imageEditor.js

/**
 * @author NHN Ent. FE Development Team <dl_javascript@nhnent.com>
 * @fileoverview Image-editor application class
 */
import snippet from 'tui-code-snippet';
import Promise from 'core-js/library/es6/promise';
import Invoker from './invoker';
import UI from './ui';
import action from './action';
import commandFactory from './factory/command';
import Graphics from './graphics';
import consts from './consts';
import {sendHostName} from './util';

const events = consts.eventNames;
const commands = consts.commandNames;
const {keyCodes, rejectMessages} = consts;
const {isUndefined, forEach, CustomEvents} = snippet;

/**
 * Image editor
 * @class
 * @param {string|jQuery|HTMLElement} wrapper - Wrapper's element or selector
 * @param {Object} [option] - Canvas max width & height of css
 *  @param {number} option.cssMaxWidth - Canvas css-max-width
 *  @param {number} option.cssMaxHeight - Canvas css-max-height
 *  @param {Boolean} [option.usageStatistics=true] - Let us know the hostname. If you don't want to send the hostname, please set to false.
 */
class ImageEditor {
    constructor(wrapper, option) {
        option = snippet.extend({
            includeUI: false,
            applyCropSelectionStyle: false,
            usageStatistics: true
        }, option);

        this.activeObjectId = null;

        /**
         * UI instance
         * @type {Ui}
         */
        if (option.includeUI) {
            this.ui = new UI(wrapper, option.includeUI, this.getActions());
        }

        /**
         * Invoker
         * @type {Invoker}
         * @private
         */
        this._invoker = new Invoker();

        /**
         * Graphics instance
         * @type {Graphics}
         * @private
         */
        this._graphics = new Graphics(
            this.ui ? this.ui.getEditorArea() : wrapper,
            option.cssMaxWidth,
            option.cssMaxHeight
        );

        if (this.ui) {
            this.ui.initCanvas();
            this.setReAction();
        }

        /**
         * Event handler list
         * @type {Object}
         * @private
         */
        this._handlers = {
            keydown: this._onKeyDown.bind(this),
            mousedown: this._onMouseDown.bind(this),
            objectActivated: this._onObjectActivated.bind(this),
            objectMoved: this._onObjectMoved.bind(this),
            objectScaled: this._onObjectScaled.bind(this),
            createdPath: this._onCreatedPath,
            addText: this._onAddText.bind(this),
            addObject: this._onAddObject.bind(this),
            textEditing: this._onTextEditing.bind(this),
            textChanged: this._onTextChanged.bind(this)
        };

        this._attachInvokerEvents();
        this._attachGraphicsEvents();
        this._attachDomEvents();
        this._setSelectionStyle(option.selectionStyle, option.applyCropSelectionStyle);

        if (option.usageStatistics) {
            sendHostName();
        }
    }

    /**
     * Image filter result
     * @typedef {Object} FilterResult
     * @property {string} type - filter type like 'mask', 'Grayscale' and so on
     * @property {string} action - action type like 'add', 'remove'
     */

    /**
     * Flip status
     * @typedef {Object} FlipStatus
     * @property {boolean} flipX - x axis
     * @property {boolean} flipY - y axis
     * @property {Number} angle - angle
     */
    /**
     * Rotation status
     * @typedef {Number} RotateStatus
     * @property {Number} angle - angle
     */

    /**
     * Old and new Size
     * @typedef {Object} SizeChange
     * @property {Number} oldWidth - old width
     * @property {Number} oldHeight - old height
     * @property {Number} newWidth - new width
     * @property {Number} newHeight - new height
     */

    /**
     * @typedef {string} ErrorMsg - {string} error message
     */

    /**
     * @typedef {Object} ObjectProps - graphics object properties
     * @property {number} id - object id
     * @property {string} type - object type
     * @property {string} text - text content
     * @property {string} left - Left
     * @property {string} top - Top
     * @property {string} width - Width
     * @property {string} height - Height
     * @property {string} fill - Color
     * @property {string} stroke - Stroke
     * @property {string} strokeWidth - StrokeWidth
     * @property {string} fontFamily - Font type for text
     * @property {number} fontSize - Font Size
     * @property {string} fontStyle - Type of inclination (normal / italic)
     * @property {string} fontWeight - Type of thicker or thinner looking (normal / bold)
     * @property {string} textAlign - Type of text align (left / center / right)
     * @property {string} textDecoraiton - Type of line (underline / line-throgh / overline)
     */

    /**
     * Set selection style by init option
     * @param {Object} selectionStyle - Selection styles
     * @param {boolean} applyCropSelectionStyle - whether apply with crop selection style or not
     * @private
     */
    _setSelectionStyle(selectionStyle, applyCropSelectionStyle) {
        if (selectionStyle) {
            this._graphics.setSelectionStyle(selectionStyle);
        }

        if (applyCropSelectionStyle) {
            this._graphics.setCropSelectionStyle(selectionStyle);
        }
    }

