Add usage ID and fix getUsagePage() on macOS

src/purejavahidapi/HidDeviceInfo.java

@@ -48,6 +48,7 @@ public class HidDeviceInfo {
 	protected short m_ProductId;
 	protected short m_ReleaseNumber;
 	protected short m_UsagePage;
+	protected short m_UsageId;
 	protected String m_SerialNumberString;
 	protected String m_ManufactureString;
 	protected String m_ProductString;
@@ -122,6 +123,20 @@ public short getReleaseNumber() {
 	public short getUsagePage() {
 		return m_UsagePage;
 	}
+
+	/**
+	 * This method returns the 16 bit Usage ID number of the device.
+	 * <p>
+	 * Note that the return type is <code>short</code> so when compared against
+	 * literals or variables of type <code>int</code> sign extension interferes
+	 * and thus it is necessary to cast the <code>int</code> type to
+	 * <code>short</code>
+	 * 
+	 * @return the 16 bit Usage Page number
+	 */
+	public short getUsageId() {
+		return m_UsageId;
+	}
 
 	/**
 	 * This method returns the Manufacturer String if available otherwise null

src/purejavahidapi/macosx/HidDeviceInfo.java

@@ -46,8 +46,8 @@ public HidDeviceInfo(IOHIDDeviceRef dev) {
 		m_SerialNumberString = getStringProperty(dev, CFSTR(kIOHIDSerialNumberKey));
 		m_ProductString = getStringProperty(dev, CFSTR(kIOHIDProductKey));
 		m_ReleaseNumber = (short) getIntProperty(dev, CFSTR(kIOHIDVersionNumberKey));
-		m_UsagePage = (short) getIntProperty(dev, CFSTR(kIOHIDPrimaryUsageKey));
-
+		m_UsagePage = (short) getIntProperty(dev, CFSTR(kIOHIDPrimaryUsagePageKey));
+		m_UsageId = (short) getIntProperty(dev, CFSTR(kIOHIDPrimaryUsageKey));
 	}
 
 }

src/purejavahidapi/windows/HidDeviceInfo.java

@@ -60,6 +60,7 @@ public HidDeviceInfo(String path, String deviceId, HANDLE handle, HIDD_ATTRIBUTE
 			if (HidD_GetPreparsedData(handle, ppd)) {
 				if (HidP_GetCaps(ppd[0], caps) == HIDP_STATUS_SUCCESS) {
 					m_UsagePage = caps.UsagePage;
+					m_UsageId = caps.Usage;
 				}
 
 				HidD_FreePreparsedData(ppd[0]);