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/* * Copyright (C) 2008 ZXing authors/* ww w .j a v a2 s . c o m*/ * * 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 transmission.thirdlib.manager; import java.io.IOException; import android.content.Context; import android.content.SharedPreferences; import android.graphics.Point; import android.graphics.Rect; import android.hardware.Camera; import android.os.Handler; import android.preference.PreferenceManager; import android.util.Log; import android.view.SurfaceHolder; import transmission.thirdlib.capture.PlanarYUVLuminanceSource; import transmission.thirdlib.capture.PreferencesActivity; /** * 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.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 = 600; private static final int MAX_FRAME_HEIGHT = 400; private final Context context; private final CameraConfigurationManager configManager; private Camera camera; private Rect framingRect; private Rect framingRectInPreview; private boolean initialized; private boolean previewing; private boolean reverseImage; private int requestedFramingRectWidth; private int requestedFramingRectHeight; /** * 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; public CameraManager(Context context) { this.context = context; this.configManager = new CameraConfigurationManager(context); previewCallback = new PreviewCallback(configManager); 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 { Camera theCamera = camera; if (theCamera == null) { theCamera = Camera.open(); if (theCamera == null) { throw new IOException(); } camera = theCamera; } theCamera.setPreviewDisplay(holder); if (!initialized) { initialized = true; configManager.initFromCameraParameters(theCamera); if (requestedFramingRectWidth > 0 && requestedFramingRectHeight > 0) { setManualFramingRect(requestedFramingRectWidth, requestedFramingRectHeight); requestedFramingRectWidth = 0; requestedFramingRectHeight = 0; } } configManager.setDesiredCameraParameters(theCamera); SharedPreferences prefs = PreferenceManager .getDefaultSharedPreferences(context); reverseImage = prefs.getBoolean(PreferencesActivity.KEY_REVERSE_IMAGE, false); } /** * Closes the camera driver if still in use. */ public void closeDriver() { if (camera != null) { camera.release(); camera = null; // Make sure to clear these each time we close the camera, so that // any scanning rect // requested by intent is forgotten. framingRect = null; framingRectInPreview = null; } } /** * Asks the camera hardware to begin drawing preview frames to the screen. */ public void startPreview() { Camera theCamera = camera; if (theCamera != null && !previewing) { theCamera.startPreview(); previewing = true; } } /** * Tells the camera to stop drawing preview frames. */ public void stopPreview() { if (camera != null && previewing) { 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) { Camera theCamera = camera; if (theCamera != null && previewing) { previewCallback.setHandler(handler, message); theCamera.setOneShotPreviewCallback(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); try { camera.autoFocus(autoFocusCallback); } catch (RuntimeException re) { // Have heard RuntimeException reported in Android 4.0.x+; // continue? Log.w(TAG, "Unexpected exception while focusing", re); } } } /** * 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; } Point screenResolution = configManager.getScreenResolution(); 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 framingRect = getFramingRect(); if (framingRect == null) { return null; } Rect rect = new Rect(framingRect); Point cameraResolution = configManager.getCameraResolution(); Point screenResolution = configManager.getScreenResolution(); 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; framingRectInPreview = rect; } return framingRectInPreview; } /** * Allows third party apps to specify the scanning rectangle dimensions, * rather than determine them automatically based on screen resolution. * * @param width * The width in pixels to scan. * @param height * The height in pixels to scan. */ public void setManualFramingRect(int width, int height) { if (initialized) { Point screenResolution = configManager.getScreenResolution(); if (width > screenResolution.x) { width = screenResolution.x; } if (height > screenResolution.y) { height = screenResolution.y; } 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 manual framing rect: " + framingRect); framingRectInPreview = null; } else { requestedFramingRectWidth = width; requestedFramingRectHeight = height; } } /** * 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(); if (rect == null) { return null; } // Go ahead and assume it's YUV rather than die. return new PlanarYUVLuminanceSource(data, width, height, rect.left, rect.top, rect.width(), rect.height(), reverseImage); } }