    /**
     * Attach invoker events
     * @private
     */
    _attachInvokerEvents() {
        const {
            UNDO_STACK_CHANGED,
            REDO_STACK_CHANGED
        } = events;

        /**
         * Undo stack changed event
         * @event ImageEditor#undoStackChanged
         * @param {Number} length - undo stack length
         * @example
         * imageEditor.on('undoStackChanged', function(length) {
         *     console.log(length);
         * });
         */
        this._invoker.on(UNDO_STACK_CHANGED, this.fire.bind(this, UNDO_STACK_CHANGED));
        /**
         * Redo stack changed event
         * @event ImageEditor#redoStackChanged
         * @param {Number} length - redo stack length
         * @example
         * imageEditor.on('redoStackChanged', function(length) {
         *     console.log(length);
         * });
         */
        this._invoker.on(REDO_STACK_CHANGED, this.fire.bind(this, REDO_STACK_CHANGED));
    }

    /**
     * Attach canvas events
     * @private
     */
    _attachGraphicsEvents() {
        this._graphics.on({
            'mousedown': this._handlers.mousedown,
            'objectMoved': this._handlers.objectMoved,
            'objectScaled': this._handlers.objectScaled,
            'objectActivated': this._handlers.objectActivated,
            'addText': this._handlers.addText,
            'addObject': this._handlers.addObject,
            'textEditing': this._handlers.textEditing,
            'textChanged': this._handlers.textChanged
        });
    }

    /**
     * Attach dom events
     * @private
     */
    _attachDomEvents() {
        // ImageEditor supports IE 9 higher
        document.addEventListener('keydown', this._handlers.keydown);
    }

    /**
     * Detach dom events
     * @private
     */
    _detachDomEvents() {
        // ImageEditor supports IE 9 higher
        document.removeEventListener('keydown', this._handlers.keydown);
    }

    /**
     * Keydown event handler
     * @param {KeyboardEvent} e - Event object
     * @private
     */
    /* eslint-disable complexity */
    _onKeyDown(e) {
        const activeObject = this._graphics.getActiveObject();
        const activeObjectId = this._graphics.getObjectId(activeObject);

        if ((e.ctrlKey || e.metaKey) && e.keyCode === keyCodes.Z) {
            // There is no error message on shortcut when it's empty
            this.undo()['catch'](() => {});
        }

        if ((e.ctrlKey || e.metaKey) && e.keyCode === keyCodes.Y) {
            // There is no error message on shortcut when it's empty
            this.redo()['catch'](() => {});
        }

        if ((e.keyCode === keyCodes.BACKSPACE || e.keyCode === keyCodes.DEL) &&
            activeObject) {
            e.preventDefault();
            this.removeObject(activeObjectId);
        }
    }
    /* eslint-enable complexity */

    /**
     * mouse down event handler
     * @param {Event} event mouse down event
     * @param {Object} originPointer origin pointer
     *  @param {Number} originPointer.x x position
     *  @param {Number} originPointer.y y position
     * @private
     */
    _onMouseDown(event, originPointer) {
        /**
         * The mouse down event with position x, y on canvas
         * @event ImageEditor#mousedown
         * @param {Object} event - browser mouse event object
         * @param {Object} originPointer origin pointer
         *  @param {Number} originPointer.x x position
         *  @param {Number} originPointer.y y position
         * @example
         * imageEditor.on('mousedown', function(event, originPointer) {
         *     console.log(event);
         *     console.log(originPointer);
         *     if (imageEditor.hasFilter('colorFilter')) {
         *         imageEditor.applyFilter('colorFilter', {
         *             x: parseInt(originPointer.x, 10),
         *             y: parseInt(originPointer.y, 10)
         *         });
         *     }
         * });
         */
        this.fire(events.MOUSE_DOWN, event, originPointer);
    }

    /**
     * Add a 'addObject' command
     * @param {Object} obj - Fabric object
     * @private
     */
    _pushAddObjectCommand(obj) {
        const command = commandFactory.create(commands.ADD_OBJECT, this._graphics, obj);
        this._invoker.pushUndoStack(command);
    }

    /**
     * 'objectActivated' event handler
     * @param {ObjectProps} props - object properties
     * @private
     */
    _onObjectActivated(props) {
        /**
         * The event when object is selected(aka activated).
         * @event ImageEditor#objectActivated
         * @param {ObjectProps} objectProps - object properties
         * @example
         * imageEditor.on('objectActivated', function(props) {
         *     console.log(props);
         *     console.log(props.type);
         *     console.log(props.id);
         * });
         */
        this.fire(events.OBJECT_ACTIVATED, props);
    }

    /**
     * 'objectMoved' event handler
     * @param {ObjectProps} props - object properties
     * @private
     */
    _onObjectMoved(props) {
        /**
         * The event when object is moved
         * @event ImageEditor#objectMoved
         * @param {ObjectProps} props - object properties
         * @example
         * imageEditor.on('objectMoved', function(props) {
         *     console.log(props);
         *     console.log(props.type);
         * });
         */
        this.fire(events.OBJECT_MOVED, props);
    }

