/*
* Copyright (C) 2008 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;
import com.google.zxing.ResultPoint;
import android.content.Context;
import android.graphics.PixelFormat;
import android.graphics.Point;
import android.graphics.Rect;
import android.hardware.Camera;
import android.os.Handler;
import android.os.Message;
import android.util.Log;
import android.view.Display;
import android.view.SurfaceHolder;
import android.view.WindowManager;
import java.io.IOException;
/**
* This object wraps the Camera service object and expects to be the only one talking to it. The
* implementation encapsulates the steps needed to take preview-sized images, which are used for
* both preview and decoding.
*
* @author dswitkin@google.com (Daniel Switkin)
*/
public final class CameraManager {
private static final String TAG = "CameraManager";
/*private static final int MIN_FRAME_WIDTH = 240;
private static final int MIN_FRAME_HEIGHT = 240;
private static final int MAX_FRAME_WIDTH = 480;
private static final int MAX_FRAME_HEIGHT = 360;*/
private static final int MIN_FRAME_WIDTH = 50;
private static final int MIN_FRAME_HEIGHT = 50;
private static int MAX_FRAME_WIDTH = 320;
private static final int MAX_FRAME_HEIGHT = 200;
private static CameraManager cameraManager;
private Camera camera;
private final Context context;
private Point screenResolution;
private Point cameraResolution;
private Rect framingRect;
private Handler previewHandler;
private int previewMessage;
private Handler autoFocusHandler;
private int autoFocusMessage;
private boolean initialized;
private boolean previewing;
private int previewFormat;
private String previewFormatString;
private boolean useOneShotPreviewCallback;
/**
* Preview frames are delivered here, which we pass on to the registered handler. Make sure to
* clear the handler so it will only receive one message.
*/
private final Camera.PreviewCallback previewCallback = new Camera.PreviewCallback() {
public void onPreviewFrame(byte[] data, Camera camera) {
if (!useOneShotPreviewCallback) {
camera.setPreviewCallback(null);
}
if (previewHandler != null) {
Message message = previewHandler.obtainMessage(previewMessage, cameraResolution.x,
cameraResolution.y, data);
message.sendToTarget();
previewHandler = null;
}
}
};
/**
* Autofocus callbacks arrive here, and are dispatched to the Handler which requested them.
*/
private final Camera.AutoFocusCallback autoFocusCallback = new Camera.AutoFocusCallback() {
public void onAutoFocus(boolean success, Camera camera) {
if (autoFocusHandler != null) {
Message message = autoFocusHandler.obtainMessage(autoFocusMessage, success);
// Simulate continuous autofocus by sending a focus request every 1.5 seconds.
autoFocusHandler.sendMessageDelayed(message, 1500L);
autoFocusHandler = null;
}
}
};
/**
* Initializes this static object with the Context of the calling Activity.
*
* @param context The Activity which wants to use the camera.
*/
public static void init(Context context) {
if (cameraManager == null) {
cameraManager = new CameraManager(context);
}
}
/**
* Gets the CameraManager singleton instance.
*
* @return A reference to the CameraManager singleton.
*/
public static CameraManager get() {
return cameraManager;
}
private CameraManager(Context context) {
this.context = context;
camera = null;
initialized = false;
previewing = false;
// Camera.setOneShotPreviewCallback() has a race condition in Cupcake, so we use the older
// Camera.setPreviewCallback() on 1.5 and earlier. For Donut and later, we need to use
// the more efficient one shot callback, as the older one can swamp the system and cause it
// to run out of memory. We can't use SDK_INT because it was introduced in the Donut SDK.
useOneShotPreviewCallback = true;
}
/**
* Opens the camera driver and initializes the hardware parameters.
*
* @param holder The surface object which the camera will draw preview frames into.
* @throws IOException Indicates the camera driver failed to open.
*/
public void openDriver(SurfaceHolder holder) throws IOException {
if (camera == null) {
camera = Camera.open();
camera.setPreviewDisplay(holder);
if (!initialized) {
initialized = true;
getScreenResolution();
}
setCameraParameters();
}
}
/**
* Closes the camera driver if still in use.
*/
public void closeDriver() {
if (previewing) stopPreview();
if (camera != null) {
camera.release();
camera = null;
}
}
/**
* Asks the camera hardware to begin drawing preview frames to the screen.
*/
public void startPreview() {
if (camera != null && !previewing) {
camera.startPreview();
previewing = true;
}
}
/**
* Tells the camera to stop drawing preview frames.
*/
public void stopPreview() {
if (camera != null && previewing) {
if (!useOneShotPreviewCallback) {
camera.setPreviewCallback(null);
}
camera.stopPreview();
previewHandler = null;
autoFocusHandler = null;
previewing = false;
}
}
/**
* A single preview frame will be returned to the handler supplied. The data will arrive as byte[]
* in the message.obj field, with width and height encoded as message.arg1 and message.arg2,
* respectively.
*
* @param handler The handler to send the message to.
* @param message The what field of the message to be sent.
*/
public void requestPreviewFrame(Handler handler, int message) {
if (camera != null && previewing) {
previewHandler = handler;
previewMessage = message;
if (useOneShotPreviewCallback) {
camera.setOneShotPreviewCallback(previewCallback);
} else {
camera.setPreviewCallback(previewCallback);
}
}
}
/**
* Asks the camera hardware to perform an autofocus.
