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.ui.motion.InterpolateUtils;
23import com.android.camera.ui.motion.Invalidator;
24
25/**
26 * Manual focus ring animation renderer.
27 */
28class 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