    /**
     * 'objectScaled' event handler
     * @param {ObjectProps} props - object properties
     * @private
     */
    _onObjectScaled(props) {
        /**
         * The event when scale factor is changed
         * @event ImageEditor#objectScaled
         * @param {ObjectProps} props - object properties
         * @example
         * imageEditor.on('objectScaled', function(props) {
         *     console.log(props);
         *     console.log(props.type);
         * });
         */
        this.fire(events.OBJECT_SCALED, props);
    }

    /**
     * Get current drawing mode
     * @returns {string}
     * @example
     * // Image editor drawing mode
     * //
     * //    NORMAL: 'NORMAL'
     * //    CROPPER: 'CROPPER'
     * //    FREE_DRAWING: 'FREE_DRAWING'
     * //    LINE_DRAWING: 'LINE_DRAWING'
     * //    TEXT: 'TEXT'
     * //
     * if (imageEditor.getDrawingMode() === 'FREE_DRAWING') {
     *     imageEditor.stopDrawingMode();
     * }
     */
    getDrawingMode() {
        return this._graphics.getDrawingMode();
    }

    /**
     * Clear all objects
     * @returns {Promise}
     * @example
     * imageEditor.clearObjects();
     */
    clearObjects() {
        return this.execute(commands.CLEAR_OBJECTS);
    }

    /**
     * Deactivate all objects
     * @example
     * imageEditor.deactivateAll();
     */
    deactivateAll() {
        this._graphics.deactivateAll();
        this._graphics.renderAll();
    }

    /**
     * Invoke command
     * @param {String} commandName - Command name
     * @param {...*} args - Arguments for creating command
     * @returns {Promise}
     * @private
     */
    execute(commandName, ...args) {
        // Inject an Graphics instance as first parameter
        const theArgs = [this._graphics].concat(args);

        return this._invoker.execute(commandName, ...theArgs);
    }

    /**
     * Undo
     * @returns {Promise}
     * @example
     * imageEditor.undo();
     */
    undo() {
        return this._invoker.undo();
    }

    /**
     * Redo
     * @returns {Promise}
     * @example
     * imageEditor.redo();
     */
    redo() {
        return this._invoker.redo();
    }

    /**
     * Load image from file
     * @param {File} imgFile - Image file
     * @param {string} [imageName] - imageName
     * @returns {Promise<SizeChange, ErrorMsg>}
     * @example
     * imageEditor.loadImageFromFile(file).then(result => {
     *      console.log('old : ' + result.oldWidth + ', ' + result.oldHeight);
     *      console.log('new : ' + result.newWidth + ', ' + result.newHeight);
     * });
     */
    loadImageFromFile(imgFile, imageName) {
        if (!imgFile) {
            return Promise.reject(rejectMessages.invalidParameters);
        }

        const imgUrl = URL.createObjectURL(imgFile);
        imageName = imageName || imgFile.name;

        return this.loadImageFromURL(imgUrl, imageName).then(value => {
            URL.revokeObjectURL(imgFile);

            return value;
        });
    }

    /**
     * Load image from url
     * @param {string} url - File url
     * @param {string} imageName - imageName
     * @returns {Promise<SizeChange, ErrorMsg>}
     * @example
     * imageEditor.loadImageFromURL('http:https://url/testImage.png', 'lena').then(result => {
     *      console.log('old : ' + result.oldWidth + ', ' + result.oldHeight);
     *      console.log('new : ' + result.newWidth + ', ' + result.newHeight);
     * });
     */
    loadImageFromURL(url, imageName) {
        if (!imageName || !url) {
            return Promise.reject(rejectMessages.invalidParameters);
        }

        return this.execute(commands.LOAD_IMAGE, imageName, url);
    }

    /**
     * Add image object on canvas
     * @param {string} imgUrl - Image url to make object
     * @returns {Promise<ObjectProps, ErrorMsg>}
     * @example
     * imageEditor.addImageObject('path/fileName.jpg').then(objectProps => {
     *     console.log(ojectProps.id);
     * });
     */
    addImageObject(imgUrl) {
        if (!imgUrl) {
            return Promise.reject(rejectMessages.invalidParameters);
        }

        return this.execute(commands.ADD_IMAGE_OBJECT, imgUrl);
    }

    /**
     * Start a drawing mode. If the current mode is not 'NORMAL', 'stopDrawingMode()' will be called first.
     * @param {String} mode Can be one of <I>'CROPPER', 'FREE_DRAWING', 'LINE_DRAWING', 'TEXT', 'SHAPE'</I>
     * @param {Object} [option] parameters of drawing mode, it's available with 'FREE_DRAWING', 'LINE_DRAWING'
     *  @param {Number} [option.width] brush width
     *  @param {String} [option.color] brush color
     * @returns {boolean} true if success or false
     * @example
     * imageEditor.startDrawingMode('FREE_DRAWING', {
     *      width: 10,
     *      color: 'rgba(255,0,0,0.5)'
     * });
     */
    startDrawingMode(mode, option) {
        return this._graphics.startDrawingMode(mode, option);
    }

