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      1 /*
      2  * Copyright (C) 2014 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package com.android.camera.one.v2.autofocus;
     18 
     19 import android.hardware.camera2.CaptureRequest;
     20 import android.hardware.camera2.CaptureResult;
     21 
     22 import com.android.camera.async.Updatable;
     23 import com.android.camera.one.v2.camera2proxy.CaptureResultProxy;
     24 import com.google.common.base.Objects;
     25 import com.google.common.collect.ImmutableSet;
     26 import com.google.common.util.concurrent.SettableFuture;
     27 
     28 import java.util.Set;
     29 import java.util.concurrent.ExecutionException;
     30 import java.util.concurrent.TimeUnit;
     31 import java.util.concurrent.TimeoutException;
     32 
     33 import javax.annotation.ParametersAreNonnullByDefault;
     34 
     35 /**
     36  * Listens for image metadata and returns the result of an AF scan caused by an
     37  * AF_TRIGGER_START.
     38  * <p>
     39  * This maintains/implements the subset of the finite state machine of
     40  * {@link android.hardware.camera2.CaptureResult#CONTROL_AF_STATE} which relates
     41  * to AF_TRIGGER.
     42  * <p>
     43  * That is, it invokes the given callback when a scan is complete, according to
     44  * the following sequence:
     45  *
     46  * <pre>
     47  * .* CONTROL_AF_TRIGGER_START .* (STATE_INACTIVE|STATE_FOCUSED_LOCKED|STATE_NOT_FOCUSED_LOCKED)
     48  * </pre>
     49  * <p>
     50  * See the android documentation for {@link CaptureResult#CONTROL_AF_STATE} for
     51  * further documentation on the state machine this class implements.
     52  */
     53 @ParametersAreNonnullByDefault
     54 public final class AFTriggerResult implements Updatable<CaptureResultProxy> {
     55     private static final Set<Integer> TRIGGER_DONE_STATES = ImmutableSet.of(
     56             CaptureResult.CONTROL_AF_STATE_INACTIVE,
     57             CaptureResult.CONTROL_AF_STATE_FOCUSED_LOCKED,
     58             CaptureResult.CONTROL_AF_STATE_NOT_FOCUSED_LOCKED);
     59 
     60     private final TriggerStateMachine mStateMachine;
     61     private final SettableFuture<Boolean> mFutureResult;
     62 
     63     public AFTriggerResult() {
     64         mFutureResult = SettableFuture.create();
     65         mStateMachine = new TriggerStateMachine(
     66                 CaptureRequest.CONTROL_AF_TRIGGER_START,
     67                 TRIGGER_DONE_STATES);
     68     }
     69 
     70     @Override
     71     public void update(CaptureResultProxy result) {
     72         Integer afState = result.get(CaptureResult.CONTROL_AF_STATE);
     73         boolean done = mStateMachine.update(
     74                 result.getFrameNumber(),
     75                 result.getRequest().get(CaptureRequest.CONTROL_AF_TRIGGER),
     76                 afState);
     77         if (done) {
     78             boolean inFocus = Objects.equal(afState, CaptureResult.CONTROL_AF_STATE_PASSIVE_FOCUSED)
     79                     || Objects.equal(afState, CaptureResult.CONTROL_AF_STATE_FOCUSED_LOCKED);
     80             mFutureResult.set(inFocus);
     81         }
     82     }
     83 
     84     /**
     85      * Blocks until the AF scan is complete.
     86      *
     87      * @return Whether the scene is in-focus or not, based on the camera driver.
     88      * @throws InterruptedException
     89      */
     90     public boolean get() throws InterruptedException {
     91         try {
     92             return mFutureResult.get();
     93         } catch (ExecutionException impossible) {
     94             throw new RuntimeException(impossible);
     95         }
     96     }
     97 
     98     /**
     99      * Blocks until the AF scan is complete.
    100      *
    101      * @return Whether the scene is in-focus or not, based on the camera driver.
    102      * @throws InterruptedException
    103      */
    104     public boolean get(long timeout, TimeUnit timeUnit) throws InterruptedException,
    105             TimeoutException {
    106         try {
    107             return mFutureResult.get(timeout, timeUnit);
    108         } catch (ExecutionException impossible) {
    109             throw new RuntimeException(impossible);
    110         }
    111     }
    112 }
    113