Add m-esr52 at 52.6.0

1 files changed, 1117 insertions, 0 deletions

diff --git a/widget/gonk/libui/InputDispatcher.h b/widget/gonk/libui/InputDispatcher.h
new file mode 100644
index 000000000..5453421f6
--- /dev/null
+++ b/widget/gonk/libui/InputDispatcher.h
@@ -0,0 +1,1117 @@
+/*
+ * 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_DISPATCHER_H
+#define _UI_INPUT_DISPATCHER_H
+
+#include "Input.h"
+#include "InputTransport.h"
+#include <utils/KeyedVector.h>
+#include <utils/Vector.h>
+#include <utils/threads.h>
+#include <utils/Timers.h>
+#include <utils/RefBase.h>
+#include <utils/String8.h>
+#include <utils/Looper.h>
+#include <utils/BitSet.h>
+#include <cutils/atomic.h>
+
+#include <stddef.h>
+#include <unistd.h>
+#include <limits.h>
+
+#include "InputWindow.h"
+#include "InputApplication.h"
+#include "InputListener.h"
+
+
+namespace android {
+
+/*
+ * Constants used to report the outcome of input event injection.
+ */
+enum {
+    /* (INTERNAL USE ONLY) Specifies that injection is pending and its outcome is unknown. */
+    INPUT_EVENT_INJECTION_PENDING = -1,
+
+    /* Injection succeeded. */
+    INPUT_EVENT_INJECTION_SUCCEEDED = 0,
+
+    /* Injection failed because the injector did not have permission to inject
+     * into the application with input focus. */
+    INPUT_EVENT_INJECTION_PERMISSION_DENIED = 1,
+
+    /* Injection failed because there were no available input targets. */
+    INPUT_EVENT_INJECTION_FAILED = 2,
+
+    /* Injection failed due to a timeout. */
+    INPUT_EVENT_INJECTION_TIMED_OUT = 3
+};
+
+/*
+ * Constants used to determine the input event injection synchronization mode.
+ */
+enum {
+    /* Injection is asynchronous and is assumed always to be successful. */
+    INPUT_EVENT_INJECTION_SYNC_NONE = 0,
+
+    /* Waits for previous events to be dispatched so that the input dispatcher can determine
+     * whether input event injection willbe permitted based on the current input focus.
+     * Does not wait for the input event to finish processing. */
+    INPUT_EVENT_INJECTION_SYNC_WAIT_FOR_RESULT = 1,
+
+    /* Waits for the input event to be completely processed. */
+    INPUT_EVENT_INJECTION_SYNC_WAIT_FOR_FINISHED = 2,
+};
+
+
+/*
+ * An input target specifies how an input event is to be dispatched to a particular window
+ * including the window's input channel, control flags, a timeout, and an X / Y offset to
+ * be added to input event coordinates to compensate for the absolute position of the
+ * window area.
+ */
+struct InputTarget {
+    enum {
+        /* This flag indicates that the event is being delivered to a foreground application. */
+        FLAG_FOREGROUND = 1 << 0,
+
+        /* This flag indicates that the target of a MotionEvent is partly or wholly
+         * obscured by another visible window above it.  The motion event should be
+         * delivered with flag AMOTION_EVENT_FLAG_WINDOW_IS_OBSCURED. */
+        FLAG_WINDOW_IS_OBSCURED = 1 << 1,
+
+        /* This flag indicates that a motion event is being split across multiple windows. */
+        FLAG_SPLIT = 1 << 2,
+
+        /* This flag indicates that the pointer coordinates dispatched to the application
+         * will be zeroed out to avoid revealing information to an application. This is
+         * used in conjunction with FLAG_DISPATCH_AS_OUTSIDE to prevent apps not sharing
+         * the same UID from watching all touches. */
+        FLAG_ZERO_COORDS = 1 << 3,
+
+        /* This flag indicates that the event should be sent as is.
+         * Should always be set unless the event is to be transmuted. */
+        FLAG_DISPATCH_AS_IS = 1 << 8,
+
+        /* This flag indicates that a MotionEvent with AMOTION_EVENT_ACTION_DOWN falls outside
+         * of the area of this target and so should instead be delivered as an
+         * AMOTION_EVENT_ACTION_OUTSIDE to this target. */
+        FLAG_DISPATCH_AS_OUTSIDE = 1 << 9,
+
+        /* This flag indicates that a hover sequence is starting in the given window.
+         * The event is transmuted into ACTION_HOVER_ENTER. */
+        FLAG_DISPATCH_AS_HOVER_ENTER = 1 << 10,
+
+        /* This flag indicates that a hover event happened outside of a window which handled
+         * previous hover events, signifying the end of the current hover sequence for that
+         * window.
+         * The event is transmuted into ACTION_HOVER_ENTER. */
+        FLAG_DISPATCH_AS_HOVER_EXIT = 1 << 11,
+
+        /* This flag indicates that the event should be canceled.
+         * It is used to transmute ACTION_MOVE into ACTION_CANCEL when a touch slips
+         * outside of a window. */
+        FLAG_DISPATCH_AS_SLIPPERY_EXIT = 1 << 12,
+
+        /* This flag indicates that the event should be dispatched as an initial down.
+         * It is used to transmute ACTION_MOVE into ACTION_DOWN when a touch slips
+         * into a new window. */
+        FLAG_DISPATCH_AS_SLIPPERY_ENTER = 1 << 13,
+
+        /* Mask for all dispatch modes. */
+        FLAG_DISPATCH_MASK = FLAG_DISPATCH_AS_IS
+                | FLAG_DISPATCH_AS_OUTSIDE
+                | FLAG_DISPATCH_AS_HOVER_ENTER
+                | FLAG_DISPATCH_AS_HOVER_EXIT
+                | FLAG_DISPATCH_AS_SLIPPERY_EXIT
+                | FLAG_DISPATCH_AS_SLIPPERY_ENTER,
+    };
+
+    // The input channel to be targeted.