    /**
     * Stop the current drawing mode and back to the 'NORMAL' mode
     * @example
     * imageEditor.stopDrawingMode();
     */
    stopDrawingMode() {
        this._graphics.stopDrawingMode();
    }

    /**
     * Crop this image with rect
     * @param {Object} rect crop rect
     *  @param {Number} rect.left left position
     *  @param {Number} rect.top top position
     *  @param {Number} rect.width width
     *  @param {Number} rect.height height
     * @returns {Promise}
     * @example
     * imageEditor.crop(imageEditor.getCropzoneRect());
     */
    crop(rect) {
        const data = this._graphics.getCroppedImageData(rect);
        if (!data) {
            return Promise.reject(rejectMessages.invalidParameters);
        }

        return this.loadImageFromURL(data.url, data.imageName);
    }

    /**
     * Get the cropping rect
     * @returns {Object}  {{left: number, top: number, width: number, height: number}} rect
     */
    getCropzoneRect() {
        return this._graphics.getCropzoneRect();
    }

    /**
     * Flip
     * @returns {Promise}
     * @param {string} type - 'flipX' or 'flipY' or 'reset'
     * @returns {Promise<FlipStatus, ErrorMsg>}
     * @private
     */
    _flip(type) {
        return this.execute(commands.FLIP_IMAGE, type);
    }

    /**
     * Flip x
     * @returns {Promise<FlipStatus, ErrorMsg>}
     * @example
     * imageEditor.flipX().then((status => {
     *     console.log('flipX: ', status.flipX);
     *     console.log('flipY: ', status.flipY);
     *     console.log('angle: ', status.angle);
     * }).catch(message => {
     *     console.log('error: ', message);
     * });
     */
    flipX() {
        return this._flip('flipX');
    }

    /**
     * Flip y
     * @returns {Promise<FlipStatus, ErrorMsg>}
     * @example
     * imageEditor.flipY().then(status => {
     *     console.log('flipX: ', status.flipX);
     *     console.log('flipY: ', status.flipY);
     *     console.log('angle: ', status.angle);
     * }).catch(message => {
     *     console.log('error: ', message);
     * });
     */
    flipY() {
        return this._flip('flipY');
    }

    /**
     * Reset flip
     * @returns {Promise<FlipStatus, ErrorMsg>}
     * @example
     * imageEditor.resetFlip().then(status => {
     *     console.log('flipX: ', status.flipX);
     *     console.log('flipY: ', status.flipY);
     *     console.log('angle: ', status.angle);
     * }).catch(message => {
     *     console.log('error: ', message);
     * });;
     */
    resetFlip() {
        return this._flip('reset');
    }

    /**
     * @param {string} type - 'rotate' or 'setAngle'
     * @param {number} angle - angle value (degree)
     * @returns {Promise<RotateStatus, ErrorMsg>}
     * @private
     */
    _rotate(type, angle) {
        return this.execute(commands.ROTATE_IMAGE, type, angle);
    }

    /**
     * Rotate image
     * @returns {Promise}
     * @param {number} angle - Additional angle to rotate image
     * @returns {Promise<RotateStatus, ErrorMsg>}
     * @example
     * imageEditor.setAngle(10); // angle = 10
     * imageEditor.rotate(10); // angle = 20
     * imageEidtor.setAngle(5); // angle = 5
     * imageEidtor.rotate(-95); // angle = -90
     * imageEditor.rotate(10).then(status => {
     *     console.log('angle: ', status.angle);
     * })).catch(message => {
     *     console.log('error: ', message);
     * });
     */
    rotate(angle) {
        return this._rotate('rotate', angle);
    }

    /**
     * Set angle
     * @param {number} angle - Angle of image
     * @returns {Promise<RotateStatus, ErrorMsg>}
     * @example
     * imageEditor.setAngle(10); // angle = 10
     * imageEditor.rotate(10); // angle = 20
     * imageEidtor.setAngle(5); // angle = 5
     * imageEidtor.rotate(50); // angle = 55
     * imageEidtor.setAngle(-40); // angle = -40
     * imageEditor.setAngle(10).then(status => {
     *     console.log('angle: ', status.angle);
     * })).catch(message => {
     *     console.log('error: ', message);
     * });
     */
    setAngle(angle) {
        return this._rotate('setAngle', angle);
    }

