Java tutorial
/* * Copyright (C) 2013 The Android Open Source Project * * 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 android.print; import android.annotation.NonNull; import android.annotation.Nullable; import android.annotation.RequiresFeature; import android.annotation.RequiresPermission; import android.annotation.SystemApi; import android.annotation.SystemService; import android.annotation.UnsupportedAppUsage; import android.app.Activity; import android.app.Application.ActivityLifecycleCallbacks; import android.content.ComponentName; import android.content.Context; import android.content.IntentSender; import android.content.IntentSender.SendIntentException; import android.content.pm.PackageManager; import android.graphics.drawable.Icon; import android.os.Bundle; import android.os.CancellationSignal; import android.os.Handler; import android.os.ICancellationSignal; import android.os.Looper; import android.os.Message; import android.os.ParcelFileDescriptor; import android.os.RemoteException; import android.print.PrintDocumentAdapter.LayoutResultCallback; import android.print.PrintDocumentAdapter.WriteResultCallback; import android.printservice.PrintServiceInfo; import android.printservice.recommendation.IRecommendationsChangeListener; import android.printservice.recommendation.RecommendationInfo; import android.text.TextUtils; import android.util.ArrayMap; import android.util.Log; import com.android.internal.os.SomeArgs; import com.android.internal.util.Preconditions; import libcore.io.IoUtils; import java.lang.ref.WeakReference; import java.util.ArrayList; import java.util.Arrays; import java.util.Collections; import java.util.List; import java.util.Map; /** * System level service for accessing the printing capabilities of the platform. * * <h3>Print mechanics</h3> * <p> * The key idea behind printing on the platform is that the content to be printed * should be laid out for the currently selected print options resulting in an * optimized output and higher user satisfaction. To achieve this goal the platform * declares a contract that the printing application has to follow which is defined * by the {@link PrintDocumentAdapter} class. At a higher level the contract is that * when the user selects some options from the print UI that may affect the way * content is laid out, for example page size, the application receives a callback * allowing it to layout the content to better fit these new constraints. After a * layout pass the system may ask the application to render one or more pages one * or more times. For example, an application may produce a single column list for * smaller page sizes and a multi-column table for larger page sizes. * </p> * <h3>Print jobs</h3> * <p> * Print jobs are started by calling the {@link #print(String, PrintDocumentAdapter, * PrintAttributes)} from an activity which results in bringing up the system print * UI. Once the print UI is up, when the user changes a selected print option that * affects the way content is laid out the system starts to interact with the * application following the mechanics described the section above. * </p> * <p> * Print jobs can be in {@link PrintJobInfo#STATE_CREATED created}, {@link * PrintJobInfo#STATE_QUEUED queued}, {@link PrintJobInfo#STATE_STARTED started}, * {@link PrintJobInfo#STATE_BLOCKED blocked}, {@link PrintJobInfo#STATE_COMPLETED * completed}, {@link PrintJobInfo#STATE_FAILED failed}, and {@link * PrintJobInfo#STATE_CANCELED canceled} state. Print jobs are stored in dedicated * system spooler until they are handled which is they are cancelled or completed. * Active print jobs, ones that are not cancelled or completed, are considered failed * if the device reboots as the new boot may be after a very long time. The user may * choose to restart such print jobs. Once a print job is queued all relevant content * is stored in the system spooler and its lifecycle becomes detached from this of * the application that created it. * </p> * <p> * An applications can query the print spooler for current print jobs it created * but not print jobs created by other applications. * </p> * * @see PrintJob * @see PrintJobInfo */ @SystemService(Context.PRINT_SERVICE) @RequiresFeature(PackageManager.FEATURE_PRINTING) public final class PrintManager { private static final String LOG_TAG = "PrintManager"; private static final boolean DEBUG = false; private static final int MSG_NOTIFY_PRINT_JOB_STATE_CHANGED = 1; /** * Package name of print spooler. * * @hide */ public static final String PRINT_SPOOLER_PACKAGE_NAME = "com.android.printspooler"; /** * Select enabled services. * </p> * @see #getPrintServices * @hide */ @SystemApi public static final int ENABLED_SERVICES = 1 << 0; /** * Select disabled services. * </p> * @see #getPrintServices * @hide */ public static final int DISABLED_SERVICES = 1 << 