/*
* Copyright (C) 2010 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.
*/
package com.google.zxing.client.android.camera;
import android.content.Context;
import android.content.SharedPreferences;
import android.graphics.Point;
import android.hardware.Camera;
import android.preference.PreferenceManager;
import android.util.Log;
import android.view.Display;
import android.view.WindowManager;
import com.google.zxing.client.android.PreferencesActivity;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.Iterator;
import java.util.List;
/**
* A class which deals with reading, parsing, and setting the camera parameters which are used to
* configure the camera hardware.
*/
final class CameraConfigurationManager {
private static final String TAG = "CameraConfiguration";
// This is bigger than the size of a small screen, which is still supported. The routine
// below will still select the default (presumably 320x240) size for these. This prevents
// accidental selection of very low resolution on some devices.
private static final int MIN_PREVIEW_PIXELS = 480 * 320; // normal screen
//private static final float MAX_EXPOSURE_COMPENSATION = 1.5f;
//private static final float MIN_EXPOSURE_COMPENSATION = 0.0f;
private static final double MAX_ASPECT_DISTORTION = 0.15;
private final Context context;
private Point screenResolution;
private Point cameraResolution;
CameraConfigurationManager(Context context) {
this.context = context;
}
/**
* Reads, one time, values from the camera that are needed by the app.
*/
void initFromCameraParameters(Camera camera) {
Camera.Parameters parameters = camera.getParameters();
WindowManager manager = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
Display display = manager.getDefaultDisplay();
Point theScreenResolution = new Point();
display.getSize(theScreenResolution);
screenResolution = theScreenResolution;
Log.i(TAG, "Screen resolution: " + screenResolution);
cameraResolution = findBestPreviewSizeValue(parameters, screenResolution);
Log.i(TAG, "Camera resolution: " + cameraResolution);
}
void setDesiredCameraParameters(Camera camera, boolean safeMode) {
Camera.Parameters parameters = camera.getParameters();
if (parameters == null) {
Log.w(TAG, "Device error: no camera parameters are available. Proceeding without configuration.");
return;
}
Log.i(TAG, "Initial camera parameters: " + parameters.flatten());
if (safeMode) {
Log.w(TAG, "In camera config safe mode -- most settings will not be honored");
}
SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
initializeTorch(parameters, prefs, safeMode);
String focusMode = null;
if (prefs.getBoolean(PreferencesActivity.KEY_AUTO_FOCUS, true)) {
if (safeMode || prefs.getBoolean(PreferencesActivity.KEY_DISABLE_CONTINUOUS_FOCUS, false)) {
focusMode = findSettableValue(parameters.getSupportedFocusModes(),
Camera.Parameters.FOCUS_MODE_AUTO);
} else {
focusMode = findSettableValue(parameters.getSupportedFocusModes(),
Camera.Parameters.FOCUS_MODE_CONTINUOUS_PICTURE,
Camera.Parameters.FOCUS_MODE_CONTINUOUS_VIDEO,
Camera.Parameters.FOCUS_MODE_AUTO);
}
}
// Maybe selected auto-focus but not available, so fall through here:
if (!safeMode && focusMode == null) {
focusMode = findSettableValue(parameters.getSupportedFocusModes(),
Camera.Parameters.FOCUS_MODE_MACRO,
Camera.Parameters.FOCUS_MODE_EDOF);
}
if (focusMode != null) {
parameters.setFocusMode(focusMode);
}
if (prefs.getBoolean(PreferencesActivity.KEY_INVERT_SCAN, false)) {
String colorMode = findSettableValue(parameters.getSupportedColorEffects(),
Camera.Parameters.EFFECT_NEGATIVE);
if (colorMode != null) {
parameters.setColorEffect(colorMode);
}
}
parameters.setPreviewSize(cameraResolution.x, cameraResolution.y);
camera.setParameters(parameters);
Camera.Parameters afterParameters = camera.getParameters();
Camera.Size afterSize = afterParameters.getPreviewSize();
if (afterSize!= null && (cameraResolution.x != afterSize.width || cameraResolution.y != afterSize.height)) {
Log.w(TAG, "Camera said it supported preview size " + cameraResolution.x + 'x' + cameraResolution.y +
", but after setting it, preview size is " + afterSize.width + 'x' + afterSize.height);
cameraResolution.x = afterSize.width;
cameraResolution.y = afterSize.height;
}
}
Point getCameraResolution() {
return cameraResolution;
}
Point getScreenResolution() {
return screenResolution;
}
boolean getTorchState(Camera camera) {
if (camera != null) {
Camera.Parameters parameters = camera.getParameters();
if (parameters != null) {
String flashMode = camera.getParameters().getFlashMode();
return flashMode != null &&
(Camera.Parameters.FLASH_MODE_ON.equals(flashMode) ||
Camera.Parameters.FLASH_MODE_TORCH.equals(flashMode));
}
}
return false;
}
void setTorch(Camera camera, boolean newSetting) {
Camera.Parameters parameters = camera.getParameters();
doSetTorch(parameters, newSetting, false);
camera.setParameters(parameters);
}
