html5版canvas自由拼圖實例

 代碼運行效果如下圖所示：

 

canvasElement.js代碼如下：

 

復制代碼 代碼如下: define('canvasElement', [ '../multi_upload/core' ], function(S) {
var Canvas = window.Canvas || {};
(function () {
Canvas.Element = function() {};
Canvas.Element.prototype.fillBackground = true;
Canvas.Element.prototype.showcorners = false;
Canvas.Element.prototype.photoborder = true;
Canvas.Element.prototype.polaroid = false;
Canvas.Element.prototype._backgroundImg = null;
Canvas.Element.prototype._groupSelector = null;
Canvas.Element.prototype._aImages = null;
Canvas.Element.prototype._oContext = null;
Canvas.Element.prototype._oElement = null;
Canvas.Element.prototype._oConfig = null;
Canvas.Element.prototype._currentTransform = null;
Canvas.Element.prototype._prevTransform = null;
Canvas.Element.prototype.curAngle = null;
Canvas.Element.prototype.init = function(el, oConfig) {
if (el == '') {
return;
}
this._initElement(el);
this._initConfig(oConfig);
this._createCanvasBackground();
this._createContainer();
this._initEvents();
this._initCustomEvents();
};
Canvas.Element.prototype._initElement = function(el) {
this._oElement = document.getElementById(el);
this._oContextTop = this._oElement.getContext('2d');
};
Canvas.Element.prototype._initCustomEvents = function() {
this.onRotateStart = new Canvas.CustomEvent('onRotateStart');
this.onRotateMove = new Canvas.CustomEvent('onRotateMove');
this.onRotateComplete = new Canvas.CustomEvent('onRotateComplete');
this.onDragStart = new Canvas.CustomEvent('onDragStart');
this.onDragMove = new Canvas.CustomEvent('onDragMove');
this.onDragComplete = new Canvas.CustomEvent('onDragComplete');
};
Canvas.Element.prototype._initConfig = function(oConfig) {
this._oConfig = oConfig;
this._oElement.width = this._oConfig.width;
this._oElement.height = this._oConfig.height;
this._oElement.style.width = this._oConfig.width + 'px';
this._oElement.style.height = this._oConfig.height + 'px';
};
Canvas.Element.prototype._initEvents = function() {
var _this=this;
S(this._oElement).on('mousedown',function(e){
_this.onMouseDown(e);
});
S(this._oElement).on( 'mouseup', function(e){
_this.onMouseUp(e);
});
S(this._oElement).on('mousemove', function(e){
_this.onMouseMove(e);
});
};
Canvas.Element.prototype._createContainer = function() {
var canvasEl = document.createElement('canvas');
canvasEl.id = this._oElement.id + '-canvas-container';
var oContainer = this._oElement.parentNode.insertBefore(canvasEl, this._oElement);
oContainer.width = this._oConfig.width;
oContainer.height = this._oConfig.height;
oContainer.style.width = this._oConfig.width + 'px';
oContainer.style.height = this._oConfig.height + 'px';
this._oContextContainer = oContainer.getContext('2d');
};
Canvas.Element.prototype._createCanvasBackground = function() {
var canvasEl = document.createElement('canvas');
canvasEl.id = this._oElement.id + '-canvas-background';
var oBackground = this._oElement.parentNode.insertBefore(canvasEl, this._oElement);
oBackground.width = this._oConfig.width;
oBackground.height = this._oConfig.height;
oBackground.style.width = this._oConfig.width + 'px';
oBackground.style.height = this._oConfig.height + 'px';
this._oContextBackground = oBackground.getContext('2d');
};
Canvas.Element.prototype.setCanvasBackground = function(oImg) {
this._backgroundImg = oImg;
var originalImgSize = oImg.getOriginalSize();
this._oContextBackground.drawImage(oImg._oElement, 0, 0, originalImgSize.width, originalImgSize.height);
};
Canvas.Element.prototype.onMouseUp = function(e) {
if (this._aImages == null) {
return;
}
if (this._currentTransform) {
this._currentTransform.target.setImageCoords();
}
if (this._currentTransform != null && this._currentTransform.action == "rotate") {
this.onRotateComplete.fire(e);
} else if (this._currentTransform != null && this._currentTransform.action == "drag") {
this.onDragComplete.fire(e);
}
this._currentTransform = null;
this._groupSelector = null;
this.renderTop();
};
Canvas.Element.prototype.onMouseDown = function(e) {
var mp = this.findMousePosition(e);
if (this._currentTransform != null || this._aImages == null) {
return;
}
var oImg = this.findTargetImage(mp, false);
if (!oImg) {
this._groupSelector = { ex: mp.ex, ey: mp.ey,
top: 0, left: 0 };
}
else {
var action = (!this.findTargetCorner(mp, oImg)) ? 'drag' : 'rotate';
if (action == "rotate") {
this.onRotateMove.fire(e);
} else if (action == "drag") {
this.onDragMove.fire(e);
}
this._prevTransform=this._currentTransform = {
target: oImg,
action: action,
scalex: oImg.scalex,
offsetX: mp.ex - oImg.left,
offsetY: mp.ey - oImg.top,
ex: mp.ex, ey: mp.ey,
left: oImg.left, top: oImg.top,
theta: oImg.theta
};
$('canvas_menu').style.transform='rotate('+oImg.theta*180/3.14+'deg)';
$('canvas_menu').style.left=oImg.left+"px";
$('canvas_menu').style.top=oImg.top+"px";
$('canvas_menu').style.display="block";
this.renderAll(false,false);
}
};
Canvas.Element.prototype.onMouseMove = function(e) {
var mp = this.findMousePosition(e);
if (this._aImages == null) {
return;
}
if (this._groupSelector != null) {
this._groupSelector.left = mp.ex - this._groupSelector.ex;
this._groupSelector.top = mp.ey - this._groupSelector.ey;
this.renderTop();
}
else if (this._currentTransform == null) {
var targetImg = this.findTargetImage(mp, true);
this.setCursor(mp, targetImg);
}
else {
if (this._currentTransform.action == 'rotate') {
this.rotateImage(mp);
this.scaleImage(mp);
this.onRotateMove.fire(e);
}
else {
this.translateImage(mp);
this.onDragMove.fire(e);
}
this.renderTop();
}
};
Canvas.Element.prototype.translateImage = function(mp) {
this._currentTransform.target.left = mp.ex - this._currentTransform.offsetX;
this._currentTransform.target.top = mp.ey - this._currentTransform.offsetY;
$('canvas_menu').style.left=this._currentTransform.target.left+"px";
$('canvas_menu').style.top=this._currentTransform.target.top +"px";
};
Canvas.Element.prototype.scaleImage = function(mp) {
var lastLen =
Math.sqrt(Math.pow(this._currentTransform.ey - this._currentTransform.top, 2) +
Math.pow(this._currentTransform.ex - this._currentTransform.left, 2));
var curLen =
Math.sqrt(Math.pow(mp.ey - this._currentTransform.top, 2) +
Math.pow(mp.ex - this._currentTransform.left, 2));
var curScalex= this._currentTransform.scalex * (curLen / lastLen);
var curScaley=this._currentTransform.target.scalex;