Files
blockly/core/keyboard_nav/ast_node.ts
2024-12-04 12:06:12 -08:00

885 lines
28 KiB
TypeScript

/**
* @license
* Copyright 2019 Google LLC
* SPDX-License-Identifier: Apache-2.0
*/
/**
* The class representing an AST node.
* Used to traverse the Blockly AST.
*
* @class
*/
// Former goog.module ID: Blockly.ASTNode
import {Block} from '../block.js';
import {BlockSvg} from '../block_svg.js';
import type {Connection} from '../connection.js';
import {ConnectionType} from '../connection_type.js';
import type {Field} from '../field.js';
import {FlyoutItem} from '../flyout_base.js';
import {FlyoutButton} from '../flyout_button.js';
import type {Input} from '../inputs/input.js';
import type {IASTNodeLocation} from '../interfaces/i_ast_node_location.js';
import type {IASTNodeLocationWithBlock} from '../interfaces/i_ast_node_location_with_block.js';
import {Coordinate} from '../utils/coordinate.js';
import type {Workspace} from '../workspace.js';
import {WorkspaceSvg} from '../workspace_svg.js';
/**
* Class for an AST node.
* It is recommended that you use one of the createNode methods instead of
* creating a node directly.
*/
export class ASTNode {
/**
* True to navigate to all fields. False to only navigate to clickable fields.
*/
static NAVIGATE_ALL_FIELDS = false;
/**
* The default y offset to use when moving the cursor from a stack to the
* workspace.
*/
private static readonly DEFAULT_OFFSET_Y: number = -20;
private readonly type: string;
private readonly isConnectionLocation: boolean;
private readonly location: IASTNodeLocation;
/** The coordinate on the workspace. */
// AnyDuringMigration because: Type 'null' is not assignable to type
// 'Coordinate'.
private wsCoordinate: Coordinate = null as AnyDuringMigration;
/**
* @param type The type of the location.
* Must be in ASTNode.types.
* @param location The position in the AST.
* @param opt_params Optional dictionary of options.
*/
constructor(type: string, location: IASTNodeLocation, opt_params?: Params) {
if (!location) {
throw Error('Cannot create a node without a location.');
}
/**
* The type of the location.
* One of ASTNode.types
*/
this.type = type;
/** Whether the location points to a connection. */
this.isConnectionLocation = ASTNode.isConnectionType(type);
/** The location of the AST node. */
this.location = location;
this.processParams(opt_params || null);
}
/**
* Parse the optional parameters.
*
* @param params The user specified parameters.
*/
private processParams(params: Params | null) {
if (!params) {
return;
}
if (params.wsCoordinate) {
this.wsCoordinate = params.wsCoordinate;
}
}
/**
* Gets the value pointed to by this node.
* It is the callers responsibility to check the node type to figure out what
* type of object they get back from this.
*
* @returns The current field, connection, workspace, or block the cursor is
* on.
*/
getLocation(): IASTNodeLocation {
return this.location;
}
/**
* The type of the current location.
* One of ASTNode.types
*
* @returns The type of the location.
*/
getType(): string {
return this.type;
}
/**
* The coordinate on the workspace.
*
* @returns The workspace coordinate or null if the location is not a
* workspace.
*/
getWsCoordinate(): Coordinate {
return this.wsCoordinate;
}
/**
* Whether the node points to a connection.
*
* @returns [description]
* @internal
*/
isConnection(): boolean {
return this.isConnectionLocation;
}
/**
* Given an input find the next editable field or an input with a non null
* connection in the same block. The current location must be an input
* connection.
*
* @returns The AST node holding the next field or connection or null if there
* is no editable field or input connection after the given input.
*/
private findNextForInput(): ASTNode | null {
const location = this.location as Connection;
const parentInput = location.getParentInput();
const block = parentInput!.getSourceBlock();
// AnyDuringMigration because: Argument of type 'Input | null' is not
// assignable to parameter of type 'Input'.
const curIdx = block!.inputList.indexOf(parentInput as AnyDuringMigration);
for (let i = curIdx + 1; i < block!.inputList.length; i++) {
const input = block!.inputList[i];
const fieldRow = input.fieldRow;
for (let j = 0; j < fieldRow.length; j++) {
const field = fieldRow[j];
if (field.isClickable() || ASTNode.NAVIGATE_ALL_FIELDS) {
return ASTNode.createFieldNode(field);
}
}
if (input.connection) {
return ASTNode.createInputNode(input);
}
}
return null;
}
/**
* Given a field find the next editable field or an input with a non null
* connection in the same block. The current location must be a field.
