p5.js-web-editor/client/modules/IDE/reducers/preferences.js

import * as ActionTypes from '../../../constants';

const initialState = {
  isVisible: false,
  fontSize: 18
};

const preferences = (state = initialState, action) => {
  switch (action.type) {
    case ActionTypes.OPEN_PREFERENCES:
      return {
        isVisible: true,
        fontSize: state.fontSize
      };
    case ActionTypes.CLOSE_PREFERENCES:
      return {
        isVisible: false,
        fontSize: state.fontSize
      };
    case ActionTypes.INCREASE_FONTSIZE:
      return {
        isVisible: state.isVisible,
        fontSize: state.fontSize + 2
      };
    case ActionTypes.DECREASE_FONTSIZE:
      return {
        isVisible: state.isVisible,
        fontSize: state.fontSize - 2
      };
    default:
      return state;
  }
};

export default preferences;