Java tutorial
//package com.java2s; /* * Copyright (C) 2014 ZXing authors * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ import android.annotation.SuppressLint; import android.graphics.Rect; import android.hardware.Camera; import android.util.Log; import java.util.Arrays; import java.util.Collection; import java.util.Collections; import java.util.Iterator; import java.util.List; public class Main { private static final String TAG = "CameraConfiguration"; private static final int AREA_PER_1000 = 400; @SuppressLint("NewApi") public static void setMetering(Camera.Parameters parameters) { if (parameters.getMaxNumMeteringAreas() > 0) { Log.i(TAG, "Old metering areas: " + parameters.getMeteringAreas()); List<Camera.Area> middleArea = buildMiddleArea(AREA_PER_1000); Log.i(TAG, "Setting metering area to : " + toString(middleArea)); parameters.setMeteringAreas(middleArea); } else { Log.i(TAG, "Device does not support metering areas"); } } @SuppressLint("NewApi") private static List<Camera.Area> buildMiddleArea(int areaPer1000) { return Collections .singletonList(new Camera.Area(new Rect(-areaPer1000, -areaPer1000, areaPer1000, areaPer1000), 1)); } private static String toString(Collection<int[]> arrays) { if (arrays == null || arrays.isEmpty()) { return "[]"; } StringBuilder buffer = new StringBuilder(); buffer.append('['); Iterator<int[]> it = arrays.iterator(); while (it.hasNext()) { buffer.append(Arrays.toString(it.next())); if (it.hasNext()) { buffer.append(", "); } } buffer.append(']'); return buffer.toString(); } @SuppressLint("NewApi") private static String toString(Iterable<Camera.Area> areas) { if (areas == null) { return null; } StringBuilder result = new StringBuilder(); for (Camera.Area area : areas) { result.append(area.rect).append(':').append(area.weight).append(' '); } return result.toString(); } }