path.js

define(["./_base", "dojo/_base/lang","dojo/_base/declare", "./matrix", "./shape"],
	function(g, lang, declare, matrix, shapeLib){

	// module:
	//		dojox/gfx/path

	var Path = declare("dojox.gfx.path.Path", shapeLib.Shape, {
		// summary:
		//		a generalized path shape

		constructor: function(rawNode){
			// summary:
			//		a path constructor
			// rawNode: Node
			//		a DOM node to be used by this path object
			this.shape = lang.clone(g.defaultPath);
			this.segments = [];
			this.tbbox = null;
			this.absolute = true;
			this.last = {};
			this.rawNode = rawNode;
			this.segmented = false;
		},

		// mode manipulations
		setAbsoluteMode: function(mode){
			// summary:
			//		sets an absolute or relative mode for path points
			// mode: Boolean
			//		true/false or "absolute"/"relative" to specify the mode
			this._confirmSegmented();
			this.absolute = typeof mode == "string" ? (mode == "absolute") : mode;
			return this; // self
		},
		getAbsoluteMode: function(){
			// summary:
			//		returns a current value of the absolute mode
			this._confirmSegmented();
			return this.absolute; // Boolean
		},

		getBoundingBox: function(){
			// summary:
			//		returns the bounding box {x, y, width, height} or null
			this._confirmSegmented();
			return (this.bbox && ("l" in this.bbox)) ? {x: this.bbox.l, y: this.bbox.t, width: this.bbox.r - this.bbox.l, height: this.bbox.b - this.bbox.t} : null; // dojox/gfx.Rectangle
		},

		_getRealBBox: function(){
			// summary:
			//		returns an array of four points or null
			//		four points represent four corners of the untransformed bounding box
			this._confirmSegmented();
			if(this.tbbox){
				return this.tbbox;	// Array
			}
			var bbox = this.bbox, matrix = this._getRealMatrix();
			this.bbox = null;
			for(var i = 0, len = this.segments.length; i < len; ++i){
				this._updateWithSegment(this.segments[i], matrix);
			}
			var t = this.bbox;
			this.bbox = bbox;
			this.tbbox = t ? [
				{x: t.l, y: t.t},
				{x: t.r, y: t.t},
				{x: t.r, y: t.b},
				{x: t.l, y: t.b}
			] : null;
			return this.tbbox;	// Array
		},

		getLastPosition: function(){
			// summary:
			//		returns the last point in the path, or null
			this._confirmSegmented();
			return "x" in this.last ? this.last : null; // Object
		},

		_applyTransform: function(){
			this.tbbox = null;
			return this.inherited(arguments);
		},

		// segment interpretation
		_updateBBox: function(x, y, m){
			// summary:
			//		updates the bounding box of path with new point
			// x: Number
			//		an x coordinate
			// y: Number
			//		a y coordinate

