// -----------------------------------------
// SoundScribe (TM) and related software.
// 
// Copyright (C) 2007-2011 Vannatech
// http://www.vannatech.com
// All rights reserved.
// 
// This source code is subject to the MIT License.
// http://www.opensource.org/licenses/mit-license.php
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
// -----------------------------------------

using System;
using System.Runtime.InteropServices;
using Vannatech.CoreAudio.Enumerations;

namespace Vannatech.CoreAudio.Interfaces
{
    /// <summary>
	/// Provides notifications of session-related events such as changes in the volume level, display name, and session state.
    /// </summary>
    /// <remarks>
	/// MSDN Reference: http://msdn.microsoft.com/en-us/library/dd368289.aspx
    /// </remarks>
	public partial interface IAudioSessionEvents
    {
		/// <summary>
		/// Notifies the client that the display name for the session has changed.
		/// </summary>
		/// <param name="displayName">The new display name for the session.</param>
		/// <param name="eventContext">A user context value that is passed to the notification callback.</param>
		/// <returns>An HRESULT code indicating whether the operation succeeded of failed.</returns>
		[PreserveSig]
		int OnDisplayNameChanged(
			[In] [MarshalAs(UnmanagedType.LPWStr)] string displayName,
			[In] ref Guid eventContext);

		/// <summary>
		/// Notifies the client that the display icon for the session has changed.
		/// </summary>
		/// <param name="iconPath">The path for the new display icon for the session.</param>
		/// <param name="eventContext">A user context value that is passed to the notification callback.</param>
		/// <returns>An HRESULT code indicating whether the operation succeeded of failed.</returns>
		[PreserveSig]
		int OnIconPathChanged(
			[In] [MarshalAs(UnmanagedType.LPWStr)] string iconPath,
			[In] ref Guid eventContext);

		/// <summary>
		/// Notifies the client that the volume level or muting state of the session has changed.
		/// </summary>
		/// <param name="volume">The new volume level for the audio session.</param>
		/// <param name="isMuted">The new muting state.</param>
		/// <param name="eventContext">A user context value that is passed to the notification callback.</param>
		/// <returns>An HRESULT code indicating whether the operation succeeded of failed.</returns>
		[PreserveSig]
		int OnSimpleVolumeChanged(
			[In] [MarshalAs(UnmanagedType.R4)] float volume,
			[In] [MarshalAs(UnmanagedType.Bool)] bool isMuted,
			[In] ref Guid eventContext);

		/// <summary>
		/// Notifies the client that the volume level of an audio channel in the session submix has changed.
		/// </summary>
		/// <param name="channelCount">The channel count.</param>
		/// <param name="newVolumes">An array of volumnes cooresponding with each channel index.</param>
		/// <param name="channelIndex">The number of the channel whose volume level changed.</param>
		/// <param name="eventContext">A user context value that is passed to the notification callback.</param>
		/// <returns>An HRESULT code indicating whether the operation succeeded of failed.</returns>
		[PreserveSig]
		int OnChannelVolumeChanged(
			[In] [MarshalAs(UnmanagedType.U4)] UInt32 channelCount,
			[In] [MarshalAs(UnmanagedType.SysInt)] IntPtr newVolumes, // Pointer to float array
			[In] [MarshalAs(UnmanagedType.U4)] UInt32 channelIndex,
			[In] ref Guid eventContext);

		/// <summary>
		/// Notifies the client that the grouping parameter for the session has changed.
		/// </summary>
		/// <param name="groupingId">The new grouping parameter for the session.</param>
		/// <param name="eventContext">A user context value that is passed to the notification callback.</param>
		/// <returns>An HRESULT code indicating whether the operation succeeded of failed.</returns>
		[PreserveSig]
		int OnGroupingParamChanged(
			[In] ref Guid groupingId,
			[In] ref Guid eventContext);

		/// <summary>
		/// Notifies the client that the stream-activity state of the session has changed.
		/// </summary>
		/// <param name="state">The new session state.</param>
		/// <returns>An HRESULT code indicating whether the operation succeeded of failed.</returns>
		[PreserveSig]
		int OnStateChanged(
			[In] AudioSessionState state);

		/// <summary>
		/// Notifies the client that the session has been disconnected.
		/// </summary>
		/// <param name="disconnectReason">The reason that the audio session was disconnected.</param>
		/// <returns>An HRESULT code indicating whether the operation succeeded of failed.</returns>
		[PreserveSig]
		int OnSessionDisconnected(
			[In] AudioSessionDisconnectReason disconnectReason);
    }
}