detectSoundlevel-spike/sourceCode/trunk/Code/CoreAudio/Interfaces/IAudioSessionControl2.cs

// -----------------------------------------
// 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>
	/// Used by a client to get information about the audio session.
    /// </summary>
    /// <remarks>
	/// MSDN Reference: http://msdn.microsoft.com/en-us/library/dd368248.aspx
    /// </remarks>
	public partial interface IAudioSessionControl2
    {
        // Note: We can't derive from IAudioSessionControl, as that will produce the wrong vtable.

        #region IAudioSessionControl Members

        /// <summary>
        /// Retrieves the current state of the audio session.
        /// </summary>
        /// <param name="state">Receives the current session state.</param>
        /// <returns>An HRESULT code indicating whether the operation succeeded of failed.</returns>
        [PreserveSig]
        int GetState(
            [Out] out AudioSessionState state);

        /// <summary>
        /// Retrieves the display name for the audio session.
        /// </summary>
        /// <param name="displayName">Receives a string that contains the display name.</param>
        /// <returns>An HRESULT code indicating whether the operation succeeded of failed.</returns>
        [PreserveSig]
        int GetDisplayName(
            [Out] [MarshalAs(UnmanagedType.LPWStr)] out string displayName);

        /// <summary>
        /// Assigns a display name to the current audio session.
        /// </summary>
        /// <param name="displayName">A string that contains 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 SetDisplayName(
            [In] [MarshalAs(UnmanagedType.LPWStr)] string displayName,
            [In] [MarshalAs(UnmanagedType.LPStruct)] Guid eventContext);

        /// <summary>
        /// Retrieves the path for the display icon for the audio session.
        /// </summary>
        /// <param name="iconPath">Receives a string that specifies the fully qualified path of the file that contains the icon.</param>
        /// <returns>An HRESULT code indicating whether the operation succeeded of failed.</returns>
        [PreserveSig]
        int GetIconPath(
            [Out] [MarshalAs(UnmanagedType.LPWStr)] out string iconPath);

        /// <summary>
        /// Assigns a display icon to the current session.
        /// </summary>
        /// <param name="iconPath">A string that specifies the fully qualified path of the file that contains the new icon.</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 SetIconPath(
            [In] [MarshalAs(UnmanagedType.LPWStr)] string iconPath,
            [In] [MarshalAs(UnmanagedType.LPStruct)] Guid eventContext);

        /// <summary>
        /// Retrieves the grouping parameter of the audio session.
        /// </summary>
        /// <param name="groupingId">Receives the grouping parameter ID.</param>
        /// <returns>An HRESULT code indicating whether the operation succeeded of failed.</returns>
        [PreserveSig]
        int GetGroupingParam(
            [Out] out Guid groupingId);

        /// <summary>
        /// Assigns a session to a grouping of sessions.
        /// </summary>
        /// <param name="groupingId">The new grouping parameter ID.</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 SetGroupingParam(
            [In] [MarshalAs(UnmanagedType.LPStruct)] Guid groupingId,
            [In] [MarshalAs(UnmanagedType.LPStruct)] Guid eventContext);

        /// <summary>
        /// Registers the client to receive notifications of session events, including changes in the session state.
        /// </summary>
        /// <param name="client">A client-implemented <see cref="IAudioSessionEvents"/> interface.</param>
        /// <returns>An HRESULT code indicating whether the operation succeeded of failed.</returns>
        [PreserveSig]
        int RegisterAudioSessionNotification(
            [In] IAudioSessionEvents client);

        /// <summary>
        /// Deletes a previous registration by the client to receive notifications.
        /// </summary>
        /// <param name="client">A client-implemented <see cref="IAudioSessionEvents"/> interface.</param>
        /// <returns>An HRESULT code indicating whether the operation succeeded of failed.</returns>
        [PreserveSig]
        int UnregisterAudioSessionNotification(
            [In] IAudioSessionEvents client);

        #endregion

        /// <summary>
		/// Retrieves the session identifier.
		/// </summary>
		/// <param name="sessionId">Receives the audio session identifier.</param>
		/// <returns>An HRESULT code indicating whether the operation succeeded of failed.</returns>
		[PreserveSig]
		int GetSessionIdentifier(
			[Out] [MarshalAs(UnmanagedType.LPWStr)] out string sessionId);

		/// <summary>
		/// Retrieves the identifier of the session instance.
		/// </summary>
		/// <param name="instanceId">Receives the identifier of a particular instance of the audio session.</param>
		/// <returns>An HRESULT code indicating whether the operation succeeded of failed.</returns>
		[PreserveSig]
		int GetSessionInstanceIdentifier(
			[Out] [MarshalAs(UnmanagedType.LPWStr)] out string instanceId);

		/// <summary>
		/// Retrieves the process identifier of the session.
		/// </summary>
		/// <param name="processId">Receives the process identifier of the audio session. </param>
		/// <returns>An HRESULT code indicating whether the operation succeeded of failed.</returns>
		[PreserveSig]
		int GetProcessId(
			[Out] [MarshalAs(UnmanagedType.U4)] out UInt32 processId);

		/// <summary>
		/// Indicates whether the session is a system sounds session.
		/// </summary>
		/// <returns>An HRESULT code returning S_OK (0x0) or S_FALSE (0x1), indicating whether or not the session is a system sounds session.</returns>
		[PreserveSig]
		int IsSystemSoundsSession();

		/// <summary>
		/// Enables or disables the default stream attenuation experience (auto-ducking) provided by the system.
		/// </summary>
        /// <param name="optOut">True to disable system auto-ducking, or false to enable.</param>
		/// <returns>An HRESULT code indicating whether the operation succeeded of failed.</returns>
		[PreserveSig]
		int SetDuckingPreference(
			[In] [MarshalAs(UnmanagedType.Bool)] bool optOut);
    }
}