The Tor Browser: widget/gonk/libui/InputTransport.h@6474c204b198 (annotated)

widget/gonk/libui/InputTransport.h@6474c204b198 (annotated)

widget/gonk/libui/InputTransport.h

Wed, 31 Dec 2014 06:09:35 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 06:09:35 +0100
changeset 0: 6474c204b198
permissions: -rw-r--r--

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

 /*
  * 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

The Tor Browser / annotate

widget/gonk/libui/InputTransport.h@6474c204b198 (annotated)

widget/gonk/libui/InputTransport.h