feat: Make toolbox and flyout focusable (diff PR against original reverted PR)

core/block_svg.ts

@@ -309,14 +309,22 @@ export class BlockSvg
       (newParent as BlockSvg).getSvgRoot().appendChild(svgRoot);
     } else if (oldParent) {
       // If we are losing a parent, we want to move our DOM element to the
-      // root of the workspace.
-      const draggingBlock = this.workspace
+      // root of the workspace.  Try to insert it before any top-level
+      // block being dragged, but note that blocks can have the
+      // blocklyDragging class even if they're not top blocks (especially
+      // at start and end of a drag).
+      const draggingBlockElement = this.workspace
         .getCanvas()
         .querySelector('.blocklyDragging');
-      if (draggingBlock) {
-        this.workspace.getCanvas().insertBefore(svgRoot, draggingBlock);
+      const draggingParentElement = draggingBlockElement?.parentElement as
+        | SVGElement
+        | null
+        | undefined;
+      const canvas = this.workspace.getCanvas();
+      if (draggingParentElement === canvas) {
+        canvas.insertBefore(svgRoot, draggingBlockElement);
       } else {
-        this.workspace.getCanvas().appendChild(svgRoot);
+        canvas.appendChild(svgRoot);
       }
       this.translate(oldXY.x, oldXY.y);
     }

core/css.ts

@@ -463,8 +463,8 @@ input[type=number] {
 }
 
 .blocklyMenuSeparator {
-  background-color: #ccc; 
-  height: 1px; 
+  background-color: #ccc;
+  height: 1px;
   border: 0;
   margin-left: 4px;
   margin-right: 4px;
@@ -494,12 +494,4 @@ input[type=number] {
   cursor: grabbing;
 }
 
-.blocklyActiveFocus {
-  outline-color: #2ae;
-  outline-width: 2px;
-}
-.blocklyPassiveFocus {
-  outline-color: #3fdfff;
-  outline-width: 1.5px;
-}
 `;

core/dragging/block_drag_strategy.ts

@@ -238,7 +238,7 @@ export class BlockDragStrategy implements IDragStrategy {
     const currCandidate = this.connectionCandidate;
     const newCandidate = this.getConnectionCandidate(draggingBlock, delta);
     if (!newCandidate) {
-      this.connectionPreviewer!.hidePreview();
+      this.connectionPreviewer?.hidePreview();
       this.connectionCandidate = null;
       return;
     }
@@ -254,7 +254,7 @@ export class BlockDragStrategy implements IDragStrategy {
       local.type === ConnectionType.OUTPUT_VALUE ||
       local.type === ConnectionType.PREVIOUS_STATEMENT;
     const neighbourIsConnectedToRealBlock =
-      neighbour.isConnected() && !neighbour.targetBlock()!.isInsertionMarker();
+      neighbour.isConnected() && !neighbour.targetBlock()?.isInsertionMarker();
     if (
       localIsOutputOrPrevious &&
       neighbourIsConnectedToRealBlock &&
@@ -264,14 +264,14 @@ export class BlockDragStrategy implements IDragStrategy {
         local.type,
       )
     ) {
-      this.connectionPreviewer!.previewReplacement(
+      this.connectionPreviewer?.previewReplacement(
         local,
         neighbour,
         neighbour.targetBlock()!,
       );
       return;
     }
-    this.connectionPreviewer!.previewConnection(local, neighbour);
+    this.connectionPreviewer?.previewConnection(local, neighbour);
   }
 
   /**
@@ -385,7 +385,7 @@ export class BlockDragStrategy implements IDragStrategy {
     dom.stopTextWidthCache();
 
     blockAnimation.disconnectUiStop();
-    this.connectionPreviewer!.hidePreview();
+    this.connectionPreviewer?.hidePreview();
 
     if (!this.block.isDeadOrDying() && this.dragging) {
       // These are expensive and don't need to be done if we're deleting, or
@@ -413,7 +413,7 @@ export class BlockDragStrategy implements IDragStrategy {
 
     // Must dispose after connections are applied to not break the dynamic
     // connections plugin. See #7859
-    this.connectionPreviewer!.dispose();
+    this.connectionPreviewer?.dispose();
     this.workspace.setResizesEnabled(true);
     eventUtils.setGroup(newGroup);
   }
@@ -445,6 +445,9 @@ export class BlockDragStrategy implements IDragStrategy {
       return;
     }
 
+    this.connectionPreviewer?.hidePreview();
+    this.connectionCandidate = null;
+
     this.startChildConn?.connect(this.block.nextConnection);
     if (this.startParentConn) {
       switch (this.startParentConn.type) {
@@ -471,9 +474,6 @@ export class BlockDragStrategy implements IDragStrategy {
     this.startChildConn = null;
     this.startParentConn = null;
 