+    sp<InputChannel> inputChannel;
+
+    // Flags for the input target.
+    int32_t flags;
+
+    // The x and y offset to add to a MotionEvent as it is delivered.
+    // (ignored for KeyEvents)
+    float xOffset, yOffset;
+
+    // Scaling factor to apply to MotionEvent as it is delivered.
+    // (ignored for KeyEvents)
+    float scaleFactor;
+
+    // The subset of pointer ids to include in motion events dispatched to this input target
+    // if FLAG_SPLIT is set.
+    BitSet32 pointerIds;
+};
+
+
+/*
+ * Input dispatcher configuration.
+ *
+ * Specifies various options that modify the behavior of the input dispatcher.
+ * The values provided here are merely defaults. The actual values will come from ViewConfiguration
+ * and are passed into the dispatcher during initialization.
+ */
+struct InputDispatcherConfiguration {
+    // The key repeat initial timeout.
+    nsecs_t keyRepeatTimeout;
+
+    // The key repeat inter-key delay.
+    nsecs_t keyRepeatDelay;
+
+    InputDispatcherConfiguration() :
+            keyRepeatTimeout(500 * 1000000LL),
+            keyRepeatDelay(50 * 1000000LL) { }
+};
+
+
+/*
+ * Input dispatcher policy interface.
+ *
+ * The input reader policy is used by the input reader to interact with the Window Manager
+ * and other system components.
+ *
+ * The actual implementation is partially supported by callbacks into the DVM
+ * via JNI.  This interface is also mocked in the unit tests.
+ */
+class InputDispatcherPolicyInterface : public virtual RefBase {
+protected:
+    InputDispatcherPolicyInterface() { }
+    virtual ~InputDispatcherPolicyInterface() { }
+
+public:
+    /* Notifies the system that a configuration change has occurred. */
+    virtual void notifyConfigurationChanged(nsecs_t when) = 0;
+
+    /* Notifies the system that an application is not responding.
+     * Returns a new timeout to continue waiting, or 0 to abort dispatch. */
+    virtual nsecs_t notifyANR(const sp<InputApplicationHandle>& inputApplicationHandle,
+            const sp<InputWindowHandle>& inputWindowHandle) = 0;
+
+    /* Notifies the system that an input channel is unrecoverably broken. */
+    virtual void notifyInputChannelBroken(const sp<InputWindowHandle>& inputWindowHandle) = 0;
+
+    /* Gets the input dispatcher configuration. */
+    virtual void getDispatcherConfiguration(InputDispatcherConfiguration* outConfig) = 0;
+
+    /* Returns true if automatic key repeating is enabled. */
+    virtual bool isKeyRepeatEnabled() = 0;
+
+    /* Filters an input event.
+     * Return true to dispatch the event unmodified, false to consume the event.
+     * A filter can also transform and inject events later by passing POLICY_FLAG_FILTERED
+     * to injectInputEvent.
+     */
+    virtual bool filterInputEvent(const InputEvent* inputEvent, uint32_t policyFlags) = 0;
+
+    /* Intercepts a key event immediately before queueing it.
+     * The policy can use this method as an opportunity to perform power management functions
+     * and early event preprocessing such as updating policy flags.
+     *
+     * This method is expected to set the POLICY_FLAG_PASS_TO_USER policy flag if the event
+     * should be dispatched to applications.
+     */
+    virtual void interceptKeyBeforeQueueing(const KeyEvent* keyEvent, uint32_t& policyFlags) = 0;
+
+    /* Intercepts a touch, trackball or other motion event before queueing it.
+     * The policy can use this method as an opportunity to perform power management functions
+     * and early event preprocessing such as updating policy flags.
+     *
+     * This method is expected to set the POLICY_FLAG_PASS_TO_USER policy flag if the event
+     * should be dispatched to applications.
+     */
+    virtual void interceptMotionBeforeQueueing(nsecs_t when, uint32_t& policyFlags) = 0;
+
+    /* Allows the policy a chance to intercept a key before dispatching. */
+    virtual nsecs_t interceptKeyBeforeDispatching(const sp<InputWindowHandle>& inputWindowHandle,
+            const KeyEvent* keyEvent, uint32_t policyFlags) = 0;
+
+    /* Allows the policy a chance to perform default processing for an unhandled key.
+     * Returns an alternate keycode to redispatch as a fallback, or 0 to give up. */
+    virtual bool dispatchUnhandledKey(const sp<InputWindowHandle>& inputWindowHandle,
+            const KeyEvent* keyEvent, uint32_t policyFlags, KeyEvent* outFallbackKeyEvent) = 0;
+
+    /* Notifies the policy about switch events.
+     */
+    virtual void notifySwitch(nsecs_t when,
+            uint32_t switchValues, uint32_t switchMask, uint32_t policyFlags) = 0;
+
+    /* Poke user activity for an event dispatched to a window. */
+    virtual void pokeUserActivity(nsecs_t eventTime, int32_t eventType) = 0;
+
+    /* Checks whether a given application pid/uid has permission to inject input events
+     * into other applications.
+     *
+     * This method is special in that its implementation promises to be non-reentrant and
+     * is safe to call while holding other locks.  (Most other methods make no such guarantees!)
+     */
+    virtual bool checkInjectEventsPermissionNonReentrant(
+            int32_t injectorPid, int32_t injectorUid) = 0;
+};
+
+
+/* Notifies the system about input events generated by the input reader.
+ * The dispatcher is expected to be mostly asynchronous. */
+class InputDispatcherInterface : public virtual RefBase, public InputListenerInterface {
+protected:
+    InputDispatcherInterface() { }
+    virtual ~InputDispatcherInterface() { }
+
+public:
+    /* Dumps the state of the input dispatcher.
