android_view_InputEventReceiver.cpp revision 603b44589682db3ff33ade172facb0c5e309f1be 
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 <androidfw/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    jmethodID dispatchBatchedInputEventPending;
44} gInputEventReceiverClassInfo;
45
46
47class NativeInputEventReceiver : public RefBase {
48public:
49    NativeInputEventReceiver(JNIEnv* env,
50            jobject receiverObj, const sp<InputChannel>& inputChannel,
51            const sp<MessageQueue>& messageQueue);
52
53    status_t initialize();
54    status_t finishInputEvent(uint32_t seq, bool handled);
55    status_t consumeEvents(bool consumeBatches);
56    static int handleReceiveCallback(int receiveFd, int events, void* data);
57
58protected:
59    virtual ~NativeInputEventReceiver();
60
61private:
62    jobject mReceiverObjGlobal;
63    InputConsumer mInputConsumer;
64    sp<MessageQueue> mMessageQueue;
65    PreallocatedInputEventFactory mInputEventFactory;
66    bool mBatchedInputEventPending;
67
68    const char* getInputChannelName() {
69        return mInputConsumer.getChannel()->getName().string();
70    }
71};
72
73
74NativeInputEventReceiver::NativeInputEventReceiver(JNIEnv* env,
75        jobject receiverObj, const sp<InputChannel>& inputChannel,
76        const sp<MessageQueue>& messageQueue) :
77        mReceiverObjGlobal(env->NewGlobalRef(receiverObj)),
78        mInputConsumer(inputChannel), mMessageQueue(messageQueue),
79        mBatchedInputEventPending(false) {
80#if DEBUG_DISPATCH_CYCLE
81    ALOGD("channel '%s' ~ Initializing input event receiver.", getInputChannelName());
82#endif
83}
84
85NativeInputEventReceiver::~NativeInputEventReceiver() {
86#if DEBUG_DISPATCH_CYCLE
87    ALOGD("channel '%s' ~ Disposing input event receiver.", getInputChannelName());
88#endif
89
90    mMessageQueue->getLooper()->removeFd(mInputConsumer.getChannel()->getFd());
91
92    JNIEnv* env = AndroidRuntime::getJNIEnv();
93    env->DeleteGlobalRef(mReceiverObjGlobal);
94}
95
96status_t NativeInputEventReceiver::initialize() {
97    int receiveFd = mInputConsumer.getChannel()->getFd();
98    mMessageQueue->getLooper()->addFd(
99            receiveFd, 0, ALOOPER_EVENT_INPUT, handleReceiveCallback, this);
100    return OK;
101}
102
103status_t NativeInputEventReceiver::finishInputEvent(uint32_t seq, bool handled) {
104#if DEBUG_DISPATCH_CYCLE
105    ALOGD("channel '%s' ~ Finished input event.", getInputChannelName());
106#endif
107
108    status_t status = mInputConsumer.sendFinishedSignal(seq, handled);
109    if (status) {
110        ALOGW("Failed to send finished signal on channel '%s'.  status=%d",
111                getInputChannelName(), status);
112    }
113    return status;
114}
115
116int NativeInputEventReceiver::handleReceiveCallback(int receiveFd, int events, void* data) {
117    sp<NativeInputEventReceiver> r = static_cast<NativeInputEventReceiver*>(data);
118
119    if (events & (ALOOPER_EVENT_ERROR | ALOOPER_EVENT_HANGUP)) {
120        ALOGE("channel '%s' ~ Publisher closed input channel or an error occurred.  "
121                "events=0x%x", r->getInputChannelName(), events);
122        return 0; // remove the callback
123    }
124
125    if (!(events & ALOOPER_EVENT_INPUT)) {
126        ALOGW("channel '%s' ~ Received spurious callback for unhandled poll event.  "
127                "events=0x%x", r->getInputChannelName(), events);
128        return 1;
129    }
130
131    status_t status = r->consumeEvents(false /*consumeBatches*/);
132    return status == OK || status == NO_MEMORY ? 1 : 0;
133}
134
135status_t NativeInputEventReceiver::consumeEvents(bool consumeBatches) {
136#if DEBUG_DISPATCH_CYCLE
137    ALOGD("channel '%s' ~ Consuming input events, consumeBatches=%s.", getInputChannelName(),
138            consumeBatches ? "true" : "false");
139#endif
140
141    if (consumeBatches) {
142        mBatchedInputEventPending = false;
143    }
144
145    JNIEnv* env = AndroidRuntime::getJNIEnv();
146    for (;;) {
147        uint32_t seq;
148        InputEvent* inputEvent;
149        status_t status = mInputConsumer.consume(&mInputEventFactory,
150                consumeBatches, &seq, &inputEvent);
151        if (status) {
152            if (status == WOULD_BLOCK) {
153                if (mInputConsumer.hasPendingBatch() && !mBatchedInputEventPending) {
154                    // There is a pending batch.  Come back later.
