Add actions/reducer/selectors for storing dragged block client ids in…

… block-editor store

docs/designers-developers/developers/data/data-core-block-editor.md

@@ -370,6 +370,20 @@ _Returns_
 
 -   `Array`: ids of top-level and descendant blocks.
 
+<a name="getDraggedBlockClientIds" href="#getDraggedBlockClientIds">#</a> **getDraggedBlockClientIds**
+
+Returns the client ids of any blocks being directly dragged.
+
+This does not include children of a parent being dragged.
+
+_Parameters_
+
+-   _state_ `Object`: Global application state.
+
+_Returns_
+
+-   `Array<string>`: Array of dragged block client ids.
+
 <a name="getFirstMultiSelectedBlockClientId" href="#getFirstMultiSelectedBlockClientId">#</a> **getFirstMultiSelectedBlockClientId**
 
 Returns the client ID of the first block in the multi-selection set, or null
@@ -744,6 +758,19 @@ _Returns_
 
 -   `boolean`: Whether the block as an inner block selected
 
+<a name="isAncestorBeingDragged" href="#isAncestorBeingDragged">#</a> **isAncestorBeingDragged**
+
+Returns whether a parent/ancestor of the block is being dragged.
+
+_Parameters_
+
+-   _state_ `Object`: Global application state.
+-   _clientId_ `string`: Client id for block to check.
+
+_Returns_
+
+-   `boolean`: Whether the block's ancestor is being dragged.
+
 <a name="isAncestorMultiSelected" href="#isAncestorMultiSelected">#</a> **isAncestorMultiSelected**
 
 Returns true if an ancestor of the block is multi-selected, or false
@@ -758,6 +785,23 @@ _Returns_
 
 -   `boolean`: Whether an ancestor of the block is in multi-selection set.
 
+<a name="isBlockBeingDragged" href="#isBlockBeingDragged">#</a> **isBlockBeingDragged**
+
+Returns whether the block is being dragged.
+
+Only returns true if the block is being directly dragged,
+not if the block is a child of a parent being dragged.
+See `isAncestorBeingDragged` for child blocks.
+
+_Parameters_
+
+-   _state_ `Object`: Global application state.
+-   _clientId_ `string`: Client id for block to check.
+
+_Returns_
+
+-   `boolean`: Whether the block is being dragged.
+
 <a name="isBlockHighlighted" href="#isBlockHighlighted">#</a> **isBlockHighlighted**
 
 Returns true if the current highlighted block matches the block clientId.
@@ -1348,6 +1392,10 @@ _Returns_
 
 Returns an action object used in signalling that the user has begun to drag blocks.
 
+_Parameters_
+
+-   _clientIds_ `Array<string>`: An array of client ids being dragged
+
 _Returns_
 
 -   `Object`: Action object.

packages/block-editor/src/components/block-draggable/index.js

@@ -71,7 +71,7 @@ const BlockDraggable = ( {
 			elementId={ `block-${ clientIds[ 0 ] }` }
 			transferData={ transferData }
 			onDragStart={ ( event ) => {
-				startDraggingBlocks();
+				startDraggingBlocks( clientIds );
 				isDragging.current = true;
 
 				startScrolling( event );

packages/block-editor/src/components/block-list/block.js

@@ -100,11 +100,11 @@ function BlockListBlock( {
 	// (editor.BlockListBlock filter)
 	const { isDragging, isHighlighted } = useSelect(
 		( select ) => {
-			const { isDraggingBlocks, isBlockHighlighted } = select(
+			const { isBlockBeingDragged, isBlockHighlighted } = select(
 				'core/block-editor'
 			);
 			return {
-				isDragging: isDraggingBlocks(),
+				isDragging: isBlockBeingDragged( clientId ),
 				isHighlighted: isBlockHighlighted( clientId ),
 			};
 		},
@@ -154,8 +154,7 @@ function BlockListBlock( {
 			'is-highlighted': isHighlighted,
 			'is-multi-selected': isMultiSelected,
 			'is-reusable': isReusableBlock( blockType ),
-			'is-dragging':
-				isDragging && ( isSelected || isPartOfMultiSelection ),
+			'is-dragging': isDragging,
 			'is-typing': isTypingWithinBlock,
 			'is-focused':
 				isFocusMode && ( isSelected || isAncestorOfSelectedBlock ),

packages/block-editor/src/store/actions.js

@@ -718,11 +718,14 @@ export function stopTyping() {
 /**
  * Returns an action object used in signalling that the user has begun to drag blocks.
  *
+ * @param {string[]} clientIds An array of client ids being dragged
+ *
  * @return {Object} Action object.
  */
-export function startDraggingBlocks() {
+export function startDraggingBlocks( clientIds ) {
 	return {
 		type: 'START_DRAGGING_BLOCKS',
+		clientIds,
 	};
 }
 

