/// <summary>
/// Constructor to convert WM_POINTER stack device info to the more generic TabletDeviceInfo
/// </summary>
/// <param name="deviceInfo">The WM_POINTER device info</param>
internal PointerTabletDeviceInfo(int id, UnsafeNativeMethods.POINTER_DEVICE_INFO deviceInfo)
{
_deviceInfo = deviceInfo;
Id = id;
Name = _deviceInfo.productString;
PlugAndPlayId = _deviceInfo.productString;
}
/// <summary>
/// Retrieves the latest device information from connected touch devices.
/// </summary>
internal void Refresh()
{
try
{
// Keep track of old tablets so that we can properly log connects/disconnects
Dictionary <IntPtr, PointerTabletDevice> oldTablets = _tabletDeviceMap;
_tabletDeviceMap = new Dictionary <IntPtr, PointerTabletDevice>();
TabletDevices.Clear();
uint deviceCount = 0;
// Pattern is to first get the count, then declare an array of that size
// which is then marshaled via the second call with the proper data.
IsValid = UnsafeNativeMethods.GetPointerDevices(ref deviceCount, null);
if (IsValid)
{
UnsafeNativeMethods.POINTER_DEVICE_INFO[] deviceInfos
= new UnsafeNativeMethods.POINTER_DEVICE_INFO[deviceCount];
IsValid = UnsafeNativeMethods.GetPointerDevices(ref deviceCount, deviceInfos);
if (IsValid)
{
foreach (var deviceInfo in deviceInfos)
{
// Old PenIMC code gets this id via a straight cast from COM pointer address
// into an int32. This does a very similar thing semantically using the pointer
// to the tablet from the WM_POINTER stack. While it may have similar issues
// (chopping the upper bits, duplicate ids) we don't use this id internally
// and have never received complaints about this in the WISP stack.
int id = MS.Win32.NativeMethods.IntPtrToInt32(deviceInfo.device);
PointerTabletDeviceInfo ptdi = new PointerTabletDeviceInfo(id, deviceInfo);
// Don't add a device that fails initialization. This means we will try a refresh
// next time around if we receive stylus input and the device is not available.
// <see cref="HwndPointerInputProvider.UpdateCurrentTabletAndStylus">
if (ptdi.TryInitialize())
{
PointerTabletDevice tablet = new PointerTabletDevice(ptdi);
if (!oldTablets.Remove(tablet.Device))
{
// We only create a TabletDevice when one is connected (physically or virtually).
// As such we have to log when there is no corresponding old tablet being refreshed.
StylusTraceLogger.LogDeviceConnect(
new StylusTraceLogger.StylusDeviceInfo(
tablet.Id,
tablet.Name,
tablet.ProductId,
tablet.TabletHardwareCapabilities,
tablet.TabletSize,
tablet.ScreenSize,
tablet.Type,
tablet.StylusDevices.Count));
}
_tabletDeviceMap[tablet.Device] = tablet;
TabletDevices.Add(tablet.TabletDevice);
}
}
}
// Any tablet leftover here was not refreshed from the previous set of tablets
// and should be logged as disconnected.
foreach (var oldTablet in oldTablets.Values)
{
StylusTraceLogger.LogDeviceDisconnect(oldTablet.Id);
}
}
}
catch (Win32Exception)
{
IsValid = false;
}
}