1; /** * Select all services. * </p> * @see #getPrintServices * @hide */ public static final int ALL_SERVICES = ENABLED_SERVICES | DISABLED_SERVICES; /** * The action for launching the print dialog activity. * * @hide */ public static final String ACTION_PRINT_DIALOG = "android.print.PRINT_DIALOG"; /** * Extra with the intent for starting the print dialog. * <p> * <strong>Type:</strong> {@link android.content.IntentSender} * </p> * * @hide */ public static final String EXTRA_PRINT_DIALOG_INTENT = "android.print.intent.extra.EXTRA_PRINT_DIALOG_INTENT"; /** * Extra with a print job. * <p> * <strong>Type:</strong> {@link android.print.PrintJobInfo} * </p> * * @hide */ public static final String EXTRA_PRINT_JOB = "android.print.intent.extra.EXTRA_PRINT_JOB"; /** * Extra with the print document adapter to be printed. * <p> * <strong>Type:</strong> {@link android.print.IPrintDocumentAdapter} * </p> * * @hide */ public static final String EXTRA_PRINT_DOCUMENT_ADAPTER = "android.print.intent.extra.EXTRA_PRINT_DOCUMENT_ADAPTER"; /** @hide */ public static final int APP_ID_ANY = -2; private final Context mContext; private final IPrintManager mService; private final int mUserId; private final int mAppId; private final Handler mHandler; private Map<PrintJobStateChangeListener, PrintJobStateChangeListenerWrapper> mPrintJobStateChangeListeners; private Map<PrintServicesChangeListener, PrintServicesChangeListenerWrapper> mPrintServicesChangeListeners; private Map<PrintServiceRecommendationsChangeListener, PrintServiceRecommendationsChangeListenerWrapper> mPrintServiceRecommendationsChangeListeners; /** @hide */ public interface PrintJobStateChangeListener { /** * Callback notifying that a print job state changed. * * @param printJobId The print job id. */ public void onPrintJobStateChanged(PrintJobId printJobId); } /** * Listen for changes to {@link #getPrintServices(int)}. * * @hide */ @SystemApi public interface PrintServicesChangeListener { /** * Callback notifying that the print services changed. */ void onPrintServicesChanged(); } /** * Listen for changes to {@link #getPrintServiceRecommendations()}. * * @hide */ @SystemApi public interface PrintServiceRecommendationsChangeListener { /** * Callback notifying that the print service recommendations changed. */ void onPrintServiceRecommendationsChanged(); } /** * Creates a new instance. * * @param context The current context in which to operate. * @param service The backing system service. * @param userId The user id in which to operate. * @param appId The application id in which to operate. * @hide */ public PrintManager(Context context, IPrintManager service, int userId, int appId) { mContext = context; mService = service; mUserId = userId; mAppId = appId; mHandler = new Handler(context.getMainLooper(), null, false) { @Override public void handleMessage(Message message) { switch (message.what) { case MSG_NOTIFY_PRINT_JOB_STATE_CHANGED: { SomeArgs args = (SomeArgs) message.obj; PrintJobStateChangeListenerWrapper wrapper = (PrintJobStateChangeListenerWrapper) args.arg1; PrintJobStateChangeListener listener = wrapper.getListener(); if (listener != null) { PrintJobId printJobId = (PrintJobId) args.arg2; listener.onPrintJobStateChanged(printJobId); } args.recycle(); } break; } } }; } /** * Creates an instance that can access all print jobs. * * @param userId The user id for which to get all print jobs. * @return An instance if the caller has the permission to access all print * jobs, null otherwise. * @hide */ public PrintManager getGlobalPrintManagerForUser(int userId) { if (mService == null) { Log.w(LOG_TAG, "Feature android.software.print not available"); return null; } return new PrintManager(mContext, mService, userId, APP_ID_ANY); } PrintJobInfo getPrintJobInfo(PrintJobId printJobId) { try { return mService.getPrintJobInfo(printJobId, mAppId, mUserId); } catch (RemoteException re) { throw re.rethrowFromSystemServer(); } } /** * Adds a listener for observing the state of print jobs. * * @param listener The listener to add. * @hide */ @UnsupportedAppUsage public void addPrintJobStateChangeListener(PrintJobStateChangeListener listener) { if (mService == null) { Log.w(LOG_TAG, "Feature android.software.print not available"); return; } if (mPrintJobStateChangeListeners == null) { mPrintJobStateChangeListeners = new ArrayMap<>(); } PrintJobStateChangeListenerWrapper wrappedListener = new PrintJobStateChangeListenerWrapper(listener, mHandler); try { mService.addPrintJobStateChangeListener(wrappedListener, mAppId, mUserId); mPrintJobStateChangeListeners.put(listener, wrappedListener); } catch (RemoteException re) { throw re.rethrowFromSystemServer(); } } /** * Removes a listener for observing the state of print jobs. * * @param listener The listener to remove. * @hide */ public void removePrintJobStateChangeListener(PrintJobStateChangeListener