*
* @returns The AST node pointing to the next field or connection or null if
* there is no editable field or input connection after the given input.
*/
private findNextForField(): ASTNode | null {
const location = this.location as Field;
const input = location.getParentInput();
const block = location.getSourceBlock();
if (!block) {
throw new Error(
'The current AST location is not associated with a block',
);
}
const curIdx = block.inputList.indexOf(input);
let fieldIdx = input.fieldRow.indexOf(location) + 1;
for (let i = curIdx; i < block.inputList.length; i++) {
const newInput = block.inputList[i];
const fieldRow = newInput.fieldRow;
while (fieldIdx < fieldRow.length) {
if (fieldRow[fieldIdx].isClickable() || ASTNode.NAVIGATE_ALL_FIELDS) {
return ASTNode.createFieldNode(fieldRow[fieldIdx]);
}
fieldIdx++;
}
fieldIdx = 0;
if (newInput.connection) {
return ASTNode.createInputNode(newInput);
}
}
return null;
}
/**
* Given an input find the previous editable field or an input with a non null
* connection in the same block. The current location must be an input
* connection.
*
* @returns The AST node holding the previous field or connection.
*/
private findPrevForInput(): ASTNode | null {
const location = this.location as Connection;
const parentInput = location.getParentInput();
const block = parentInput!.getSourceBlock();
// AnyDuringMigration because: Argument of type 'Input | null' is not
// assignable to parameter of type 'Input'.
const curIdx = block!.inputList.indexOf(parentInput as AnyDuringMigration);
for (let i = curIdx; i >= 0; i--) {
const input = block!.inputList[i];
if (input.connection && input !== parentInput) {
return ASTNode.createInputNode(input);
}
const fieldRow = input.fieldRow;
for (let j = fieldRow.length - 1; j >= 0; j--) {
const field = fieldRow[j];
if (field.isClickable() || ASTNode.NAVIGATE_ALL_FIELDS) {
return ASTNode.createFieldNode(field);
}
}
}
return null;
}
/**
* Given a field find the previous editable field or an input with a non null
* connection in the same block. The current location must be a field.
*
* @returns The AST node holding the previous input or field.
*/
private findPrevForField(): ASTNode | null {
const location = this.location as Field;
const parentInput = location.getParentInput();
const block = location.getSourceBlock();
if (!block) {
throw new Error(
'The current AST location is not associated with a block',
);
}
const curIdx = block.inputList.indexOf(parentInput);
let fieldIdx = parentInput.fieldRow.indexOf(location) - 1;
for (let i = curIdx; i >= 0; i--) {
const input = block.inputList[i];
if (input.connection && input !== parentInput) {
return ASTNode.createInputNode(input);
}
const fieldRow = input.fieldRow;
while (fieldIdx > -1) {
if (fieldRow[fieldIdx].isClickable() || ASTNode.NAVIGATE_ALL_FIELDS) {
return ASTNode.createFieldNode(fieldRow[fieldIdx]);
}
fieldIdx--;
}
// Reset the fieldIdx to the length of the field row of the previous
// input.
if (i - 1 >= 0) {
fieldIdx = block.inputList[i - 1].fieldRow.length - 1;
}
}
return null;
}
/**
* Navigate between stacks of blocks on the workspace.
*
* @param forward True to go forward. False to go backwards.
* @returns The first block of the next stack or null if there are no blocks
* on the workspace.
