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.TargetApi; import android.hardware.Camera; import android.os.Build; import android.util.Log; import java.util.Arrays; import java.util.Collection; import java.util.Iterator; import java.util.List; public class Main { private static final String TAG = "CameraConfiguration"; public static void setTorch(Camera.Parameters parameters, boolean on) { List<String> supportedFlashModes = parameters.getSupportedFlashModes(); String flashMode; if (on) { flashMode = findSettableValue("flash mode", supportedFlashModes, Camera.Parameters.FLASH_MODE_TORCH, Camera.Parameters.FLASH_MODE_ON); } else { flashMode = findSettableValue("flash mode", supportedFlashModes, Camera.Parameters.FLASH_MODE_OFF); } if (flashMode != null) { if (flashMode.equals(parameters.getFlashMode())) { Log.i(TAG, "Flash mode already set to " + flashMode); } else { Log.i(TAG, "Setting flash mode to " + flashMode); parameters.setFlashMode(flashMode); } } } private static String findSettableValue(String name, Collection<String> supportedValues, String... desiredValues) { Log.i(TAG, "Requesting " + name + " value from among: " + Arrays.toString(desiredValues)); Log.i(TAG, "Supported " + name + " values: " + supportedValues); if (supportedValues != null) { for (String desiredValue : desiredValues) { if (supportedValues.contains(desiredValue)) { Log.i(TAG, "Can set " + name + " to: " + desiredValue); return desiredValue; } } } Log.i(TAG, "No supported values match"); return null; } 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(); } @TargetApi(Build.VERSION_CODES.ICE_CREAM_SANDWICH) 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(); } }