listener) { if (mService == null) { Log.w(LOG_TAG, "Feature android.software.print not available"); return; } if (mPrintJobStateChangeListeners == null) { return; } PrintJobStateChangeListenerWrapper wrappedListener = mPrintJobStateChangeListeners.remove(listener); if (wrappedListener == null) { return; } if (mPrintJobStateChangeListeners.isEmpty()) { mPrintJobStateChangeListeners = null; } wrappedListener.destroy(); try { mService.removePrintJobStateChangeListener(wrappedListener, mUserId); } catch (RemoteException re) { throw re.rethrowFromSystemServer(); } } /** * Gets a print job given its id. * * @param printJobId The id of the print job. * @return The print job list. * @see PrintJob * @hide */ public PrintJob getPrintJob(PrintJobId printJobId) { if (mService == null) { Log.w(LOG_TAG, "Feature android.software.print not available"); return null; } try { PrintJobInfo printJob = mService.getPrintJobInfo(printJobId, mAppId, mUserId); if (printJob != null) { return new PrintJob(printJob, this); } } catch (RemoteException re) { throw re.rethrowFromSystemServer(); } return null; } /** * Get the custom icon for a printer. If the icon is not cached, the icon is * requested asynchronously. Once it is available the printer is updated. * * @param printerId the id of the printer the icon should be loaded for * @return the custom icon to be used for the printer or null if the icon is * not yet available * @see android.print.PrinterInfo.Builder#setHasCustomPrinterIcon(boolean) * @hide */ public Icon getCustomPrinterIcon(PrinterId printerId) { if (mService == null) { Log.w(LOG_TAG, "Feature android.software.print not available"); return null; } try { return mService.getCustomPrinterIcon(printerId, mUserId); } catch (RemoteException re) { throw re.rethrowFromSystemServer(); } } /** * Gets the print jobs for this application. * * @return The print job list. * @see PrintJob */ public @NonNull List<PrintJob> getPrintJobs() { if (mService == null) { Log.w(LOG_TAG, "Feature android.software.print not available"); return Collections.emptyList(); } try { List<PrintJobInfo> printJobInfos = mService.getPrintJobInfos(mAppId, mUserId); if (printJobInfos == null) { return Collections.emptyList(); } final int printJobCount = printJobInfos.size(); List<PrintJob> printJobs = new ArrayList<PrintJob>(printJobCount); for (int i = 0; i < printJobCount; i++) { printJobs.add(new PrintJob(printJobInfos.get(i), this)); } return printJobs; } catch (RemoteException re) { throw re.rethrowFromSystemServer(); } } void cancelPrintJob(PrintJobId printJobId) { if (mService == null) { Log.w(LOG_TAG, "Feature android.software.print not available"); return; } try { mService.cancelPrintJob(printJobId, mAppId, mUserId); } catch (RemoteException re) { throw re.rethrowFromSystemServer(); } } void restartPrintJob(PrintJobId printJobId) { if (mService == null) { Log.w(LOG_TAG, "Feature android.software.print not available"); return; } try { mService.restartPrintJob(printJobId, mAppId, mUserId); } catch (RemoteException re) { throw re.rethrowFromSystemServer(); } } /** * Creates a print job for printing a {@link PrintDocumentAdapter} with * default print attributes. * <p> * Calling this method brings the print UI allowing the user to customize * the print job and returns a {@link PrintJob} object without waiting for the * user to customize or confirm the print job. The returned print job instance * is in a {@link PrintJobInfo#STATE_CREATED created} state. * <p> * This method can be called only from an {@link Activity}. The rationale is that * printing from a service will create an inconsistent user experience as the print * UI would appear without any context. * </p> * <p> * Also the passed in {@link PrintDocumentAdapter} will be considered invalid if * your activity is finished. The rationale is that once the activity that * initiated printing is finished, the provided adapter may be in an inconsistent * state as it may depend on the UI presented by the activity. * </p> * <p> * The default print attributes are a hint to the system how the data is to * be printed. For example, a photo editor may look at the photo aspect ratio * to determine the default orientation and provide a hint whether the printing * should be in portrait or landscape. The system will do a best effort to * selected the hinted options in the print dialog, given the current printer * supports them. * </p> * <p> * <strong>Note:</strong> Calling this method will bring the print dialog and * the system will connect to the provided {@link PrintDocumentAdapter}. If a * configuration change occurs that you application does not handle, for example * a rotation change, the system will drop the connection to the adapter as the * activity has to be recreated and the old adapter may be invalid in this context, * hence a new adapter instance is required. As