/*

* @author Valentin Simonov / http://va.lent.in/

*/

using System;

using System.Collections.Generic;

using TouchScript.Devices.Display;

using TouchScript.Hit;

using TouchScript.Layers;

using UnityEngine;

namespace TouchScript

{

/// <summary>

/// <para>Core manager of all touch input in <b>TouchScript</b>. It is responsible for assigning unique touch ids and keeping the list of active touches. Controls touch frames and dispatches touch events.</para>

/// </summary>

/// <remarks>

/// <para>Every frame touch events are dispatched in this order:</para>

/// <list type="number">

/// <item><description>FrameStarted</description></item>

/// <item><description>TouchesBegan</description></item>

/// <item><description>TouchesMoved</description></item>

/// <item><description>TouchesEnded</description></item>

/// <item><description>TouchesCancelled</description></item>

/// <item><description>FrameFinished</description></item>

/// </list>

/// <para>FrameStarted and FrameFinished events mark the start and the end of current touch frame and allow to implement specific logic at these moments.</para>

/// <para>Current instance of an active object implementing <see cref="ITouchManager"/> can be obtained via <see cref="TouchManager.Instance"/>.</para>

/// </remarks>

/// <seealso cref="TouchEventArgs"/>

/// <example>

/// This sample shows how to get Touch Manager instance and subscribe to events.

/// <code>

/// TouchManager.Instance.TouchesBegan +=

/// (sender, args) => { foreach (var touch in args.Touches) Debug.Log("Began: " + touch.Id); };

/// TouchManager.Instance.TouchesEnded +=

/// (sender, args) => { foreach (var touch in args.Touches) Debug.Log("Ended: " + touch.Id); };

/// </code>

/// </example>

public interface ITouchManager

{

/// <summary>

/// Occurs when a new frame is started before all other events.

/// </summary>

event EventHandler FrameStarted;

/// <summary>

/// Occurs when a frame is finished. After all other events.

/// </summary>

event EventHandler FrameFinished;

/// <summary>

/// Occurs when new touch points are added.

/// </summary>

event EventHandler<TouchEventArgs> TouchesBegan;

/// <summary>

/// Occurs when touch points are updated.

/// </summary>

event EventHandler<TouchEventArgs> TouchesMoved;

/// <summary>

/// Occurs when touch points are removed.

/// </summary>

event EventHandler<TouchEventArgs> TouchesEnded;

/// <summary>

/// Occurs when touch points are cancelled.

/// </summary>

event EventHandler<TouchEventArgs> TouchesCancelled;

/// <summary>

/// Gets or sets current display device.

/// </summary>

/// <value>Object which holds properties of current display device, like DPI and others.</value>

IDisplayDevice DisplayDevice { get; set; }

/// <summary>

/// Gets current DPI.

/// </summary>

/// <remarks>Shortcut for <see cref="IDisplayDevice.DPI"/>.</remarks>

float DPI { get; }

/// <summary>

/// Gets the list of touch layers.

/// </summary>

/// <value>A sorted list of currently active touch layers.</value>

IList<TouchLayer> Layers { get; }

/// <summary>

/// Gets number of pixels in a cm with current DPI.

/// </summary>

float DotsPerCentimeter { get; }

/// <summary>

/// Gets number of active touches.

/// </summary>

int NumberOfTouches { get; }

/// <summary>

/// Gets the list of active touches.

/// </summary>

/// <value>An unsorted list of all touches which began but have not ended yet.</value>

IList<ITouch> ActiveTouches { get; }

/// <summary>

/// Adds a touch layer.

/// </summary>

/// <param name="layer">The layer to add.</param>

/// <returns>True if the layer was added.</returns>

bool AddLayer(TouchLayer layer);

/// <summary>

/// Adds a touch layer in a specific position.

/// </summary>

/// <param name="layer">The layer to add.</param>

/// <param name="index">Layer index to add the layer to.</param>

/// <returns>True if the layer was added.</returns>

bool AddLayer(TouchLayer layer, int index);

/// <summary>

/// Removes a touch layer.

/// </summary>

/// <param name="layer">The layer to remove.</param>

/// <returns>True if the layer was removed.</returns>

bool RemoveLayer(TouchLayer layer);

/// <summary>

/// Swaps layers.

/// </summary>

/// <param name="at">Layer index 1.</param>

/// <param name="to">Layer index 2.</param>

void ChangeLayerIndex(int at, int to);

/// <summary>

/// Checks if a touch hits anything.

/// </summary>

/// <param name="position">Screen position of the touch.</param>

/// <returns>Transform which has been hit or null otherwise.</returns>

Transform GetHitTarget(Vector2 position);

/// <summary>

/// Checks if a touch hits anything.

/// <seealso cref="ITouchHit"/>

/// </summary>

/// <param name="position">Screen position of the touch.</param>

/// <param name="hit">An object which represents hit information.</param>

/// <returns>True if the touch hits any Transform.</returns>

bool GetHitTarget(Vector2 position, out ITouchHit hit);

/// <summary>

/// Checks if a touch hits anything.

/// <seealso cref="ITouchHit"/>

/// <seealso cref="TouchLayer"/>

/// </summary>

/// <param name="position">Screen position of the touch.</param>

/// <param name="hit">An object which represents hit information.</param>

/// <param name="layer">A layer which was hit.</param>

/// <returns>True if the touch hits any Transform.</returns>

bool GetHitTarget(Vector2 position, out ITouchHit hit, out TouchLayer layer);

}

/// <summary>

/// Arguments dispatched with Touch Manager events.

/// </summary>

public class TouchEventArgs : EventArgs

{

/// <summary>

/// Gets list of touches participating in the event.

/// </summary>

/// <value>List of touches added, changed or removed this frame.</value>

public IList<ITouch> Touches { get; private set; }

/// <summary>

/// Initializes a new instance of the <see cref="TouchEventArgs"/> class.

/// </summary>

/// <param name="touches">List of touches for an event.</param>

public TouchEventArgs(IList<ITouch> touches)

{

Touches = touches;

}

}

}