Add evdev_reader JNI library

jni/evdev_reader/Android.mk

@@ -0,0 +1,12 @@
+# Android.mk for Limelight's Evdev Reader
+MY_LOCAL_PATH := $(call my-dir)
+
+include $(call all-subdir-makefiles)
+
+LOCAL_PATH := $(MY_LOCAL_PATH)
+
+include $(CLEAR_VARS)
+LOCAL_MODULE    := evdev_reader
+LOCAL_SRC_FILES := evdev_reader.c
+
+include $(BUILD_SHARED_LIBRARY)

jni/evdev_reader/evdev_reader.c

@@ -0,0 +1,65 @@
+#include <stdlib.h>
+#include <jni.h>
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <linux/input.h>
+#include <unistd.h>
+
+JNIEXPORT jint JNICALL
+Java_com_limelight_binding_input_evdev_EvdevReader_open(JNIEnv *env, jobject this, jstring absolutePath) {
+	const char *path;
+	
+	path = (*env)->GetStringUTFChars(env, absolutePath, NULL);
+	
+	return open(path, O_RDWR);
+}
+
+JNIEXPORT jboolean JNICALL
+Java_com_limelight_binding_input_evdev_EvdevReader_grab(JNIEnv *env, jobject this, jint fd) {
+    return ioctl(fd, EVIOCGRAB, 1) == 0;
+}
+
+JNIEXPORT jboolean JNICALL
+Java_com_limelight_binding_input_evdev_EvdevReader_ungrab(JNIEnv *env, jobject this, jint fd) {
+    return ioctl(fd, EVIOCGRAB, 0) == 0;
+}
+
+// isMouse() and friends are based on Android's EventHub.cpp
+
+#define test_bit(bit, array)    (array[bit/8] & (1<<(bit%8)))
+
+JNIEXPORT jboolean JNICALL
+Java_com_limelight_binding_input_evdev_EvdevReader_isMouse(JNIEnv *env, jobject this, jint fd) {
+    unsigned char keyBitmask[(KEY_MAX + 1) / 8];
+    unsigned char relBitmask[(REL_MAX + 1) / 8];
+    
+    ioctl(fd, EVIOCGBIT(EV_KEY, sizeof(keyBitmask)), keyBitmask);
+    ioctl(fd, EVIOCGBIT(EV_REL, sizeof(relBitmask)), relBitmask);
+    
+    // If this device has all required features of a mouse, it's a mouse!
+    return test_bit(BTN_MOUSE, keyBitmask) &&
+        test_bit(REL_X, relBitmask) &&
+        test_bit(REL_Y, relBitmask);
+}
+
+JNIEXPORT jint JNICALL
+Java_com_limelight_binding_input_evdev_EvdevReader_read(JNIEnv *env, jint fd, jbyteArray buffer) {
+    jint ret;
+    jbyte *data = (*env)->GetByteArrayElements(env, buffer, NULL);
+    if (data == NULL) {
+        return -1;
+    }
+
+    ret = read(fd, data, sizeof(struct input_event));
+    
+    (*env)->ReleaseByteArrayElements(env, buffer, data, 0);
+
+	return ret;
+}
+
+JNIEXPORT jint JNICALL
+Java_com_limelight_binding_input_evdev_EvdevReader_close(JNIEnv *env, jobject this, jint fd) {
+	return close(fd);
+}