/* * Copyright (C) 2010 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #ifndef _UI_INPUT_TRANSPORT_H #define _UI_INPUT_TRANSPORT_H /** * Native input transport. * * The InputChannel provides a mechanism for exchanging InputMessage structures across processes. * * The InputPublisher and InputConsumer each handle one end-point of an input channel. * The InputPublisher is used by the input dispatcher to send events to the application. * The InputConsumer is used by the application to receive events from the input dispatcher. */ #include #include #include #include #include namespace android { /* * Intermediate representation used to send input events and related signals. */ struct InputMessage { enum { TYPE_KEY = 1, TYPE_MOTION = 2, TYPE_FINISHED = 3, }; struct Header { uint32_t type; uint32_t padding; // 8 byte alignment for the body that follows } header; union Body { struct Key { uint32_t seq; nsecs_t eventTime; int32_t deviceId; int32_t source; int32_t action; int32_t flags; int32_t keyCode; int32_t scanCode; int32_t metaState; int32_t repeatCount; nsecs_t downTime; inline size_t size() const { return sizeof(Key); } } key; struct Motion { uint32_t seq; nsecs_t eventTime; int32_t deviceId; int32_t source; int32_t action; int32_t flags; int32_t metaState; int32_t buttonState; int32_t edgeFlags; nsecs_t downTime; float xOffset; float yOffset; float xPrecision; float yPrecision; size_t pointerCount; struct Pointer { PointerProperties properties; PointerCoords coords; } pointers[MAX_POINTERS]; inline size_t size() const { return sizeof(Motion) - sizeof(Pointer) * MAX_POINTERS + sizeof(Pointer) * pointerCount; } } motion; struct Finished { uint32_t seq; bool handled; inline size_t size() const { return sizeof(Finished); } } finished; } body; bool isValid(size_t actualSize) const; size_t size() const; }; /* * An input channel consists of a local unix domain socket used to send and receive * input messages across processes. Each channel has a descriptive name for debugging purposes. * * Each endpoint has its own InputChannel object that specifies its file descriptor. * * The input channel is closed when all references to it are released. */ class InputChannel : public RefBase { protected: virtual ~InputChannel(); public: InputChannel(const String8& name, int fd); /* Creates a pair of input channels. * * Returns OK on success. */ static status_t openInputChannelPair(const String8& name, sp& outServerChannel, sp& outClientChannel); inline String8 getName() const { return mName; } inline int getFd() const { return mFd; } /* Sends a message to the other endpoint. * * If the channel is full then the message is guaranteed not to have been sent at all. * Try again after the consumer has sent a finished signal indicating that it has * consumed some of the pending messages from the channel. * * Returns OK on success. * Returns WOULD_BLOCK if the channel is full. * Returns DEAD_OBJECT if the channel's peer has been closed. * Other errors probably indicate that the channel is broken. */ status_t sendMessage(const InputMessage* msg); /* Receives a message sent by the other endpoint. * * If there is no message present, try again after poll() indicates that the fd * is readable. * * Returns OK on success. * Returns WOULD_BLOCK if there is no message present. * Returns DEAD_OBJECT if the channel's peer has been closed. * Other errors probably indicate that the channel is broken. */ status_t receiveMessage(InputMessage* msg); private: String8 mName; int mFd; }; /* * Publishes input events to an input channel. */ class InputPublisher { public: /* Creates a publisher associated with an input channel. */ explicit InputPublisher(const sp& channel); /* Destroys the publisher and releases its input channel. */ ~InputPublisher(); /* Gets the underlying input channel. */ inline sp getChannel() { return mChannel; } /* Publishes a key event to the input channel. * * Returns OK on success. * Returns WOULD_BLOCK if the channel is full. * Returns DEAD_OBJECT if the channel's peer has been closed. * Returns BAD_VALUE if seq is 0. * Other errors probably indicate that the channel is broken. */ status_t publishKeyEvent( uint32_t seq, int32_t deviceId, int32_t source, int32_t action, int32_t flags, int32_t keyCode, int32_t scanCode, int32_t metaState, int32_t repeatCount, nsecs_t downTime, nsecs_t eventTime); /* Publishes a motion event to the input channel. * * Returns OK on success. * Returns