applet.js

applet在線上繪圖,允許在瀏覽器上繪圖,最後儲存成各式的圖檔

/* 
 * By Igor Zhukovsky. www.izhuk.com, April 2006.
 *
 * Use this class to output applet tags on a web page
 * This resolves the IE security issue.
 * (read about the issue http://izhuk.com/docs/ie7fix.html)
 *
 * How to use:
 *
 *  1. Include this script in your HTML page:
 *
 *     <script language="javascript" src="applet.js"></script>
 *
 *  2. Write JavaScript code:
 *
 *     var myapplet = new Applet(); // create new Applet object
 *
 *     //  assign necessary attributes
 *     myapplet.attr['code'] = 'MyClass.class';
 *     myapplet.attr['width']  = 200;
 *     myapplet.attr['height'] = 100;
 *     ....
 *
 *     // assign parameters (if any)
 *     myapplet.param['param1'] = 'value1';
 *     ....
 *
 *     myapplet.write(); // output the applet definition
 */

function Applet() {

    this.param   = new Object();
    this.attr    = new Object();
    
    // required attributes
    this.attr.width    = false;
    this.attr.height   = false;
    this.attr.code     = false;

    // optional attributes
    this.attr.codebase = './';
    this.attr.archive  = false;
    this.attr.id       = false;
    this.attr.name     = false;

    this.noJava = '';

    this.use_classical_applet =
    	!((navigator.appVersion.indexOf("MSIE") >= 0) &&
    	  (navigator.userAgent.indexOf(' MSIE 5.')==-1));
    
// for MSIE 5.x to run Ms Java 1.1
// = navigator.userAgent.indexOf(' MSIE 5.') > 0; 
// navigator.appVersion.indexOf("Win") != -1 &&
// navigator.appVersion.indexOf("MSIE")!= -1 &&
// navigator.javaEnabled()) { // Windows, IE, java enabled

}

Applet.prototype.write = function() {

    // check presence of mandatory attributes

    var missing_attrs = '';
    
    if (this.attr.code==false) {
    	missing_attrs += ' Applet.code';
    }
    if (this.attr.width==false) {
    	missing_attrs += ' Applet.width';
    }
    if (this.attr.height==false) {
    	missing_attrs += ' Applet.height';
    }

    if (missing_attrs.length > 0) {
    	window.alert('Missing attribute(s) :'+missing_attrs);
    	return;
    }

    if (this.use_classical_applet) {
	this.writeApplet(); // using Java 1.1
	return;
    }

    // else using JRE 1.4 or later

    s = '<OBJECT classid = "clsid:8AD9C840-044E-11D1-B3E9-00805F499D93"\n';
    if (this.attr.id != false) {
    	s += 'id = "'+this.attr.id+'"\n';
    }
    s += 'codebase = "http://java.sun.com/update/1.4.2/jinstall-1_4-windows-i586.cab#Version=1,4,0,0"\n';
    s += 'WIDTH = "'+this.attr.width+'" HEIGHT = "'+this.attr.height+'" >\n';
    s += '<PARAM NAME = CODE VALUE = "'+this.attr.code+'" >\n';
    s += '<PARAM NAME = CODEBASE VALUE = "'+this.attr.codebase+'">\n';
    if (this.attr.archive != false)
    	s += '<PARAM NAME = "ARCHIVE" VALUE="'+this.attr.archive+'">\n';
    s += '<PARAM NAME = "type" VALUE = "application/x-java-applet;version=1.4">\n';
    s += '<PARAM NAME = "scriptable" VALUE = "false">\n';
    for (name in this.param) {
        var value = this.param[name];
	s += '<PARAM NAME="'+name+'" VALUE="'+value+'">';
    }
    s += '<COMMENT><EMBED type = "application/x-java-applet;version=1.4"\n';
    if (this.attr.id != false) {
    	s += 'name = "'+this.attr.id+'"\n';
    }
    s += 'CODE = "'+this.attr.code+'"\n';    
    s += 'JAVA_CODEBASE = "'+this.attr.codebase+'"\n';
    if (this.attr.archive != false)
    	s += 'ARCHIVE = "'+this.attr.archive+'"\n';
    s += 'WIDTH="'+this.attr.width+'" HEIGHT="'+this.attr.height+'"\n';
    s += 'scriptable = false\n';
    s += 'pluginspage = "http://java.sun.com/products/plugin/index.html#download"\n';
    for (name in this.param) {
        var value = this.param[name];
	s += name+'="'+value+'"\n';
    }
    s += '><NOEMBED></NOEMBED></EMBED></COMMENT>';
    s += '</OBJECT>';

    //window.alert(s);
    document.write(s);

} // end of Applet.write()

// creates the classical <applet> tag
Applet.prototype.writeApplet = function() {

    if (this.attr.id != false && this.attr.name==false) {
    	this.attr.name = this.attr.id;
    }

    document.write('<applet ');

    // write attributes of the <applet> tag
    for (name in this.attr) {
        var value = this.attr[name];
	document.write(name+'="'+value+'" ');
    }
    document.write('>');

    // write the applet parameters
    for (name in this.param) {
        var value = this.param[name];
	document.write('<param name="'+name+'" value="'+value+'">');
    }
    document.write(this.noJava);
    document.write('</applet>');
}

Applet.prototype.getAppletRef = function() {
    return document.applets[this.attr.id];
}