-    this.connectionPreviewer!.hidePreview();
-    this.connectionCandidate = null;
-
     this.block.setDragging(false);
     this.dragging = false;
   }

core/flyout_base.ts

@@ -21,9 +21,12 @@ import * as eventUtils from './events/utils.js';
 import {FlyoutItem} from './flyout_item.js';
 import {FlyoutMetricsManager} from './flyout_metrics_manager.js';
 import {FlyoutSeparator, SeparatorAxis} from './flyout_separator.js';
+import {getFocusManager} from './focus_manager.js';
 import {IAutoHideable} from './interfaces/i_autohideable.js';
 import type {IFlyout} from './interfaces/i_flyout.js';
 import type {IFlyoutInflater} from './interfaces/i_flyout_inflater.js';
+import {IFocusableNode} from './interfaces/i_focusable_node.js';
+import {IFocusableTree} from './interfaces/i_focusable_tree.js';
 import type {Options} from './options.js';
 import * as registry from './registry.js';
 import * as renderManagement from './render_management.js';
@@ -43,7 +46,7 @@ import {WorkspaceSvg} from './workspace_svg.js';
  */
 export abstract class Flyout
   extends DeleteArea
-  implements IAutoHideable, IFlyout
+  implements IAutoHideable, IFlyout, IFocusableNode
 {
   /**
    * Position the flyout.
@@ -303,6 +306,7 @@ export abstract class Flyout
     // hide/show code will set up proper visibility and size later.
     this.svgGroup_ = dom.createSvgElement(tagName, {
       'class': 'blocklyFlyout',
+      'tabindex': '0',
     });
     this.svgGroup_.style.display = 'none';
     this.svgBackground_ = dom.createSvgElement(
@@ -317,6 +321,9 @@ export abstract class Flyout
     this.workspace_
       .getThemeManager()
       .subscribe(this.svgBackground_, 'flyoutOpacity', 'fill-opacity');
+
+    getFocusManager().registerTree(this);
+
     return this.svgGroup_;
   }
 
@@ -398,6 +405,7 @@ export abstract class Flyout
     if (this.svgGroup_) {
       dom.removeNode(this.svgGroup_);
     }
+    getFocusManager().unregisterTree(this);
   }
 
   /**
@@ -961,4 +969,63 @@ export abstract class Flyout
 
     return null;
   }
+
+  /** See IFocusableNode.getFocusableElement. */
+  getFocusableElement(): HTMLElement | SVGElement {
+    if (!this.svgGroup_) throw new Error('Flyout DOM is not yet created.');
+    return this.svgGroup_;
+  }
+
+  /** See IFocusableNode.getFocusableTree. */
+  getFocusableTree(): IFocusableTree {
+    return this;
+  }
+
+  /** See IFocusableNode.onNodeFocus. */
+  onNodeFocus(): void {}
+
+  /** See IFocusableNode.onNodeBlur. */
+  onNodeBlur(): void {}
+
+  /** See IFocusableTree.getRootFocusableNode. */
+  getRootFocusableNode(): IFocusableNode {
+    return this;
+  }
+
+  /** See IFocusableTree.getRestoredFocusableNode. */
+  getRestoredFocusableNode(
+    _previousNode: IFocusableNode | null,
+  ): IFocusableNode | null {
+    return null;
+  }
+
+  /** See IFocusableTree.getNestedTrees. */
+  getNestedTrees(): Array<IFocusableTree> {
+    return [this.workspace_];
+  }
+
+  /** See IFocusableTree.lookUpFocusableNode. */
+  lookUpFocusableNode(_id: string): IFocusableNode | null {
+    // No focusable node needs to be returned since the flyout's subtree is a
+    // workspace that will manage its own focusable state.
+    return null;
+  }
+
+  /** See IFocusableTree.onTreeFocus. */
+  onTreeFocus(
+    _node: IFocusableNode,
+    _previousTree: IFocusableTree | null,
+  ): void {}
+
+  /** See IFocusableTree.onTreeBlur. */
+  onTreeBlur(nextTree: IFocusableTree | null): void {
+    const toolbox = this.targetWorkspace.getToolbox();
+    // If focus is moving to either the toolbox or the flyout's workspace, do
+    // not close the flyout. For anything else, do close it since the flyout is
+    // no longer focused.
+    if (toolbox && nextTree === toolbox) return;
+    if (nextTree == this.workspace_) return;
+    if (toolbox) toolbox.clearSelection();
+    this.autoHide(false);
+  }
 }

core/flyout_button.ts

@@ -15,7 +15,10 @@ import type {IASTNodeLocationSvg} from './blockly.js';
 import * as browserEvents from './browser_events.js';
 import * as Css from './css.js';
 import type {IBoundedElement} from './interfaces/i_bounded_element.js';
+import type {IFocusableNode} from './interfaces/i_focusable_node.js';
+import type {IFocusableTree} from './interfaces/i_focusable_tree.js';
 import type {IRenderedElement} from './interfaces/i_rendered_element.js';
+import {idGenerator} from './utils.js';
 import {Coordinate} from './utils/coordinate.js';
 import * as dom from './utils/dom.js';
 import * as parsing from './utils/parsing.js';
@@ -29,7 +32,11 @@ import type {WorkspaceSvg} from './workspace_svg.js';
  * Class for a button or label in the flyout.
  */
 export class FlyoutButton
-  implements IASTNodeLocationSvg, IBoundedElement, IRenderedElement
+  implements
+    IASTNodeLocationSvg,
+    IBoundedElement,
+    IRenderedElement,
+    IFocusableNode
 {
   /** The horizontal margin around the text in the button. */
   static TEXT_MARGIN_X = 5;
@@ -68,6 +75,9 @@ export class FlyoutButton
    */
   cursorSvg: SVGElement | null = null;
 