packages/block-editor/src/store/reducer.js

@@ -1131,20 +1131,20 @@ export function isTyping( state = false, action ) {
 }
 
 /**
- * Reducer returning dragging state.
+ * Reducer returning dragged block client id.
  *
  * @param {boolean} state  Current state.
  * @param {Object}  action Dispatched action.
  *
  * @return {boolean} Updated state.
  */
-export function isDraggingBlocks( state = false, action ) {
+export function draggedBlocks( state = null, action ) {
 	switch ( action.type ) {
 		case 'START_DRAGGING_BLOCKS':
-			return true;
+			return action.clientIds;
 
 		case 'STOP_DRAGGING_BLOCKS':
-			return false;
+			return null;
 	}
 
 	return state;
@@ -1653,7 +1653,7 @@ export function highlightedBlock( state, action ) {
 export default combineReducers( {
 	blocks,
 	isTyping,
-	isDraggingBlocks,
+	draggedBlocks,
 	isCaretWithinFormattedText,
 	selectionStart,
 	selectionEnd,

packages/block-editor/src/store/selectors.js

@@ -1036,7 +1036,57 @@ export function isTyping( state ) {
  * @return {boolean} Whether user is dragging blocks.
  */
 export function isDraggingBlocks( state ) {
-	return state.isDraggingBlocks;
+	return !! state.draggedBlocks;
+}
+
+/**
+ * Returns the client ids of any blocks being directly dragged.
+ *
+ * This does not include children of a parent being dragged.
+ *
+ * @param {Object} state Global application state.
+ *
+ * @return {string[]} Array of dragged block client ids.
+ */
+export function getDraggedBlockClientIds( state ) {
+	return state.draggedBlocks;
+}
+
+/**
+ * Returns whether the block is being dragged.
+ *
+ * Only returns true if the block is being directly dragged,
+ * not if the block is a child of a parent being dragged.
+ * See `isAncestorBeingDragged` for child blocks.
+ *
+ * @param {Object} state    Global application state.
+ * @param {string} clientId Client id for block to check.
+ *
+ * @return {boolean} Whether the block is being dragged.
+ */
+export function isBlockBeingDragged( state, clientId ) {
+	return !! state.draggedBlocks && state.draggedBlocks.includes( clientId );
+}
+
+/**
+ * Returns whether a parent/ancestor of the block is being dragged.
+ *
+ * @param {Object} state    Global application state.
+ * @param {string} clientId Client id for block to check.
+ *
+ * @return {boolean} Whether the block's ancestor is being dragged.
+ */
+export function isAncestorBeingDragged( state, clientId ) {
+	// Return early if no blocks are being dragged rather than
+	// the more expensive check for parents.
+	if ( ! state.draggedBlocks ) {
+		return false;
+	}
+
+	const parents = getBlockParents( state, clientId );
+	return some( parents, ( parentClientId ) =>
+		isBlockBeingDragged( state, parentClientId )
+	);
 }
 
 /**

packages/block-editor/src/store/test/actions.js

@@ -24,6 +24,8 @@ import {
 	startTyping,
 	stopMultiSelect,
 	stopTyping,
+	startDraggingBlocks,
+	stopDraggingBlocks,
 	toggleBlockMode,
 	toggleSelection,
 	updateBlock,
@@ -847,6 +849,24 @@ describe( 'actions', () => {
 		} );
 	} );
 
+	describe( 'startDraggingBlocks', () => {
+		it( 'should return the START_DRAGGING_BLOCKS action with the list of clientIds passed', () => {
+			const clientIds = [ 'block-1', 'block-2', 'block-3' ];
+			expect( startDraggingBlocks( clientIds ) ).toEqual( {
+				type: 'START_DRAGGING_BLOCKS',
+				clientIds,
+			} );
+		} );
+	} );
+
+	describe( 'stopDraggingBlocks', () => {
+		it( 'should return the STOP_DRAGGING_BLOCKS action', () => {
+			expect( stopDraggingBlocks() ).toEqual( {
+				type: 'STOP_DRAGGING_BLOCKS',
+			} );
+		} );
+	} );
+
 	describe( 'enterFormattedText', () => {
 		it( 'should return the ENTER_FORMATTED_TEXT action', () => {
 			expect( enterFormattedText() ).toEqual( {

packages/block-editor/src/store/test/reducer.js

@@ -21,6 +21,7 @@ import {
 	isUpdatingSameBlockAttribute,
 	blocks,
 	isTyping,
+	draggedBlocks,
 	isCaretWithinFormattedText,
 	selectionStart,
 	selectionEnd,
@@ -2064,6 +2065,27 @@ describe( 'state', () => {
 		} );
 	} );
 
