src/reducers/hovered-target.js

const SET_HOVERED_SPRITE = 'scratch-gui/hovered-target/SET_HOVERED_SPRITE';
const SET_RECEIVED_BLOCKS = 'scratch-gui/hovered-target/SET_RECEIVED_BLOCKS';

const initialState = {
    sprite: null,
    receivedBlocks: false
};

const reducer = function (state, action) {
    if (typeof state === 'undefined') state = initialState;
    switch (action.type) {
    case SET_HOVERED_SPRITE:
        return {
            sprite: action.spriteId === null ? null : String(action.spriteId),
            receivedBlocks: false
        };
    case SET_RECEIVED_BLOCKS:
        return {
            sprite: state.sprite,
            receivedBlocks: action.receivedBlocks
        };
    default:
        return state;
    }
};

const setHoveredSprite = function (spriteId) {
    return {
        type: SET_HOVERED_SPRITE,
        spriteId: spriteId === null ? null : String(spriteId),
        meta: {
            throttle: 30
        }
    };
};

const setReceivedBlocks = function (receivedBlocks) {
    return {
        type: SET_RECEIVED_BLOCKS,
        receivedBlocks: receivedBlocks
    };
};

export {
    reducer as default,
    initialState as hoveredTargetInitialState,
    setHoveredSprite,
    setReceivedBlocks
};