diff options
Diffstat (limited to 'services/java/com/android/server/gesture/EdgeGestureInputFilter.java')
| -rw-r--r-- | services/java/com/android/server/gesture/EdgeGestureInputFilter.java | 539 |
1 files changed, 539 insertions, 0 deletions
diff --git a/services/java/com/android/server/gesture/EdgeGestureInputFilter.java b/services/java/com/android/server/gesture/EdgeGestureInputFilter.java new file mode 100644 index 0000000..c42b7d0 --- /dev/null +++ b/services/java/com/android/server/gesture/EdgeGestureInputFilter.java @@ -0,0 +1,539 @@ +/* + * Copyright (C) 2013 The CyanogenMod Project (Jens Doll) + * + * 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. + */ +package com.android.server.gesture; + +import android.content.Context; +import android.content.res.Resources; +import android.os.Handler; +import android.os.IBinder; +import android.os.RemoteException; +import android.os.SystemClock; +import android.os.Trace; +import android.util.Slog; +import android.view.Display; +import android.view.DisplayInfo; +import android.view.IInputFilter; +import android.view.IInputFilterHost; +import android.view.InputDevice; +import android.view.InputEvent; +import android.view.MotionEvent; +import android.view.WindowManagerPolicy; +import android.view.MotionEvent.PointerCoords; +import android.view.MotionEvent.PointerProperties; + +import com.android.internal.R; +import com.android.internal.util.gesture.EdgeGesturePosition; +import com.android.server.gesture.EdgeGestureTracker.OnActivationListener; + +import java.io.PrintWriter; + +/** + * A simple input filter, that listens for edge swipe gestures in the motion event input + * stream. + * <p> + * There are 5 distinct states of this filter. + * 1) LISTEN: + * mTracker.active == false + * All motion events are passed through. If a ACTION_DOWN within a gesture trigger area happen + * switch to DETECTING. + * 2) DETECTING: + * mTracker.active == true + * All events are buffered now, and the gesture is checked by mTracker. If mTracker rejects + * the gesture (hopefully as fast as possible) all cached events will be flushed out and the + * filter falls back to LISTEN. + * If mTracker accepts the gesture, clear all cached events and go to LOCKED. + * 3) LOCKED: + * mTracker.active == false + * All events will be cached until the state changes to SYNTHESIZE through a filter + * unlock event. If there is a ACTION_UP, _CANCEL or any PointerId differently to the last + * event seen when mTracker accepted the gesture, we flush all events and go to LISTEN. + * 4) SYNTHESIZE: + * The first motion event found will be turned into a ACTION_DOWN event, all previous events + * will be discarded. + * 5) POSTSYNTHESIZE: + * mSyntheticDownTime != -1 + * All following events will have the down time set to the synthesized ACTION_DOWN event time + * until an ACTION_UP or ACTION_CANCEL is encountered and the state is reset to LISTEN. + * 6) DROP: + * All following events will be discarded. If there is an ACTION_UP, _CANCEL + * we go to LISTEN state. + * <p> + * If you are reading this within Java Doc, you are doing something wrong ;) + */ +public class EdgeGestureInputFilter implements IInputFilter { + /* WARNING!! The IInputFilter interface is used directly, there is no Binder between this and + * the InputDispatcher. + * This is fine, because it prevents unnecessary parceling, but beware: + * This means we are running on the dispatch or listener thread of the input dispatcher. Every + * cycle we waste here adds to the overall input latency. + */ + private static final String TAG = "EdgeGestureInputFilter"; + private static final boolean DEBUG = false; + private static final boolean DEBUG_INPUT = false; + // TODO: Should be turned off in final commit + private static final boolean SYSTRACE = false; + + private final Handler mHandler; + + private IInputFilterHost mHost = null; // dispatcher thread + + private static final class MotionEventInfo { + private static final int MAX_POOL_SIZE = 16; + + private static final Object sLock = new Object(); + private static MotionEventInfo sPool; + private static int sPoolSize; + + private boolean mInPool; + + public static MotionEventInfo obtain(MotionEvent event, int policyFlags) { + synchronized (sLock) { + MotionEventInfo info; + if (sPoolSize > 0) { + sPoolSize--; + info = sPool; + sPool = info.next; + info.next = null; + info.mInPool = false; + } else { + info = new