			if(m){
				var t = matrix.multiplyPoint(m, x, y);
				x = t.x;
				y = t.y;
			}

			// we use {l, b, r, t} representation of a bbox
			if(this.bbox && ("l" in this.bbox)){
				if(this.bbox.l > x) this.bbox.l = x;
				if(this.bbox.r < x) this.bbox.r = x;
				if(this.bbox.t > y) this.bbox.t = y;
				if(this.bbox.b < y) this.bbox.b = y;
			}else{
				this.bbox = {l: x, b: y, r: x, t: y};
			}
		},
		_updateWithSegment: function(segment, matrix){
			// summary:
			//		updates the bounding box of path with new segment
			// segment: Object
			//		a segment
			var n = segment.args, l = n.length, i;
			// update internal variables: bbox, absolute, last
			switch(segment.action){
				case "M":
				case "L":
				case "C":
				case "S":
				case "Q":
				case "T":
					for(i = 0; i < l; i += 2){
						this._updateBBox(n[i], n[i + 1], matrix);
					}
					this.last.x = n[l - 2];
					this.last.y = n[l - 1];
					this.absolute = true;
					break;
				case "H":
					for(i = 0; i < l; ++i){
						this._updateBBox(n[i], this.last.y, matrix);
					}
					this.last.x = n[l - 1];
					this.absolute = true;
					break;
				case "V":
					for(i = 0; i < l; ++i){
						this._updateBBox(this.last.x, n[i], matrix);
					}
					this.last.y = n[l - 1];
					this.absolute = true;
					break;
				case "m":
					var start = 0;
					if(!("x" in this.last)){
						this._updateBBox(this.last.x = n[0], this.last.y = n[1], matrix);
						start = 2;
					}
					for(i = start; i < l; i += 2){
						this._updateBBox(this.last.x += n[i], this.last.y += n[i + 1], matrix);
					}
					this.absolute = false;
					break;
				case "l":
				case "t":
					for(i = 0; i < l; i += 2){
						this._updateBBox(this.last.x += n[i], this.last.y += n[i + 1], matrix);
					}
					this.absolute = false;
					break;
				case "h":
					for(i = 0; i < l; ++i){
						this._updateBBox(this.last.x += n[i], this.last.y, matrix);
					}
					this.absolute = false;
					break;
				case "v":
					for(i = 0; i < l; ++i){
						this._updateBBox(this.last.x, this.last.y += n[i], matrix);
					}
					this.absolute = false;
					break;
				case "c":
					for(i = 0; i < l; i += 6){
						this._updateBBox(this.last.x + n[i], this.last.y + n[i + 1], matrix);
						this._updateBBox(this.last.x + n[i + 2], this.last.y + n[i + 3], matrix);
						this._updateBBox(this.last.x += n[i + 4], this.last.y += n[i + 5], matrix);
					}
					this.absolute = false;
					break;
				case "s":
				case "q":
					for(i = 0; i < l; i += 4){
						this._updateBBox(this.last.x + n[i], this.last.y + n[i + 1], matrix);
						this._updateBBox(this.last.x += n[i + 2], this.last.y += n[i + 3], matrix);
					}
					this.absolute = false;
					break;
				case "A":
					for(i = 0; i < l; i += 7){
						this._updateBBox(n[i + 5], n[i + 6], matrix);
					}
					this.last.x = n[l - 2];
					this.last.y = n[l - 1];
					this.absolute = true;
					break;
				case "a":
					for(i = 0; i < l; i += 7){
						this._updateBBox(this.last.x += n[i + 5], this.last.y += n[i + 6], matrix);
					}
					this.absolute = false;
					break;
			}
			// add an SVG path segment
			var path = [segment.action];
			for(i = 0; i < l; ++i){
				path.push(g.formatNumber(n[i], true));
			}
			if(typeof this.shape.path == "string"){
				this.shape.path += path.join("");
			}else{
				for(i = 0, l = path.length; i < l; ++i){
					this.shape.path.push(path[i]);
				}
			}
		},

		// a dictionary, which maps segment type codes to a number of their arguments
		_validSegments: {m: 2, l: 2, h: 1, v: 1, c: 6, s: 4, q: 4, t: 2, a: 7, z: 0},

		_pushSegment: function(action, args){
			// summary:
			//		adds a segment
			// action: String
			//		valid SVG code for a segment's type
			// args: Array
			//		a list of parameters for this segment
			this.tbbox = null;
			var group = this._validSegments[action.toLowerCase()], segment;
			if(typeof group == "number"){
				if(group){
					if(args.length >= group){
						segment = {action: action, args: args.slice(0, args.length - args.length % group)};
						this.segments.push(segment);
						this._updateWithSegment(segment);
					}
				}else{
					segment = {action: action, args: []};
					this.segments.push(segment);
					this._updateWithSegment(segment);
				}
			}
		},

		_collectArgs: function(array, args){
			// summary:
			//		converts an array of arguments to plain numeric values
			// array: Array
			//		an output argument (array of numbers)
			// args: Array
			//		an input argument (can be values of Boolean, Number, dojox/gfx.Point, or an embedded array of them)
			for(var i = 0; i < args.length; ++i){
				var t = args[i];
				if(typeof t == "boolean"){
					array.push(t ? 1 : 0);
				}else if(typeof t == "number"){
					array.push(t);
				}else if(t instanceof Array){
					this._collectArgs(array, t);
				}else if("x" in t && "y" in t){
					array.push(t.x, t.y);
				}
			}
		},

