Java tutorial
/* * Artcodes recognises a different marker scheme that allows the * creation of aesthetically pleasing, even beautiful, codes. * Copyright (C) 2013-2016 The University of Nottingham * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU Affero General Public License as published * by the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU Affero General Public License for more details. * * You should have received a copy of the GNU Affero General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. */ package uk.ac.horizon.artcodes.camera; import android.Manifest; import android.annotation.TargetApi; import android.content.Context; import android.content.pm.PackageManager; import android.hardware.Camera; import android.os.Build; import android.os.Handler; import android.os.HandlerThread; import android.os.Looper; import android.support.v4.content.ContextCompat; import android.util.AttributeSet; import android.util.Log; import android.view.Surface; import android.view.SurfaceHolder; import android.view.SurfaceView; import android.view.WindowManager; import java.io.IOException; import java.util.List; import uk.ac.horizon.artcodes.detect.Detector; import uk.ac.horizon.artcodes.model.Experience; import uk.ac.horizon.artcodes.scanner.R; import uk.ac.horizon.artcodes.detect.DetectorSetting; @SuppressWarnings("deprecation") public class CameraView extends SurfaceView implements CameraFocusControl { private static final String THREAD_NAME = "Frame Processor"; private CameraInfo info; private Camera camera; private int facing = Camera.CameraInfo.CAMERA_FACING_BACK; private Detector detector; private HandlerThread cameraThread; private SurfaceHolder surface; private int surfaceWidth; private int surfaceHeight; private boolean deviceNeedsTapToFocus = false; private final Object cameraFocusLock = new Object(); private boolean cameraIsFocused = true; private Experience experience; private String debug_resolution; public CameraView(Context context) { super(context); init(); } public CameraView(Context context, AttributeSet attrs) { super(context, attrs); init(); } public CameraView(Context context, AttributeSet attrs, int defStyleAttr) { super(context, attrs, defStyleAttr); init(); } @TargetApi(Build.VERSION_CODES.LOLLIPOP) public CameraView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) { super(context, attrs, defStyleAttr, defStyleRes); init(); } public void setDetector(Detector processor) { setDetector(processor, null); } public void setDetector(Detector processor, Experience experience) { this.experience = experience; this.detector = processor; if (detector != null) { if (camera == null) { createCamera(); } if (camera != null) { cameraIsFocused = !deviceNeedsTapToFocus; camera.addCallbackBuffer(detector.createBuffer(info, surfaceWidth, surfaceHeight)); camera.setPreviewCallbackWithBuffer(new Camera.PreviewCallback() { @Override public void onPreviewFrame(final byte[] data, final Camera camera) { boolean focusedOnThisFrame = false; if (deviceNeedsTapToFocus || !cameraIsFocused) { synchronized (cameraFocusLock) { while (!cameraIsFocused) { try { Log.i("FOCUS", "cameraFocusLock.wait(); Thread: " + Thread.currentThread().getName()); focusedOnThisFrame = true; cameraFocusLock.wait(); } catch (InterruptedException ignored) { } } Log.i("FOCUS", "notified Thread: " + Thread.currentThread().getName()); } } if (cameraIsFocused) { Log.i("FOCUS", "cameraIsFocused test: " + cameraIsFocused); if (!focusedOnThisFrame) { detector.setData(data); } camera.addCallbackBuffer(data); } } }); } if (Camera.getNumberOfCameras() > 1) { detector.getSettings().add(new DetectorSetting() { @Override public void nextValue() { stopCamera(); facing = 1 - facing; startCamera(); } @Override public int getIcon() { switch (facing) { case Camera.CameraInfo.CAMERA_FACING_BACK: return R.drawable.ic_camera_rear_24dp; case Camera.CameraInfo.CAMERA_FACING_FRONT: return R.drawable.ic_camera_front_24dp; } return 0; } @Override public int getText() { switch (facing) { case Camera.CameraInfo.CAMERA_FACING_BACK: return R.string.camera_rear; case Camera.CameraInfo.CAMERA_FACING_FRONT: return R.string.camera_front; } return 0; } }); } } } private void init() { getHolder().addCallback(new SurfaceHolder.Callback() { @Override public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) { if (holder.getSurface() == null) { Log.i("scanner", "No surface?"); return; } surface = holder; stopCamera(); surfaceWidth = width; surfaceHeight = height; startCamera(); } @Override public void surfaceCreated(SurfaceHolder holder) { } @Override public void surfaceDestroyed(SurfaceHolder holder) { stopCamera(); } }); } private void createCamera() { if (ContextCompat.checkSelfPermission(getContext(), Manifest.permission.CAMERA) == PackageManager.PERMISSION_GRANTED) { for (int cameraId = 0; cameraId < Camera.getNumberOfCameras(); cameraId++) { try { Camera.CameraInfo info = new Camera.CameraInfo(); Camera.getCameraInfo(cameraId, info); if (info.facing == facing) { openCamera(cameraId); return; } } catch (RuntimeException e) { Log.e("Scanner", "Failed to open scanner " + cameraId + ": " + e.getLocalizedMessage(), e); } } for (int cameraId = 0; cameraId < Camera.getNumberOfCameras(); cameraId++) { try { openCamera(cameraId); return; } catch (RuntimeException e) { Log.e("Scanner", "Failed to open scanner " + cameraId + ": " + e.getLocalizedMessage(), e); } } } } private void openCamera(int cameraId) { Log.i("Scanner", "Device manufacturer: " + android.os.Build.MANUFACTURER + " model: " + android.os.Build.MODEL); camera = Camera.open(cameraId); Camera.CameraInfo cameraInfo = new Camera.CameraInfo(); Camera.getCameraInfo(cameraId, cameraInfo); Camera.Parameters parameters = camera.getParameters(); List<String> focusModes = parameters.getSupportedFocusModes(); if (//!android.os.Build.MANUFACTURER.equalsIgnoreCase("SAMSUNG") && focusModes != null && !