+     *
+     * This method may be called on any thread (usually by the input manager). */
+    virtual void dump(String8& dump) = 0;
+
+    /* Called by the heatbeat to ensures that the dispatcher has not deadlocked. */
+    virtual void monitor() = 0;
+
+    /* Runs a single iteration of the dispatch loop.
+     * Nominally processes one queued event, a timeout, or a response from an input consumer.
+     *
+     * This method should only be called on the input dispatcher thread.
+     */
+    virtual void dispatchOnce() = 0;
+
+    /* Injects an input event and optionally waits for sync.
+     * The synchronization mode determines whether the method blocks while waiting for
+     * input injection to proceed.
+     * Returns one of the INPUT_EVENT_INJECTION_XXX constants.
+     *
+     * This method may be called on any thread (usually by the input manager).
+     */
+    virtual int32_t injectInputEvent(const InputEvent* event,
+            int32_t injectorPid, int32_t injectorUid, int32_t syncMode, int32_t timeoutMillis,
+            uint32_t policyFlags) = 0;
+
+    /* Sets the list of input windows.
+     *
+     * This method may be called on any thread (usually by the input manager).
+     */
+    virtual void setInputWindows(const Vector<sp<InputWindowHandle> >& inputWindowHandles) = 0;
+
+    /* Sets the focused application.
+     *
+     * This method may be called on any thread (usually by the input manager).
+     */
+    virtual void setFocusedApplication(
+            const sp<InputApplicationHandle>& inputApplicationHandle) = 0;
+
+    /* Sets the input dispatching mode.
+     *
+     * This method may be called on any thread (usually by the input manager).
+     */
+    virtual void setInputDispatchMode(bool enabled, bool frozen) = 0;
+
+    /* Sets whether input event filtering is enabled.
+     * When enabled, incoming input events are sent to the policy's filterInputEvent
+     * method instead of being dispatched.  The filter is expected to use
+     * injectInputEvent to inject the events it would like to have dispatched.
+     * It should include POLICY_FLAG_FILTERED in the policy flags during injection.
+     */
+    virtual void setInputFilterEnabled(bool enabled) = 0;
+
+    /* Transfers touch focus from the window associated with one channel to the
+     * window associated with the other channel.
+     *
+     * Returns true on success.  False if the window did not actually have touch focus.
+     */
+    virtual bool transferTouchFocus(const sp<InputChannel>& fromChannel,
+            const sp<InputChannel>& toChannel) = 0;
+
+    /* Registers or unregister input channels that may be used as targets for input events.
+     * If monitor is true, the channel will receive a copy of all input events.
+     *
+     * These methods may be called on any thread (usually by the input manager).
+     */
+    virtual status_t registerInputChannel(const sp<InputChannel>& inputChannel,
+            const sp<InputWindowHandle>& inputWindowHandle, bool monitor) = 0;
+    virtual status_t unregisterInputChannel(const sp<InputChannel>& inputChannel) = 0;
+};
+
+/* Dispatches events to input targets.  Some functions of the input dispatcher, such as
+ * identifying input targets, are controlled by a separate policy object.
+ *
+ * IMPORTANT INVARIANT:
+ *     Because the policy can potentially block or cause re-entrance into the input dispatcher,
+ *     the input dispatcher never calls into the policy while holding its internal locks.
+ *     The implementation is also carefully designed to recover from scenarios such as an
+ *     input channel becoming unregistered while identifying input targets or processing timeouts.
+ *
+ *     Methods marked 'Locked' must be called with the lock acquired.
+ *
+ *     Methods marked 'LockedInterruptible' must be called with the lock acquired but
+ *     may during the course of their execution release the lock, call into the policy, and
+ *     then reacquire the lock.  The caller is responsible for recovering gracefully.
+ *
+ *     A 'LockedInterruptible' method may called a 'Locked' method, but NOT vice-versa.
+ */
+class InputDispatcher : public InputDispatcherInterface {
+protected:
+    virtual ~InputDispatcher();
+
+public:
+    explicit InputDispatcher(const sp<InputDispatcherPolicyInterface>& policy);
+
+    virtual void dump(String8& dump);
+    virtual void monitor();
+
+    virtual void dispatchOnce();
+
+    virtual void notifyConfigurationChanged(const NotifyConfigurationChangedArgs* args);
+    virtual void notifyKey(const NotifyKeyArgs* args);
+    virtual void notifyMotion(const NotifyMotionArgs* args);
+    virtual void notifySwitch(const NotifySwitchArgs* args);
+    virtual void notifyDeviceReset(const NotifyDeviceResetArgs* args);
+
+    virtual int32_t injectInputEvent(const InputEvent* event,
+            int32_t injectorPid, int32_t injectorUid, int32_t syncMode, int32_t timeoutMillis,
+            uint32_t policyFlags);
+
+    virtual void setInputWindows(const Vector<sp<InputWindowHandle> >& inputWindowHandles);
+    virtual void setFocusedApplication(const sp<InputApplicationHandle>& inputApplicationHandle);
+    virtual void setInputDispatchMode(bool enabled, bool frozen);
+    virtual void setInputFilterEnabled(bool enabled);
+
+    virtual bool transferTouchFocus(const sp<InputChannel>& fromChannel,
+            const sp<InputChannel>& toChannel);
+
+    virtual status_t registerInputChannel(const sp<InputChannel>& inputChannel,
+            const sp<InputWindowHandle>& inputWindowHandle, bool monitor);
+    virtual status_t unregisterInputChannel(const sp<InputChannel>& inputChannel);
+
+private:
+    template <typename T>
+    struct Link {