MotionEventInfo(); + } + info.initialize(event, policyFlags); + return info; + } + } + + private void initialize(MotionEvent event, int policyFlags) { + this.event = MotionEvent.obtain(event); + this.policyFlags = policyFlags; + cachedTimeMillis = SystemClock.uptimeMillis(); + } + + public void recycle() { + synchronized (sLock) { + if (mInPool) { + throw new IllegalStateException("Already recycled."); + } + clear(); + if (sPoolSize < MAX_POOL_SIZE) { + sPoolSize++; + next = sPool; + sPool = this; + mInPool = true; + } + } + } + + private void clear() { + event.recycle(); + event = null; + policyFlags = 0; + } + + public MotionEventInfo next; + public MotionEvent event; + public int policyFlags; + public long cachedTimeMillis; + } + private final Object mLock = new Object(); + private MotionEventInfo mMotionEventQueue; // guarded by mLock + private MotionEventInfo mMotionEventQueueTail; // guarded by mLock + /* DEBUG */ + private int mMotionEventQueueCountDebug; // guarded by mLock + + private int mDeviceId; // dispatcher only + private enum State { + LISTEN, DETECTING, LOCKED, SYNTHESIZE, POSTSYNTHESIZE, DROP; + } + private State mState = State.LISTEN; // guarded by mLock + private EdgeGestureTracker mTracker; // guarded by mLock + private volatile int mPositions; // written by handler / read by dispatcher + private volatile int mSensitivity; // written by handler / read by dispatcher + + // only used by dispatcher + private long mSyntheticDownTime = -1; + private PointerCoords[] mTempPointerCoords = new PointerCoords[1]; + private PointerProperties[] mTempPointerProperties = new PointerProperties[1]; + + public EdgeGestureInputFilter(Context context, Handler handler) { + mHandler = handler; + + final Resources res = context.getResources(); + mTracker = new EdgeGestureTracker(res.getDimensionPixelSize( + R.dimen.edge_gesture_trigger_thickness), + res.getDimensionPixelSize(R.dimen.edge_gesture_trigger_distance), + res.getDimensionPixelSize(R.dimen.edge_gesture_perpendicular_distance)); + mTracker.setOnActivationListener(new OnActivationListener() { + public void onActivation(MotionEvent event, int touchX, int touchY, EdgeGesturePosition position) { + // mLock is held by #processMotionEvent + mHandler.obtainMessage(EdgeGestureService.MSG_EDGE_GESTURE_ACTIVATION, + touchX, touchY, position).sendToTarget(); + mState = State.LOCKED; + } + }); + mTempPointerCoords[0] = new PointerCoords(); + mTempPointerProperties[0] = new PointerProperties(); + } + + // called from handler thread (lock taken) + public void updateDisplay(Display display, DisplayInfo displayInfo) { + synchronized (mLock) { + mTracker.updateDisplay(display); + } + } + + // called from handler thread (lock taken) + public void updatePositions(int positions) { + mPositions = positions; + } + + // called from handler thread (lock taken) + public void updateSensitivity(int sensitivity) { + mSensitivity = sensitivity; + } + + // called from handler thread + public boolean unlockFilter() { + synchronized (mLock) { + if (mState == State.LOCKED) { + mState = State.SYNTHESIZE; + return true; + } + } + return false; + } + + public boolean dropSequence() { + synchronized (mLock) { + if (mState == State.LOCKED) { + mState = State.DROP; + return true; + } + } + return false; + } + + /** + * Called to enqueue the input event for filtering. + * The event must be recycled after the input filter processed it. + * This method is guaranteed to be non-reentrant. + * + * @see InputFilter#filterInputEvent(InputEvent, int) + * @param event The input event to enqueue. + */ + // called by the input dispatcher thread + public void filterInputEvent(InputEvent event, int policyFlags) throws RemoteException { + if (SYSTRACE) { + Trace.traceBegin(Trace.TRACE_TAG_INPUT, "filterInputEvent"); + } + try { + if (((event.getSource() & InputDevice.SOURCE_TOUCHSCREEN) + != InputDevice.SOURCE_TOUCHSCREEN) + || !