void
TabletProtocolHandler::AddHandlers(HIDDevice &device, HIDCollection &collection,
ProtocolHandler *&handlerList)
{
bool supported = false;
switch (collection.UsagePage()) {
case B_HID_USAGE_PAGE_GENERIC_DESKTOP:
{
switch (collection.UsageID()) {
case B_HID_UID_GD_MOUSE:
case B_HID_UID_GD_POINTER:
// NOTE: Maybe it is supported if X-axis and Y-axis are
// absolute. This is determined below by scanning the
// report items for absolute X and Y axis.
supported = true;
break;
}
break;
}
case B_HID_USAGE_PAGE_DIGITIZER:
{
switch (collection.UsageID()) {
case B_HID_UID_DIG_DIGITIZER:
case B_HID_UID_DIG_PEN:
case B_HID_UID_DIG_LIGHT_PEN:
case B_HID_UID_DIG_TOUCH_SCREEN:
case B_HID_UID_DIG_TOUCH_PAD:
case B_HID_UID_DIG_WHITE_BOARD:
TRACE("found tablet/digitizer\n");
supported = true;
break;
}
break;
}
}
if (!supported) {
TRACE("collection not a tablet/digitizer\n");
return;
}
HIDParser &parser = device.Parser();
uint32 maxReportCount = parser.CountReports(HID_REPORT_TYPE_INPUT);
if (maxReportCount == 0)
return;
uint32 inputReportCount = 0;
HIDReport *inputReports[maxReportCount];
collection.BuildReportList(HID_REPORT_TYPE_INPUT, inputReports,
inputReportCount);
for (uint32 i = 0; i < inputReportCount; i++) {
HIDReport *inputReport = inputReports[i];
// try to find at least an absolute x and y axis
HIDReportItem *xAxis = inputReport->FindItem(
B_HID_USAGE_PAGE_GENERIC_DESKTOP, B_HID_UID_GD_X);
if (xAxis == NULL || xAxis->Relative())
continue;
HIDReportItem *yAxis = inputReport->FindItem(
B_HID_USAGE_PAGE_GENERIC_DESKTOP, B_HID_UID_GD_Y);
if (yAxis == NULL || yAxis->Relative())
continue;
ProtocolHandler *newHandler = new(std::nothrow) TabletProtocolHandler(
*inputReport, *xAxis, *yAxis);
if (newHandler == NULL) {
TRACE("failed to allocated tablet protocol handler\n");
continue;
}
newHandler->SetNextHandler(handlerList);
handlerList = newHandler;
}
}