+        T* next;
+        T* prev;
+
+    protected:
+        inline Link() : next(NULL), prev(NULL) { }
+    };
+
+    struct InjectionState {
+        mutable int32_t refCount;
+
+        int32_t injectorPid;
+        int32_t injectorUid;
+        int32_t injectionResult;  // initially INPUT_EVENT_INJECTION_PENDING
+        bool injectionIsAsync; // set to true if injection is not waiting for the result
+        int32_t pendingForegroundDispatches; // the number of foreground dispatches in progress
+
+        InjectionState(int32_t injectorPid, int32_t injectorUid);
+        void release();
+
+    private:
+        ~InjectionState();
+    };
+
+    struct EventEntry : Link<EventEntry> {
+        enum {
+            TYPE_CONFIGURATION_CHANGED,
+            TYPE_DEVICE_RESET,
+            TYPE_KEY,
+            TYPE_MOTION
+        };
+
+        mutable int32_t refCount;
+        int32_t type;
+        nsecs_t eventTime;
+        uint32_t policyFlags;
+        InjectionState* injectionState;
+
+        bool dispatchInProgress; // initially false, set to true while dispatching
+
+        inline bool isInjected() const { return injectionState != NULL; }
+
+        void release();
+
+        virtual void appendDescription(String8& msg) const = 0;
+
+    protected:
+        EventEntry(int32_t type, nsecs_t eventTime, uint32_t policyFlags);
+        virtual ~EventEntry();
+        void releaseInjectionState();
+    };
+
+    struct ConfigurationChangedEntry : EventEntry {
+        ConfigurationChangedEntry(nsecs_t eventTime);
+        virtual void appendDescription(String8& msg) const;
+
+    protected:
+        virtual ~ConfigurationChangedEntry();
+    };
+
+    struct DeviceResetEntry : EventEntry {
+        int32_t deviceId;
+
+        DeviceResetEntry(nsecs_t eventTime, int32_t deviceId);
+        virtual void appendDescription(String8& msg) const;
+
+    protected:
+        virtual ~DeviceResetEntry();
+    };
+
+    struct KeyEntry : EventEntry {
+        int32_t deviceId;
+        uint32_t source;
+        int32_t action;
+        int32_t flags;
+        int32_t keyCode;
+        int32_t scanCode;
+        int32_t metaState;
+        int32_t repeatCount;
+        nsecs_t downTime;
+
+        bool syntheticRepeat; // set to true for synthetic key repeats
+
+        enum InterceptKeyResult {
+            INTERCEPT_KEY_RESULT_UNKNOWN,
+            INTERCEPT_KEY_RESULT_SKIP,
+            INTERCEPT_KEY_RESULT_CONTINUE,
+            INTERCEPT_KEY_RESULT_TRY_AGAIN_LATER,
+        };
+        InterceptKeyResult interceptKeyResult; // set based on the interception result
+        nsecs_t interceptKeyWakeupTime; // used with INTERCEPT_KEY_RESULT_TRY_AGAIN_LATER
+
+        KeyEntry(nsecs_t eventTime,
+                int32_t deviceId, uint32_t source, uint32_t policyFlags, int32_t action,
+                int32_t flags, int32_t keyCode, int32_t scanCode, int32_t metaState,
+                int32_t repeatCount, nsecs_t downTime);
+        virtual void appendDescription(String8& msg) const;
+        void recycle();
+
+    protected:
+        virtual ~KeyEntry();
+    };
+
+    struct MotionEntry : EventEntry {
+        nsecs_t eventTime;
+        int32_t deviceId;
+        uint32_t source;
+        int32_t action;
+        int32_t flags;
+        int32_t metaState;
+        int32_t buttonState;
+        int32_t edgeFlags;
+        float xPrecision;
+        float yPrecision;
+        nsecs_t downTime;
+        int32_t displayId;
+        uint32_t pointerCount;
+        PointerProperties pointerProperties[MAX_POINTERS];
+        PointerCoords pointerCoords[MAX_POINTERS];
+
+        MotionEntry(nsecs_t eventTime,
+                int32_t deviceId, uint32_t source, uint32_t policyFlags,
+                int32_t action, int32_t flags,
+                int32_t metaState, int32_t buttonState, int32_t edgeFlags,
+                float xPrecision, float yPrecision,
+                nsecs_t downTime, int32_t displayId, uint32_t pointerCount,
+                const PointerProperties* pointerProperties, const PointerCoords* pointerCoords);
+        virtual void appendDescription(String8& msg) const;
+
+    protected:
+        virtual ~MotionEntry();
+    };
+
+    // Tracks the progress of dispatching a particular event to a particular connection.
+    struct DispatchEntry : Link<DispatchEntry> {
+        const uint32_t seq; // unique sequence number, never 0
+
+        EventEntry* eventEntry; // the event to dispatch
+        int32_t targetFlags;
+        float xOffset;
+        float yOffset;
+        float scaleFactor;
+        nsecs_t deliveryTime; // time when the event was actually delivered
+
+        // Set to the resolved action and flags when the event is enqueued.
+        int32_t resolvedAction;
+        int32_t resolvedFlags;
+
+        DispatchEntry(EventEntry* eventEntry,
+                int32_t targetFlags, float xOffset, float yOffset, float scaleFactor);
+        ~DispatchEntry();
+
+        inline bool hasForegroundTarget() const {
+            return targetFlags & InputTarget::FLAG_FOREGROUND;
+        }
+
+        inline bool isSplit() const {
+            return targetFlags & InputTarget::FLAG_SPLIT;
+        }
+
+    private:
+        static volatile int32_t sNextSeqAtomic;
+
+        static uint32_t nextSeq();
+    };
+
+    // A command entry captures state and behavior for an action to be performed in the
+    // dispatch loop after the initial processing has taken place.  It is essentially
+    // a kind of continuation used to postpone sensitive policy interactions to a point
+    // in the dispatch loop where it is safe to release the lock (generally after finishing
+    // the critical parts of the dispatch cycle).
