1s linear,
+				border-style 0.1s linear,
+				box-shadow 0.1s linear;
+			right: 0;
+			left: 0;
+			top: -$default-block-margin / 2;
+			border-radius: $radius-block-ui;
+			border-top: 4px solid $blue-medium-focus;
+		}
+		&::after {
+			content: none;
+		}
+	}
 }
 
+.is-navigate-mode.block-editor-block-list__breadcrumb {
+	// Should be invisible but not unfocusable.
+	opacity: 0;
+}
 
 /**
  * Block styles and alignments
diff --git a/packages/block-editor/src/components/writing-flow/index.js b/packages/block-editor/src/components/writing-flow/index.js
index 9d77ada45eba3..4364c4854a3ef 100644
--- a/packages/block-editor/src/components/writing-flow/index.js
+++ b/packages/block-editor/src/components/writing-flow/index.js
@@ -26,6 +26,7 @@ import {
 	TAB,
 	isKeyboardEvent,
 	ESCAPE,
+	SPACE,
 } from '@wordpress/keycodes';
 import { useSelect, useDispatch } from '@wordpress/data';
 import { __ } from '@wordpress/i18n';
@@ -203,6 +204,10 @@ function selector( select ) {
 		hasMultiSelection,
 		getBlockOrder,
 		isNavigationMode,
+		isBlockMovingMode,
+		getBlockIndex,
+		getBlockRootClientId,
+		getClientIdsOfDescendants,
 		isSelectionEnabled,
 		getBlockSelectionStart,
 		isMultiSelecting,
@@ -226,6 +231,10 @@ function selector( select ) {
 		hasMultiSelection: hasMultiSelection(),
 		blocks: getBlockOrder(),
 		isNavigationMode: isNavigationMode(),
+		isBlockMovingMode,
+		getBlockIndex,
+		getBlockRootClientId,
+		getClientIdsOfDescendants,
 		isSelectionEnabled: isSelectionEnabled(),
 		blockSelectionStart: getBlockSelectionStart(),
 		isMultiSelecting: isMultiSelecting(),
@@ -263,17 +272,22 @@ export default function WritingFlow( { children } ) {
 		hasMultiSelection,
 		blocks,
 		isNavigationMode,
+		isBlockMovingMode,
 		isSelectionEnabled,
 		blockSelectionStart,
 		isMultiSelecting,
+		getBlockIndex,
+		getBlockRootClientId,
+		getClientIdsOfDescendants,
 	} = useSelect( selector, [] );
 	const {
 		multiSelect,
 		selectBlock,
 		clearSelectedBlock,
 		setNavigationMode,
+		setBlockMovingMode,
+		moveBlockToPosition,
 	} = useDispatch( 'core/block-editor' );
-
 	function onMouseDown( event ) {
 		verticalRect.current = null;
 
@@ -367,6 +381,7 @@ export default function WritingFlow( { children } ) {
 		const isRight = keyCode === RIGHT;
 		const isTab = keyCode === TAB;
 		const isEscape = keyCode === ESCAPE;
+		const isSpace = keyCode === SPACE;
 		const isReverse = isUp || isLeft;
 		const isHorizontal = isLeft || isRight;
 		const isVertical = isUp || isDown;
@@ -380,11 +395,57 @@ export default function WritingFlow( { children } ) {
 		if ( isNavigationMode ) {
 			const navigateUp = ( isTab && isShift ) || isUp;
 			const navigateDown = ( isTab && ! isShift ) || isDown;
-			const focusedBlockUid = navigateUp
-				? selectionBeforeEndClientId
-				: selectionAfterEndClientId;
+			// Move out of current nesting level (no effect if at root level).
+			const navigateOut = isLeft;
+			// Move into next nesting level (no effect if the current block has no innerBlocks).
+			const navigateIn = isRight;
+
+			let focusedBlockUid;
+			if ( navigateUp ) {
+				focusedBlockUid = selectionBeforeEndClientId;
+			} else if ( navigateDown ) {
+				focusedBlockUid = selectionAfterEndClientId;
+			} else if ( navigateOut ) {
+				focusedBlockUid =
+					getBlockRootClientId( selectedBlockClientId ) ||
+					selectedBlockClientId;
+			} else if ( navigateIn ) {
+				focusedBlockUid =
+					getClientIdsOfDescendants( [
+						selectedBlockClientId,
+					] )[ 0 ] || selectedBlockClientId;
+			}
+			const startingBlockClientId = isBlockMovingMode();
 