155                    mBatchedInputEventPending = true;
156#if DEBUG_DISPATCH_CYCLE
157                    ALOGD("channel '%s' ~ Dispatching batched input event pending notification.",
158                            getInputChannelName());
159#endif
160                    env->CallVoidMethod(mReceiverObjGlobal,
161                            gInputEventReceiverClassInfo.dispatchBatchedInputEventPending);
162                    if (mMessageQueue->raiseAndClearException(
163                            env, "dispatchBatchedInputEventPending")) {
164                        mBatchedInputEventPending = false; // try again later
165                    }
166                }
167                return OK;
168            }
169            ALOGE("channel '%s' ~ Failed to consume input event.  status=%d",
170                    getInputChannelName(), status);
171            return status;
172        }
173        assert(inputEvent);
174
175        jobject inputEventObj;
176        switch (inputEvent->getType()) {
177        case AINPUT_EVENT_TYPE_KEY:
178#if DEBUG_DISPATCH_CYCLE
179            ALOGD("channel '%s' ~ Received key event.", getInputChannelName());
180#endif
181            inputEventObj = android_view_KeyEvent_fromNative(env,
182                    static_cast<KeyEvent*>(inputEvent));
183            mMessageQueue->raiseAndClearException(env, "new KeyEvent");
184            break;
185
186        case AINPUT_EVENT_TYPE_MOTION:
187#if DEBUG_DISPATCH_CYCLE
188            ALOGD("channel '%s' ~ Received motion event.", getInputChannelName());
189#endif
190            inputEventObj = android_view_MotionEvent_obtainAsCopy(env,
191                    static_cast<MotionEvent*>(inputEvent));
192            mMessageQueue->raiseAndClearException(env, "new MotionEvent");
193            break;
194
195        default:
196            assert(false); // InputConsumer should prevent this from ever happening
197            inputEventObj = NULL;
198        }
199
200        if (!inputEventObj) {
201            ALOGW("channel '%s' ~ Failed to obtain event object.", getInputChannelName());
202            mInputConsumer.sendFinishedSignal(seq, false);
203            continue;
204        }
205
206#if DEBUG_DISPATCH_CYCLE
207        ALOGD("channel '%s' ~ Dispatching input event.", getInputChannelName());
208#endif
209        env->CallVoidMethod(mReceiverObjGlobal,
210                gInputEventReceiverClassInfo.dispatchInputEvent, seq, inputEventObj);
211
212        env->DeleteLocalRef(inputEventObj);
213
214        if (mMessageQueue->raiseAndClearException(env, "dispatchInputEvent")) {
215            mInputConsumer.sendFinishedSignal(seq, false);
216        }
217    }
218}
219
220
221static jint nativeInit(JNIEnv* env, jclass clazz, jobject receiverObj,
222        jobject inputChannelObj, jobject messageQueueObj) {
223    sp<InputChannel> inputChannel = android_view_InputChannel_getInputChannel(env,
224            inputChannelObj);
225    if (inputChannel == NULL) {
226        jniThrowRuntimeException(env, "InputChannel is not initialized.");
227        return 0;
228    }
229
230    sp<MessageQueue> messageQueue = android_os_MessageQueue_getMessageQueue(env, messageQueueObj);
231    if (messageQueue == NULL) {
232        jniThrowRuntimeException(env, "MessageQueue is not initialized.");
233        return 0;
234    }
235
236    sp<NativeInputEventReceiver> receiver = new NativeInputEventReceiver(env,
237            receiverObj, inputChannel, messageQueue);
238    status_t status = receiver->initialize();
