/// <summary>
/// Asynchronously refreshes the framebuffer: fetches the latest framebuffer data from the device. Access the <see cref="Header"/>
/// and <see cref="Data"/> properties to get the updated framebuffer data.
/// </summary>
/// <param name="cancellationToken">
/// A <see cref="CancellationToken"/> which can be used to cancel the asynchronous task.
/// </param>
/// <returns>
/// A <see cref="Task"/> which represents the asynchronous operation.
/// </returns>
public async Task RefreshAsync(CancellationToken cancellationToken)
{
this.EnsureNotDisposed();
using (var socket = Factories.AdbSocketFactory(this.client.EndPoint))
{
// Select the target device
this.client.SetDevice(socket, this.Device);
// Send the framebuffer command
socket.SendAdbRequest("framebuffer:");
socket.ReadAdbResponse();
// The result first is a FramebufferHeader object,
await socket.ReadAsync(this.headerData, cancellationToken).ConfigureAwait(false);
if (!this.headerInitialized)
{
this.Header = FramebufferHeader.Read(this.headerData);
this.headerInitialized = true;
}
if (this.Data == null || this.Data.Length < this.Header.Size)
{
#if !NETFX
// Optimization on .NET Core: Use the BufferPool to rent buffers
if (this.Data != null)
{
ArrayPool <byte> .Shared.Return(this.Data, clearArray : false);
}
this.Data = ArrayPool <byte> .Shared.Rent((int)this.Header.Size);
#else
this.Data = new byte[(int)this.Header.Size];
#endif
}
// followed by the actual framebuffer content
await socket.ReadAsync(this.Data, (int)this.Header.Size, cancellationToken).ConfigureAwait(false);
}
}
/// <summary>
/// Creates a new <see cref="FramebufferHeader"/> object based on a byte arra which contains the data.
/// </summary>
/// <param name="data">
/// The data that feeds the <see cref="FramebufferHeader"/> structure.
/// </param>
/// <returns>
/// A new <see cref="FramebufferHeader"/> object.
/// </returns>
public static FramebufferHeader Read(byte[] data)
{
// as defined in https://android.googlesource.com/platform/system/core/+/master/adb/framebuffer_service.cpp
FramebufferHeader header = default(FramebufferHeader);
// Read the data from a MemoryStream so we can use the BinaryReader to process the data.
using (MemoryStream stream = new MemoryStream(data))
using (BinaryReader reader = new BinaryReader(stream, Encoding.ASCII, leaveOpen: true))
{
header.Version = reader.ReadUInt32();
header.Bpp = reader.ReadUInt32();
header.Size = reader.ReadUInt32();
header.Width = reader.ReadUInt32();
header.Height = reader.ReadUInt32();
header.Red = new ColorData()
{
Offset = reader.ReadUInt32(),
Length = reader.ReadUInt32()
};
header.Blue = new ColorData()
{
Offset = reader.ReadUInt32(),
Length = reader.ReadUInt32()
};
header.Green = new ColorData()
{
Offset = reader.ReadUInt32(),
Length = reader.ReadUInt32()
};
header.Alpha = new ColorData()
{
Offset = reader.ReadUInt32(),
Length = reader.ReadUInt32()
};
}
return(header);
}
