/// <summary>
/// Pres the process wm key down_ page up.
/// </summary>
/// <param name="m">The m.</param>
/// <returns></returns>
protected virtual bool PreProcessWmKeyDown_PageUp(ref Message m)
{
long pos = HexViewer.bytePosition;
int cp = HexViewer.byteCharacterPosition;
if (pos == 0 && cp == 0)
{
return(true);
}
pos = Math.Max(0, pos - HexViewer.hexMaxBytes);
if (pos == 0)
{
return(true);
}
HexViewer.SetPosition(pos);
if (pos < HexViewer.startByte)
{
HexViewer.PerformScrollPageUp();
}
HexViewer.ReleaseSelection();
HexViewer.UpdateCaret();
HexViewer.Invalidate();
return(true);
}