    /**
     * Set drawing brush
     * @param {Object} option brush option
     *  @param {Number} option.width width
     *  @param {String} option.color color like 'FFFFFF', 'rgba(0, 0, 0, 0.5)'
     * @example
     * imageEditor.startDrawingMode('FREE_DRAWING');
     * imageEditor.setBrush({
     *     width: 12,
     *     color: 'rgba(0, 0, 0, 0.5)'
     * });
     * imageEditor.setBrush({
     *     width: 8,
     *     color: 'FFFFFF'
     * });
     */
    setBrush(option) {
        this._graphics.setBrush(option);
    }

    /**
     * Set states of current drawing shape
     * @param {string} type - Shape type (ex: 'rect', 'circle', 'triangle')
     * @param {Object} [options] - Shape options
     *      @param {string} [options.fill] - Shape foreground color (ex: '#fff', 'transparent')
     *      @param {string} [options.stoke] - Shape outline color
     *      @param {number} [options.strokeWidth] - Shape outline width
     *      @param {number} [options.width] - Width value (When type option is 'rect', this options can use)
     *      @param {number} [options.height] - Height value (When type option is 'rect', this options can use)
     *      @param {number} [options.rx] - Radius x value (When type option is 'circle', this options can use)
     *      @param {number} [options.ry] - Radius y value (When type option is 'circle', this options can use)
     *      @param {number} [options.isRegular] - Whether resizing shape has 1:1 ratio or not
     * @example
     * imageEditor.setDrawingShape('rect', {
     *     fill: 'red',
     *     width: 100,
     *     height: 200
     * });
     * @example
     * imageEditor.setDrawingShape('circle', {
     *     fill: 'transparent',
     *     stroke: 'blue',
     *     strokeWidth: 3,
     *     rx: 10,
     *     ry: 100
     * });
     * @example
     * imageEditor.setDrawingShape('triangle', { // When resizing, the shape keep the 1:1 ratio
     *     width: 1,
     *     height: 1,
     *     isRegular: true
     * });
     * @example
     * imageEditor.setDrawingShape('circle', { // When resizing, the shape keep the 1:1 ratio
     *     rx: 10,
     *     ry: 10,
     *     isRegular: true
     * });
     */
    setDrawingShape(type, options) {
        this._graphics.setDrawingShape(type, options);
    }

    /**
     * Add shape
     * @param {string} type - Shape type (ex: 'rect', 'circle', 'triangle')
     * @param {Object} options - Shape options
     *      @param {string} [options.fill] - Shape foreground color (ex: '#fff', 'transparent')
     *      @param {string} [options.stroke] - Shape outline color
     *      @param {number} [options.strokeWidth] - Shape outline width
     *      @param {number} [options.width] - Width value (When type option is 'rect', this options can use)
     *      @param {number} [options.height] - Height value (When type option is 'rect', this options can use)
     *      @param {number} [options.rx] - Radius x value (When type option is 'circle', this options can use)
     *      @param {number} [options.ry] - Radius y value (When type option is 'circle', this options can use)
     *      @param {number} [options.left] - Shape x position
     *      @param {number} [options.top] - Shape y position
     *      @param {number} [options.isRegular] - Whether resizing shape has 1:1 ratio or not
     * @returns {Promise<ObjectProps, ErrorMsg>}
     * @example
     * imageEditor.addShape('rect', {
     *     fill: 'red',
     *     stroke: 'blue',
     *     strokeWidth: 3,
     *     width: 100,
     *     height: 200,
     *     left: 10,
     *     top: 10,
     *     isRegular: true
     * });
     * @example
     * imageEditor.addShape('circle', {
     *     fill: 'red',
     *     stroke: 'blue',
     *     strokeWidth: 3,
     *     rx: 10,
     *     ry: 100,
     *     isRegular: false
     * }).then(objectProps => {
     *     console.log(objectProps.id);
     * });
     */
    addShape(type, options) {
        options = options || {};

        this._setPositions(options);

        return this.execute(commands.ADD_SHAPE, type, options);
    }

    /**
     * Change shape
     * @param {number} id - object id
     * @param {Object} options - Shape options
     *      @param {string} [options.fill] - Shape foreground color (ex: '#fff', 'transparent')
     *      @param {string} [options.stroke] - Shape outline color
     *      @param {number} [options.strokeWidth] - Shape outline width
     *      @param {number} [options.width] - Width value (When type option is 'rect', this options can use)
     *      @param {number} [options.height] - Height value (When type option is 'rect', this options can use)
     *      @param {number} [options.rx] - Radius x value (When type option is 'circle', this options can use)
     *      @param {number} [options.ry] - Radius y value (When type option is 'circle', this options can use)
     *      @param {number} [options.isRegular] - Whether resizing shape has 1:1 ratio or not
     * @returns {Promise}
     * @example
     * // call after selecting shape object on canvas
     * imageEditor.changeShape(id, { // change rectagle or triangle
     *     fill: 'red',
     *     stroke: 'blue',
     *     strokeWidth: 3,
     *     width: 100,
     *     height: 200
     * });
     * @example
     * // call after selecting shape object on canvas
     * imageEditor.changeShape(id, { // change circle
     *     fill: 'red',
     *     stroke: 'blue',
     *     strokeWidth: 3,
     *     rx: 10,
     *     ry: 100
     * });
     */
    changeShape(id, options) {
        return this.execute(commands.CHANGE_SHAPE, id, options);
    }

