Android自定义后台打印服务

接前一篇文章（Android调用系统默认打印机并反射获取打印任务状态 https://blog.csdn.net/yan1348/article/details/90666657）所说，完全按照系统默认的打印流程是有缺陷的，所以我在这里又实现了一个自定义服务来实现后台打印的。
首先，我们先来看看PrintManager.print方法到底做了什么动作，先看看源码```
在这里插入代码片
/*** 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;
}
```
这个是print方法的源码，我们可以看看，最后是实现了一个intent操作，这个intent会跳转到哪里去，我们可以看下intent的参数，接下来我们看看这个参数的定义在哪里，我们可以看到，intent是由mService.print方法产生的，我们来看看PrintManagerService.print方法```
在这里插入代码片
@Override
public Bundle print(String printJobName, IPrintDocumentAdapter adapter,PrintAttributes attributes, String packageName, int appId, int userId) {final int resolvedAppId = resolveCallingAppEnforcingPermissions(appId);final int resolvedUserId = resolveCallingUserEnforcingPermissions(userId);String resolvedPackageName = resolveCallingPackageNameEnforcingSecurity(packageName);final UserState userState;synchronized (mLock) {userState = getOrCreateUserStateLocked(resolvedUserId);}final long identity = Binder.clearCallingIdentity();try {return userState.print(printJobName, adapter, attributes,resolvedPackageName, resolvedAppId);} finally {Binder.restoreCallingIdentity(identity);}
}
```
可以看到，接下来我们要看的是UserState.print方法，我们跳到UserState.java```
在这里插入代码片
@SuppressWarnings("deprecation")
public Bundle print(String printJobName, IPrintDocumentAdapter adapter,PrintAttributes attributes, String packageName, int appId) {// Create print job place holder.final PrintJobInfo printJob = new PrintJobInfo();printJob.setId(new PrintJobId());printJob.setAppId(appId);printJob.setLabel(printJobName);printJob.setAttributes(attributes);printJob.setState(PrintJobInfo.STATE_CREATED);printJob.setCopies(1);printJob.setCreationTime(System.currentTimeMillis());// Track this job so we can forget it when the creator dies.if (!mPrintJobForAppCache.onPrintJobCreated(adapter.asBinder(), appId,printJob)) {// Not adding a print job means the client is dead - done.return null;}// Spin the spooler to add the job and show the config UI.new AsyncTask<Void, Void, Void>() {@Overrideprotected Void doInBackground(Void... params) {mSpooler.createPrintJob(printJob);return null;}}.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR, (Void[]) null);final long identity = Binder.clearCallingIdentity();try {Intent intent = new Intent(PrintManager.ACTION_PRINT_DIALOG);intent.setData(Uri.fromParts("printjob", printJob.getId().flattenToString(), null));intent.putExtra(PrintManager.EXTRA_PRINT_DOCUMENT_ADAPTER, adapter.asBinder());intent.putExtra(PrintManager.EXTRA_PRINT_JOB, printJob);intent.putExtra(DocumentsContract.EXTRA_PACKAGE_NAME, packageName);IntentSender intentSender = PendingIntent.getActivityAsUser(mContext, 0, intent, PendingIntent.FLAG_ONE_SHOT| PendingIntent.FLAG_CANCEL_CURRENT, null, new UserHandle(mUserId)).getIntentSender();Bundle result = new Bundle();result.putParcelable(PrintManager.EXTRA_PRINT_JOB, printJob);result.putParcelable(PrintManager.EXTRA_PRINT_DIALOG_INTENT, intentSender);return result;} finally {Binder.restoreCallingIdentity(identity);}
}
```
在这里，我们可以看到，其实这个intent的action是PrintManager.ACTION_PRINT_DIALOG，接下来我们先看看这个action是怎么定义的，回到PrintManager.java文件。```
在这里插入代码片
/*** The action for launching the print dialog activity.** @hide*/
public static final String ACTION_PRINT_DIALOG = "android.print.PRINT_DIALOG";
```
接下来我们使用一种笨办法来查找一下这个action是在哪里定义的，就用全文搜索吧，查找这个字符串，我这里用的是Source Insight 4.0,已经把这个frameworks目录导进去了，接下来我们全文搜索一下这个字符串.```
在这里插入代码片
<activityandroid:name=".PrintJobConfigActivity"android:configChanges="orientation|screenSize"android:permission="android.permission.BIND_PRINT_SPOOLER_SERVICE"android:theme="@style/PrintJobConfigActivityTheme"><intent-filter><action android:name="android.print.PRINT_DIALOG" /><category android:name="android.intent.category.DEFAULT" /><data android:scheme="printjob" android:pathPattern="*" /></intent-filter></activity>
```
我们可以找到，在frameworks\base\packages\PrintSpooler\AndroidManifest.xml里面有这个定义，说明上面那个intent就是跳转到这个PrintJobConfigActivity里面的，接下来我们分析一下这个\frameworks\base\packages\PrintSpooler\src\com\android\printspooler\PrintJobConfigActivity.
