1/*
2 * Copyright (C) 2011 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;
18
19import android.content.Context;
20import android.content.res.Resources;
21import android.graphics.Canvas;
22import android.graphics.Matrix;
23import android.graphics.Paint;
24import android.graphics.Paint.Style;
25import android.graphics.RectF;
26import android.hardware.Camera.Face;
27import android.os.Handler;
28import android.os.Message;
29import android.util.AttributeSet;
30import android.view.View;
31
32import com.android.camera.debug.Log;
33import com.android.camera.util.CameraUtil;
34import com.android.camera2.R;
35
36public class FaceView extends View
37    implements Rotatable, PreviewStatusListener.PreviewAreaChangedListener {
38    private static final Log.Tag TAG = new Log.Tag("FaceView");
39    private final boolean LOGV = false;
40    // The value for android.hardware.Camera.setDisplayOrientation.
41    private int mDisplayOrientation;
42    // The orientation compensation for the face indicator to make it look
43    // correctly in all device orientations. Ex: if the value is 90, the
44    // indicator should be rotated 90 degrees counter-clockwise.
45    private int mOrientation;
46    private boolean mMirror;
47    private boolean mPause;
48    private Matrix mMatrix = new Matrix();
49    private RectF mRect = new RectF();
50    // As face detection can be flaky, we add a layer of filtering on top of it
51    // to avoid rapid changes in state (eg, flickering between has faces and
52    // not having faces)
53    private Face[] mFaces;
54    private Face[] mPendingFaces;
55    private int mColor;
56    private Paint mPaint;
57    private volatile boolean mBlocked;
58
59    private static final int MSG_SWITCH_FACES = 1;
60    private static final int SWITCH_DELAY = 70;
61    private boolean mStateSwitchPending = false;
62    private Handler mHandler = new Handler() {
63        @Override
64        public void handleMessage(Message msg) {
65            switch (msg.what) {
66            case MSG_SWITCH_FACES:
67                mStateSwitchPending = false;
68                mFaces = mPendingFaces;
69                invalidate();
70                break;
71            }
72        }
73    };
74    private final RectF mPreviewArea = new RectF();
75
76    public FaceView(Context context, AttributeSet attrs) {
77        super(context, attrs);
78        Resources res = getResources();
79        mColor = res.getColor(R.color.face_detect_start);
80        mPaint = new Paint();
81        mPaint.setAntiAlias(true);
82        mPaint.setStyle(Style.STROKE);
83        mPaint.setStrokeWidth(res.getDimension(R.dimen.face_circle_stroke));
84    }
85
86    public void setFaces(Face[] faces) {
87        if (LOGV) {
88            Log.v(TAG, "Num of faces=" + faces.length);
89        }
90        if (mPause) return;
91        if (mFaces != null) {
92            if ((faces.length > 0 && mFaces.length == 0)
93                    || (faces.length == 0 && mFaces.length > 0)) {
94                mPendingFaces = faces;
95                if (!mStateSwitchPending) {
96                    mStateSwitchPending = true;
97                    mHandler.sendEmptyMessageDelayed(MSG_SWITCH_FACES, SWITCH_DELAY);
98                }
99                return;
100            }
101        }
102        if (mStateSwitchPending) {
103            mStateSwitchPending = false;
104            mHandler.removeMessages(MSG_SWITCH_FACES);
105        }
106        mFaces = faces;
107        invalidate();
108    }
109
110    public void setDisplayOrientation(int orientation) {
111        mDisplayOrientation = orientation;
112        if (LOGV) {
113            Log.v(TAG, "mDisplayOrientation=" + orientation);
114        }
115    }
116
117    @Override
118    public void setOrientation(int orientation, boolean animation) {
119        mOrientation = orientation;
120        invalidate();
121    }
122
123    public void setMirror(boolean mirror) {
124        mMirror = mirror;
125        if (LOGV) {
126            Log.v(TAG, "mMirror=" + mirror);
127        }
128    }
129
130    public boolean faceExists() {
131        return (mFaces != null && mFaces.length > 0);
132    }
133
134    public void clear() {
135        // Face indicator is displayed during preview. Do not clear the
136        // drawable.
137        mFaces = null;
138        invalidate();
139    }
140
141    public void pause() {
142        mPause = true;
143    }
144
145    public void resume() {
146        mPause = false;
147    }
148
149    public void setBlockDraw(boolean block) {
150        mBlocked = block;
151    }
152
153    @Override
154    protected void onDraw(Canvas canvas) {
155        if (!mBlocked && (mFaces != null) && (mFaces.length > 0)) {
156            int rw, rh;
157            rw = (int) mPreviewArea.width();
158            rh = (int) mPreviewArea.height();
159            // Prepare the matrix.
160            if (((rh > rw) && ((mDisplayOrientation == 0) || (mDisplayOrientation == 180)))
161                    || ((rw > rh) && ((mDisplayOrientation == 90) || (mDisplayOrientation == 270)))) {
162                int temp = rw;
163                rw = rh;
164                rh = temp;
165            }
166            CameraUtil.prepareMatrix(mMatrix, mMirror, mDisplayOrientation, rw, rh);
167            // Focus indicator is directional. Rotate the matrix and the canvas
168            // so it looks correctly in all orientations.
169            canvas.save();
170            mMatrix.postRotate(mOrientation); // postRotate is clockwise
171            canvas.rotate(-mOrientation); // rotate is counter-clockwise (for canvas)
172            for (int i = 0; i < mFaces.length; i++) {
173                // Filter out false positives.
174                if (mFaces[i].score < 50) continue;
175
176                // Transform the coordinates.
177                mRect.set(mFaces[i].rect);
178                if (LOGV) {
179                    CameraUtil.dumpRect(mRect, "Original rect");
180                }
181                mMatrix.mapRect(mRect);
182                if (LOGV) {
183                    CameraUtil.dumpRect(mRect, "Transformed rect");
184                }
185                mPaint.setColor(mColor);
186                mRect.offset(mPreviewArea.left, mPreviewArea.top);
187                canvas.drawRect(mRect, mPaint);
188            }
189            canvas.restore();
190        }
191        super.onDraw(canvas);
192    }
193
194    @Override
195    public void onPreviewAreaChanged(RectF previewArea) {
196        mPreviewArea.set(previewArea);
197    }
198}
199