		// segments
		moveTo: function(){
			// summary:
			//		forms a move segment
			this._confirmSegmented();
			var args = [];
			this._collectArgs(args, arguments);
			this._pushSegment(this.absolute ? "M" : "m", args);
			return this; // self
		},
		lineTo: function(){
			// summary:
			//		forms a line segment
			this._confirmSegmented();
			var args = [];
			this._collectArgs(args, arguments);
			this._pushSegment(this.absolute ? "L" : "l", args);
			return this; // self
		},
		hLineTo: function(){
			// summary:
			//		forms a horizontal line segment
			this._confirmSegmented();
			var args = [];
			this._collectArgs(args, arguments);
			this._pushSegment(this.absolute ? "H" : "h", args);
			return this; // self
		},
		vLineTo: function(){
			// summary:
			//		forms a vertical line segment
			this._confirmSegmented();
			var args = [];
			this._collectArgs(args, arguments);
			this._pushSegment(this.absolute ? "V" : "v", args);
			return this; // self
		},
		curveTo: function(){
			// summary:
			//		forms a curve segment
			this._confirmSegmented();
			var args = [];
			this._collectArgs(args, arguments);
			this._pushSegment(this.absolute ? "C" : "c", args);
			return this; // self
		},
		smoothCurveTo: function(){
			// summary:
			//		forms a smooth curve segment
			this._confirmSegmented();
			var args = [];
			this._collectArgs(args, arguments);
			this._pushSegment(this.absolute ? "S" : "s", args);
			return this; // self
		},
		qCurveTo: function(){
			// summary:
			//		forms a quadratic curve segment
			this._confirmSegmented();
			var args = [];
			this._collectArgs(args, arguments);
			this._pushSegment(this.absolute ? "Q" : "q", args);
			return this; // self
		},
		qSmoothCurveTo: function(){
			// summary:
			//		forms a quadratic smooth curve segment
			this._confirmSegmented();
			var args = [];
			this._collectArgs(args, arguments);
			this._pushSegment(this.absolute ? "T" : "t", args);
			return this; // self
		},
		arcTo: function(){
			// summary:
			//		forms an elliptic arc segment
			this._confirmSegmented();
			var args = [];
			this._collectArgs(args, arguments);
			this._pushSegment(this.absolute ? "A" : "a", args);
			return this; // self
		},
		closePath: function(){
			// summary:
			//		closes a path
			this._confirmSegmented();
			this._pushSegment("Z", []);
			return this; // self
		},

		_confirmSegmented: function() {
			if (!this.segmented) {
				var path = this.shape.path;
				// switch to non-updating version of path building
				this.shape.path = [];
				this._setPath(path);
				// switch back to the string path
				this.shape.path = this.shape.path.join("");
				// become segmented
				this.segmented = true;
			}
		},

		// setShape
		_setPath: function(path){
			// summary:
			//		forms a path using an SVG path string
			// path: String
			//		an SVG path string
			var p = lang.isArray(path) ? path : path.match(g.pathSvgRegExp);
			this.segments = [];
			this.absolute = true;
			this.bbox = {};
			this.last = {};
			if(!p) return;
			// create segments
			var action = "",	// current action
				args = [],		// current arguments
				l = p.length;
			for(var i = 0; i < l; ++i){
				var t = p[i], x = parseFloat(t);
				if(isNaN(x)){
					if(action){
						this._pushSegment(action, args);
					}
					args = [];
					action = t;
				}else{
					args.push(x);
				}
			}
			this._pushSegment(action, args);
		},
		setShape: function(newShape){
			// summary:
			//		forms a path using a shape
			// newShape: Object
			//		an SVG path string or a path object (see dojox/gfx.defaultPath)
			this.inherited(arguments, [typeof newShape == "string" ? {path: newShape} : newShape]);

			this.segmented = false;
			this.segments = [];
			if(!g.lazyPathSegmentation){
				this._confirmSegmented();
			}
			return this; // self
		},

		// useful constant for descendants
		_2PI: Math.PI * 2
	});

	var TextPath = declare("dojox.gfx.path.TextPath", Path, {
		// summary:
		//		a generalized TextPath shape

		constructor: function(rawNode){
			// summary:
			//		a TextPath shape constructor
			// rawNode: Node
			//		a DOM node to be used by this TextPath object
			if(!("text" in this)){
				this.text = lang.clone(g.defaultTextPath);
			}
			if(!("fontStyle" in this)){
				this.fontStyle = lang.clone(g.defaultFont);
			}
		},
		getText: function(){
			// summary:
			//		returns the current text object or null
			return this.text;	// Object
		},
		setText: function(newText){
			// summary:
			//		sets a text to be drawn along the path
			this.text = g.makeParameters(this.text,
				typeof newText == "string" ? {text: newText} : newText);
			this._setText();
			return this;	// self
		},
		getFont: function(){
			// summary:
			//		returns the current font object or null
			return this.fontStyle;	// Object
		},
		setFont: function(newFont){
			// summary:
			//		sets a font for text
			this.fontStyle = typeof newFont == "string" ?
				g.splitFontString(newFont) :
				g.makeParameters(g.defaultFont, newFont);
			this._setFont();
			return this;	// self
		}
	});

	/*=====
	g.Path = Path;
	g.TextPath = TextPath;
	=====*/

	return g.path = {
		// summary:
		//		This module contains the core graphics Path API.
		//		Path command format follows the W3C SVG 1.0 Path api.

		Path: Path,
		TextPath: TextPath
	};
});