WOULD_BLOCK if the channel is full. * Returns DEAD_OBJECT if the channel's peer has been closed. * Returns BAD_VALUE if seq is 0 or if pointerCount is less than 1 or greater than MAX_POINTERS. * Other errors probably indicate that the channel is broken. */ status_t publishMotionEvent( uint32_t seq, int32_t deviceId, int32_t source, int32_t action, int32_t flags, int32_t edgeFlags, int32_t metaState, int32_t buttonState, float xOffset, float yOffset, float xPrecision, float yPrecision, nsecs_t downTime, nsecs_t eventTime, size_t pointerCount, const PointerProperties* pointerProperties, const PointerCoords* pointerCoords); /* Receives the finished signal from the consumer in reply to the original dispatch signal. * If a signal was received, returns the message sequence number, * and whether the consumer handled the message. * * The returned sequence number is never 0 unless the operation failed. * * Returns OK on success. * Returns WOULD_BLOCK if there is no signal present. * Returns DEAD_OBJECT if the channel's peer has been closed. * Other errors probably indicate that the channel is broken. */ status_t receiveFinishedSignal(uint32_t* outSeq, bool* outHandled); private: sp mChannel; }; /* * Consumes input events from an input channel. */ class InputConsumer { public: /* Creates a consumer associated with an input channel. */ explicit InputConsumer(const sp& channel); /* Destroys the consumer and releases its input channel. */ ~InputConsumer(); /* Gets the underlying input channel. */ inline sp getChannel() { return mChannel; } /* Consumes an input event from the input channel and copies its contents into * an InputEvent object created using the specified factory. * * Tries to combine a series of move events into larger batches whenever possible. * * If consumeBatches is false, then defers consuming pending batched events if it * is possible for additional samples to be added to them later. Call hasPendingBatch() * to determine whether a pending batch is available to be consumed. * * If consumeBatches is true, then events are still batched but they are consumed * immediately as soon as the input channel is exhausted. * * The returned sequence number is never 0 unless the operation failed. * * Returns OK on success. * Returns WOULD_BLOCK if there is no event present. * Returns DEAD_OBJECT if the channel's peer has been closed. * Returns NO_MEMORY if the event could not be created. * Other errors probably indicate that the channel is broken. */ status_t consume(InputEventFactoryInterface* factory, bool consumeBatches, uint32_t* outSeq, InputEvent** outEvent); /* Sends a finished signal to the publisher to inform it that the message * with the specified sequence number has finished being process and whether * the message was handled by the consumer. * * Returns OK on success. * Returns BAD_VALUE if seq is 0. * Other errors probably indicate that the channel is broken. */ status_t sendFinishedSignal(uint32_t seq, bool handled); /* Returns true if there is a pending batch. */ bool hasPendingBatch() const; private: sp mChannel; // The current input message. InputMessage mMsg; // True if mMsg contains a valid input message that was deferred from the previous // call to consume and that still needs to be handled. bool mMsgDeferred; // Batched motion events per device and source. struct Batch { uint32_t seq; // sequence number of last input message batched in the event MotionEvent event; }; Vector mBatches; // Chain of batched sequence numbers. When multiple input messages are combined into // a batch, we append a record here that associates the last sequence number in the // batch with the previous one. When the finished signal is sent, we traverse the // chain to individually finish all input messages that were part of the batch. struct SeqChain { uint32_t seq; // sequence number of batched input message uint32_t chain; // sequence number of previous batched input message }; Vector mSeqChains; ssize_t findBatch(int32_t deviceId, int32_t source) const; status_t sendUnchainedFinishedSignal(uint32_t seq, bool handled); static void initializeKeyEvent(KeyEvent* event, const InputMessage* msg); static void initializeMotionEvent(MotionEvent* event, const InputMessage* msg); static bool canAppendSamples(const MotionEvent* event, const InputMessage* msg); static void appendSamples(MotionEvent* event, const InputMessage* msg); }; } // namespace android #endif // _UI_INPUT_TRANSPORT_H