/*
* 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.zxing.camera;
import java.io.IOException;
import android.content.Context;
import android.graphics.PixelFormat;
import android.graphics.Point;
import android.graphics.Rect;
import android.hardware.Camera;
import android.os.Build;
import android.os.Handler;
import android.util.Log;
import android.view.SurfaceHolder;
/**
* 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.
*
*/
public final class CameraManager {
private static final String TAG = CameraManager.class.getSimpleName();
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 CameraManager cameraManager;
static final int SDK_INT; // Later we can use Build.VERSION.SDK_INT
static {
int sdkInt;
try {
sdkInt = Integer.parseInt(Build.VERSION.SDK);
} catch (NumberFormatException nfe) {
// Just to be safe
sdkInt = 10000;
}
SDK_INT = sdkInt;
}
private final Context context;
private final CameraConfigurationManager configManager;
private Camera camera;
private Rect framingRect;
private Rect framingRectInPreview;
private boolean initialized;
private boolean previewing;
private final 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 PreviewCallback previewCallback;
/**
* Autofocus callbacks arrive here, and are dispatched to the Handler which
* requested them.
*/
private final AutoFocusCallback autoFocusCallback;
/**
* 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;
this.configManager = new CameraConfigurationManager(context);
// 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 = Integer.parseInt(Build.VERSION.SDK) >
// Build.VERSION_CODES.CUPCAKE;
useOneShotPreviewCallback = Integer.parseInt(Build.VERSION.SDK) > 3; // 3
// =
// Cupcake
previewCallback = new PreviewCallback(configManager,
useOneShotPreviewCallback);
autoFocusCallback = new AutoFocusCallback();
}
/**
* 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();
if (camera == null) {
throw new IOException();
}
camera.setPreviewDisplay(holder);
if (!initialized) {
initialized = true;
configManager.initFromCameraParameters(camera);
}
configManager.setDesiredCameraParameters(camera);
FlashlightManager.enableFlashlight();
}
}
/**
* Closes the camera driver if still in use.
*/
public void closeDriver() {
if (camera != null) {
FlashlightManager.disableFlashlight();
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();
previewCallback.setHandler(null, 0);
autoFocusCallback.setHandler(null, 0);
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) {
previewCallback.setHandler(handler, 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) {
autoFocusCallback.setHandler(handler, message);
// Log.d(TAG, "Requesting auto-focus callback");
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() {
Point screenResolution = configManager.getScreenResolution();
if (framingRect == null) {
if (camera == null) {
return null;
}
int width = screenResolution.x * 3 / 4;
if (width < MIN_FRAME_WIDTH) {
width = MIN_FRAME_WIDTH;
} else if (width > MAX_FRAME_WIDTH) {
width = MAX_FRAME_WIDTH;
}
int height = screenResolution.y * 3 / 4;
if (height < MIN_FRAME_HEIGHT) {
height = MIN_FRAME_HEIGHT;
} else if (height > MAX_FRAME_HEIGHT) {
height = MAX_FRAME_HEIGHT;
}
int leftOffset = (screenResolution.x - width) / 2;
int topOffset = (screenResolution.y - height) / 2;
framingRect = new Rect(leftOffset, topOffset, leftOffset + width,
topOffset + height);
Log.d(TAG, "Calculated framing rect: " + framingRect);
}
return framingRect;
}
/**
* Like {@link #getFramingRect} but coordinates are in terms of the preview
* frame, not UI / screen.
*/
public Rect getFramingRectInPreview() {
if (framingRectInPreview == null) {
Rect rect = new Rect(getFramingRect());
Point cameraResolution = configManager.getCameraResolution();
Point screenResolution = configManager.getScreenResolution();
// modify here
// rect.left = rect.left * cameraResolution.x / screenResolution.x;
// rect.right = rect.right * cameraResolution.x /
// screenResolution.x;
// rect.top = rect.top * cameraResolution.y / screenResolution.y;
// rect.bottom = rect.bottom * cameraResolution.y /
// screenResolution.y;
rect.left = rect.left * cameraResolution.y / screenResolution.x;
rect.right = rect.right * cameraResolution.y / screenResolution.x;
rect.top = rect.top * cameraResolution.x / screenResolution.y;
rect.bottom = rect.bottom * cameraResolution.x / screenResolution.y;
framingRectInPreview = rect;
}
return framingRectInPreview;
}
/**
* 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 =
* getFramingRectInPreview(); 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 PlanarYUVLuminanceSource instance.
*/
public PlanarYUVLuminanceSource buildLuminanceSource(byte[] data,
int width, int height) {
Rect rect = getFramingRectInPreview();
int previewFormat = configManager.getPreviewFormat();
String previewFormatString = configManager.getPreviewFormatString();
switch (previewFormat) {
// This is the standard Android format which all devices are REQUIRED to
// support.
// In theory, it's the only one we should ever care about.
case PixelFormat.YCbCr_420_SP:
// This format has never been seen in the wild, but is compatible as
// we only care
// about the Y channel, so allow it.
case PixelFormat.YCbCr_422_SP:
return new PlanarYUVLuminanceSource(data, width, height, rect.left,
rect.top, rect.width(), rect.height());
default:
// The Samsung Moment incorrectly uses this variant instead of the
// 'sp' version.
// Fortunately, it too has all the Y data up front, so we can read
// it.
if ("yuv420p".equals(previewFormatString)) {
return new PlanarYUVLuminanceSource(data, width, height,
rect.left, rect.top, rect.width(), rect.height());
}
}
throw new IllegalArgumentException("Unsupported picture format: "
+ previewFormat + '/' + previewFormatString);
}
public Context getContext() {
return context;
}
}