+    //
+    // The special thing about commands is that they can voluntarily release and reacquire
+    // the dispatcher lock at will.  Initially when the command starts running, the
+    // dispatcher lock is held.  However, if the command needs to call into the policy to
+    // do some work, it can release the lock, do the work, then reacquire the lock again
+    // before returning.
+    //
+    // This mechanism is a bit clunky but it helps to preserve the invariant that the dispatch
+    // never calls into the policy while holding its lock.
+    //
+    // Commands are implicitly 'LockedInterruptible'.
+    struct CommandEntry;
+    typedef void (InputDispatcher::*Command)(CommandEntry* commandEntry);
+
+    class Connection;
+    struct CommandEntry : Link<CommandEntry> {
+        CommandEntry(Command command);
+        ~CommandEntry();
+
+        Command command;
+
+        // parameters for the command (usage varies by command)
+        sp<Connection> connection;
+        nsecs_t eventTime;
+        KeyEntry* keyEntry;
+        sp<InputApplicationHandle> inputApplicationHandle;
+        sp<InputWindowHandle> inputWindowHandle;
+        int32_t userActivityEventType;
+        uint32_t seq;
+        bool handled;
+    };
+
+    // Generic queue implementation.
+    template <typename T>
+    struct Queue {
+        T* head;
+        T* tail;
+
+        inline Queue() : head(NULL), tail(NULL) {
+        }
+
+        inline bool isEmpty() const {
+            return !head;
+        }
+
+        inline void enqueueAtTail(T* entry) {
+            entry->prev = tail;
+            if (tail) {
+                tail->next = entry;
+            } else {
+                head = entry;
+            }
+            entry->next = NULL;
+            tail = entry;
+        }
+
+        inline void enqueueAtHead(T* entry) {
+            entry->next = head;
+            if (head) {
+                head->prev = entry;
+            } else {
+                tail = entry;
+            }
+            entry->prev = NULL;
+            head = entry;
+        }
+
+        inline void dequeue(T* entry) {
+            if (entry->prev) {
+                entry->prev->next = entry->next;
+            } else {
+                head = entry->next;
+            }
+            if (entry->next) {
+                entry->next->prev = entry->prev;
+            } else {
+                tail = entry->prev;
+            }
+        }
+
+        inline T* dequeueAtHead() {
+            T* entry = head;
+            head = entry->next;
+            if (head) {
+                head->prev = NULL;
+            } else {
+                tail = NULL;
+            }
+            return entry;
+        }
+
+        uint32_t count() const;
+    };
+
+    /* Specifies which events are to be canceled and why. */
+    struct CancelationOptions {
+        enum Mode {
+            CANCEL_ALL_EVENTS = 0,
+            CANCEL_POINTER_EVENTS = 1,
+            CANCEL_NON_POINTER_EVENTS = 2,
+            CANCEL_FALLBACK_EVENTS = 3,
+        };
+
+        // The criterion to use to determine which events should be canceled.
+        Mode mode;
+
+        // Descriptive reason for the cancelation.
+        const char* reason;
+
+        // The specific keycode of the key event to cancel, or -1 to cancel any key event.
+        int32_t keyCode;
+
+        // The specific device id of events to cancel, or -1 to cancel events from any device.
+        int32_t deviceId;
+
+        CancelationOptions(Mode mode, const char* reason) :
+                mode(mode), reason(reason), keyCode(-1), deviceId(-1) { }
+    };
+
+    /* Tracks dispatched key and motion event state so that cancelation events can be
+     * synthesized when events are dropped. */
+    class InputState {
+    public:
+        InputState();
+        ~InputState();
+
+        // Returns true if there is no state to be canceled.
+        bool isNeutral() const;
+
+        // Returns true if the specified source is known to have received a hover enter
+        // motion event.
+        bool isHovering(int32_t deviceId, uint32_t source, int32_t displayId) const;
+
+        // Records tracking information for a key event that has just been published.
+        // Returns true if the event should be delivered, false if it is inconsistent
+        // and should be skipped.
+        bool trackKey(const KeyEntry* entry, int32_t action, int32_t flags);
+
+        // Records tracking information for a motion event that has just been published.
+        // Returns true if the event should be delivered, false if it is inconsistent
+        // and should be skipped.
+        bool trackMotion(const MotionEntry* entry, int32_t action, int32_t flags);
+
+        // Synthesizes cancelation events for the current state and resets the tracked state.
+        void synthesizeCancelationEvents(nsecs_t currentTime,
+                Vector<EventEntry*>& outEvents, const CancelationOptions& options);
+
+        // Clears the current state.
+        void clear();
+
+        // Copies pointer-related parts of the input state to another instance.
+        void copyPointerStateTo(InputState& other) const;
+
+        // Gets the fallback key associated with a keycode.
+        // Returns -1 if none.
+        // Returns AKEYCODE_UNKNOWN if we are only dispatching the unhandled key to the policy.
+        int32_t getFallbackKey(int32_t originalKeyCode);
+
+        // Sets the fallback key for a particular keycode.
+        void setFallbackKey(int32_t originalKeyCode, int32_t fallbackKeyCode);
+
+        // Removes the fallback key for a particular keycode.