*/
private navigateBetweenStacks(forward: boolean): ASTNode | null {
let curLocation = this.getLocation();
// TODO(#6097): Use instanceof checks to exit early for values of
// curLocation that don't make sense.
if ((curLocation as IASTNodeLocationWithBlock).getSourceBlock) {
const block = (curLocation as IASTNodeLocationWithBlock).getSourceBlock();
if (block) {
curLocation = block;
}
}
// TODO(#6097): Use instanceof checks to exit early for values of
// curLocation that don't make sense.
const curLocationAsBlock = curLocation as Block;
if (!curLocationAsBlock || curLocationAsBlock.isDeadOrDying()) {
return null;
}
if (curLocationAsBlock.workspace.isFlyout) {
return this.navigateFlyoutContents(forward);
}
const curRoot = curLocationAsBlock.getRootBlock();
const topBlocks = curRoot.workspace.getTopBlocks(true);
for (let i = 0; i < topBlocks.length; i++) {
const topBlock = topBlocks[i];
if (curRoot.id === topBlock.id) {
const offset = forward ? 1 : -1;
const resultIndex = i + offset;
if (resultIndex === -1 || resultIndex === topBlocks.length) {
return null;
}
return ASTNode.createStackNode(topBlocks[resultIndex]);
}
}
throw Error(
"Couldn't find " + (forward ? 'next' : 'previous') + ' stack?!',
);
}
/**
* Navigate between buttons and stacks of blocks on the flyout workspace.
*
* @param forward True to go forward. False to go backwards.
* @returns The next button, or next stack's first block, or null
*/
private navigateFlyoutContents(forward: boolean): ASTNode | null {
const nodeType = this.getType();
let location;
let targetWorkspace;
switch (nodeType) {
case ASTNode.types.STACK: {
location = this.getLocation() as Block;
const workspace = location.workspace as WorkspaceSvg;
targetWorkspace = workspace.targetWorkspace as WorkspaceSvg;
break;
}
case ASTNode.types.BUTTON: {
location = this.getLocation() as FlyoutButton;
targetWorkspace = location.getTargetWorkspace() as WorkspaceSvg;
break;
}
default:
return null;
}
const flyout = targetWorkspace.getFlyout();
if (!flyout) return null;
const nextItem = this.findNextLocationInFlyout(
flyout.getContents(),
location,
forward,
);
if (!nextItem) return null;
if (nextItem.element instanceof FlyoutButton) {
return ASTNode.createButtonNode(nextItem.element);
} else if (nextItem.element instanceof BlockSvg) {
return ASTNode.createStackNode(nextItem.element);
}
return null;
}
/**
* Finds the next (or previous if navigating backward) item in the flyout that should be navigated to.
*
* @param flyoutContents Contents of the current flyout.
* @param currentLocation Current ASTNode location.
* @param forward True if we're navigating forward, else false.
* @returns The next (or previous) FlyoutItem, or null if there is none.
*/
private findNextLocationInFlyout(
flyoutContents: FlyoutItem[],
currentLocation: IASTNodeLocation,
forward: boolean,
): FlyoutItem | null {
const currentIndex = flyoutContents.findIndex((item: FlyoutItem) => {
if (
currentLocation instanceof BlockSvg &&
item.element === currentLocation
) {
return true;
}
if (
currentLocation instanceof FlyoutButton &&
item.element === currentLocation
) {
return true;
}
return false;
});
if (currentIndex < 0) return null;
const resultIndex = forward ? currentIndex + 1 : currentIndex - 1;
if (resultIndex === -1 || resultIndex === flyoutContents.length) {
return null;
}
return flyoutContents[resultIndex];
}
/**
* Finds the top most AST node for a given block.
* This is either the previous connection, output connection or block
* depending on what kind of connections the block has.
*
* @param block The block that we want to find the top connection on.
* @returns The AST node containing the top connection.
*/
private findTopASTNodeForBlock(block: Block): ASTNode | null {
const topConnection = getParentConnection(block);
if (topConnection) {
return ASTNode.createConnectionNode(topConnection);
} else {
return ASTNode.createBlockNode(block);
}
}
/**
* Get the AST node pointing to the input that the block is nested under or if
* the block is not nested then get the stack AST node.
*
* @param block The source block of the current location.
* @returns The AST node pointing to the input connection or the top block of
* the stack this block is in.
