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
17package com.android.camera.ui.focus;
18
19import android.graphics.Canvas;
20import android.graphics.Paint;
21
22import com.android.camera.debug.Log.Tag;
23import com.android.camera.ui.motion.InterpolateUtils;
24import com.android.camera.ui.motion.Invalidator;
25
26/**
27 * Passive focus ring animation renderer.
28 */
29class AutoFocusRing extends FocusRingRenderer {
30    private static final Tag TAG = new Tag("AutoFocusRing");
31
32    /**
33     * The auto focus ring encapsulates the animation logic for visualizing
34     * a focus event when triggered by the camera subsystem.
35     *
36     * @param invalidator the object to invalidate while running.
37     * @param ringPaint the paint to draw the ring with.
38     * @param enterDurationMillis the fade in time in milliseconds.
39     * @param exitDurationMillis the fade out time in milliseconds.
40     */
41    public AutoFocusRing(Invalidator invalidator, Paint ringPaint, float enterDurationMillis,
42          float exitDurationMillis) {
43        super(invalidator, ringPaint, enterDurationMillis, exitDurationMillis);
44    }
45
46    @Override
47    public void draw(long t, long dt, Canvas canvas) {
48        float ringRadius = mRingRadius.update(dt);
49        processStates(t);
50
51        if (!isActive()) {
52            return;
53        }
54
55        mInvalidator.invalidate();
56        int ringAlpha = 255;
57
58        if (mFocusState == FocusState.STATE_ENTER) {
59            float rFade = InterpolateUtils.unitRatio(t, mEnterStartMillis, mEnterDurationMillis);
60            ringAlpha = (int) InterpolateUtils
61                  .lerp(0, 255, mEnterOpacityCurve.valueAt(rFade));
62        } else if (mFocusState == FocusState.STATE_FADE_OUT) {
63            float rFade = InterpolateUtils.unitRatio(t, mExitStartMillis, mExitDurationMillis);
64            ringAlpha = (int) InterpolateUtils
65                  .lerp(255, 0, mExitOpacityCurve.valueAt(rFade));
66        } else if (mFocusState == FocusState.STATE_HARD_STOP) {
67            float rFade = InterpolateUtils
68                  .unitRatio(t, mHardExitStartMillis, mHardExitDurationMillis);
69            ringAlpha = (int) InterpolateUtils
70                  .lerp(255, 0, mExitOpacityCurve.valueAt(rFade));
71        } else if (mFocusState == FocusState.STATE_INACTIVE) {
72            ringAlpha = 0;
73        }
74
75        mRingPaint.setAlpha(ringAlpha);
76        canvas.drawCircle(getCenterX(), getCenterY(), ringRadius, mRingPaint);
77    }
78
79    private void processStates(long t) {
80        if (mFocusState == FocusState.STATE_INACTIVE) {
81            return;
82        }
83
84        if (mFocusState == FocusState.STATE_ENTER && t > mEnterStartMillis + mEnterDurationMillis) {
85            mFocusState = FocusState.STATE_ACTIVE;
86        }
87
88        if (mFocusState == FocusState.STATE_ACTIVE && !mRingRadius.isActive()) {
89            mFocusState = FocusState.STATE_FADE_OUT;
90            mExitStartMillis = t;
91        }
92
93        if (mFocusState == FocusState.STATE_FADE_OUT && t > mExitStartMillis + mExitDurationMillis) {
94            mFocusState = FocusState.STATE_INACTIVE;
95        }
96
97        if (mFocusState == FocusState.STATE_HARD_STOP
98              && t > mHardExitStartMillis + mHardExitDurationMillis) {
99            mFocusState = FocusState.STATE_INACTIVE;
100        }
101    }
102}
103