dojo.provide("dojo.gfx.path");
dojo.require("dojo.math");
dojo.require("dojo.gfx.shape");
dojo.declare("dojo.gfx.path.Path", dojo.gfx.Shape, {
// summary: a generalized path shape
initializer: function(rawNode){
// summary: a constructor of a path shape object
// rawNode: Node: a DOM node to be used by this path object
this.shape = dojo.lang.shallowCopy(dojo.gfx.defaultPath, true);
this.segments = [];
this.absolute = true;
this.last = {};
this.attach(rawNode);
},
// 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.absolute = typeof(mode) == "string" ? (mode == "absolute") : mode;
return this; // self
},
getAbsoluteMode: function(){
// summary: returns a current value of the absolute mode
return this.absolute; // Boolean
},
getBoundingBox: function(){
// summary: returns the bounding box {x, y, width, height} or null
return "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; // dojo.gfx.Rectangle
},
getLastPosition: function(){
// summary: returns the last point in the path, or null
return "x" in this.last ? this.last : null; // Object
},
// segment interpretation
_updateBBox: function(x, y){
// summary: updates the bounding box of path with new point
// x: Number: an x coordinate
// y: Number: a y coordinate
// we use {l, b, r, t} representation of a bbox
if("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){
// summary: updates the bounding box of path with new segment
// segment: Object: a segment
var n = segment.args;
var l = n.length;
// update internal variables: bbox, absolute, last
switch(segment.action){
case "M":
case "L":
case "C":
case "S":
case "Q":
case "T":
for(var i = 0; i < l; i += 2){
this._updateBBox(this.bbox, n[i], n[i + 1]);
}
this.last.x = n[l - 2];
this.last.y = n[l - 1];
this.absolute = true;
break;
case "H":
for(var i = 0; i < l; ++i){
this._updateBBox(this.bbox, n[i], this.last.y);
}
this.last.x = n[l - 1];
this.absolute = true;
break;
case "V":
for(var i = 0; i < l; ++i){
this._updateBBox(this.bbox, this.last.x, n[i]);
}
this.last.y = n[l - 1];
this.absolute = true;
break;
case "m":
var start = 0;
if(!("x" in this.last)){
this._updateBBox(this.bbox, this.last.x = n[0], this.last.y = n[1]);
start = 2;
}
for(var i = start; i < l; i += 2){
this._updateBBox(this.bbox, this.last.x += n[i], this.last.y += n[i + 1]);
}
this.absolute = false;
break;
case "l":
case "t":
for(var i = 0; i < l; i += 2){
this._updateBBox(this.bbox, this.last.x += n[i], this.last.y += n[i + 1]);
}
this.absolute = false;
break;
case "h":
for(var i = 0; i < l; ++i){
this._updateBBox(this.bbox, this.last.x += n[i], this.last.y);
}
this.absolute = false;
break;
case "v":
for(var i = 0; i < l; ++i){
this._updateBBox(this.bbox, this.last.x, this.last.y += n[i]);
}
this.absolute = false;
break;
case "c":
for(var i = 0; i < l; i += 6){
this._updateBBox(this.bbox, this.last.x + n[i], this.last.y + n[i + 1]);
this._updateBBox(this.bbox, this.last.x + n[i + 2], this.last.y + n[i + 3]);
this._updateBBox(this.bbox, this.last.x += n[i + 4], this.last.y += n[i + 5]);
}
this.absolute = false;
break;
case "s":
case "q":
for(var i = 0; i < l; i += 4){
this._updateBBox(this.bbox, this.last.x + n[i], this.last.y + n[i + 1]);
this._updateBBox(this.bbox, this.last.x += n[i + 2], this.last.y += n[i + 3]);
}
this.absolute = false;
break;
case "A":
for(var i = 0; i < l; i += 7){
this._updateBBox(this.bbox, n[i + 5], n[i + 6]);
}
this.last.x = n[l - 2];
this.last.y = n[l - 1];
this.absolute = true;
break;
case "a":
for(var i = 0; i < l; i += 7){
this._updateBBox(this.bbox, this.last.x += n[i + 5], this.last.y += n[i + 6]);
}
this.absolute = false;
break;
}
// add an SVG path segment
var path = [segment.action];
for(var i = 0; i < l; ++i){
path.push(dojo.gfx.formatNumber(n[i], true));
}
if(typeof(this.shape.path) == "string"){
this.shape.path += path.join("");
}else{
this.shape.path = this.shape.path.concat(path);
}
},
// a dictionary, which maps segment type codes to a number of their argemnts
_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
var group = this._validSegments[action.toLowerCase()];
if(typeof(group) == "number"){
if(group){
if(args.length >= group){
var segment = {action: action, args: args.slice(0, args.length - args.length % group)};
this.segments.push(segment);
this._updateWithSegment(segment);
}
}else{
var 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, dojo.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);
array.push(t.y);
}
}
},
// segments
moveTo: function(){
// summary: formes a move segment
var args = [];
this._collectArgs(args, arguments);
this._pushSegment(this.absolute ? "M" : "m", args);
return this; // self
},
lineTo: function(){
// summary: formes a line segment
var args = [];
this._collectArgs(args, arguments);
this._pushSegment(this.absolute ? "L" : "l", args);
return this; // self
},
hLineTo: function(){
// summary: formes a horizontal line segment
var args = [];
this._collectArgs(args, arguments);
this._pushSegment(this.absolute ? "H" : "h", args);
return this; // self
},
vLineTo: function(){
// summary: formes a vertical line segment
var args = [];
this._collectArgs(args, arguments);
this._pushSegment(this.absolute ? "V" : "v", args);
return this; // self
},
curveTo: function(){
// summary: formes a curve segment
var args = [];
this._collectArgs(args, arguments);
this._pushSegment(this.absolute ? "C" : "c", args);
return this; // self
},
smoothCurveTo: function(){
// summary: formes a smooth curve segment
var args = [];
this._collectArgs(args, arguments);
this._pushSegment(this.absolute ? "S" : "s", args);
return this; // self
},
qCurveTo: function(){
// summary: formes a quadratic curve segment
var args = [];
this._collectArgs(args, arguments);
this._pushSegment(this.absolute ? "Q" : "q", args);
return this; // self
},
qSmoothCurveTo: function(){
// summary: formes a quadratic smooth curve segment
var args = [];
this._collectArgs(args, arguments);
this._pushSegment(this.absolute ? "T" : "t", args);
return this; // self
},
arcTo: function(){
// summary: formes an elliptic arc segment
var args = [];
this._collectArgs(args, arguments);
for(var i = 2; i < args.length; i += 7){
args[i] = -args[i];
}
this._pushSegment(this.absolute ? "A" : "a", args);
return this; // self
},
closePath: function(){
// summary: closes a path
this._pushSegment("Z", []);
return this; // self
},
// setShape
_setPath: function(path){
// summary: forms a path using an SVG path string
// path: String: an SVG path string
var p = path.match(dojo.gfx.pathRegExp);
this.segments = [];
this.absolute = true;
this.bbox = {};
this.last = {};
if(!p) return;
// create segments
var action = ""; // current action
var args = []; // current arguments
for(var i = 0; i < p.length; ++i){
var t = p[i];
var 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 dojo.gfx.defaultPath)
this.shape = dojo.gfx.makeParameters(this.shape, typeof(newShape) == "string" ? {path: newShape} : newShape);
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("");
return this; // self
},
// useful constant for descendants
_2PI: Math.PI * 2
});