*/
private getOutAstNodeForBlock(block: Block): ASTNode | null {
if (!block) {
return null;
}
// If the block doesn't have a previous connection then it is the top of the
// substack.
const topBlock = block.getTopStackBlock();
const topConnection = getParentConnection(topBlock);
// If the top connection has a parentInput, create an AST node pointing to
// that input.
if (
topConnection &&
topConnection.targetConnection &&
topConnection.targetConnection.getParentInput()
) {
// AnyDuringMigration because: Argument of type 'Input | null' is not
// assignable to parameter of type 'Input'.
return ASTNode.createInputNode(
topConnection.targetConnection.getParentInput() as AnyDuringMigration,
);
} else {
// Go to stack level if you are not underneath an input.
return ASTNode.createStackNode(topBlock);
}
}
/**
* Find the first editable field or input with a connection on a given block.
*
* @param block The source block of the current location.
* @returns An AST node pointing to the first field or input.
* Null if there are no editable fields or inputs with connections on the
* block.
*/
private findFirstFieldOrInput(block: Block): ASTNode | null {
const inputs = block.inputList;
for (let i = 0; i < inputs.length; i++) {
const input = inputs[i];
const fieldRow = input.fieldRow;
for (let j = 0; j < fieldRow.length; j++) {
const field = fieldRow[j];
if (field.isClickable() || ASTNode.NAVIGATE_ALL_FIELDS) {
return ASTNode.createFieldNode(field);
}
}
if (input.connection) {
return ASTNode.createInputNode(input);
}
}
return null;
}
/**
* Finds the source block of the location of this node.
*
* @returns The source block of the location, or null if the node is of type
* workspace or button.
*/
getSourceBlock(): Block | null {
if (this.getType() === ASTNode.types.BLOCK) {
return this.getLocation() as Block;
} else if (this.getType() === ASTNode.types.STACK) {
return this.getLocation() as Block;
} else if (this.getType() === ASTNode.types.WORKSPACE) {
return null;
} else if (this.getType() === ASTNode.types.BUTTON) {
return null;
} else {
return (this.getLocation() as IASTNodeLocationWithBlock).getSourceBlock();
}
}
/**
* Find the element to the right of the current element in the AST.
*
* @returns An AST node that wraps the next field, connection, block, or
* workspace. Or null if there is no node to the right.
*/
next(): ASTNode | null {
switch (this.type) {
case ASTNode.types.STACK:
return this.navigateBetweenStacks(true);
case ASTNode.types.OUTPUT: {
const connection = this.location as Connection;
return ASTNode.createBlockNode(connection.getSourceBlock());
}
case ASTNode.types.FIELD:
return this.findNextForField();
case ASTNode.types.INPUT:
return this.findNextForInput();
case ASTNode.types.BLOCK: {
const block = this.location as Block;
const nextConnection = block.nextConnection;
if (!nextConnection) return null;
return ASTNode.createConnectionNode(nextConnection);
}
case ASTNode.types.PREVIOUS: {
const connection = this.location as Connection;
return ASTNode.createBlockNode(connection.getSourceBlock());
}
case ASTNode.types.NEXT: {
const connection = this.location as Connection;
const targetConnection = connection.targetConnection;
return ASTNode.createConnectionNode(targetConnection!);
}
case ASTNode.types.BUTTON:
return this.navigateFlyoutContents(true);
}
return null;
}
/**
* Find the element one level below and all the way to the left of the current
* location.
*
* @returns An AST node that wraps the next field, connection, workspace, or
* block. Or null if there is nothing below this node.
*/
in(): ASTNode | null {
switch (this.type) {
case ASTNode.types.WORKSPACE: {
const workspace = this.location as Workspace;
const topBlocks = workspace.getTopBlocks(true);
if (topBlocks.length > 0) {
return ASTNode.createStackNode(topBlocks[0]);
}
break;
}
case ASTNode.types.STACK: {
const block = this.location as Block;
return this.findTopASTNodeForBlock(block);
}
case ASTNode.types.BLOCK: {
const block = this.location as Block;
return this.findFirstFieldOrInput(block);
}
case ASTNode.types.INPUT: {
const connection = this.location as Connection;
const targetConnection = connection.targetConnection;
return ASTNode.createConnectionNode(targetConnection!);
}
}
return null;
}
/**
* Find the element to the left of the current element in the AST.
*
* @returns An AST node that wraps the previous field, connection, workspace
* or block. Or null if no node exists to the left. null.