-			if ( navigateDown || navigateUp ) {
+			if ( isSpace && startingBlockClientId ) {
+				const sourceRoot = getBlockRootClientId(
+					startingBlockClientId
+				);
+				const destRoot = getBlockRootClientId( selectedBlockClientId );
+				const sourceBlockIndex = getBlockIndex(
+					startingBlockClientId,
+					sourceRoot
+				);
+				let destinationBlockIndex = getBlockIndex(
+					selectedBlockClientId,
+					destRoot
+				);
+				if (
+					sourceBlockIndex < destinationBlockIndex &&
+					sourceRoot === destRoot
+				) {
+					destinationBlockIndex -= 1;
+				}
+				moveBlockToPosition(
+					startingBlockClientId,
+					sourceRoot,
+					destRoot,
+					destinationBlockIndex
+				);
+				selectBlock( startingBlockClientId );
+				setBlockMovingMode( '' );
+			}
+			if ( navigateDown || navigateUp || navigateOut || navigateIn ) {
 				if ( focusedBlockUid ) {
 					event.preventDefault();
 					selectBlock( focusedBlockUid );
@@ -585,6 +646,7 @@ export default function WritingFlow( { children } ) {
 
 	const className = classnames( 'block-editor-writing-flow', {
 		'is-navigate-mode': isNavigationMode,
+		'is-block-moving-mode': !! isBlockMovingMode(),
 	} );
 
 	// Disable reason: Wrapper itself is non-interactive, but must capture
diff --git a/packages/block-editor/src/store/actions.js b/packages/block-editor/src/store/actions.js
index 5aef9e4ce2dd6..1422c05096d04 100644
--- a/packages/block-editor/src/store/actions.js
+++ b/packages/block-editor/src/store/actions.js
@@ -883,6 +883,18 @@ export function* setNavigationMode( isNavigationMode = true ) {
 	}
 }
 
+/**
+ * Generators that triggers an action used to enable or disable the block moving mode.
+ *
+ * @param {string} isBlockMovingMode Enable/Disable block moving mode.
+ */
+export function* setBlockMovingMode( isBlockMovingMode = '' ) {
+	yield {
+		type: 'SET_BLOCK_MOVING_MODE',
+		isBlockMovingMode,
+	};
+}
+
 /**
  * Generator that triggers an action used to duplicate a list of blocks.
  *
diff --git a/packages/block-editor/src/store/reducer.js b/packages/block-editor/src/store/reducer.js
index 223fe26950884..5a9d8f5df2305 100644
--- a/packages/block-editor/src/store/reducer.js
+++ b/packages/block-editor/src/store/reducer.js
@@ -1519,6 +1519,24 @@ export function isNavigationMode( state = false, action ) {
 	return state;
 }
 
+/**
+ * Reducer returning whether the block moving mode is enabled or not.
+ *
+ * @param {string} state  Current state.
+ * @param {Object} action Dispatched action.
+ *
+ * @return {string} Updated state.
+ */
+export function isBlockMovingMode( state = '', action ) {
+	// Let inserting block always trigger Edit mode.
+
+	if ( action.type === 'SET_BLOCK_MOVING_MODE' ) {
+		return action.isBlockMovingMode;
+	}
+
+	return state;
+}
+
 /**
  * Reducer return an updated state representing the most recent block attribute
  * update. The state is structured as an object where the keys represent the
@@ -1621,6 +1639,7 @@ export default combineReducers( {
 	preferences,
 	lastBlockAttributesChange,
 	isNavigationMode,
+	isBlockMovingMode,
 	automaticChangeStatus,
 	highlightedBlock,
 } );
diff --git a/packages/block-editor/src/store/selectors.js b/packages/block-editor/src/store/selectors.js
index 183210fc14c79..a21e035fbec19 100644
--- a/packages/block-editor/src/store/selectors.js
+++ b/packages/block-editor/src/store/selectors.js
@@ -1627,6 +1627,17 @@ export function isNavigationMode( state ) {
 	return state.isNavigationMode;
 }
 
+/**
+ * Returns whether block moving mode is enabled.
+ *
+ * @param {Object} state Editor state.
+ *
+ * @return {string}     Client Id of moving block.
+ */
+export function isBlockMovingMode( state ) {
+	return state.isBlockMovingMode;
+}
+
 /**
  * Returns true if the last change was an automatic change, false otherwise.
  *