    /**
     * Add text on image
     * @param {string} text - Initial input text
     * @param {Object} [options] Options for generating text
     *     @param {Object} [options.styles] Initial styles
     *         @param {string} [options.styles.fill] Color
     *         @param {string} [options.styles.fontFamily] Font type for text
     *         @param {number} [options.styles.fontSize] Size
     *         @param {string} [options.styles.fontStyle] Type of inclination (normal / italic)
     *         @param {string} [options.styles.fontWeight] Type of thicker or thinner looking (normal / bold)
     *         @param {string} [options.styles.textAlign] Type of text align (left / center / right)
     *         @param {string} [options.styles.textDecoraiton] Type of line (underline / line-throgh / overline)
     *     @param {{x: number, y: number}} [options.position] - Initial position
     * @returns {Promise}
     * @example
     * imageEditor.addText('init text');
     * @example
     * imageEditor.addText('init text', {
     *     styles: {
     *         fill: '#000',
     *         fontSize: '20',
     *         fontWeight: 'bold'
     *     },
     *     position: {
     *         x: 10,
     *         y: 10
     *     }
     * }).then(objectProps => {
     *     console.log(objectProps.id);
     * });
     */
    addText(text, options) {
        text = text || '';
        options = options || {};

        return this.execute(commands.ADD_TEXT, text, options);
    }

    /**
     * Change contents of selected text object on image
     * @param {number} id - object id
     * @param {string} text - Changing text
     * @returns {Promise<ObjectProps, ErrorMsg>}
     * @example
     * imageEditor.changeText(id, 'change text');
     */
    changeText(id, text) {
        text = text || '';

        return this.execute(commands.CHANGE_TEXT, id, text);
    }

    /**
     * Set style
     * @param {number} id - object id
     * @param {Object} styleObj - text styles
     *     @param {string} [styleObj.fill] Color
     *     @param {string} [styleObj.fontFamily] Font type for text
     *     @param {number} [styleObj.fontSize] Size
     *     @param {string} [styleObj.fontStyle] Type of inclination (normal / italic)
     *     @param {string} [styleObj.fontWeight] Type of thicker or thinner looking (normal / bold)
     *     @param {string} [styleObj.textAlign] Type of text align (left / center / right)
     *     @param {string} [styleObj.textDecoraiton] Type of line (underline / line-throgh / overline)
     * @returns {Promise}
     * @example
     * imageEditor.changeTextStyle(id, {
     *     fontStyle: 'italic'
     * });
     */
    changeTextStyle(id, styleObj) {
        return this.execute(commands.CHANGE_TEXT_STYLE, id, styleObj);
    }

    _changeActivateMode(type) {
        if (type === 'ICON') {
            this.stopDrawingMode();
        } else if (this.getDrawingMode() !== type) {
            this.stopDrawingMode();
            this.startDrawingMode(type);
        }
    }

    /**
     * 'textChanged' event handler
     * @param {Object} objectProps changed object properties
     * @private
     */
    _onTextChanged(objectProps) {
        this.changeText(objectProps.id, objectProps.text);
    }

    /**
     * 'textEditing' event handler
     * @private
     */
    _onTextEditing() {
        /**
         * The event which starts to edit text object
         * @event ImageEditor#textEditing
         * @example
         * imageEditor.on('textEditing', function() {
         *     console.log('text editing');
         * });
         */
        this.fire(events.TEXT_EDITING);
    }

    /**
     * Mousedown event handler in case of 'TEXT' drawing mode
     * @param {fabric.Event} event - Current mousedown event object
     * @private
     */
    _onAddText(event) {
        /**
         * The event when 'TEXT' drawing mode is enabled and click non-object area.
         * @event ImageEditor#addText
         * @param {Object} pos
         *  @param {Object} pos.originPosition - Current position on origin canvas
         *      @param {Number} pos.originPosition.x - x
         *      @param {Number} pos.originPosition.y - y
         *  @param {Object} pos.clientPosition - Current position on client area
         *      @param {Number} pos.clientPosition.x - x
         *      @param {Number} pos.clientPosition.y - y
         * @example
         * imageEditor.on('addText', function(pos) {
         *     imageEditor.addText('Double Click', {
         *         position: pos.originPosition
         *     });
         *     console.log('text position on canvas: ' + pos.originPosition);
         *     console.log('text position on brwoser: ' + pos.clientPosition);
         * });
         */
        this.fire(events.ADD_TEXT, {
            originPosition: event.originPosition,
            clientPosition: event.clientPosition
        });
    }

