/* tslint:disable:no-unused-variable */

import definition = require("ui/core/control-state-change");

import * as visualStateConstants from "ui/styling/visual-state-constants";

var ObserverClass = NSObject.extend(

{

observeValueForKeyPathOfObjectChangeContext: function (path: string, obj: Object, change: NSDictionary, context: any) {

if (path === "selected") {

this["_owner"]._onSelectedChanged();

} else if (path === "enabled") {

this["_owner"]._onEnabledChanged();

} else if (path === "highlighted") {

this["_owner"]._onHighlightedChanged();

}

}

},

{

});

export class ControlStateChangeListener implements definition.ControlStateChangeListener {

private _observer: NSObject;

private _states: string[];

private _control: UIControl;

private _callback: (state: string) => void;

constructor(control: UIControl, callback: (state: string) => void) {

this._observer = ObserverClass.alloc();

this._observer["_owner"] = this;

// TODO: Commenting for now, needs revision later since we must detach the observers upon control deallocation

//control.addObserverForKeyPathOptionsContext(this._observer, "selected", NSKeyValueObservingOptions.NSKeyValueObservingOptionNew, null);

//control.addObserverForKeyPathOptionsContext(this._observer, "enabled", NSKeyValueObservingOptions.NSKeyValueObservingOptionNew, null);

//control.addObserverForKeyPathOptionsContext(this._observer, "highlighted", NSKeyValueObservingOptions.NSKeyValueObservingOptionNew, null);

this._control = control;

this._callback = callback;

}

private _onEnabledChanged() {

this._updateState();

}

private _onSelectedChanged() {

this._updateState();

}

private _onHighlightedChanged() {

this._updateState();

}

private _updateState() {

var state = visualStateConstants.Normal;

if (this._control.highlighted) {

state = visualStateConstants.Pressed;

} else if (this._control.highlighted) {

// TODO:

}

this._callback(state);

}

}