a consequence, if your activity * does not handle configuration changes (default behavior), you have to save the * state that you were printing and call this method again when your activity * is recreated. * </p> * * @param printJobName A name for the new print job which is shown to the user. * @param documentAdapter An adapter that emits the document to print. * @param attributes The default print job attributes or <code>null</code>. * @return The created print job on success or null on failure. * @throws IllegalStateException If not called from an {@link Activity}. * @throws IllegalArgumentException If the print job name is empty or the * document adapter is null. * * @see PrintJob */ public @NonNull PrintJob print(@NonNull String printJobName, @NonNull PrintDocumentAdapter documentAdapter, @Nullable PrintAttributes attributes) { if (mService == null) { Log.w(LOG_TAG, "Feature android.software.print not available"); return null; } if (!(mContext instanceof Activity)) { throw new IllegalStateException("Can print only from an activity"); } if (TextUtils.isEmpty(printJobName)) { throw new IllegalArgumentException("printJobName cannot be empty"); } if (documentAdapter == null) { throw new IllegalArgumentException("documentAdapter cannot be null"); } PrintDocumentAdapterDelegate delegate = new PrintDocumentAdapterDelegate((Activity) mContext, documentAdapter); try { Bundle result = mService.print(printJobName, delegate, attributes, mContext.getPackageName(), mAppId, mUserId); if (result != null) { PrintJobInfo printJob = result.getParcelable(EXTRA_PRINT_JOB); IntentSender intent = result.getParcelable(EXTRA_PRINT_DIALOG_INTENT); if (printJob == null || intent == null) { return null; } try { mContext.startIntentSender(intent, null, 0, 0, 0); return new PrintJob(printJob, this); } catch (SendIntentException sie) { Log.e(LOG_TAG, "Couldn't start print job config activity.", sie); } } } catch (RemoteException re) { throw re.rethrowFromSystemServer(); } return null; } /** * Listen for changes to the installed and enabled print services. * * @param listener the listener to add * @param handler the handler the listener is called back on * * @see android.print.PrintManager#getPrintServices * * @hide */ @SystemApi @RequiresPermission(android.Manifest.permission.READ_PRINT_SERVICES) public void addPrintServicesChangeListener(@NonNull PrintServicesChangeListener listener, @Nullable Handler handler) { Preconditions.checkNotNull(listener); if (handler == null) { handler = mHandler; } if (mService == null) { Log.w(LOG_TAG, "Feature android.software.print not available"); return; } if (mPrintServicesChangeListeners == null) { mPrintServicesChangeListeners = new ArrayMap<>(); } PrintServicesChangeListenerWrapper wrappedListener = new PrintServicesChangeListenerWrapper(listener, handler); try { mService.addPrintServicesChangeListener(wrappedListener, mUserId); mPrintServicesChangeListeners.put(listener, wrappedListener); } catch (RemoteException re) { throw re.rethrowFromSystemServer(); } } /** * Stop listening for changes to the installed and enabled print services. * * @param listener the listener to remove * * @see android.print.PrintManager#getPrintServices * * @hide */ @SystemApi @RequiresPermission(android.Manifest.permission.READ_PRINT_SERVICES) public void removePrintServicesChangeListener(@NonNull PrintServicesChangeListener listener) { Preconditions.checkNotNull(listener); if (mService == null) { Log.w(LOG_TAG, "Feature android.software.print not available"); return; } if (mPrintServicesChangeListeners == null) { return; } PrintServicesChangeListenerWrapper wrappedListener = mPrintServicesChangeListeners.remove(listener); if (wrappedListener == null) { return; } if (mPrintServicesChangeListeners.isEmpty()) { mPrintServicesChangeListeners = null; } wrappedListener.destroy(); try { mService.removePrintServicesChangeListener(wrappedListener, mUserId); } catch (RemoteException re) { Log.e(LOG_TAG, "Error removing print services change listener", re); } } /** * Gets the list of print services, but does not register for updates. The user has to register * for updates by itself, or use {@link PrintServicesLoader}. * * @param selectionFlags flags selecting which services to get. Either * {@link #ENABLED_SERVICES},{@link #DISABLED_SERVICES}, or both. * * @return The print service list or an empty list. * * @see #addPrintServicesChangeListener(PrintServicesChangeListener, Handler) * @see #removePrintServicesChangeListener(PrintServicesChangeListener) * * @hide */ @SystemApi @RequiresPermission(android.Manifest.permission.READ_PRINT_SERVICES) public @NonNull List<PrintServiceInfo> getPrintServices(int selectionFlags) { Preconditions.checkFlagsArgument(selectionFlags, ALL_SERVICES); try { List<PrintServiceInfo> services = mService.getPrintServices(selectionFlags, mUserId); if (services != null) { return services; } } catch (RemoteException re) { throw re.rethrowFromSystemServer(); } return Collections.emptyList(); } /** * Listen for changes to the print service recommendations. * * @param listener the listener to add * @param handler the handler the listener is called back on * * @see android.print.PrintManager#getPrintServiceRecommendations * * @hide */ @SystemApi @RequiresPermission(android.Manifest.permission.READ_PRINT_SERVICE_RECOMMENDATIONS) public void addPrintServiceRecommendationsChangeListener( @NonNull PrintServiceRecommendationsChangeListener listener, @Nullable Handler handler) { Preconditions.checkNotNull(listener); if (handler == null) { handler = mHandler; } if (mService == null) { Log.w(LOG_TAG, "Feature android.software.print not available"); return; } if (mPrintServiceRecommendationsChangeListeners == null) { mPrintServiceRecommendationsChangeListeners = new ArrayMap<>(); } PrintServiceRecommendationsChangeListenerWrapper wrappedListener = new PrintServiceRecommendationsChangeListenerWrapper( listener, handler); try { mService.addPrintServiceRecommendationsChangeListener(wrappedListener, mUserId); mPrintServiceRecommendationsChangeListeners.put(listener, wrappedListener); } catch (RemoteException re) { throw re.rethrowFromSystemServer(); } } /** * Stop listening for changes to the print service recommendations. * * @param listener the listener to remove * * @see android.print.PrintManager#getPrintServiceRecommendations * * @hide */ @SystemApi @RequiresPermission(android.Manifest.permission.READ_PRINT_SERVICE_RECOMMENDATIONS) public void removePrintServiceRecommendationsChangeListener( @NonNull PrintServiceRecommendationsChangeListener listener) { Preconditions.checkNotNull(listener); if (mService == null) { Log.w(LOG_TAG, "Feature android.software.print not available"); return; } if (mPrintServiceRecommendationsChangeListeners == null) { return; } PrintServiceRecommendationsChangeListenerWrapper wrappedListener = mPrintServiceRecommendationsChangeListeners .remove(listener); if (wrappedListener == null) { return; } if (mPrintServiceRecommendationsChangeListeners.isEmpty()) { mPrintServiceRecommendationsChangeListeners = null; } wrappedListener.destroy(); try { mService.removePrintServiceRecommendationsChangeListener(wrappedListener, mUserId); } catch (RemoteException re) { throw re.rethrowFromSystemServer(); } } /** * Gets the list of print service recommendations, but does not register for updates. The user * has to register for updates by itself, or use {@link PrintServiceRecommendationsLoader}. * * @return The print service recommendations list or an empty list. * * @see #addPrintServiceRecommendationsChangeListener * @see #removePrintServiceRecommendationsChangeListener * * @hide */ @SystemApi @RequiresPermission(android.Manifest.permission.READ_PRINT_SERVICE_RECOMMENDATIONS) public @NonNull List<RecommendationInfo> getPrintServiceRecommendations() { try { List<RecommendationInfo> recommendations = mService.getPrintServiceRecommendations(mUserId); if (recommendations != null) { return recommendations; } } catch (RemoteException re) { throw re.rethrowFromSystemServer(); } return Collections.emptyList(); } /** * @hide */ public PrinterDiscoverySession createPrinterDiscoverySession() { if (mService == null) { Log.w(LOG_TAG, "Feature android.software.print not available"); return null; } return new PrinterDiscoverySession(mService, mContext, mUserId); } /** * Enable or disable a print service. * * @param service The service to enabled or disable * @param isEnabled whether the service should be enabled or disabled * * @hide */ public void setPrintServiceEnabled(@NonNull ComponentName service, boolean isEnabled) { if (mService == null) { Log.w(LOG_TAG, "Feature android.software.print not available"); return; } try { mService.setPrintServiceEnabled(service, isEnabled, mUserId); } catch (RemoteException re) { Log.e(LOG_TAG, "Error enabling or disabling " + service, re); } } /** * @hide */ public static final class PrintDocumentAdapterDelegate extends IPrintDocumentAdapter.Stub implements ActivityLifecycleCallbacks { private final Object mLock = new Object(); private Activity mActivity; // Strong reference OK - cleared in destroy private PrintDocumentAdapter mDocumentAdapter; // Strong reference OK - cleared in destroy private Handler mHandler; // Strong reference OK - cleared in destroy private IPrintDocumentAdapterObserver mObserver; // Strong reference OK - cleared in destroy private DestroyableCallback mPendingCallback; public PrintDocumentAdapterDelegate(Activity activity, PrintDocumentAdapter documentAdapter) { if (activity.isFinishing()) { // The activity is already dead hence the onActivityDestroyed callback won't be // triggered. Hence it is not save to print in this situation. throw new IllegalStateException("Cannot start