*/
prev(): ASTNode | null {
switch (this.type) {
case ASTNode.types.STACK:
return this.navigateBetweenStacks(false);
case ASTNode.types.OUTPUT:
return null;
case ASTNode.types.FIELD:
return this.findPrevForField();
case ASTNode.types.INPUT:
return this.findPrevForInput();
case ASTNode.types.BLOCK: {
const block = this.location as Block;
const topConnection = getParentConnection(block);
if (!topConnection) return null;
return ASTNode.createConnectionNode(topConnection);
}
case ASTNode.types.PREVIOUS: {
const connection = this.location as Connection;
const targetConnection = connection.targetConnection;
if (targetConnection && !targetConnection.getParentInput()) {
return ASTNode.createConnectionNode(targetConnection);
}
break;
}
case ASTNode.types.NEXT: {
const connection = this.location as Connection;
return ASTNode.createBlockNode(connection.getSourceBlock());
}
case ASTNode.types.BUTTON:
return this.navigateFlyoutContents(false);
}
return null;
}
/**
* Find the next element that is one position above and all the way to the
* left of the current location.
*
* @returns An AST node that wraps the next field, connection, workspace or
* block. Or null if we are at the workspace level.
*/
out(): ASTNode | null {
switch (this.type) {
case ASTNode.types.STACK: {
const block = this.location as Block;
const blockPos = block.getRelativeToSurfaceXY();
// TODO: Make sure this is in the bounds of the workspace.
const wsCoordinate = new Coordinate(
blockPos.x,
blockPos.y + ASTNode.DEFAULT_OFFSET_Y,
);
return ASTNode.createWorkspaceNode(block.workspace, wsCoordinate);
}
case ASTNode.types.OUTPUT: {
const connection = this.location as Connection;
const target = connection.targetConnection;
if (target) {
return ASTNode.createConnectionNode(target);
}
return ASTNode.createStackNode(connection.getSourceBlock());
}
case ASTNode.types.FIELD: {
const field = this.location as Field;
const block = field.getSourceBlock();
if (!block) {
throw new Error(
'The current AST location is not associated with a block',
);
}
return ASTNode.createBlockNode(block);
}
case ASTNode.types.INPUT: {
const connection = this.location as Connection;
return ASTNode.createBlockNode(connection.getSourceBlock());
}
case ASTNode.types.BLOCK: {
const block = this.location as Block;
return this.getOutAstNodeForBlock(block);
}
case ASTNode.types.PREVIOUS: {
const connection = this.location as Connection;
return this.getOutAstNodeForBlock(connection.getSourceBlock());
}
case ASTNode.types.NEXT: {
const connection = this.location as Connection;
return this.getOutAstNodeForBlock(connection.getSourceBlock());
}
}
return null;
}
/**
* Whether an AST node of the given type points to a connection.
*
* @param type The type to check. One of ASTNode.types.
* @returns True if a node of the given type points to a connection.
*/
private static isConnectionType(type: string): boolean {
switch (type) {
case ASTNode.types.PREVIOUS:
case ASTNode.types.NEXT:
case ASTNode.types.INPUT:
case ASTNode.types.OUTPUT:
return true;
}
return false;
}
/**
* Create an AST node pointing to a field.
*
* @param field The location of the AST node.
* @returns An AST node pointing to a field.
*/
static createFieldNode(field: Field): ASTNode | null {
if (!field) {
return null;
}
return new ASTNode(ASTNode.types.FIELD, field);
}
/**
* Creates an AST node pointing to a connection. If the connection has a
* parent input then create an AST node of type input that will hold the
* connection.
*
* @param connection This is the connection the node will point to.
* @returns An AST node pointing to a connection.