+  /** The unique ID for this FlyoutButton. */
+  private id: string;
+
   /**
    * @param workspace The workspace in which to place this button.
    * @param targetWorkspace The flyout's target workspace.
@@ -105,9 +115,10 @@ export class FlyoutButton
       cssClass += ' ' + this.cssClass;
     }
 
+    this.id = idGenerator.getNextUniqueId();
     this.svgGroup = dom.createSvgElement(
       Svg.G,
-      {'class': cssClass},
+      {'id': this.id, 'class': cssClass, 'tabindex': '-1'},
       this.workspace.getCanvas(),
     );
 
@@ -389,6 +400,22 @@ export class FlyoutButton
   getSvgRoot() {
     return this.svgGroup;
   }
+
+  /** See IFocusableNode.getFocusableElement. */
+  getFocusableElement(): HTMLElement | SVGElement {
+    return this.svgGroup;
+  }
+
+  /** See IFocusableNode.getFocusableTree. */
+  getFocusableTree(): IFocusableTree {
+    return this.workspace;
+  }
+
+  /** See IFocusableNode.onNodeFocus. */
+  onNodeFocus(): void {}
+
+  /** See IFocusableNode.onNodeBlur. */
+  onNodeBlur(): void {}
 }
 
 /** CSS for buttons and labels. See css.js for use. */

core/interfaces/i_flyout.ts

@@ -12,12 +12,13 @@ import type {Coordinate} from '../utils/coordinate.js';
 import type {Svg} from '../utils/svg.js';
 import type {FlyoutDefinition} from '../utils/toolbox.js';
 import type {WorkspaceSvg} from '../workspace_svg.js';
+import {IFocusableTree} from './i_focusable_tree.js';
 import type {IRegistrable} from './i_registrable.js';
 
 /**
  * Interface for a flyout.
  */
-export interface IFlyout extends IRegistrable {
+export interface IFlyout extends IRegistrable, IFocusableTree {
   /** Whether the flyout is laid out horizontally or not. */
   horizontalLayout: boolean;
 

core/interfaces/i_toolbox.ts

@@ -9,13 +9,14 @@
 import type {ToolboxInfo} from '../utils/toolbox.js';
 import type {WorkspaceSvg} from '../workspace_svg.js';
 import type {IFlyout} from './i_flyout.js';
+import type {IFocusableTree} from './i_focusable_tree.js';
 import type {IRegistrable} from './i_registrable.js';
 import type {IToolboxItem} from './i_toolbox_item.js';
 
 /**
  * Interface for a toolbox.
  */
-export interface IToolbox extends IRegistrable {
+export interface IToolbox extends IRegistrable, IFocusableTree {
   /** Initializes the toolbox. */
   init(): void;
 

core/interfaces/i_toolbox_item.ts

@@ -6,10 +6,12 @@
 
 // Former goog.module ID: Blockly.IToolboxItem
 
+import type {IFocusableNode} from './i_focusable_node.js';
+
 /**
  * Interface for an item in the toolbox.
  */
-export interface IToolboxItem {
+export interface IToolboxItem extends IFocusableNode {
   /**
    * Initializes the toolbox item.
    * This includes creating the DOM and updating the state of any items based

core/keyboard_nav/line_cursor.ts

@@ -146,10 +146,12 @@ export class LineCursor extends Marker {
     if (!curNode) {
       return null;
     }
-    const newNode = this.getPreviousNodeImpl(
+    const newNode = this.getPreviousNode(
       curNode,
       this.validLineNode.bind(this),
+      true,
     );
+
     if (newNode) {
       this.setCurNode(newNode);
     }
@@ -168,9 +170,10 @@ export class LineCursor extends Marker {
     if (!curNode) {
       return null;
     }
-    const newNode = this.getPreviousNodeImpl(
+    const newNode = this.getPreviousNode(
       curNode,
       this.validInLineNode.bind(this),
+      true,
     );
 
     if (newNode) {

core/toolbox/category.ts

@@ -225,6 +225,8 @@ export class ToolboxCategory
    */
   protected createContainer_(): HTMLDivElement {
     const container = document.createElement('div');
+    container.tabIndex = -1;
+    container.id = this.getId();
     const className = this.cssConfig_['container'];
     if (className) {
       dom.addClass(container, className);

core/toolbox/separator.ts

@@ -54,6 +54,8 @@ export class ToolboxSeparator extends ToolboxItem {
    */
   protected createDom_(): HTMLDivElement {
     const container = document.createElement('div');
+    container.tabIndex = -1;
+    container.id = this.getId();
     const className = this.cssConfig_['container'];
     if (className) {
       dom.addClass(container, className);