+        void removeFallbackKey(int32_t originalKeyCode);
+
+        inline const KeyedVector<int32_t, int32_t>& getFallbackKeys() const {
+            return mFallbackKeys;
+        }
+
+    private:
+        struct KeyMemento {
+            int32_t deviceId;
+            uint32_t source;
+            int32_t keyCode;
+            int32_t scanCode;
+            int32_t metaState;
+            int32_t flags;
+            nsecs_t downTime;
+            uint32_t policyFlags;
+        };
+
+        struct MotionMemento {
+            int32_t deviceId;
+            uint32_t source;
+            int32_t flags;
+            float xPrecision;
+            float yPrecision;
+            nsecs_t downTime;
+            int32_t displayId;
+            uint32_t pointerCount;
+            PointerProperties pointerProperties[MAX_POINTERS];
+            PointerCoords pointerCoords[MAX_POINTERS];
+            bool hovering;
+            uint32_t policyFlags;
+
+            void setPointers(const MotionEntry* entry);
+        };
+
+        Vector<KeyMemento> mKeyMementos;
+        Vector<MotionMemento> mMotionMementos;
+        KeyedVector<int32_t, int32_t> mFallbackKeys;
+
+        ssize_t findKeyMemento(const KeyEntry* entry) const;
+        ssize_t findMotionMemento(const MotionEntry* entry, bool hovering) const;
+
+        void addKeyMemento(const KeyEntry* entry, int32_t flags);
+        void addMotionMemento(const MotionEntry* entry, int32_t flags, bool hovering);
+
+        static bool shouldCancelKey(const KeyMemento& memento,
+                const CancelationOptions& options);
+        static bool shouldCancelMotion(const MotionMemento& memento,
+                const CancelationOptions& options);
+    };
+
+    /* Manages the dispatch state associated with a single input channel. */
+    class Connection : public RefBase {
+    protected:
+        virtual ~Connection();
+
+    public:
+        enum Status {
+            // Everything is peachy.
+            STATUS_NORMAL,
+            // An unrecoverable communication error has occurred.
+            STATUS_BROKEN,
+            // The input channel has been unregistered.
+            STATUS_ZOMBIE
+        };
+
+        Status status;
+        sp<InputChannel> inputChannel; // never null
+        sp<InputWindowHandle> inputWindowHandle; // may be null
+        bool monitor;
+        InputPublisher inputPublisher;
+        InputState inputState;
+
+        // True if the socket is full and no further events can be published until
+        // the application consumes some of the input.
+        bool inputPublisherBlocked;
+
+        // Queue of events that need to be published to the connection.
+        Queue<DispatchEntry> outboundQueue;
+
+        // Queue of events that have been published to the connection but that have not
+        // yet received a "finished" response from the application.
+        Queue<DispatchEntry> waitQueue;
+
+        explicit Connection(const sp<InputChannel>& inputChannel,
+                const sp<InputWindowHandle>& inputWindowHandle, bool monitor);
+
+        inline const char* getInputChannelName() const { return inputChannel->getName().string(); }
+
+        const char* getWindowName() const;
+        const char* getStatusLabel() const;
+
+        DispatchEntry* findWaitQueueEntry(uint32_t seq);
+    };
+
+    enum DropReason {
+        DROP_REASON_NOT_DROPPED = 0,
+        DROP_REASON_POLICY = 1,
+        DROP_REASON_APP_SWITCH = 2,
+        DROP_REASON_DISABLED = 3,
+        DROP_REASON_BLOCKED = 4,
+        DROP_REASON_STALE = 5,
+    };
+
+    sp<InputDispatcherPolicyInterface> mPolicy;
+    InputDispatcherConfiguration mConfig;
+
+    Mutex mLock;
+
+    Condition mDispatcherIsAliveCondition;
+
+    sp<Looper> mLooper;
+
+    EventEntry* mPendingEvent;
+    Queue<EventEntry> mInboundQueue;
+    Queue<CommandEntry> mCommandQueue;
+
+    void dispatchOnceInnerLocked(nsecs_t* nextWakeupTime);
+
+    // Enqueues an inbound event.  Returns true if mLooper->wake() should be called.
+    bool enqueueInboundEventLocked(EventEntry* entry);
+
+    // Cleans up input state when dropping an inbound event.
+    void dropInboundEventLocked(EventEntry* entry, DropReason dropReason);
+
+    // App switch latency optimization.
+    bool mAppSwitchSawKeyDown;
+    nsecs_t mAppSwitchDueTime;
+
+    static bool isAppSwitchKeyCode(int32_t keyCode);
+    bool isAppSwitchKeyEventLocked(KeyEntry* keyEntry);
+    bool isAppSwitchPendingLocked();
+    void resetPendingAppSwitchLocked(bool handled);
+
+    // Stale event latency optimization.
+    static bool isStaleEventLocked(nsecs_t currentTime, EventEntry* entry);
+
+    // Blocked event latency optimization.  Drops old events when the user intends
+    // to transfer focus to a new application.
+    EventEntry* mNextUnblockedEvent;
+
+    sp<InputWindowHandle> findTouchedWindowAtLocked(int32_t displayId, int32_t x, int32_t y);
+
+    // All registered connections mapped by channel file descriptor.
+    KeyedVector<int, sp<Connection> > mConnectionsByFd;
+
+    ssize_t getConnectionIndexLocked(const sp<InputChannel>& inputChannel);
+
+    // Input channels that will receive a copy of all input events.
+    Vector<sp<InputChannel> > mMonitoringChannels;
+
+    // Event injection and synchronization.
+    Condition mInjectionResultAvailableCondition;
+    bool hasInjectionPermission(int32_t injectorPid, int32_t injectorUid);
+    void setInjectionResultLocked(EventEntry* entry, int32_t injectionResult);
+
+    Condition mInjectionSyncFinishedCondition;
+    void incrementPendingForegroundDispatchesLocked(EventEntry* entry);
+    void decrementPendingForegroundDispatchesLocked(EventEntry* entry);
+
+    // Key repeat tracking.