(event instanceof MotionEvent)) { + sendInputEvent(event, policyFlags); + return; + } + if (DEBUG_INPUT) { + Slog.d(TAG, "Received event: " + event + ", policyFlags=0x" + + Integer.toHexString(policyFlags)); + } + MotionEvent motionEvent = (MotionEvent) event; + final int deviceId = event.getDeviceId(); + if (deviceId != mDeviceId) { + processDeviceSwitch(deviceId, motionEvent, policyFlags); + } else { + if ((policyFlags & WindowManagerPolicy.FLAG_PASS_TO_USER) == 0) { + synchronized (mLock) { + clearAndResetStateLocked(false, true); + } + } + processMotionEvent(motionEvent, policyFlags); + } + } finally { + event.recycle(); + if (SYSTRACE) { + Trace.traceEnd(Trace.TRACE_TAG_INPUT); + } + } + } + + private void processDeviceSwitch(int deviceId, MotionEvent motionEvent, int policyFlags) { + if (motionEvent.getActionMasked() == MotionEvent.ACTION_DOWN) { + mDeviceId = deviceId; + synchronized (mLock) { + clearAndResetStateLocked(true, false); + processMotionEvent(motionEvent, policyFlags); + } + } else { + sendInputEvent(motionEvent, policyFlags); + } + } + + private void processMotionEvent(MotionEvent motionEvent, int policyFlags) { + final int action = motionEvent.getActionMasked(); + + synchronized (mLock) { + switch (mState) { + case LISTEN: + if (action == MotionEvent.ACTION_DOWN) { + boolean hit = mPositions != 0 + && mTracker.start(motionEvent, mPositions, mSensitivity); + if (DEBUG) Slog.d(TAG, "start:" + hit); + if (hit) { + // cache the down event + cacheDelayedMotionEventLocked(motionEvent, policyFlags); + mState = State.DETECTING; + return; + } + } + sendInputEvent(motionEvent, policyFlags); + break; + case DETECTING: + cacheDelayedMotionEventLocked(motionEvent, policyFlags); + if (action == MotionEvent.ACTION_MOVE) { + if (mTracker.move(motionEvent)) { + // return: the tracker is either detecting or triggered onActivation + return; + } + } + if (DEBUG) { + Slog.d(TAG, "move: reset!"); + } + clearAndResetStateLocked(false, true); + break; + case LOCKED: + cacheDelayedMotionEventLocked(motionEvent, policyFlags); + if (action != MotionEvent.ACTION_MOVE) { + clearAndResetStateLocked(false, true); + } + break; + case SYNTHESIZE: + if (action == MotionEvent.ACTION_MOVE) { + clearDelayedMotionEventsLocked(); + sendSynthesizedMotionEventLocked(motionEvent, policyFlags); + mState = State.POSTSYNTHESIZE; + } else { + // This is the case where a race condition caught us: We already + // returned the handler thread that it is all right to call + // #gainTouchFocus(), but apparently this was wrong, as the gesture + // was canceled now. + clearAndResetStateLocked(false, true); + } + break; + case POSTSYNTHESIZE: + motionEvent.setDownTime(mSyntheticDownTime); + if (action == MotionEvent.ACTION_UP || action == MotionEvent.ACTION_CANCEL) { + mState = State.LISTEN; + mSyntheticDownTime = -1; + } + sendInputEvent(motionEvent, policyFlags); + break; + case DROP: + if (action == MotionEvent.ACTION_UP || action == MotionEvent.ACTION_CANCEL) { + clearDelayedMotionEventsLocked(); + mState = State.LISTEN; + } + break; + } + } + } + + private void clearAndResetStateLocked(boolean force, boolean shift) { + // ignore soft reset in POSTSYNTHESIZE, because we need to tamper with + // the event stream and going to LISTEN after an ACTION_UP anyway + if (!force && (mState == State.POSTSYNTHESIZE)) { + return; + } + switch (mState) { + case LISTEN: + // this is a nop + break; + case DETECTING: + mTracker.reset(); + // intentionally no break here + case LOCKED: + case SYNTHESIZE: + sendDelayedMotionEventsLocked(shift); + break; + case POSTSYNTHESIZE: + // hard reset (this will break the event stream) + Slog.w(TAG, "Quit POSTSYNTHESIZE without ACTION_UP from ACTION_DOWN at " + + mSyntheticDownTime); + mSyntheticDownTime = -1; + break; + } + // if there are future events that need to be tampered with, goto POSTSYNTHESIZE + mState = mSyntheticDownTime == -1 ? State.LISTEN : State.POSTSYNTHESIZE; + } + + private void sendInputEvent(InputEvent event, int policyFlags) { + try { + mHost.sendInputEvent(event, policyFlags); + } catch (RemoteException e) { + /* ignore */ + } + } + + private void cacheDelayedMotionEventLocked(MotionEvent event, int policyFlags) { + MotionEventInfo info = MotionEventInfo.obtain(event, policyFlags); + if (mMotionEventQueue == null) { + mMotionEventQueue = info; + } else { + mMotionEventQueueTail.next = info; + } + mMotionEventQueueTail = info; + mMotionEventQueueCountDebug++; + if (SYSTRACE) { + Trace.traceCounter(Trace.TRACE_TAG_INPUT, "meq", mMotionEventQueueCountDebug); + } + } + + private void sendDelayedMotionEventsLocked(boolean shift) { + while (mMotionEventQueue != null) { + MotionEventInfo info = mMotionEventQueue; + mMotionEventQueue = info.next; + + if (DEBUG) { + Slog.d(TAG, "Replay event: " + info.event); + } + mMotionEventQueueCountDebug--; + if (SYSTRACE) { + Trace.traceCounter(Trace.TRACE_TAG_INPUT, "meq", mMotionEventQueueCountDebug); + } + if (shift) { + final long offset = SystemClock.uptimeMillis() - info.cachedTimeMillis; + if (info.event.getActionMasked() == MotionEvent.ACTION_DOWN) { + mSyntheticDownTime = info.event.getDownTime() + offset; + } + sendMotionEventWithOffsetLocked(info.event, info.policyFlags, mSyntheticDownTime, offset); + if (info.event.getActionMasked() == MotionEvent.ACTION_UP) { + mSyntheticDownTime = -1; + } + } else { + sendInputEvent(info.event, info.policyFlags); + } + info.recycle(); + } + mMotionEventQueueTail = null; + } + + private void clearDelayedMotionEventsLocked() { + while (mMotionEventQueue != null) { + MotionEventInfo next = mMotionEventQueue.next; + mMotionEventQueue.recycle(); + mMotionEventQueue = next; + } + mMotionEventQueueTail = null; + mMotionEventQueueCountDebug = 0; + if (SYSTRACE) { + Trace.traceCounter(Trace.TRACE_TAG_INPUT, "meq", mMotionEventQueueCountDebug); + } + } + + private void sendMotionEventWithOffsetLocked(MotionEvent event, int policyFlags, + long downTime, long offset) { + final int pointerCount = event.getPointerCount(); + PointerCoords[] coords = getTempPointerCoordsWithMinSizeLocked(pointerCount); + PointerProperties[] properties = getTempPointerPropertiesWithMinSizeLocked(pointerCount); + for (int i = 0; i < pointerCount; i++) { + event.getPointerCoords(i, coords[i]); + event.getPointerProperties(i, properties[i]); + } + final long eventTime = event.getEventTime() + offset; + sendInputEvent(MotionEvent.obtain(downTime, eventTime, event.getAction(), pointerCount, + properties, coords, event.getMetaState(), event.getButtonState(), 1.0f, 1.0f, + event.getDeviceId(), event.getEdgeFlags(), event.getSource(), event.getFlags()), + policyFlags); + } + + private PointerCoords[] getTempPointerCoordsWithMinSizeLocked(int size) { + final int oldSize = mTempPointerCoords.length; + if (oldSize < size) { + PointerCoords[] oldTempPointerCoords = mTempPointerCoords; + mTempPointerCoords = new PointerCoords[size]; + System.arraycopy(oldTempPointerCoords, 0, mTempPointerCoords, 0, oldSize); + } + for (int i = oldSize; i < size; i++) { + mTempPointerCoords[i] = new PointerCoords(); + } + return mTempPointerCoords; + } + + private PointerProperties[] getTempPointerPropertiesWithMinSizeLocked(int size) { + final int oldSize = mTempPointerProperties.length; + if (oldSize < size) { + PointerProperties[] oldTempPointerProperties = mTempPointerProperties; + mTempPointerProperties = new PointerProperties[size]; + System.arraycopy(oldTempPointerProperties, 0, mTempPointerProperties, 0, oldSize); + } + for (int i = oldSize; i < size; i++) { + mTempPointerProperties[i] = new PointerProperties(); + } + return mTempPointerProperties; + } + + private void sendSynthesizedMotionEventLocked(MotionEvent event, int policyFlags) { + if (event.getPointerCount() == 1) { + event.getPointerCoords(0, mTempPointerCoords[0]); + event.getPointerProperties(0, mTempPointerProperties[0]); + MotionEvent down = MotionEvent.obtain(event.getEventTime(), event.getEventTime(), + MotionEvent.ACTION_DOWN, 1, mTempPointerProperties, mTempPointerCoords, + event.getMetaState(), event.getButtonState(), + 1.0f, 1.0f, event.getDeviceId(), event.getEdgeFlags(), + event.getSource(), event.getFlags()); + Slog.d(TAG, "Synthesized event:" + down); + sendInputEvent(down, policyFlags); + mSyntheticDownTime = event.getEventTime(); + } else { + Slog.w(TAG, "Could not synthesize MotionEvent, this will drop all following events!"); + } + } + + // should never be called + public IBinder asBinder() { + throw new UnsupportedOperationException(); + } + + // called by the input dispatcher thread + public void install(IInputFilterHost host) throws RemoteException { + if (DEBUG) { + Slog.d(TAG, "EdgeGesture input filter installed."); + } + mHost = host; + synchronized (mLock) { + clearAndResetStateLocked(true, false); + } + } + + // called by the input dispatcher thread + public void uninstall() throws RemoteException { + if (DEBUG) { + Slog.d(TAG, "EdgeGesture input filter uninstalled."); + } + } + + // called by a Binder thread + public void dump(PrintWriter pw, String prefix) { + synchronized (mLock) { + pw.print(prefix); + pw.println("mState=" + mState.name()); + pw.print(prefix); + pw.println("mPositions=0x" + Integer.toHexString(mPositions)); + pw.print(prefix); + pw.println("mQueue=" + mMotionEventQueueCountDebug + " items"); + } + } +} |