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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.ui.focus;
     18 
     19 import android.graphics.Canvas;
     20 import android.graphics.Paint;
     21 
     22 import com.android.camera.ui.motion.InterpolateUtils;
     23 import com.android.camera.ui.motion.Invalidator;
     24 
     25 /**
     26  * Manual focus ring animation renderer.
     27  */
     28 class ManualFocusRing extends FocusRingRenderer {
     29     /**
     30      * The manual focus ring encapsulates the animation logic for visualizing
     31      * a focus event when triggered by a physical screen touch.
     32      *
     33      * @param invalidator the object to invalidate while running.
     34      * @param ringPaint the paint to draw the ring with.
     35      * @param exitDurationMillis the fade out time in milliseconds.
     36      */
     37     public ManualFocusRing(Invalidator invalidator, Paint ringPaint,
     38           float exitDurationMillis) {
     39         super(invalidator, ringPaint, 0.0f, exitDurationMillis);
     40     }
     41 
     42     @Override
     43     public void draw(long t, long dt, Canvas canvas) {
     44         float ringRadius = mRingRadius.update(dt);
     45         processStates(t);
     46 
     47         if (!isActive()) {
     48             return;
     49         }
     50 
     51         mInvalidator.invalidate();
     52         int ringAlpha = 255;
     53 
     54         if (mFocusState == FocusState.STATE_FADE_OUT) {
     55             float rFade = InterpolateUtils.unitRatio(t, mExitStartMillis, mExitDurationMillis);
     56             ringAlpha = (int) InterpolateUtils.lerp(255, 0, mExitOpacityCurve.valueAt(rFade));
     57         } else if (mFocusState == FocusState.STATE_HARD_STOP) {
     58             float rFade = InterpolateUtils.unitRatio(t, mHardExitStartMillis,
     59                   mHardExitDurationMillis);
     60             ringAlpha = (int) InterpolateUtils.lerp(255, 0, mExitOpacityCurve.valueAt(rFade));
     61         } else if (mFocusState == FocusState.STATE_INACTIVE) {
     62             ringAlpha = 0;
     63         }
     64 
     65         mRingPaint.setAlpha(ringAlpha);
     66         canvas.drawCircle(getCenterX(), getCenterY(), ringRadius, mRingPaint);
     67     }
     68 
     69     private void processStates(long t) {
     70         if (mFocusState == FocusState.STATE_INACTIVE) {
     71             return;
     72         }
     73 
     74         if (mFocusState == FocusState.STATE_ENTER
     75               && (t > mEnterStartMillis + mEnterDurationMillis)) {
     76             mFocusState = FocusState.STATE_ACTIVE;
     77         }
     78 
     79         if (mFocusState == FocusState.STATE_ACTIVE && !mRingRadius.isActive()) {
     80             mFocusState = FocusState.STATE_FADE_OUT;
     81             mExitStartMillis = t;
     82         }
     83 
     84         if (mFocusState == FocusState.STATE_FADE_OUT && t > mExitStartMillis + mExitDurationMillis) {
     85             mFocusState = FocusState.STATE_INACTIVE;
     86         }
     87 
     88         if (mFocusState == FocusState.STATE_HARD_STOP
     89               && t > mHardExitStartMillis + mHardExitDurationMillis) {
     90             mFocusState = FocusState.STATE_INACTIVE;
     91         }
     92     }
     93 }
     94