Ext.namespace("Samples");
Samples.ObservableList = function() {
this.items = [];
this.length = 0;
// The events our custom class will expose.
// The parent Class, Observable, will handle event publishing
//for us.
this.addEvents("add", "remove", "clear");
Samples.ObservableList.superclass.constructor.call(this);
};

Ext.extend(Samples.ObservableList, Ext.util.Observable, {
//Disable having functions as items.
allowFunctions: false,
//Our Class members go here...
});

Ext.extend(Samples.ObservableList, Ext.util.Observable, {
allowFunctions: false,
//Adds an item to the list and
//returns the position into which the new element was inserted.
add: function(o) {
this.items.push(o);
this.length++;
// Fire the add event, returning the position
// into which the new element was inserted.
pos = this.length - 1;
this.fireEvent("add", pos);
return pos;
},
// Inserts an item to the List at the specified index.
insert: function(index, o) {
//If the index is outside the list, insert the element at
// the end of the list.
if (index >= this.length) {
return this.add(o);
}
this.length++;
this.items.splice(index, 0, o);
this.fireEvent("add", index);
},
// Removes all items from the list.
clear: function() {
this.length = 0;
this.items = [];
this.fireEvent("clear");
},
// Determines the index of a specific item in the list.
indexOf: function(o) {
return this.items.indexOf(o);
},
// Determines whether the List contains a specific value.
contains: function(o) {
return this.indexOf(o) != -1;
},
// Our enumerator function. Executes the specified function
//once for every element in the list.
each: function(fn, scope) {
var items = [].concat(this.items); for (var i = 0, len = items.length; i < len; i++) {
if (fn.call(scope || items[i], items[i], i, len) === false) {
break;
}
}
},
// Removes the item at the specified index.
removeAt: function(index) {
if (index < this.length && index >= 0) {
this.length--;
var o = this.items[index];
this.items.splice(index, 1);
this.fireEvent("remove", o);
}
},
// Removes the first occurrence of a specific object.
remove: function(o) {
this.removeAt(this.indexOf(o));
},
// Return the element at the specified index.
item: function(index) {
var item = this.items[index];
return item;
}
});
Samples.ObservableList.prototype.get = Samples.ObservableList.prototype.item;

Ext.onReady(function() {
list = new Samples.ObservableList();
for (var i = 0; i < 15; i++) {
pos = list.add("test " + i);
}
// Add handlers for the list's events.
list.on("remove", function(o) {
alert("Removed: " + o);
});
list.on("add", function(index) {
alert("Added at position: " + index);
});
list.on("clear", function() {
alert("List length is: " + list.length);
});
document.write("List length is " + list.length + "<br/>");
// Insert an additional element and
//check that the add event fires.
var index = 2;
list.insert(index, "A new item");
document.write("Just inserted: " + list.item(index) + "<br/>");
document.write("List length is: " + list.length + "<br/>");
// Remove an item an verify that the remove event fires.
index = 5;
document.write("Removing item at position" + index + "<br/>");
list.removeAt(index);
document.write("List length after removal: " + list.length + "<br/>");
document.write("Clearing list...<br/>");
// Remove all items and check that the clear event fires.
list.clear();
document.write("List length after clear: " + list.length + "<br/>");
});