private void initializeTorch(Camera.Parameters parameters, SharedPreferences prefs, boolean safeMode) {
boolean currentSetting = FrontLightMode.readPref(prefs) == FrontLightMode.ON;
doSetTorch(parameters, currentSetting, safeMode);
}
private void doSetTorch(Camera.Parameters parameters, boolean newSetting, boolean safeMode) {
String flashMode;
if (newSetting) {
flashMode = findSettableValue(parameters.getSupportedFlashModes(),
Camera.Parameters.FLASH_MODE_TORCH,
Camera.Parameters.FLASH_MODE_ON);
} else {
flashMode = findSettableValue(parameters.getSupportedFlashModes(),
Camera.Parameters.FLASH_MODE_OFF);
}
if (flashMode != null) {
parameters.setFlashMode(flashMode);
}
/*
SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
if (!prefs.getBoolean(PreferencesActivity.KEY_DISABLE_EXPOSURE, false)) {
if (!safeMode) {
int minExposure = parameters.getMinExposureCompensation();
int maxExposure = parameters.getMaxExposureCompensation();
if (minExposure != 0 || maxExposure != 0) {
float step = parameters.getExposureCompensationStep();
int desiredCompensation;
if (newSetting) {
// Light on; set low exposue compensation
desiredCompensation = Math.max((int) (MIN_EXPOSURE_COMPENSATION / step), minExposure);
} else {
// Light off; set high compensation
desiredCompensation = Math.min((int) (MAX_EXPOSURE_COMPENSATION / step), maxExposure);
}
Log.i(TAG, "Setting exposure compensation to " + desiredCompensation + " / " + (step * desiredCompensation));
parameters.setExposureCompensation(desiredCompensation);
} else {
Log.i(TAG, "Camera does not support exposure compensation");
}
}
}
*/
}
private Point findBestPreviewSizeValue(Camera.Parameters parameters, Point screenResolution) {
List<Camera.Size> rawSupportedSizes = parameters.getSupportedPreviewSizes();
if (rawSupportedSizes == null) {
Log.w(TAG, "Device returned no supported preview sizes; using default");
Camera.Size defaultSize = parameters.getPreviewSize();
return new Point(defaultSize.width, defaultSize.height);
}
// Sort by size, descending
List<Camera.Size> supportedPreviewSizes = new ArrayList<Camera.Size>(rawSupportedSizes);
Collections.sort(supportedPreviewSizes, new Comparator<Camera.Size>() {
@Override
public int compare(Camera.Size a, Camera.Size b) {
int aPixels = a.height * a.width;
int bPixels = b.height * b.width;
if (bPixels < aPixels) {
return -1;
}
if (bPixels > aPixels) {
return 1;
}
return 0;
}
});
if (Log.isLoggable(TAG, Log.INFO)) {
StringBuilder previewSizesString = new StringBuilder();
for (Camera.Size supportedPreviewSize : supportedPreviewSizes) {
previewSizesString.append(supportedPreviewSize.width).append('x')
.append(supportedPreviewSize.height).append(' ');
}
Log.i(TAG, "Supported preview sizes: " + previewSizesString);
}
double screenAspectRatio = (double) screenResolution.x / (double) screenResolution.y;
// Remove sizes that are unsuitable
Iterator<Camera.Size> it = supportedPreviewSizes.iterator();
while (it.hasNext()) {
Camera.Size supportedPreviewSize = it.next();
int realWidth = supportedPreviewSize.width;
int realHeight = supportedPreviewSize.height;
if (realWidth * realHeight < MIN_PREVIEW_PIXELS) {
it.remove();
continue;
}
boolean isCandidatePortrait = realWidth < realHeight;
int maybeFlippedWidth = isCandidatePortrait ? realHeight : realWidth;
int maybeFlippedHeight = isCandidatePortrait ? realWidth : realHeight;
double aspectRatio = (double) maybeFlippedWidth / (double) maybeFlippedHeight;
double distortion = Math.abs(aspectRatio - screenAspectRatio);
if (distortion > MAX_ASPECT_DISTORTION) {
it.remove();
continue;
}
if (maybeFlippedWidth == screenResolution.x && maybeFlippedHeight == screenResolution.y) {
Point exactPoint = new Point(realWidth, realHeight);
Log.i(TAG, "Found preview size exactly matching screen size: " + exactPoint);
return exactPoint;
}
}
// If no exact match, use largest preview size. This was not a great idea on older devices because
// of the additional computation needed. We're likely to get here on newer Android 4+ devices, where
// the CPU is much more powerful.
if (!supportedPreviewSizes.isEmpty()) {
Camera.Size largestPreview = supportedPreviewSizes.get(0);
Point largestSize = new Point(largestPreview.width, largestPreview.height);
Log.i(TAG, "Using largest suitable preview size: " + largestSize);
return largestSize;
}
// If there is nothing at all suitable, return current preview size
Camera.Size defaultPreview = parameters.getPreviewSize();
Point defaultSize = new Point(defaultPreview.width, defaultPreview.height);
Log.i(TAG, "No suitable preview sizes, using default: " + defaultSize);
return defaultSize;
}
private static String findSettableValue(Collection<String> supportedValues,
String... desiredValues) {
Log.i(TAG, "Supported values: " + supportedValues);
String result = null;
if (supportedValues != null) {
for (String desiredValue : desiredValues) {
if (supportedValues.contains(desiredValue)) {
result = desiredValue;
break;
}
}
}
Log.i(TAG, "Settable value: " + result);
return result;
}
}