konva/src/util/Type.js

(function() {
    /*
     * utilities that handle data type detection, conversion, and manipulation
     */
    Kinetic.Type = {
        /*
         * cherry-picked utilities from underscore.js
         */
        _isElement: function(obj) {
            return !!(obj && obj.nodeType == 1);
        },
        _isFunction: function(obj) {
            return !!(obj && obj.constructor && obj.call && obj.apply);
        },
        _isObject: function(obj) {
            return (!!obj && obj.constructor == Object);
        },
        _isArray: function(obj) {
            return Object.prototype.toString.call(obj) == '[object Array]';
        },
        _isNumber: function(obj) {
            return Object.prototype.toString.call(obj) == '[object Number]';
        },
        _isString: function(obj) {
            return Object.prototype.toString.call(obj) == '[object String]';
        },
        /*
         * other utils
         */
        _hasMethods: function(obj) {
            var names = [];
            for(var key in obj) {
                if(this._isFunction(obj[key]))
                    names.push(key);
            }
            return names.length > 0;
        },
        _isInDocument: function(el) {
            while( el = el.parentNode) {
                if(el == document) {
                    return true;
                }
            }
            return false;
        },
        /*
         * The argument can be:
         * - an integer (will be applied to both x and y)
         * - an array of one integer (will be applied to both x and y)
         * - an array of two integers (contains x and y)
         * - an array of four integers (contains x, y, width, and height)
         * - an object with x and y properties
         * - an array of one element which is an array of integers
         * - an array of one element of an object
         */
        _getXY: function(arg) {
            if(this._isNumber(arg)) {
                return {
                    x: arg,
                    y: arg
                };
            }
            else if(this._isArray(arg)) {
                // if arg is an array of one element
                if(arg.length === 1) {
                    var val = arg[0];
                    // if arg is an array of one element which is a number
                    if(this._isNumber(val)) {
                        return {
                            x: val,
                            y: val
                        };
                    }
                    // if arg is an array of one element which is an array
                    else if(this._isArray(val)) {
                        return {
                            x: val[0],
                            y: val[1]
                        };
                    }
                    // if arg is an array of one element which is an object
                    else if(this._isObject(val)) {
                        return val;
                    }
                }
                // if arg is an array of two or more elements
                else if(arg.length >= 2) {
                    return {
                        x: arg[0],
                        y: arg[1]
                    };
                }
            }
            // if arg is an object return the object
            else if(this._isObject(arg)) {
                return arg;
            }

            // default
            return null;
        },
        /*
         * The argument can be:
         * - an integer (will be applied to both width and height)
         * - an array of one integer (will be applied to both width and height)
         * - an array of two integers (contains width and height)
         * - an array of four integers (contains x, y, width, and height)
         * - an object with width and height properties
         * - an array of one element which is an array of integers
         * - an array of one element of an object
         */
        _getSize: function(arg) {
            if(this._isNumber(arg)) {
                return {
                    width: arg,
                    height: arg
                };
            }
            else if(this._isArray(arg)) {
                // if arg is an array of one element
                if(arg.length === 1) {
                    var val = arg[0];
                    // if arg is an array of one element which is a number
                    if(this._isNumber(val)) {
                        return {
                            width: val,
                            height: val
                        };
                    }
                    // if arg is an array of one element which is an array
                    else if(this._isArray(val)) {
                        /*
                         * if arg is an array of one element which is an
                         * array of four elements
                         */
                        if(val.length >= 4) {
                            return {
                                width: val[2],
                                height: val[3]
                            };
                        }
                        /*
                         * if arg is an array of one element which is an
                         * array of two elements
                         */
                        else if(val.length >= 2) {
                            return {
                                width: val[0],
                                height: val[1]
                            };
                        }
                    }
                    // if arg is an array of one element which is an object
                    else if(this._isObject(val)) {
                        return val;
                    }
                }
                // if arg is an array of four elements
                else if(arg.length >= 4) {
                    return {
                        width: arg[2],
                        height: arg[3]
                    };
                }
                // if arg is an array of two elements
                else if(arg.length >= 2) {
                    return {
                        width: arg[0],
                        height: arg[1]
                    };
                }
            }
            // if arg is an object return the object
            else if(this._isObject(arg)) {
                return arg;
            }

            // default
            return null;
        },
        /*
         * arg will be an array of numbers or
         *  an array of point arrays or
         *  an array of point objects
         */
        _getPoints: function(arg) {
            if(arg === undefined) {
                return [];
            }

            // an array of arrays
            if(this._isArray(arg[0])) {
                /*
                 * convert array of arrays into an array
                 * of objects containing x, y
                 */
                var arr = [];
                for(var n = 0; n < arg.length; n++) {
                    arr.push({
                        x: arg[n][0],
                        y: arg[n][1]
                    });
                }

                return arr;
            }
            // an array of objects
            if(this._isObject(arg[0])) {
                return arg;
            }
            // an array of integers
            else {
                /*
                 * convert array of numbers into an array
                 * of objects containing x, y
                 */
                var arr = [];
                for(var n = 0; n < arg.length; n += 2) {
                    arr.push({
                        x: arg[n],
                        y: arg[n + 1]
                    });
                }

                return arr;
            }
        },
        /*
         * arg can be an image object or image data
         */
        _getImage: function(arg, callback) {
            // if arg is null or undefined
            if(!arg) {
                callback(null);
            }

            // if arg is already an image object
            else if(this._isElement(arg)) {
                callback(arg);
            }

            // if arg is a string, then it's a data url
            else if(this._isString(arg)) {
                var imageObj = new Image();
                /** @ignore */
                imageObj.onload = function() {
                    callback(imageObj);
                }
                imageObj.src = arg;
            }

            //if arg is an object that contains the data property, it's an image object
            else if(arg.data) {
                var canvas = document.createElement('canvas');
                canvas.width = arg.width;
                canvas.height = arg.height;
                var context = canvas.getContext('2d');
                context.putImageData(arg, 0, 0);
                var dataUrl = canvas.toDataURL();
                var imageObj = new Image();
                /** @ignore */
                imageObj.onload = function() {
                    callback(imageObj);
                }
                imageObj.src = dataUrl;
            }
            else {
                callback(null);
            }
        },
        _rgbToHex: function(r, g, b) {
            return ((1 << 24) + (r << 16) + (g << 8) + b).toString(16).slice(1);
        },
        _hexToRgb: function(hex) {
            var bigint = parseInt(hex, 16);
            return {
                r: (bigint >> 16) & 255,
                g: (bigint >> 8) & 255,
                b: bigint & 255
            };
        },
        _getRandomColorKey: function() {
            var r = (Math.random() * 255) | 0;
            var g = (Math.random() * 255) | 0;
            var b = (Math.random() * 255) | 0;
            return this._rgbToHex(r, g, b);
        },
        // o1 takes precedence over o2
        _merge: function(o1, o2) {
            var retObj = this._clone(o2);
            for(var key in o1) {
                if(this._isObject(o1[key])) {
                    retObj[key] = this._merge(o1[key], retObj[key]);
                }
                else {
                    retObj[key] = o1[key];
                }
            }
            return retObj;
        },
        // deep clone
        _clone: function(obj) {
            var retObj = {};
            for(var key in obj) {
                if(this._isObject(obj[key])) {
                    retObj[key] = this._clone(obj[key]);
                }
                else {
                    retObj[key] = obj[key];
                }
            }
            return retObj;
        },
        _degToRad: function(deg) {
            return deg * Math.PI / 180;
        },
        _radToDeg: function(rad) {
            return rad * 180 / Math.PI;
        }
    };
})();