unit X11_SHM_Extension;

{$MODE OBJFPC}
{$M+}

interface
uses X11, type_fixes, xlib, X11_Objects, X, sysutils;

type
  EUnsupportedPixmapFormat = class(Exception)
  end;

  TSHMExtension = class(TInterfacedObject, ISHMExtension, IInterface)
  private
    fMajorVersion : Integer;
    fMinorVersion : Integer;
    fBSharedMemoryPixmaps : Longint;
    fPixmapFormat : TPixmapFormat;
  protected
    function GetMajorVersion : Integer;
    function GetMinorVersion : Integer;
    function GetBSharedMemoryPixmaps : Boolean;
  public
    function GetPixmapFormat : TPixmapFormat;
  published
    property MajorVersion : Integer read GetMajorVersion;
    property MinorVersion : Integer read GetMinorVersion;
    property BSharedMemoryPixmaps : Boolean read GetBSharedMemoryPixmaps;
    constructor Open(aDisplay : PDisplay);
  public
    property PixmapFormat : TPixmapFormat read GetPixmapFormat; // depth, bits_per_pixel, scanline_pad.
  end;

implementation
uses xshm;

function TSHMExtension.GetMajorVersion : Integer;
begin
  Result := fMajorVersion;
end;

function TSHMExtension.GetMinorVersion : Integer;
begin
  Result := fMinorVersion;
end;

function TSHMExtension.GetBSharedMemoryPixmaps : Boolean;
begin
  Result := Boolean(fBSharedMemoryPixmaps);
end;

function TSHMExtension.GetPixmapFormat : TPixmapFormat;
begin
  Result := fPixmapFormat;
end;

constructor TSHMExtension.Open(aDisplay : PDisplay);
var
  vPixmapFormat : TStatus;
begin
  if (XShmQueryExtension(aDisplay) = LongInt(False)) or
     (XShmQueryVersion(aDisplay, @fMajorVersion, @fMinorVersion, @fBSharedMemoryPixmaps) = LongInt(False)) then
    raise EFormatError.Create('X11 SHM Extension not available.');
    
  vPixmapFormat := CheckError(XShmPixmapFormat(aDisplay));
  if vPixmapFormat <> ZPixmap then begin
    raise EUnsupportedPixmapFormat.Create(IntToStr(vPixmapFormat));
  end;
  // FIXME -> fPixmapFormat.
end;

end.