+    struct KeyRepeatState {
+        KeyEntry* lastKeyEntry; // or null if no repeat
+        nsecs_t nextRepeatTime;
+    } mKeyRepeatState;
+
+    void resetKeyRepeatLocked();
+    KeyEntry* synthesizeKeyRepeatLocked(nsecs_t currentTime);
+
+    // Deferred command processing.
+    bool haveCommandsLocked() const;
+    bool runCommandsLockedInterruptible();
+    CommandEntry* postCommandLocked(Command command);
+
+    // Input filter processing.
+    bool shouldSendKeyToInputFilterLocked(const NotifyKeyArgs* args);
+    bool shouldSendMotionToInputFilterLocked(const NotifyMotionArgs* args);
+
+    // Inbound event processing.
+    void drainInboundQueueLocked();
+    void releasePendingEventLocked();
+    void releaseInboundEventLocked(EventEntry* entry);
+
+    // Dispatch state.
+    bool mDispatchEnabled;
+    bool mDispatchFrozen;
+    bool mInputFilterEnabled;
+
+    Vector<sp<InputWindowHandle> > mWindowHandles;
+
+    sp<InputWindowHandle> getWindowHandleLocked(const sp<InputChannel>& inputChannel) const;
+    bool hasWindowHandleLocked(const sp<InputWindowHandle>& windowHandle) const;
+
+    // Focus tracking for keys, trackball, etc.
+    sp<InputWindowHandle> mFocusedWindowHandle;
+
+    // Focus tracking for touch.
+    struct TouchedWindow {
+        sp<InputWindowHandle> windowHandle;
+        int32_t targetFlags;
+        BitSet32 pointerIds;        // zero unless target flag FLAG_SPLIT is set
+    };
+    struct TouchState {
+        bool down;
+        bool split;
+        int32_t deviceId; // id of the device that is currently down, others are rejected
+        uint32_t source;  // source of the device that is current down, others are rejected
+        int32_t displayId; // id to the display that currently has a touch, others are rejected
+        Vector<TouchedWindow> windows;
+
+        TouchState();
+        ~TouchState();
+        void reset();
+        void copyFrom(const TouchState& other);
+        void addOrUpdateWindow(const sp<InputWindowHandle>& windowHandle,
+                int32_t targetFlags, BitSet32 pointerIds);
+        void removeWindow(const sp<InputWindowHandle>& windowHandle);
+        void filterNonAsIsTouchWindows();
+        sp<InputWindowHandle> getFirstForegroundWindowHandle() const;
+        bool isSlippery() const;
+    };
+
+    TouchState mTouchState;
+    TouchState mTempTouchState;
+
+    // Focused application.
+    sp<InputApplicationHandle> mFocusedApplicationHandle;
+
+    // Dispatcher state at time of last ANR.
+    String8 mLastANRState;
+
+    // Dispatch inbound events.
+    bool dispatchConfigurationChangedLocked(
+            nsecs_t currentTime, ConfigurationChangedEntry* entry);
+    bool dispatchDeviceResetLocked(
+            nsecs_t currentTime, DeviceResetEntry* entry);
+    bool dispatchKeyLocked(
+            nsecs_t currentTime, KeyEntry* entry,
+            DropReason* dropReason, nsecs_t* nextWakeupTime);
+    bool dispatchMotionLocked(
+            nsecs_t currentTime, MotionEntry* entry,
+            DropReason* dropReason, nsecs_t* nextWakeupTime);
+    void dispatchEventLocked(nsecs_t currentTime, EventEntry* entry,
+            const Vector<InputTarget>& inputTargets);
+
+    void logOutboundKeyDetailsLocked(const char* prefix, const KeyEntry* entry);
+    void logOutboundMotionDetailsLocked(const char* prefix, const MotionEntry* entry);
+
+    // Keeping track of ANR timeouts.
+    enum InputTargetWaitCause {
+        INPUT_TARGET_WAIT_CAUSE_NONE,
+        INPUT_TARGET_WAIT_CAUSE_SYSTEM_NOT_READY,
+        INPUT_TARGET_WAIT_CAUSE_APPLICATION_NOT_READY,
+    };
+
+    InputTargetWaitCause mInputTargetWaitCause;
+    nsecs_t mInputTargetWaitStartTime;
+    nsecs_t mInputTargetWaitTimeoutTime;
+    bool mInputTargetWaitTimeoutExpired;
+    sp<InputApplicationHandle> mInputTargetWaitApplicationHandle;
+
+    // Contains the last window which received a hover event.
+    sp<InputWindowHandle> mLastHoverWindowHandle;
+
+    // Finding targets for input events.
+    int32_t handleTargetsNotReadyLocked(nsecs_t currentTime, const EventEntry* entry,
+            const sp<InputApplicationHandle>& applicationHandle,
+            const sp<InputWindowHandle>& windowHandle,
+            nsecs_t* nextWakeupTime, const char* reason);
+    void resumeAfterTargetsNotReadyTimeoutLocked(nsecs_t newTimeout,
+            const sp<InputChannel>& inputChannel);
+    nsecs_t getTimeSpentWaitingForApplicationLocked(nsecs_t currentTime);
+    void resetANRTimeoutsLocked();
+
+    int32_t findFocusedWindowTargetsLocked(nsecs_t currentTime, const EventEntry* entry,
+            Vector<InputTarget>& inputTargets, nsecs_t* nextWakeupTime);
+    int32_t findTouchedWindowTargetsLocked(nsecs_t currentTime, const MotionEntry* entry,
+            Vector<InputTarget>& inputTargets, nsecs_t* nextWakeupTime,
+            bool* outConflictingPointerActions);
+
+    void addWindowTargetLocked(const sp<InputWindowHandle>& windowHandle,
+            int32_t targetFlags, BitSet32 pointerIds, Vector<InputTarget>& inputTargets);
+    void addMonitoringTargetsLocked(Vector<InputTarget>& inputTargets);
+
+    void pokeUserActivityLocked(const EventEntry* eventEntry);
+    bool checkInjectionPermission(const sp<InputWindowHandle>& windowHandle,
+            const InjectionState* injectionState);
+    bool isWindowObscuredAtPointLocked(const sp<InputWindowHandle>& windowHandle,
+            int32_t x, int32_t y) const;
+    bool isWindowReadyForMoreInputLocked(nsecs_t currentTime,
+            const sp<InputWindowHandle>& windowHandle, const EventEntry* eventEntry);
+    String8 getApplicationWindowLabelLocked(const sp<InputApplicationHandle>& applicationHandle,
+            const sp<InputWindowHandle>& windowHandle);
+
+    // Manage the dispatch cycle for a single connection.
