android_view_InputEventReceiver.cpp revision cbee6d6ede0499fb4a2c00bfc00d5db8d9ed5139 
1/*
2 * Copyright (C) 2011 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#define LOG_TAG "InputEventReceiver"
18
19//#define LOG_NDEBUG 0
20
21// Log debug messages about the dispatch cycle.
22#define DEBUG_DISPATCH_CYCLE 0
23
24
25#include "JNIHelp.h"
26
27#include <android_runtime/AndroidRuntime.h>
28#include <utils/Log.h>
29#include <utils/Looper.h>
30#include <utils/threads.h>
31#include <ui/InputTransport.h>
32#include "android_os_MessageQueue.h"
33#include "android_view_InputChannel.h"
34#include "android_view_KeyEvent.h"
35#include "android_view_MotionEvent.h"
36
37namespace android {
38
39static struct {
40    jclass clazz;
41
42    jmethodID dispatchInputEvent;
43} gInputEventReceiverClassInfo;
44
45
46class NativeInputEventReceiver : public RefBase {
47public:
48    NativeInputEventReceiver(JNIEnv* env,
49            jobject receiverObj, const sp<InputChannel>& inputChannel,
50            const sp<Looper>& looper);
51
52    status_t initialize();
53    status_t finishInputEvent(bool handled);
54    static int handleReceiveCallback(int receiveFd, int events, void* data);
55
56protected:
57    virtual ~NativeInputEventReceiver();
58
59private:
60    jobject mReceiverObjGlobal;
61    InputConsumer mInputConsumer;
62    sp<Looper> mLooper;
63    bool mEventInProgress;
64    PreallocatedInputEventFactory mInputEventFactory;
65
66    const char* getInputChannelName() {
67        return mInputConsumer.getChannel()->getName().string();
68    }
69};
70
71
72NativeInputEventReceiver::NativeInputEventReceiver(JNIEnv* env,
73        jobject receiverObj, const sp<InputChannel>& inputChannel, const sp<Looper>& looper) :
74        mReceiverObjGlobal(env->NewGlobalRef(receiverObj)),
75        mInputConsumer(inputChannel), mLooper(looper), mEventInProgress(false) {
76#if DEBUG_DISPATCH_CYCLE
77    ALOGD("channel '%s' ~ Initializing input event receiver.", getInputChannelName());
78#endif
79}
80
81NativeInputEventReceiver::~NativeInputEventReceiver() {
82#if DEBUG_DISPATCH_CYCLE
83    ALOGD("channel '%s' ~ Disposing input event receiver.", getInputChannelName());
84#endif
85
86    mLooper->removeFd(mInputConsumer.getChannel()->getFd());
87    if (mEventInProgress) {
88        mInputConsumer.sendFinishedSignal(false); // ignoring result
89    }
90
91    JNIEnv* env = AndroidRuntime::getJNIEnv();
92    env->DeleteGlobalRef(mReceiverObjGlobal);
93}
94
95status_t NativeInputEventReceiver::initialize() {
96    int32_t receiveFd = mInputConsumer.getChannel()->getFd();
97    mLooper->addFd(receiveFd, 0, ALOOPER_EVENT_INPUT, handleReceiveCallback, this);
98    return OK;
99}
100
101status_t NativeInputEventReceiver::finishInputEvent(bool handled) {
102    if (mEventInProgress) {
103#if DEBUG_DISPATCH_CYCLE
104        ALOGD("channel '%s' ~ Finished input event.", getInputChannelName());
105#endif
106        mEventInProgress = false;
107
108        status_t status = mInputConsumer.sendFinishedSignal(handled);
109        if (status) {
110            ALOGW("Failed to send finished signal on channel '%s'.  status=%d",
111                    getInputChannelName(), status);
112        }
113        return status;
114    } else {
115        ALOGW("Ignoring attempt to finish input event while no event is in progress.");
116        return OK;
117    }
118}
119
120int NativeInputEventReceiver::handleReceiveCallback(int receiveFd, int events, void* data) {
121    sp<NativeInputEventReceiver> r = static_cast<NativeInputEventReceiver*>(data);
122
123    if (events & (ALOOPER_EVENT_ERROR | ALOOPER_EVENT_HANGUP)) {
124        ALOGE("channel '%s' ~ Publisher closed input channel or an error occurred.  "
125                "events=0x%x", r->getInputChannelName(), events);
126        return 0; // remove the callback
127    }
128
129    if (!(events & ALOOPER_EVENT_INPUT)) {
130        ALOGW("channel '%s' ~ Received spurious callback for unhandled poll event.  "
131                "events=0x%x", r->getInputChannelName(), events);
132        return 1;
133    }
134
135    if (r->mEventInProgress) {
136        ALOGW("channel '%s' ~ Publisher sent spurious dispatch signal.",
137                r->getInputChannelName());
138        return 1;
139    }
140
141    InputEvent* inputEvent;
142    status_t status = r->mInputConsumer.consume(&r->mInputEventFactory, &inputEvent);
143    if (status) {
144        ALOGW("channel '%s' ~ Failed to consume input event.  status=%d",
145                r->getInputChannelName(), status);
146        r->mInputConsumer.sendFinishedSignal(false);
147        return 1;
148    }
149
150    JNIEnv* env = AndroidRuntime::getJNIEnv();
151    jobject inputEventObj;
152    switch (inputEvent->getType()) {
153    case AINPUT_EVENT_TYPE_KEY:
154#if DEBUG_DISPATCH_CYCLE
155        ALOGD("channel '%s' ~ Received key event.",
156                r->getInputChannelName());
157#endif
158        inputEventObj = android_view_KeyEvent_fromNative(env,
159                static_cast<KeyEvent*>(inputEvent));
160        break;