    /**
     * 'addObject' event handler
     * @param {Object} objectProps added object properties
     * @private
     */
    _onAddObject(objectProps) {
        const obj = this._graphics.getObject(objectProps.id);
        this._pushAddObjectCommand(obj);
    }

    /**
     * Register custom icons
     * @param {{iconType: string, pathValue: string}} infos - Infos to register icons
     * @example
     * imageEditor.registerIcons({
     *     customIcon: 'M 0 0 L 20 20 L 10 10 Z',
     *     customArrow: 'M 60 0 L 120 60 H 90 L 75 45 V 180 H 45 V 45 L 30 60 H 0 Z'
     * });
     */
    registerIcons(infos) {
        this._graphics.registerPaths(infos);
    }

    /**
     * Add icon on canvas
     * @param {string} type - Icon type ('arrow', 'cancel', custom icon name)
     * @param {Object} options - Icon options
     *      @param {string} [options.fill] - Icon foreground color
     *      @param {string} [options.left] - Icon x position
     *      @param {string} [options.top] - Icon y position
     * @returns {Promise<ObjectProps, ErrorMsg>}
     * @example
     * imageEditor.addIcon('arrow'); // The position is center on canvas
     * @example
     * imageEditor.addIcon('arrow', {
     *     left: 100,
     *     top: 100
     * }).then(objectProps => {
     *     console.log(objectProps.id);
     * });
     */
    addIcon(type, options) {
        options = options || {};

        this._setPositions(options);

        return this.execute(commands.ADD_ICON, type, options);
    }

    /**
     * Change icon color
     * @param {number} id - object id
     * @param {string} color - Color for icon
     * @returns {Promise}
     * @example
     * imageEditor.changeIconColor(id, '#000000');
     */
    changeIconColor(id, color) {
        return this.execute(commands.CHANGE_ICON_COLOR, id, color);
    }

    /**
     * Remove an object or group by id
     * @param {number} id - object id
     * @returns {Promise}
     * @example
     * imageEditor.removeObject(id);
     */
    removeObject(id) {
        return this.execute(commands.REMOVE_OBJECT, id);
    }

    /**
     * Whether it has the filter or not
     * @param {string} type - Filter type
     * @returns {boolean} true if it has the filter
     */
    hasFilter(type) {
        return this._graphics.hasFilter(type);
    }

    /**
     * Remove filter on canvas image
     * @param {string} type - Filter type
     * @returns {Promise<FilterResult, ErrorMsg>}
     * @example
     * imageEditor.removeFilter('Grayscale').then(obj => {
     *     console.log('filterType: ', obj.type);
     *     console.log('actType: ', obj.action);
     * }).catch(message => {
     *     console.log('error: ', message);
     * });
     */
    removeFilter(type) {
        return this.execute(commands.REMOVE_FILTER, type);
    }

    /**
     * Apply filter on canvas image
     * @param {string} type - Filter type
     * @param {Object} options - Options to apply filter
     *  @param {number} options.maskObjId - masking image object id
     * @returns {Promise<FilterResult, ErrorMsg>}
     * @example
     * imageEditor.applyFilter('Grayscale');
     * @example
     * imageEditor.applyFilter('mask', {maskObjId: id}).then(obj => {
     *     console.log('filterType: ', obj.type);
     *     console.log('actType: ', obj.action);
     * }).catch(message => {
     *     console.log('error: ', message);
     * });;
     */
    applyFilter(type, options) {
        return this.execute(commands.APPLY_FILTER, type, options);
    }

    /**
     * Get data url
     * @param {string} type - A DOMString indicating the image format. The default type is image/png.
     * @returns {string} A DOMString containing the requested data URI
     * @example
     * imgEl.src = imageEditor.toDataURL();
     *
     * imageEditor.loadImageFromURL(imageEditor.toDataURL(), 'FilterImage').then(() => {
     *      imageEditor.addImageObject(imgUrl);
     * });
     */
    toDataURL(type) {
        return this._graphics.toDataURL(type);
    }

    /**
     * Get image name
     * @returns {string} image name
     * @example
     * console.log(imageEditor.getImageName());
     */
    getImageName() {
        return this._graphics.getImageName();
    }

    /**
     * Clear undoStack
     * @example
     * imageEditor.clearUndoStack();
     */
    clearUndoStack() {
        this._invoker.clearUndoStack();
    }

    /**
     * Clear redoStack
     * @example
     * imageEditor.clearRedoStack();
     */
    clearRedoStack() {
        this._invoker.clearRedoStack();
    }

    /**
     * Whehter the undo stack is empty or not
     * @returns {boolean}
     * imageEditor.isEmptyUndoStack();
     */
    isEmptyUndoStack() {
        return this._invoker.isEmptyUndoStack();
    }

    /**
     * Whehter the redo stack is empty or not
     * @returns {boolean}
     * imageEditor.isEmptyRedoStack();
     */
    isEmptyRedoStack() {
        return this._invoker.isEmptyRedoStack();
    }