(this.experience != null && this.experience.getRequestedAutoFocusMode() != null && (this.experience.getRequestedAutoFocusMode().equals("tapToFocus") || this.experience.getRequestedAutoFocusMode().equals("blurScore")) && focusModes.contains(Camera.Parameters.FOCUS_MODE_AUTO)) && focusModes.contains(Camera.Parameters.FOCUS_MODE_CONTINUOUS_VIDEO)) { parameters.setFocusMode(Camera.Parameters.FOCUS_MODE_CONTINUOUS_VIDEO); } else if (focusModes != null && focusModes.contains(Camera.Parameters.FOCUS_MODE_AUTO)) { // if FOCUS_MODE_CONTINUOUS_VIDEO is not supported flag that manual auto-focus is needed every few seconds Log.w("Scanner", "Camera requires manual focusing"); parameters.setFocusMode(Camera.Parameters.FOCUS_MODE_AUTO); if (!(this.experience.getRequestedAutoFocusMode() != null && this.experience.getRequestedAutoFocusMode().equals("blurScore"))) { deviceNeedsTapToFocus = true; } } float ratioOfSurface = (float) surfaceHeight / surfaceWidth; if (ratioOfSurface < 1) { ratioOfSurface = 1 / ratioOfSurface; } Log.i("Scanner", "Surface size: " + surfaceWidth + "x" + surfaceHeight + " (Ratio: " + ratioOfSurface + ")"); Log.i("Scanner", "Format = " + parameters.getPictureFormat()); // Step 2: Find scanner preview that is best match for estimated surface ratio final List<Camera.Size> supportedPreviewSizes = parameters.getSupportedPreviewSizes(); Camera.Size bestFitSoFar = null; float ratioDifferenceOfBestFitSoFar = 0; StringBuilder cameraPreviewSizeDebugMessage = new StringBuilder("Available camera preview sizes: "); for (Camera.Size supportedSize : supportedPreviewSizes) { float ratio = (float) supportedSize.width / supportedSize.height; float ratioDifference = Math.abs(ratio - ratioOfSurface); cameraPreviewSizeDebugMessage.append(supportedSize.width); cameraPreviewSizeDebugMessage.append('x'); cameraPreviewSizeDebugMessage.append(supportedSize.height); cameraPreviewSizeDebugMessage.append(" ("); cameraPreviewSizeDebugMessage.append(ratio); cameraPreviewSizeDebugMessage.append(") "); if (bestFitSoFar == null || ratioDifference < ratioDifferenceOfBestFitSoFar) { bestFitSoFar = supportedSize; ratioDifferenceOfBestFitSoFar = ratioDifference; } } Log.i("Scanner", cameraPreviewSizeDebugMessage.toString()); if (bestFitSoFar != null) { // Would only be null if there are no supportedPreviewSizes this.debug_resolution = "Selected Preview Size: " + bestFitSoFar.width + "x" + bestFitSoFar.height + " (" + ((float) bestFitSoFar.width / (float) bestFitSoFar.height) + ")"; Log.i("Scanner", this.debug_resolution); parameters.setPreviewSize(bestFitSoFar.width, bestFitSoFar.height); camera.setParameters(parameters); info = new CameraInfo(cameraInfo, parameters, getDeviceRotation()); camera.setDisplayOrientation(info.getRotation()); setDetector(detector, experience); try { camera.setPreviewDisplay(surface); } catch (IOException e) { Log.w("Scanner", e.getMessage(), e); } camera.startPreview(); } } private int getDeviceRotation() { WindowManager manager = (WindowManager) getContext().getSystemService(Context.WINDOW_SERVICE); int rotation = manager.getDefaultDisplay().getRotation(); switch (rotation) { case Surface.ROTATION_0: return 0; case Surface.ROTATION_90: return 90; case Surface.ROTATION_180: return 180; case Surface.ROTATION_270: return 270; } return 0; } private void startCamera() { if (cameraThread == null) { cameraThread = new HandlerThread(THREAD_NAME); cameraThread.start(); Handler cameraHandler = new Handler(cameraThread.getLooper()); cameraHandler.post(new Runnable() { @Override public void run() { createCamera(); } }); } else { camera.startPreview(); } } private void stopCamera() { if (camera != null) { camera.stopPreview(); camera.setPreviewCallback(null); camera.release(); if (cameraThread != null) { cameraThread.quit(); cameraThread = null; } camera = null; } } /* Auto focus methods */ public boolean deviceNeedsTapToFocus() { return this.deviceNeedsTapToFocus; } @Override public void focus(final Runnable callback) { synchronized (cameraFocusLock) { Log.i("FOCUS", "cameraIsFocused = false;"); cameraIsFocused = false; } if (camera != null) { Log.i("FOCUS", "Attempting to focus camera."); camera.autoFocus(null); } // set a timeout rather than use the auto focus callback // (because the auto focus callback never gets called on some devices) Handler h = new Handler(Looper.getMainLooper()); h.postDelayed(new Runnable() { @Override public void run() { Log.i("FOCUS", "Firing auto focus timeout."); synchronized (cameraFocusLock) { Log.i("FOCUS", "cameraIsFocused = true;"); cameraIsFocused = true; Log.i("FOCUS", "notifyAll()"); cameraFocusLock.notifyAll(); } callback.run(); } }, 1000); } }