+	describe( 'draggedBlocks', () => {
+		it( 'should store the dragged client ids when a user starts dragging blocks', () => {
+			const clientIds = [ 'block-1', 'block-2', 'block-3' ];
+			const state = draggedBlocks( null, {
+				type: 'START_DRAGGING_BLOCKS',
+				clientIds,
+			} );
+
+			expect( state ).toBe( clientIds );
+		} );
+
+		it( 'should set the state to null when a user stops dragging blocks', () => {
+			const previousState = [ 'block-1', 'block-2', 'block-3' ];
+			const state = draggedBlocks( previousState, {
+				type: 'STOP_DRAGGING_BLOCKS',
+			} );
+
+			expect( state ).toBe( null );
+		} );
+	} );
+
 	describe( 'isCaretWithinFormattedText()', () => {
 		it( 'should set the flag to true', () => {
 			const state = isCaretWithinFormattedText( false, {

packages/block-editor/src/store/test/selectors.js

@@ -50,6 +50,10 @@ const {
 	isFirstMultiSelectedBlock,
 	getBlockMode,
 	isTyping,
+	isDraggingBlocks,
+	getDraggedBlockClientIds,
+	isBlockBeingDragged,
+	isAncestorBeingDragged,
 	isCaretWithinFormattedText,
 	getBlockInsertionPoint,
 	isBlockInsertionPointVisible,
@@ -1849,6 +1853,96 @@ describe( 'selectors', () => {
 		} );
 	} );
 
+	describe( 'isDraggingBlocks', () => {
+		it( 'should return true if a block is being dragged', () => {
+			const state = {
+				draggedBlocks: [ 'block-client-id' ],
+			};
+			expect( isDraggingBlocks( state ) ).toBe( true );
+		} );
+
+		it( 'should return false if a block is not being dragged', () => {
+			const state = {
+				draggedBlocks: null,
+			};
+			expect( isDraggingBlocks( state ) ).toBe( false );
+		} );
+	} );
+
+	describe( 'getDraggedBlockClientIds', () => {
+		it( 'returns the draggedBlocks state', () => {
+			const draggedBlocks = [ 'block-client-id' ];
+			const state = {
+				draggedBlocks,
+			};
+			expect( getDraggedBlockClientIds( state ) ).toBe( draggedBlocks );
+		} );
+	} );
+
+	describe( 'isBlockBeingDragged', () => {
+		it( 'returns true if the given client id is one of the blocks being dragged', () => {
+			const state = {
+				draggedBlocks: [ 'block-1', 'block-2', 'block-3' ],
+			};
+			expect( isBlockBeingDragged( state, 'block-2' ) ).toBe( true );
+		} );
+
+		it( 'returns false if the given client id is not one of the blocks being dragged', () => {
+			const state = {
+				draggedBlocks: [ 'block-1', 'block-2', 'block-3' ],
+			};
+			expect( isBlockBeingDragged( state, 'block-4' ) ).toBe( false );
+		} );
+
+		it( 'returns false if no blocks are being dragged', () => {
+			const state = {
+				draggedBlocks: null,
+			};
+			expect( isBlockBeingDragged( state, 'block-1' ) ).toBe( false );
+		} );
+	} );
+
+	describe( 'isAncestorBeingDragged', () => {
+		it( 'returns true if the given client id is a child of one of the blocks being dragged', () => {
+			const state = {
+				draggedBlocks: [ 'block-1_grandparent' ],
+				blocks: {
+					parents: {
+						'block-1': 'block-1_parent',
+						'block-1_parent': 'block-1_grandparent',
+					},
+				},
+			};
+			expect( isAncestorBeingDragged( state, 'block-1' ) ).toBe( true );
+		} );
+
+		it( 'returns false if the given client id does not have an ancestor being dragged', () => {
+			const state = {
+				draggedBlocks: [ 'block-2_grandparent' ],
+				blocks: {
+					parents: {
+						'block-1': 'block-1_parent',
+						'block-1_parent': 'block-1_grandparent',
+					},
+				},
+			};
+			expect( isAncestorBeingDragged( state, 'block-1' ) ).toBe( false );
+		} );
+
+		it( 'returns false if no blocks are being dragged', () => {
+			const state = {
+				draggedBlocks: null,
+				blocks: {
+					parents: {
+						'block-1': 'block-1_parent',
+						'block-1_parent': 'block-1_grandparent',
+					},
+				},
+			};
+			expect( isAncestorBeingDragged( state, 'block-1' ) ).toBe( false );
+		} );
+	} );
+
 	describe( 'isCaretWithinFormattedText', () => {
 		it( 'returns true if the isCaretWithinFormattedText state is also true', () => {
 			const state = {