*
* @param handler The Handler to notify when the autofocus completes.
* @param message The message to deliver.
*/
public void requestAutoFocus(Handler handler, int message) {
if (camera != null && previewing) {
autoFocusHandler = handler;
autoFocusMessage = message;
camera.autoFocus(autoFocusCallback);
}
}
/**
* Calculates the framing rect which the UI should draw to show the user where to place the
* barcode. This target helps with alignment as well as forces the user to hold the device
* far enough away to ensure the image will be in focus.
*
* @return The rectangle to draw on screen in window coordinates.
*/
public Rect getFramingRect() {
if (framingRect == null) {
if (camera == null) {
return null;
}
int width = cameraResolution.x * 3 / 4;
if (width < MIN_FRAME_WIDTH) {
width = MIN_FRAME_WIDTH;
} else if (width > MAX_FRAME_WIDTH) {
width = MAX_FRAME_WIDTH;
}
int height = cameraResolution.y * 3 / 4;
if (height < MIN_FRAME_HEIGHT) {
height = MIN_FRAME_HEIGHT;
} else if (height > MAX_FRAME_HEIGHT) {
height = MAX_FRAME_HEIGHT;
}
int leftOffset = (cameraResolution.x - width) / 2;
int topOffset = (cameraResolution.y - height) / 2;
framingRect = new Rect(leftOffset, topOffset, leftOffset + width, topOffset + height);
Log.i(TAG, "Calculated framing rect: " + framingRect);
}
return framingRect;
}
/**
* Converts the result points from still resolution coordinates to screen coordinates.
*
* @param points The points returned by the Reader subclass through Result.getResultPoints().
* @return An array of Points scaled to the size of the framing rect and offset appropriately
* so they can be drawn in screen coordinates.
*/
public Point[] convertResultPoints(ResultPoint[] points) {
Rect frame = getFramingRect();
int count = points.length;
Point[] output = new Point[count];
for (int x = 0; x < count; x++) {
output[x] = new Point();
output[x].x = frame.left + (int) (points[x].getX() + 0.5f);
output[x].y = frame.top + (int) (points[x].getY() + 0.5f);
}
return output;
}
/**
* A factory method to build the appropriate LuminanceSource object based on the format
* of the preview buffers, as described by Camera.Parameters.
*
* @param data A preview frame.
* @param width The width of the image.
* @param height The height of the image.
* @return A BaseLuminanceSource subclass.
*/
public BaseLuminanceSource buildLuminanceSource(byte[] data, int width, int height) {
Rect rect = getFramingRect();
switch (previewFormat) {
case PixelFormat.YCbCr_420_SP:
case PixelFormat.YCbCr_422_SP:
// return new PlanarYUVLuminanceSource(data, width, height, rect.left, rect.top, rect.width(), rect.height());
return new Rotate90LuminanceSource(data, width, height, rect.left, rect.top, rect.width(), rect.height());
default:
// There's no PixelFormat constant for this buffer format yet.
if (previewFormatString != null && previewFormatString.equals("yuv422i-yuyv")) {
return new InterleavedYUV422LuminanceSource(data, width, height, rect.left, rect.top,
rect.width(), rect.height());
}
else
{
Log.i("CameraManager", "Preview format not supported!!");
}
break;
}
return null;
}
/**
* Sets the camera up to take preview images which are used for both preview and decoding.
* We detect the preview format here so that buildLuminanceSource() can build an appropriate
* LuminanceSource subclass. In the future we may want to force YUV420SP as it's the smallest,
* and the planar Y can be used for barcode scanning without a copy in some cases.
*/
private void setCameraParameters() {
Camera.Parameters parameters = camera.getParameters();
Camera.Size size = parameters.getPreviewSize();
Log.i(TAG, "Default preview size: " + size.width + ", " + size.height);
previewFormat = parameters.getPreviewFormat();
previewFormatString = parameters.get("preview-format");
parameters.setPreviewFormat(PixelFormat.YCbCr_422_SP);
Log.i(TAG, "Default preview format: " + previewFormat);
// Ensure that the camera resolution is a multiple of 8, as the screen may not be.
// TODO: A better solution would be to request the supported preview resolutions
// and pick the best match, but this parameter is not standardized in Cupcake.
cameraResolution = new Point();
cameraResolution.x = (screenResolution.x >> 3) << 3;
cameraResolution.y = (screenResolution.y >> 3) << 3;
Log.i(TAG, "Setting preview size: " + cameraResolution.x + ", " + cameraResolution.y);
parameters.setPreviewSize(cameraResolution.x, cameraResolution.y);
// FIXME: This is a hack to turn the flash off on the Samsung Galaxy.
parameters.set("flash-value", 2);
// This is the standard setting to turn the flash off that all devices should honor.
parameters.set("flash-mode", "off");
camera.setParameters(parameters);
}
private Point getScreenResolution() {
if (screenResolution == null) {
WindowManager manager = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
Display display = manager.getDefaultDisplay();
// screenResolution = new Point(display.getWidth(), display.getHeight());
MAX_FRAME_WIDTH = display.getWidth();
screenResolution = new Point(display.getWidth(), 200);
}
return screenResolution;
}
}