239    if (status) {
240        String8 message;
241        message.appendFormat("Failed to initialize input event receiver.  status=%d", status);
242        jniThrowRuntimeException(env, message.string());
243        return 0;
244    }
245
246    receiver->incStrong(gInputEventReceiverClassInfo.clazz); // retain a reference for the object
247    return reinterpret_cast<jint>(receiver.get());
248}
249
250static void nativeDispose(JNIEnv* env, jclass clazz, jint receiverPtr) {
251    sp<NativeInputEventReceiver> receiver =
252            reinterpret_cast<NativeInputEventReceiver*>(receiverPtr);
253    receiver->decStrong(gInputEventReceiverClassInfo.clazz); // drop reference held by the object
254}
255
256static void nativeFinishInputEvent(JNIEnv* env, jclass clazz, jint receiverPtr,
257        jint seq, jboolean handled) {
258    sp<NativeInputEventReceiver> receiver =
259            reinterpret_cast<NativeInputEventReceiver*>(receiverPtr);
260    status_t status = receiver->finishInputEvent(seq, handled);
261    if (status && status != DEAD_OBJECT) {
262        String8 message;
263        message.appendFormat("Failed to finish input event.  status=%d", status);
264        jniThrowRuntimeException(env, message.string());
265    }
266}
267
268static void nativeConsumeBatchedInputEvents(JNIEnv* env, jclass clazz, jint receiverPtr) {
269    sp<NativeInputEventReceiver> receiver =
270            reinterpret_cast<NativeInputEventReceiver*>(receiverPtr);
271    status_t status = receiver->consumeEvents(true /*consumeBatches*/);
272    if (status && status != DEAD_OBJECT) {
273        String8 message;
274        message.appendFormat("Failed to consume batched input event.  status=%d", status);
275        jniThrowRuntimeException(env, message.string());
276    }
277}
278
279
280static JNINativeMethod gMethods[] = {
281    /* name, signature, funcPtr */
282    { "nativeInit",
283            "(Landroid/view/InputEventReceiver;Landroid/view/InputChannel;Landroid/os/MessageQueue;)I",
284            (void*)nativeInit },
285    { "nativeDispose", "(I)V",
286            (void*)nativeDispose },
287    { "nativeFinishInputEvent", "(IIZ)V",
288            (void*)nativeFinishInputEvent },
289    { "nativeConsumeBatchedInputEvents", "(I)V",
290            (void*)nativeConsumeBatchedInputEvents },
291};
292
293#define FIND_CLASS(var, className) \
294        var = env->FindClass(className); \
295        LOG_FATAL_IF(! var, "Unable to find class " className); \
296        var = jclass(env->NewGlobalRef(var));
297
298#define GET_METHOD_ID(var, clazz, methodName, methodDescriptor) \
299        var = env->GetMethodID(clazz, methodName, methodDescriptor); \
300        LOG_FATAL_IF(! var, "Unable to find method " methodName);
301
302int register_android_view_InputEventReceiver(JNIEnv* env) {
303    int res = jniRegisterNativeMethods(env, "android/view/InputEventReceiver",
304            gMethods, NELEM(gMethods));
305    LOG_FATAL_IF(res < 0, "Unable to register native methods.");
306
307    FIND_CLASS(gInputEventReceiverClassInfo.clazz, "android/view/InputEventReceiver");
308
309    GET_METHOD_ID(gInputEventReceiverClassInfo.dispatchInputEvent,
310            gInputEventReceiverClassInfo.clazz,
311            "dispatchInputEvent", "(ILandroid/view/InputEvent;)V");
312    GET_METHOD_ID(gInputEventReceiverClassInfo.dispatchBatchedInputEventPending,
313            gInputEventReceiverClassInfo.clazz,
314            "dispatchBatchedInputEventPending", "()V");
315    return 0;
316}
317
318} // namespace android
319