printing for finishing activity"); } mActivity = activity; mDocumentAdapter = documentAdapter; mHandler = new MyHandler(mActivity.getMainLooper()); mActivity.getApplication().registerActivityLifecycleCallbacks(this); } @Override public void setObserver(IPrintDocumentAdapterObserver observer) { final boolean destroyed; synchronized (mLock) { mObserver = observer; destroyed = isDestroyedLocked(); } if (destroyed && observer != null) { try { observer.onDestroy(); } catch (RemoteException re) { Log.e(LOG_TAG, "Error announcing destroyed state", re); } } } @Override public void start() { synchronized (mLock) { // If destroyed the handler is null. if (!isDestroyedLocked()) { mHandler.obtainMessage(MyHandler.MSG_ON_START, mDocumentAdapter).sendToTarget(); } } } @Override public void layout(PrintAttributes oldAttributes, PrintAttributes newAttributes, ILayoutResultCallback callback, Bundle metadata, int sequence) { ICancellationSignal cancellationTransport = CancellationSignal.createTransport(); try { callback.onLayoutStarted(cancellationTransport, sequence); } catch (RemoteException re) { // The spooler is dead - can't recover. Log.e(LOG_TAG, "Error notifying for layout start", re); return; } synchronized (mLock) { // If destroyed the handler is null. if (isDestroyedLocked()) { return; } CancellationSignal cancellationSignal = CancellationSignal.fromTransport(cancellationTransport); SomeArgs args = SomeArgs.obtain(); args.arg1 = mDocumentAdapter; args.arg2 = oldAttributes; args.arg3 = newAttributes; args.arg4 = cancellationSignal; args.arg5 = new MyLayoutResultCallback(callback, sequence); args.arg6 = metadata; mHandler.obtainMessage(MyHandler.MSG_ON_LAYOUT, args).sendToTarget(); } } @Override public void write(PageRange[] pages, ParcelFileDescriptor fd, IWriteResultCallback callback, int sequence) { ICancellationSignal cancellationTransport = CancellationSignal.createTransport(); try { callback.onWriteStarted(cancellationTransport, sequence); } catch (RemoteException re) { // The spooler is dead - can't recover. Log.e(LOG_TAG, "Error notifying for write start", re); return; } synchronized (mLock) { // If destroyed the handler is null. if (isDestroyedLocked()) { return; } CancellationSignal cancellationSignal = CancellationSignal.fromTransport(cancellationTransport); SomeArgs args = SomeArgs.obtain(); args.arg1 = mDocumentAdapter; args.arg2 = pages; args.arg3 = fd; args.arg4 = cancellationSignal; args.arg5 = new MyWriteResultCallback(callback, fd, sequence); mHandler.obtainMessage(MyHandler.MSG_ON_WRITE, args).sendToTarget(); } } @Override public void finish() { synchronized (mLock) { // If destroyed the handler is null. if (!isDestroyedLocked()) { mHandler.obtainMessage(MyHandler.MSG_ON_FINISH, mDocumentAdapter).sendToTarget(); } } } @Override public void kill(String reason) { synchronized (mLock) { // If destroyed the handler is null. if (!isDestroyedLocked()) { mHandler.obtainMessage(MyHandler.MSG_ON_KILL, reason).sendToTarget(); } } } @Override public void onActivityPaused(Activity activity) { /* do nothing */ } @Override public void onActivityCreated(Activity activity, Bundle savedInstanceState) { /* do nothing */ } @Override public void onActivityStarted(Activity activity) { /* do nothing */ } @Override public void onActivityResumed(Activity activity) { /* do nothing */ } @Override public void onActivityStopped(Activity activity) { /* do nothing */ } @Override public void onActivitySaveInstanceState(Activity activity, Bundle outState) { /* do nothing */ } @Override public void onActivityDestroyed(Activity activity) { // We really care only if the activity is being destroyed to // notify the the print spooler so it can close the print dialog. // Note the the spooler has a death recipient that observes if // this process gets killed so we cover the case of onDestroy not // being called due to this process being killed to reclaim memory. IPrintDocumentAdapterObserver observer = null; synchronized (mLock) { if (activity == mActivity) { observer = mObserver; destroyLocked(); } } if (observer != null) { try { observer.onDestroy(); } catch (RemoteException re) { Log.e(LOG_TAG, "Error announcing destroyed state", re); } } } private boolean isDestroyedLocked() { return (mActivity == null); } private void destroyLocked() { mActivity.getApplication().unregisterActivityLifecycleCallbacks(PrintDocumentAdapterDelegate.this); mActivity = null; mDocumentAdapter = null; // This method is only called from the main thread, so // clearing the messages guarantees that any time a // message is handled we are not in a destroyed state. mHandler.removeMessages(MyHandler.MSG_ON_START); mHandler.removeMessages(MyHandler.MSG_ON_LAYOUT); mHandler.removeMessages(MyHandler.MSG_ON_WRITE); mHandler.removeMessages(MyHandler.MSG_ON_FINISH); mHandler = null; mObserver = null; if (mPendingCallback != null) { mPendingCallback.destroy(); mPendingCallback = null; } } private final class MyHandler extends Handler { public static final int MSG_ON_START = 1; public static final int MSG_ON_LAYOUT = 2; public static final int MSG_ON_WRITE = 3; public static final int MSG_ON_FINISH = 4; public static final int MSG_ON_KILL = 5; public MyHandler(Looper looper) { super(looper, null, true); } @Override public void handleMessage(Message message) { switch (message.what) { case MSG_ON_START: { if (DEBUG) { Log.i(LOG_TAG, "onStart()"); } ((PrintDocumentAdapter) message.obj).onStart(); } break; case MSG_ON_LAYOUT: { SomeArgs args = (SomeArgs) message.obj; PrintDocumentAdapter adapter = (PrintDocumentAdapter) args.arg1; PrintAttributes oldAttributes = (PrintAttributes) args.arg2; PrintAttributes newAttributes = (PrintAttributes) args.arg3; CancellationSignal cancellation = (CancellationSignal) args.arg4; LayoutResultCallback callback = (LayoutResultCallback) args.arg5; Bundle metadata = (Bundle) args.arg6; args.recycle(); if (DEBUG) { StringBuilder builder = new StringBuilder(); builder.append("PrintDocumentAdapter#onLayout() {\n"); builder.append("\n oldAttributes:").append(oldAttributes); builder.append("\n newAttributes:").append(newAttributes); builder.append("\n preview:") .append(metadata.getBoolean(PrintDocumentAdapter.EXTRA_PRINT_PREVIEW)); builder.append("\n}"); Log.i(LOG_TAG, builder.toString()); } adapter.onLayout(oldAttributes, newAttributes, cancellation, callback, metadata); } break; case MSG_ON_WRITE: { SomeArgs args = (SomeArgs) message.obj; PrintDocumentAdapter adapter = (PrintDocumentAdapter) args.arg1; PageRange[] pages = (PageRange[]) args.arg2; ParcelFileDescriptor fd = (ParcelFileDescriptor) args.arg3; CancellationSignal cancellation = (CancellationSignal) args.arg4; WriteResultCallback callback = (WriteResultCallback) args.arg5; args.recycle(); if (DEBUG) { StringBuilder builder = new StringBuilder(); builder.append("PrintDocumentAdapter#onWrite() {\n"); builder.append("\n pages:").append(Arrays.toString(pages)); builder.append("\n}"); Log.i(LOG_TAG, builder.toString()); } adapter.onWrite(pages, fd, cancellation, callback); } break; case MSG_ON_FINISH: { if (DEBUG) { Log.i(LOG_TAG, "onFinish()"); } ((PrintDocumentAdapter) message.obj).onFinish(); // Done printing, so destroy this instance as it // should not be used anymore. synchronized (mLock) { destroyLocked(); } } break; case MSG_ON_KILL: { if (DEBUG) { Log.i(LOG_TAG, "onKill()"); } String reason = (String) message.obj; throw new RuntimeException(reason); } default: { throw new IllegalArgumentException("Unknown message: " + message.what); } } } } private interface DestroyableCallback { public void destroy(); } private final class MyLayoutResultCallback extends LayoutResultCallback implements DestroyableCallback { private ILayoutResultCallback mCallback; private final int mSequence; public MyLayoutResultCallback(ILayoutResultCallback callback, int sequence) { mCallback = callback; mSequence = sequence; } @Override public void onLayoutFinished(PrintDocumentInfo info, boolean changed) { final ILayoutResultCallback callback; synchronized (mLock) { callback = mCallback; } // If the callback is null we are destroyed. if (callback == null) { Log.e(LOG_TAG, "PrintDocumentAdapter is destroyed. Did you " + "finish the printing activity before print completion " + "or did you invoke a callback after finish?"); return; } try { if (info == null) { throw new NullPointerException("document info cannot be null"); } try { callback.onLayoutFinished(info, changed, mSequence); } catch (RemoteException re) { Log.e(LOG_TAG, "Error calling onLayoutFinished", re); } } finally { destroy(); } } @Override public void onLayoutFailed(CharSequence error) { final ILayoutResultCallback callback; synchronized (mLock) { callback = mCallback; } // If the callback is null we are destroyed. if (callback == null) { Log.e(LOG_TAG, "PrintDocumentAdapter is destroyed. Did you " + "finish the printing activity before print completion " + "or did you invoke a callback after finish?"); return; } try { callback.onLayoutFailed(error, mSequence); } catch (RemoteException re) { Log.e(LOG_TAG, "Error calling onLayoutFailed", re); } finally { destroy(); } } @Override public void onLayoutCancelled() { final ILayoutResultCallback callback; synchronized (mLock) { callback = mCallback; } // If the callback is null we are destroyed. if (callback == null) { Log.e(LOG_TAG, "PrintDocumentAdapter is destroyed. Did you " + "finish the printing activity before print completion " + "or did you invoke a callback after finish?"); return; } try { callback.onLayoutCanceled(mSequence); } catch (RemoteException re) { Log.e(LOG_TAG, "Error calling onLayoutFailed", re); } finally { destroy(); } } @Override public void destroy() { synchronized (mLock) { mCallback = null; mPendingCallback = null; } } } private final class MyWriteResultCallback extends WriteResultCallback implements DestroyableCallback { private ParcelFileDescriptor mFd; private IWriteResultCallback mCallback; private final int mSequence; public MyWriteResultCallback(IWriteResultCallback callback, ParcelFileDescriptor fd, int sequence) { mFd = fd; mSequence = sequence; mCallback = callback; } @Override public void onWriteFinished(PageRange[] pages) { final IWriteResultCallback callback; synchronized (mLock) { callback = mCallback; } // If the callback is null we are destroyed. if (callback == null) { Log.e(LOG_TAG, "PrintDocumentAdapter is destroyed. Did you " + "finish the printing activity before print completion " + "or did you invoke a callback after finish?"); return; } try { if (pages == null) { throw new IllegalArgumentException("pages cannot be null"); } if (pages.length == 0) { throw new IllegalArgumentException("pages cannot be empty"); } try { callback.onWriteFinished(pages, mSequence); } catch (RemoteException re) { Log.e(LOG_TAG, "Error calling onWriteFinished", re); } } finally { destroy(); } } @Override public void onWriteFailed(CharSequence error) { final IWriteResultCallback callback; synchronized (mLock) { callback = mCallback; } // If the callback is null we are destroyed. if (callback == null) { Log.e(LOG_TAG, "PrintDocumentAdapter is destroyed. Did you " + "finish the printing activity before print completion " + "or did you invoke a callback after finish?"); return; } try { callback.onWriteFailed(error, mSequence); } catch (RemoteException re) { Log.e(LOG_TAG, "Error calling onWriteFailed", re); } finally { destroy(); } } @Override public void onWriteCancelled() { final IWriteResultCallback callback; synchronized (mLock) { callback = mCallback; } // If the callback is null we are destroyed. if (callback == null) { Log.e(LOG_TAG, "PrintDocumentAdapter is destroyed. Did you " + "finish the printing activity before print completion " + "or did you invoke a callback after finish?"); return; } try { callback.onWriteCanceled(mSequence); } catch (RemoteException re) { Log.e(LOG_TAG, "Error calling onWriteCanceled", re); } finally { destroy(); } } @Override public void destroy() { synchronized (mLock) { IoUtils.closeQuietly(mFd); mCallback = null; mFd = null; mPendingCallback = null; } } } } /** * @hide */ public static final class PrintJobStateChangeListenerWrapper extends IPrintJobStateChangeListener.Stub { private final WeakReference<PrintJobStateChangeListener> mWeakListener; private final WeakReference<Handler> mWeakHandler; public PrintJobStateChangeListenerWrapper(PrintJobStateChangeListener listener, Handler handler) { mWeakListener = new WeakReference<PrintJobStateChangeListener>(listener); mWeakHandler = new WeakReference<Handler>(handler); } @Override public void onPrintJobStateChanged(PrintJobId printJobId) { Handler handler = mWeakHandler.get(); PrintJobStateChangeListener listener = mWeakListener.get(); if (handler != null && listener != null) { SomeArgs args = SomeArgs.obtain(); args.arg1 = this; args.arg2 = printJobId; handler.obtainMessage(MSG_NOTIFY_PRINT_JOB_STATE_CHANGED, args).sendToTarget(); } } public void destroy() { mWeakListener.clear(); } public PrintJobStateChangeListener getListener() { return mWeakListener.get(); } } /** * @hide */ public static final class PrintServicesChangeListenerWrapper extends IPrintServicesChangeListener.Stub { private final WeakReference<PrintServicesChangeListener> mWeakListener; private final WeakReference<Handler> mWeakHandler; public PrintServicesChangeListenerWrapper(PrintServicesChangeListener listener, Handler handler) { mWeakListener = new WeakReference<>(listener); mWeakHandler = new WeakReference<>(handler); } @Override public void onPrintServicesChanged() { Handler handler = mWeakHandler.get(); PrintServicesChangeListener listener = mWeakListener.get(); if (handler != null && listener != null) { handler.post(listener::onPrintServicesChanged); } } public void destroy() { mWeakListener.clear(); } } /** * @hide */ public static final class PrintServiceRecommendationsChangeListenerWrapper extends IRecommendationsChangeListener.Stub { private final WeakReference<PrintServiceRecommendationsChangeListener> mWeakListener; private final WeakReference<Handler> mWeakHandler; public PrintServiceRecommendationsChangeListenerWrapper(PrintServiceRecommendationsChangeListener listener, Handler handler) { mWeakListener = new WeakReference<>(listener); mWeakHandler = new WeakReference<>(handler); } @Override public void onRecommendationsChanged() { Handler handler = mWeakHandler.get(); PrintServiceRecommendationsChangeListener listener = mWeakListener.get(); if (handler != null && listener != null) { handler.post(listener::onPrintServiceRecommendationsChanged); } } public void destroy() { mWeakListener.clear(); } } }