    /**
     * Resize canvas dimension
     * @param {{width: number, height: number}} dimension - Max width & height
     * @returns {Promise}
     */
    resizeCanvasDimension(dimension) {
        if (!dimension) {
            return Promise.reject(rejectMessages.invalidParameters);
        }

        return this.execute(commands.RESIZE_CANVAS_DIMENSION, dimension);
    }

    /**
     * Destroy
     */
    destroy() {
        this.stopDrawingMode();
        this._detachDomEvents();
        this._graphics.destroy();
        this._graphics = null;

        forEach(this, (value, key) => {
            this[key] = null;
        }, this);
    }

    /**
     * Set position
     * @param {Object} options - Position options (left or top)
     * @private
     */
    _setPositions(options) {
        const centerPosition = this._graphics.getCenter();

        if (isUndefined(options.left)) {
            options.left = centerPosition.left;
        }

        if (isUndefined(options.top)) {
            options.top = centerPosition.top;
        }
    }

    /**
     * Set properties of active object
     * @param {number} id - object id
     * @param {Object} keyValue - key & value
     * @returns {Promise}
     * @example
     * imageEditor.setObjectProperties(id, {
     *     left:100,
     *     top:100,
     *     width: 200,
     *     height: 200,
     *     opacity: 0.5
     * });
     */
    setObjectProperties(id, keyValue) {
        return this.execute(commands.SET_OBJECT_PROPERTIES, id, keyValue);
    }

    /**
     * Get properties of active object corresponding key
     * @param {number} id - object id
     * @param {Array<string>|ObjectProps|string} keys - property's key
     * @returns {ObjectProps} properties if id is valid or null
     * @example
     * var props = imageEditor.getObjectProperties(id, 'left');
     * console.log(props);
     * @example
     * var props = imageEditor.getObjectProperties(id, ['left', 'top', 'width', 'height']);
     * console.log(props);
     * @example
     * var props = imageEditor.getObjectProperties(id, {
     *     left: null,
     *     top: null,
     *     width: null,
     *     height: null,
     *     opacity: null
     * });
     * console.log(props);
     */
    getObjectProperties(id, keys) {
        const object = this._graphics.getObject(id);
        if (!object) {
            return null;
        }

        return this._graphics.getObjectProperties(id, keys);
    }

    /**
     * Get the canvas size
     * @returns {Object} {{width: number, height: number}} canvas size
     * @example
     * var canvasSize = imageEditor.getCanvasSize();
     * console.log(canvasSize.width);
     * console.height(canvasSize.height);
     */
    getCanvasSize() {
        return this._graphics.getCanvasSize();
    }

    /**
     * Get object position by originX, originY
     * @param {number} id - object id
     * @param {string} originX - can be 'left', 'center', 'right'
     * @param {string} originY - can be 'top', 'center', 'bottom'
     * @returns {Object} {{x:number, y: number}} position by origin if id is valid, or null
     * @example
     * var position = imageEditor.getObjectPosition(id, 'left', 'top');
     * console.log(position);
     */
    getObjectPosition(id, originX, originY) {
        return this._graphics.getObjectPosition(id, originX, originY);
    }

    /**
     * Set object position  by originX, originY
     * @param {number} id - object id
     * @param {Object} posInfo - position object
     *  @param {number} posInfo.x - x position
     *  @param {number} posInfo.y - y position
     *  @param {string} posInfo.originX - can be 'left', 'center', 'right'
     *  @param {string} posInfo.originY - can be 'top', 'center', 'bottom'
     * @returns {Promise}
     * @example
     * // align the object to 'left', 'top'
     * imageEditor.setObjectPosition(id, {
     *     x: 0,
     *     y: 0,
     *     originX: 'left',
     *     originY: 'top'
     * });
     * @example
     * // align the object to 'right', 'top'
     * var canvasSize = imageEditor.getCanvasSize();
     * imageEditor.setObjectPosition(id, {
     *     x: canvasSize.width,
     *     y: 0,
     *     originX: 'right',
     *     originY: 'top'
     * });
     * @example
     * // align the object to 'left', 'bottom'
     * var canvasSize = imageEditor.getCanvasSize();
     * imageEditor.setObjectPosition(id, {
     *     x: 0,
     *     y: canvasSize.height,
     *     originX: 'left',
     *     originY: 'bottom'
     * });
     * @example
     * // align the object to 'right', 'bottom'
     * var canvasSize = imageEditor.getCanvasSize();
     * imageEditor.setObjectPosition(id, {
     *     x: canvasSize.width,
     *     y: canvasSize.height,
     *     originX: 'right',
     *     originY: 'bottom'
     * });
     */
    setObjectPosition(id, posInfo) {
        return this.execute(commands.SET_OBJECT_POSITION, id, posInfo);
    }
}

action.mixin(ImageEditor);
CustomEvents.mixin(ImageEditor);

module.exports = ImageEditor;