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Diffstat (limited to 'widget/gonk/libui/InputTransport.h')
| -rw-r--r-- | widget/gonk/libui/InputTransport.h | 443 |
1 files changed, 443 insertions, 0 deletions
diff --git a/widget/gonk/libui/InputTransport.h b/widget/gonk/libui/InputTransport.h new file mode 100644 index 000000000..66ef2850a --- /dev/null +++ b/widget/gonk/libui/InputTransport.h @@ -0,0 +1,443 @@ +/* + * 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 _ANDROIDFW_INPUT_TRANSPORT_H +#define _ANDROIDFW_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 "Input.h" +#include <utils/Errors.h> +#include <utils/Timers.h> +#include <utils/RefBase.h> +#include <utils/String8.h> +#include <utils/Vector.h> +#include <utils/BitSet.h> + +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]; + + int32_t getActionId() const { + uint32_t index = (action & AMOTION_EVENT_ACTION_POINTER_INDEX_MASK) + >> AMOTION_EVENT_ACTION_POINTER_INDEX_SHIFT; + return pointers[index].properties.id; + } + + 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<InputChannel>& outServerChannel, sp<InputChannel>& 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); + + /* Returns a new object that has a duplicate of this channel's fd. */ + sp<InputChannel> dup() const; + +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<InputChannel>& channel); + + /* Destroys the publisher and releases its input channel. */ + ~InputPublisher(); + + /* Gets the underlying input channel. */ + inline sp<InputChannel> 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<InputChannel> mChannel; +}; + +/* + * Consumes input events from an input channel. + */ +class InputConsumer { +public: + /* Creates a consumer associated with an input channel. */ + explicit InputConsumer(const sp<InputChannel>& channel); + + /* Destroys the consumer and releases its input channel. */ + ~InputConsumer(); + + /* Gets the underlying input channel. */ + inline sp<InputChannel> 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 frameTime parameter specifies the time when the current display frame started + * rendering in the CLOCK_MONOTONIC time base, or -1 if unknown. + * + * 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, + nsecs_t frameTime, 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 deferred event waiting. + * + * Should be called after calling consume() to determine whether the consumer + * has a deferred event to be processed. Deferred events are somewhat special in + * that they have already been removed from the input channel. If the input channel + * becomes empty, the client may need to do extra work to ensure that it processes + * the deferred event despite the fact that the input channel's file descriptor + * is not readable. + * + * One option is simply to call consume() in a loop until it returns WOULD_BLOCK. + * This guarantees that all deferred events will be processed. + * + * Alternately, the caller can call hasDeferredEvent() to determine whether there is + * a deferred event waiting and then ensure that its event loop wakes up at least + * one more time to consume the deferred event. + */ + bool hasDeferredEvent() const; + + /* Returns true if there is a pending batch. + * + * Should be called after calling consume() with consumeBatches == false to determine + * whether consume() should be called again later on with consumeBatches == true. + */ + bool hasPendingBatch() const; + +private: + // True if touch resampling is enabled. + const bool mResampleTouch; + + // The input channel. + sp<InputChannel> 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 { + Vector<InputMessage> samples; + }; + Vector<Batch> mBatches; + + // Touch state per device and source, only for sources of class pointer. + struct History { + nsecs_t eventTime; + BitSet32 idBits; + int32_t idToIndex[MAX_POINTER_ID + 1]; + PointerCoords pointers[MAX_POINTERS]; + + void initializeFrom(const InputMessage* msg) { + eventTime = msg->body.motion.eventTime; + idBits.clear(); + for (size_t i = 0; i < msg->body.motion.pointerCount; i++) { + uint32_t id = msg->body.motion.pointers[i].properties.id; + idBits.markBit(id); + idToIndex[id] = i; + pointers[i].copyFrom(msg->body.motion.pointers[i].coords); + } + } + + const PointerCoords& getPointerById(uint32_t id) const { + return pointers[idToIndex[id]]; + } + }; + struct TouchState { + int32_t deviceId; + int32_t source; + size_t historyCurrent; + size_t historySize; + History history[2]; + History lastResample; + + void initialize(int32_t deviceId, int32_t source) { + this->deviceId = deviceId; + this->source = source; + historyCurrent = 0; + historySize = 0; + lastResample.eventTime = 0; + lastResample.idBits.clear(); + } + + void addHistory(const InputMessage* msg) { + historyCurrent ^= 1; + if (historySize < 2) { + historySize += 1; + } + history[historyCurrent].initializeFrom(msg); + } + + const History* getHistory(size_t index) const { + return &history[(historyCurrent + index) & 1]; + } + }; + Vector<TouchState> mTouchStates; + + // 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<SeqChain> mSeqChains; + + status_t consumeBatch(InputEventFactoryInterface* factory, + nsecs_t frameTime, uint32_t* outSeq, InputEvent** outEvent); + status_t consumeSamples(InputEventFactoryInterface* factory, + Batch& batch, size_t count, uint32_t* outSeq, InputEvent** outEvent); + + void updateTouchState(InputMessage* msg); + void rewriteMessage(const TouchState& state, InputMessage* msg); + void resampleTouchState(nsecs_t frameTime, MotionEvent* event, + const InputMessage *next); + + ssize_t findBatch(int32_t deviceId, int32_t source) const; + ssize_t findTouchState(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 void addSample(MotionEvent* event, const InputMessage* msg); + static bool canAddSample(const Batch& batch, const InputMessage* msg); + static ssize_t findSampleNoLaterThan(const Batch& batch, nsecs_t time); + static bool shouldResampleTool(int32_t toolType); + + static bool isTouchResamplingEnabled(); +}; + +} // namespace android + +#endif // _ANDROIDFW_INPUT_TRANSPORT_H |