+    // These methods are deliberately not Interruptible because doing all of the work
+    // with the mutex held makes it easier to ensure that connection invariants are maintained.
+    // If needed, the methods post commands to run later once the critical bits are done.
+    void prepareDispatchCycleLocked(nsecs_t currentTime, const sp<Connection>& connection,
+            EventEntry* eventEntry, const InputTarget* inputTarget);
+    void enqueueDispatchEntriesLocked(nsecs_t currentTime, const sp<Connection>& connection,
+            EventEntry* eventEntry, const InputTarget* inputTarget);
+    void enqueueDispatchEntryLocked(const sp<Connection>& connection,
+            EventEntry* eventEntry, const InputTarget* inputTarget, int32_t dispatchMode);
+    void startDispatchCycleLocked(nsecs_t currentTime, const sp<Connection>& connection);
+    void finishDispatchCycleLocked(nsecs_t currentTime, const sp<Connection>& connection,
+            uint32_t seq, bool handled);
+    void abortBrokenDispatchCycleLocked(nsecs_t currentTime, const sp<Connection>& connection,
+            bool notify);
+    void drainDispatchQueueLocked(Queue<DispatchEntry>* queue);
+    void releaseDispatchEntryLocked(DispatchEntry* dispatchEntry);
+    static int handleReceiveCallback(int fd, int events, void* data);
+
+    void synthesizeCancelationEventsForAllConnectionsLocked(
+            const CancelationOptions& options);
+    void synthesizeCancelationEventsForInputChannelLocked(const sp<InputChannel>& channel,
+            const CancelationOptions& options);
+    void synthesizeCancelationEventsForConnectionLocked(const sp<Connection>& connection,
+            const CancelationOptions& options);
+
+    // Splitting motion events across windows.
+    MotionEntry* splitMotionEvent(const MotionEntry* originalMotionEntry, BitSet32 pointerIds);
+
+    // Reset and drop everything the dispatcher is doing.
+    void resetAndDropEverythingLocked(const char* reason);
+
+    // Dump state.
+    void dumpDispatchStateLocked(String8& dump);
+    void logDispatchStateLocked();
+
+    // Registration.
+    void removeMonitorChannelLocked(const sp<InputChannel>& inputChannel);
+    status_t unregisterInputChannelLocked(const sp<InputChannel>& inputChannel, bool notify);
+
+    // Add or remove a connection to the mActiveConnections vector.
+    void activateConnectionLocked(Connection* connection);
+    void deactivateConnectionLocked(Connection* connection);
+
+    // Interesting events that we might like to log or tell the framework about.
+    void onDispatchCycleFinishedLocked(
+            nsecs_t currentTime, const sp<Connection>& connection, uint32_t seq, bool handled);
+    void onDispatchCycleBrokenLocked(
+            nsecs_t currentTime, const sp<Connection>& connection);
+    void onANRLocked(
+            nsecs_t currentTime, const sp<InputApplicationHandle>& applicationHandle,
+            const sp<InputWindowHandle>& windowHandle,
+            nsecs_t eventTime, nsecs_t waitStartTime, const char* reason);
+
+    // Outbound policy interactions.
+    void doNotifyConfigurationChangedInterruptible(CommandEntry* commandEntry);
+    void doNotifyInputChannelBrokenLockedInterruptible(CommandEntry* commandEntry);
+    void doNotifyANRLockedInterruptible(CommandEntry* commandEntry);
+    void doInterceptKeyBeforeDispatchingLockedInterruptible(CommandEntry* commandEntry);
+    void doDispatchCycleFinishedLockedInterruptible(CommandEntry* commandEntry);
+    bool afterKeyEventLockedInterruptible(const sp<Connection>& connection,
+            DispatchEntry* dispatchEntry, KeyEntry* keyEntry, bool handled);
+    bool afterMotionEventLockedInterruptible(const sp<Connection>& connection,
+            DispatchEntry* dispatchEntry, MotionEntry* motionEntry, bool handled);
+    void doPokeUserActivityLockedInterruptible(CommandEntry* commandEntry);
+    void initializeKeyEvent(KeyEvent* event, const KeyEntry* entry);
+
+    // Statistics gathering.
+    void updateDispatchStatisticsLocked(nsecs_t currentTime, const EventEntry* entry,
+            int32_t injectionResult, nsecs_t timeSpentWaitingForApplication);
+    void traceInboundQueueLengthLocked();
+    void traceOutboundQueueLengthLocked(const sp<Connection>& connection);
+    void traceWaitQueueLengthLocked(const sp<Connection>& connection);
+};
+
+/* Enqueues and dispatches input events, endlessly. */
+class InputDispatcherThread : public Thread {
+public:
+    explicit InputDispatcherThread(const sp<InputDispatcherInterface>& dispatcher);
+    ~InputDispatcherThread();
+
+private:
+    virtual bool threadLoop();
+
+    sp<InputDispatcherInterface> mDispatcher;
+};
+
+} // namespace android
+
+#endif // _UI_INPUT_DISPATCHER_H