161
162    case AINPUT_EVENT_TYPE_MOTION:
163#if DEBUG_DISPATCH_CYCLE
164        ALOGD("channel '%s' ~ Received motion event.",
165                r->getInputChannelName());
166#endif
167        inputEventObj = android_view_MotionEvent_obtainAsCopy(env,
168                static_cast<MotionEvent*>(inputEvent));
169        break;
170
171    default:
172        assert(false); // InputConsumer should prevent this from ever happening
173        inputEventObj = NULL;
174    }
175
176    if (!inputEventObj) {
177        ALOGW("channel '%s' ~ Failed to obtain event object.",
178                r->getInputChannelName());
179        r->mInputConsumer.sendFinishedSignal(false);
180        return 1;
181    }
182
183    r->mEventInProgress = true;
184
185#if DEBUG_DISPATCH_CYCLE
186    ALOGD("channel '%s' ~ Invoking input handler.", r->getInputChannelName());
187#endif
188    env->CallVoidMethod(r->mReceiverObjGlobal,
189            gInputEventReceiverClassInfo.dispatchInputEvent, inputEventObj);
190#if DEBUG_DISPATCH_CYCLE
191    ALOGD("channel '%s' ~ Returned from input handler.", r->getInputChannelName());
192#endif
193
194    if (env->ExceptionCheck()) {
195        ALOGE("channel '%s' ~ An exception occurred while dispatching an event.",
196                r->getInputChannelName());
197        LOGE_EX(env);
198        env->ExceptionClear();
199
200        if (r->mEventInProgress) {
201            r->mInputConsumer.sendFinishedSignal(false);
202            r->mEventInProgress = false;
203        }
204    }
205
206    env->DeleteLocalRef(inputEventObj);
207    return 1;
208}
209
210
211static jint nativeInit(JNIEnv* env, jclass clazz, jobject receiverObj,
212        jobject inputChannelObj, jobject messageQueueObj) {
213    sp<InputChannel> inputChannel = android_view_InputChannel_getInputChannel(env,
214            inputChannelObj);
215    if (inputChannel == NULL) {
216        jniThrowRuntimeException(env, "InputChannel is not initialized.");
217        return 0;
218    }
219
220    sp<Looper> looper = android_os_MessageQueue_getLooper(env, messageQueueObj);
221    if (looper == NULL) {
222        jniThrowRuntimeException(env, "MessageQueue is not initialized.");
223        return 0;
224    }
225
226    sp<NativeInputEventReceiver> receiver = new NativeInputEventReceiver(env,
227            receiverObj, inputChannel, looper);
228    status_t status = receiver->initialize();
229    if (status) {
230        String8 message;
231        message.appendFormat("Failed to initialize input event receiver.  status=%d", status);
232        jniThrowRuntimeException(env, message.string());
233        return 0;
234    }
235
236    receiver->incStrong(gInputEventReceiverClassInfo.clazz); // retain a reference for the object
237    return reinterpret_cast<jint>(receiver.get());
238}
239
240static void nativeDispose(JNIEnv* env, jclass clazz, jint receiverPtr) {
241    sp<NativeInputEventReceiver> receiver =
242            reinterpret_cast<NativeInputEventReceiver*>(receiverPtr);
243    receiver->decStrong(gInputEventReceiverClassInfo.clazz); // drop reference held by the object
244}
245
246static void nativeFinishInputEvent(JNIEnv* env, jclass clazz, jint receiverPtr, jboolean handled) {
247    sp<NativeInputEventReceiver> receiver =
248            reinterpret_cast<NativeInputEventReceiver*>(receiverPtr);
249    status_t status = receiver->finishInputEvent(handled);
250    if (status) {
251        String8 message;
252        message.appendFormat("Failed to finish input event.  status=%d", status);
253        jniThrowRuntimeException(env, message.string());
254    }
255}
256
257
258static JNINativeMethod gMethods[] = {
259    /* name, signature, funcPtr */
260    { "nativeInit",
261            "(Landroid/view/InputEventReceiver;Landroid/view/InputChannel;Landroid/os/MessageQueue;)I",
262            (void*)nativeInit },
263    { "nativeDispose",
264            "(I)V",
265            (void*)nativeDispose },
266    { "nativeFinishInputEvent", "(IZ)V",
267            (void*)nativeFinishInputEvent }
268};
269
270#define FIND_CLASS(var, className) \
271        var = env->FindClass(className); \
272        LOG_FATAL_IF(! var, "Unable to find class " className); \
273        var = jclass(env->NewGlobalRef(var));
274
275#define GET_METHOD_ID(var, clazz, methodName, methodDescriptor) \
276        var = env->GetMethodID(clazz, methodName, methodDescriptor); \
277        LOG_FATAL_IF(! var, "Unable to find method " methodName);
278
279int register_android_view_InputEventReceiver(JNIEnv* env) {
280    int res = jniRegisterNativeMethods(env, "android/view/InputEventReceiver",
281            gMethods, NELEM(gMethods));
282    LOG_FATAL_IF(res < 0, "Unable to register native methods.");
283
284    FIND_CLASS(gInputEventReceiverClassInfo.clazz, "android/view/InputEventReceiver");
285
286    GET_METHOD_ID(gInputEventReceiverClassInfo.dispatchInputEvent,
287            gInputEventReceiverClassInfo.clazz,
288            "dispatchInputEvent", "(Landroid/view/InputEvent;)V");
289    return 0;
290}
291
292} // namespace android
293