javascript-code/JavaScript-Design-Patterns/The-Flyweight-Pattern/4 - Storing instances for later reuse.js at master · Windancer/javascript-code · GitHub

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/* DisplayModule interface. */

var DisplayModule = new Interface('DisplayModule', ['show', 'hide', 'state']);

/* DialogBox class. */

var DialogBox = function() { // implements DisplayModule

//todo

};

DialogBox.prototype = {

show: function(header, body, footer) { // Sets the content and shows the

//todo // dialog box.

},

hide: function() { // Hides the dialog box.

//todo

},

state: function() { // Returns 'visible' or 'hidden';

//todo

}

};

/* DialogBoxManager singleton. */

// 用一个单例来包装管理器需要的部件

var DialogBoxManager = (function() {

// 保存所生成的对话框的数据结构

var created = []; // Stores created instances.

return {

// 用来显示对话框的方法

displayDialogBox: function(header, body, footer) {

var inUse = this.numberInUse(); // Find the number currently in use.

// 这种技术类似于服务器语言中的SQL连接池，仅当现有连接都在使用当中时才会创建新连接

if(inUse > created.length) {

created.push(this.createDialogBox()); // Augment it if need be.

}

created[inUse].show(header, body, footer); // Show the dialog box.

},

createDialogBox: function() { // Factory method.

var db = new DialogBox();

return db;

},

// 检查当前网页上正在使用的对话框的数目的方法

numberInUse: function() {

var inUse = 0;

for(var i = 0, len = created.length; i < len; i++) {

if(created[i].state() === 'visible') {

inUse++;

}

}

return inUse;

}

};

})();