jQuery Canvas Rounded Corners - jQuery圆角插件

// Copyright 2006 Google Inc. // // Licensed under the Apache License, Version 2.0 (the "License"); // you may not use this file except in compliance with the License. // You may obtain a copy of the License at // // http://www.apache.org/licenses/LICENSE-2.0 // // Unless required by applicable law or agreed to in writing, software // distributed under the License is distributed on an "AS IS" BASIS, // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. // See the License for the specific language governing permissions and // limitations under the License. // Known Issues: // // * Patterns are not implemented. // * Radial gradient are not implemented. The VML version of these look very // different from the canvas one. // * Clipping paths are not implemented. // * Coordsize. The width and height attribute have higher priority than the // width and height style values which isn't correct. // * Painting mode isn't implemented. // * Canvas width/height should is using content-box by default. IE in // Quirks mode will draw the canvas using border-box. Either change your // doctype to HTML5 // (http://www.whatwg.org/specs/web-apps/current-work/#the-doctype) // or use Box Sizing Behavior from WebFX // (http://webfx.eae.net/dhtml/boxsizing/boxsizing.html) // * Optimize. There is always room for speed improvements. // only add this code if we do not already have a canvas implementation var excanvas = function(canvas){if (arguments.length == 1) return canvas;} if (!window.CanvasRenderingContext2D) { excanvas = function (canvasObject) { // alias some functions to make (compiled) code shorter var m = Math; var mr = m.round; var ms = m.sin; var mc = m.cos; // this is used for sub pixel precision var Z = 10; var Z2 = Z / 2; var G_vmlCanvasManager_ = { init: function (opt_doc, canvasObject) { var doc = opt_doc || document; if (/MSIE/.test(navigator.userAgent) && !window.opera) { var self = this; if (typeof canvasObject != "undefined") { return self.init_(doc, canvasObject); } else { doc.attachEvent("onreadystatechange", function () {self.init_(doc);}); } } }, init_: function (doc, canvasObject) { if (typeof canvasObject != "undefined") { if (!canvasObject.getContext) { return this.initElement(canvasObject); } return; } if (doc.readyState == "complete") { // create xmlns if (!doc.namespaces["g_vml_"]) { doc.namespaces.add("g_vml_", "urn:schemas-microsoft-com:vml"); } // setup default css var ss = doc.createStyleSheet(); ss.cssText = "canvas{display:inline-block;/*overflow:hidden;*/" + // default size is 300x150 in Gecko and Opera "text-align:left;width:300px;height:150px}" + "g_vml_\\:*{behavior:url(#default#VML)}"; // find all canvas elements var els = doc.getElementsByTagName("canvas"); for (var i = 0; i < els.length; i++) { if (!els[i].getContext) { this.initElement(els[i]); } } } }, fixElement_: function (el) { // in IE before version 5.5 we would need to add HTML: to the tag name // but we do not care about IE before version 6 var outerHTML = el.outerHTML; var newEl = el.ownerDocument.createElement(outerHTML); // if the tag is still open IE has created the children as siblings and // it has also created a tag with the name "/FOO" if (outerHTML.slice(-2) != "/>") { var tagName = "/" + el.tagName; var ns; // remove content while ((ns = el.nextSibling) && ns.tagName != tagName) { ns.removeNode(); } // remove the incorrect closing tag if (ns) { ns.removeNode(); } } if (el.parentNode == null) { return el; } el.parentNode.replaceChild(newEl, el); return newEl; }, /** * Public initializes a canvas element so that it can be used as canvas * element from now on. This is called automatically before the page is * loaded but if you are creating elements using createElement you need to * make sure this is called on the element. * @param {HTMLElement} el The canvas element to initialize. * @return {HTMLElement} the element that was created. */ initElement: function (el) { el = this.fixElement_(el); el.getContext = function () { if (this.context_) { return this.context_; } return this.context_ = new CanvasRenderingContext2D_(this); }; // do not use inline function because that will leak memory el.attachEvent('onpropertychange', onPropertyChange); el.attachEvent('onresize', onResize); var attrs = el.attributes; if (attrs.width && attrs.width.specified) { // TODO: use runtimeStyle and coordsize // el.getContext().setWidth_(attrs.width.nodeValue); el.style.width = attrs.width.nodeValue + "px"; } else { el.width = el.clientWidth; } if (attrs.height && attrs.height.specified) { // TODO: use runtimeStyle and coordsize // el.getContext().setHeight_(attrs.height.nodeValue); el.style.height = attrs.height.nodeValue + "px"; } else { el.height = el.clientHeight; } //el.getContext().setCoordsize_() return el; } }; function onPropertyChange(e) { var el = e.srcElement; switch (e.propertyName) { case 'width': el.style.width = el.attributes.width.nodeValue + "px"; el.getContext().clearRect(); break; case 'height': el.style.height = el.attributes.height.nodeValue + "px"; el.getContext().clearRect(); break; } } function onResize(e) { var el = e.srcElement; if (el.firstChild) { el.firstChild.style.width = el.clientWidth + 'px'; el.firstChild.style.height = el.clientHeight + 'px'; } } var newCanvas = G_vmlCanvasManager_.init(null, canvasObject); // precompute "00" to "FF" var dec2hex = []; for (var i = 0; i < 16; i++) { for (var j = 0; j < 16; j++) { dec2hex[i * 16 + j] = i.toString(16) + j.toString(16); } } function createMatrixIdentity() { return [ [1, 0, 0], [0, 1, 0], [0, 0, 1] ]; } function matrixMultiply(m1, m2) { var result = createMatrixIdentity(); for (var x = 0; x < 3; x++) { for (var y = 0; y < 3; y++) { var sum = 0; for (var z = 0; z < 3; z++) { sum += m1[x][z] * m2[z][y]; } result[x][y] = sum; } } return result; } function copyState(o1, o2) { o2.fillStyle = o1.fillStyle; o2.lineCap = o1.lineCap; o2.lineJoin = o1.lineJoin; o2.lineWidth = o1.lineWidth; o2.miterLimit = o1.miterLimit; o2.shadowBlur = o1.shadowBlur; o2.shadowColor = o1.shadowColor; o2.shadowOffsetX = o1.shadowOffsetX; o2.shadowOffsetY = o1.shadowOffsetY; o2.strokeStyle = o1.strokeStyle; o2.arcScaleX_ = o1.arcScaleX_; o2.arcScaleY_ = o1.arcScaleY_; } function processStyle(styleString) { var str, alpha = 1; styleString = String(styleString); if (styleString.substring(0, 3) == "rgb") { var start = styleString.indexOf("(", 3); var end = styleString.indexOf(")", start + 1); var guts = styleString.substring(start + 1, end).split(","); str = "#"; for (var i = 0; i < 3; i++) { str += dec2hex[Number(guts[i])]; } if ((guts.length == 4) && (styleString.substr(3, 1) == "a")) { alpha = guts[3]; } } else { str = styleString; } return [str, alpha]; }