*/
static createConnectionNode(connection: Connection): ASTNode | null {
if (!connection) {
return null;
}
const type = connection.type;
if (type === ConnectionType.INPUT_VALUE) {
// AnyDuringMigration because: Argument of type 'Input | null' is not
// assignable to parameter of type 'Input'.
return ASTNode.createInputNode(
connection.getParentInput() as AnyDuringMigration,
);
} else if (
type === ConnectionType.NEXT_STATEMENT &&
connection.getParentInput()
) {
// AnyDuringMigration because: Argument of type 'Input | null' is not
// assignable to parameter of type 'Input'.
return ASTNode.createInputNode(
connection.getParentInput() as AnyDuringMigration,
);
} else if (type === ConnectionType.NEXT_STATEMENT) {
return new ASTNode(ASTNode.types.NEXT, connection);
} else if (type === ConnectionType.OUTPUT_VALUE) {
return new ASTNode(ASTNode.types.OUTPUT, connection);
} else if (type === ConnectionType.PREVIOUS_STATEMENT) {
return new ASTNode(ASTNode.types.PREVIOUS, connection);
}
return null;
}
/**
* Creates an AST node pointing to an input. Stores the input connection as
* the location.
*
* @param input The input used to create an AST node.
* @returns An AST node pointing to a input.
*/
static createInputNode(input: Input): ASTNode | null {
if (!input || !input.connection) {
return null;
}
return new ASTNode(ASTNode.types.INPUT, input.connection);
}
/**
* Creates an AST node pointing to a block.
*
* @param block The block used to create an AST node.
* @returns An AST node pointing to a block.
*/
static createBlockNode(block: Block): ASTNode | null {
if (!block) {
return null;
}
return new ASTNode(ASTNode.types.BLOCK, block);
}
/**
* Create an AST node of type stack. A stack, represented by its top block, is
* the set of all blocks connected to a top block, including the top
* block.
*
* @param topBlock A top block has no parent and can be found in the list
* returned by workspace.getTopBlocks().
* @returns An AST node of type stack that points to the top block on the
* stack.
*/
static createStackNode(topBlock: Block): ASTNode | null {
if (!topBlock) {
return null;
}
return new ASTNode(ASTNode.types.STACK, topBlock);
}
/**
* Create an AST node of type button. A button in this case refers
* specifically to a button in a flyout.
*
* @param button A top block has no parent and can be found in the list
* returned by workspace.getTopBlocks().
* @returns An AST node of type stack that points to the top block on the
* stack.
*/
static createButtonNode(button: FlyoutButton): ASTNode | null {
if (!button) {
return null;
}
return new ASTNode(ASTNode.types.BUTTON, button);
}
/**
* Creates an AST node pointing to a workspace.
*
* @param workspace The workspace that we are on.
* @param wsCoordinate The position on the workspace for this node.
* @returns An AST node pointing to a workspace and a position on the
* workspace.
*/
static createWorkspaceNode(
workspace: Workspace | null,
wsCoordinate: Coordinate | null,
): ASTNode | null {
if (!wsCoordinate || !workspace) {
return null;
}
const params = {wsCoordinate};
return new ASTNode(ASTNode.types.WORKSPACE, workspace, params);
}
/**
* Creates an AST node for the top position on a block.
* This is either an output connection, previous connection, or block.
*
* @param block The block to find the top most AST node on.
* @returns The AST node holding the top most position on the block.
*/
static createTopNode(block: Block): ASTNode | null {
let astNode;
const topConnection = getParentConnection(block);
if (topConnection) {
astNode = ASTNode.createConnectionNode(topConnection);
} else {
astNode = ASTNode.createBlockNode(block);
}
return astNode;
}
}
export namespace ASTNode {
export interface Params {
wsCoordinate: Coordinate;
}
export enum types {
FIELD = 'field',
BLOCK = 'block',
INPUT = 'input',
OUTPUT = 'output',
NEXT = 'next',
PREVIOUS = 'previous',
STACK = 'stack',
WORKSPACE = 'workspace',
BUTTON = 'button',
}
}
export type Params = ASTNode.Params;
// No need to export ASTNode.types from the module at this time because (1) it
// wasn't automatically converted by the automatic migration script, (2) the
// name doesn't follow the styleguide.
/**
* Gets the parent connection on a block.
* This is either an output connection, previous connection or undefined.
* If both connections exist return the one that is actually connected
* to another block.
*
* @param block The block to find the parent connection on.
* @returns The connection connecting to the parent of the block.
*/
function getParentConnection(block: Block): Connection | null {
let topConnection = block.outputConnection;
if (
!topConnection ||
(block.previousConnection && block.previousConnection.isConnected())
) {
topConnection = block.previousConnection;
}
return topConnection;
}