我们先来看看这个activity的onCreate方法，在这里，我们可以看到，这个activity使用了intent传递过来的两个参数，PrintJob和PrintDocumentAdapter。这个activity的逻辑比较复杂，在这里我就不一一的去解释，大家自己去看就行了，看不懂的自己去打log去看看流程怎么走的，我在这里主要介绍两个内部类，一个是Editor，一个是PrintController。
我们先来看看Editor。
先看看Editor的postCreate方法。```
在这里插入代码片
public void postCreate() {// Destination.mMediaSizeComparator = new MediaSizeComparator(PrintJobConfigActivity.this);mDestinationSpinnerAdapter = new DestinationAdapter();mDestinationSpinnerAdapter.registerDataSetObserver(new DataSetObserver() {@Overridepublic void onChanged() {Log.e(LOG_TAG, "postCreate-onChanged");// Initially, we have only safe to PDF as a printer but after some// printers are loaded we want to select the user's favorite one// which is the first.if (!mFavoritePrinterSelected && mDestinationSpinnerAdapter.getCount() > 2) {mFavoritePrinterSelected = true;mDestinationSpinner.setSelection(0);// Workaround again the weird spinner behavior to notify for selection// change on the next layout pass as the current printer is used below.mCurrentPrinter = (PrinterInfo) mDestinationSpinnerAdapter.getItem(0);}// If there is a next printer to select and we succeed selecting// it - done. Let the selection handling code make everything right.if (mNextPrinterId != null && selectPrinter(mNextPrinterId)) {mNextPrinterId = null;return;}// If the current printer properties changed, we update the UI.if (mCurrentPrinter != null) {final int printerCount = mDestinationSpinnerAdapter.getCount();for (int i = 0; i < printerCount; i++) {Object item = mDestinationSpinnerAdapter.getItem(i);// Some items are not printersif (item instanceof PrinterInfo) {PrinterInfo printer = (PrinterInfo) item;if (!printer.getId().equals(mCurrentPrinter.getId())) {continue;}// If nothing changed - done.if (mCurrentPrinter.equals(printer)) {return;}// If the current printer became available and has no// capabilities, we refresh it.if (mCurrentPrinter.getStatus() == PrinterInfo.STATUS_UNAVAILABLE&& printer.getStatus() != PrinterInfo.STATUS_UNAVAILABLE&& printer.getCapabilities() == null) {if (!mCapabilitiesTimeout.isPosted()) {mCapabilitiesTimeout.post();}mCurrentPrinter.copyFrom(printer);refreshCurrentPrinter();return;}// If the current printer became unavailable or its// capabilities go away, we update the UI and add a// timeout to declare the printer as unavailable.if ((mCurrentPrinter.getStatus() != PrinterInfo.STATUS_UNAVAILABLE&& printer.getStatus() == PrinterInfo.STATUS_UNAVAILABLE)|| (mCurrentPrinter.getCapabilities() != null&& printer.getCapabilities() == null)) {if (!mCapabilitiesTimeout.isPosted()) {mCapabilitiesTimeout.post();}mCurrentPrinter.copyFrom(printer);updateUi();return;}// We just refreshed the current printer.if (printer.getCapabilities() != null&& mCapabilitiesTimeout.isPosted()) {mCapabilitiesTimeout.remove();updatePrintAttributes(printer.getCapabilities());updateUi();mController.update();}// Update the UI if capabilities changed.boolean capabilitiesChanged = false;if (mCurrentPrinter.getCapabilities() == null) {if (printer.getCapabilities() != null) {capabilitiesChanged = true;}} else if (!mCurrentPrinter.getCapabilities().equals(printer.getCapabilities())) {capabilitiesChanged = true;}// Update the UI if the status changed.final boolean statusChanged = mCurrentPrinter.getStatus()!= printer.getStatus();// Update the printer with the latest info.if (!mCurrentPrinter.equals(printer)) {mCurrentPrinter.copyFrom(printer);}if (capabilitiesChanged || statusChanged) {// If something changed during update...if (updateUi() || !mController.hasPerformedLayout()) {// Update the document.mController.update();}}break;}}}}@Overridepublic void onInvalidated() {/* do nothing - we always have one fake PDF printer */}});// Media size.mMediaSizeSpinnerAdapter = new ArrayAdapter<SpinnerItem<MediaSize>>(PrintJobConfigActivity.this,R.layout.spinner_dropdown_item, R.id.title);// Color mode.mColorModeSpinnerAdapter = new ArrayAdapter<SpinnerItem<Integer>>(PrintJobConfigActivity.this,R.layout.spinner_dropdown_item, R.id.title);// OrientationmOrientationSpinnerAdapter = new ArrayAdapter<SpinnerItem<Integer>>(PrintJobConfigActivity.this,R.layout.spinner_dropdown_item, R.id.title);String[] orientationLabels = getResources().getStringArray(R.array.orientation_labels);mOrientationSpinnerAdapter.add(new SpinnerItem<Integer>(ORIENTATION_PORTRAIT, orientationLabels[0]));mOrientationSpinnerAdapter.add(new SpinnerItem<Integer>(ORIENTATION_LANDSCAPE, orientationLabels[1]));// Range optionsmRangeOptionsSpinnerAdapter = new ArrayAdapter<SpinnerItem<Integer>>(PrintJobConfigActivity.this,R.layout.spinner_dropdown_item, R.id.title);final int[] rangeOptionsValues = getResources().getIntArray(R.array.page_options_values);String[] rangeOptionsLabels = getResources().getStringArray(R.array.page_options_labels);final int rangeOptionsCount = rangeOptionsLabels.length;for (int i = 0; i < rangeOptionsCount; i++) {mRangeOptionsSpinnerAdapter.add(new SpinnerItem<Integer>(rangeOptionsValues[i], rangeOptionsLabels[i]));}showUi(UI_EDITING_PRINT_JOB, null);bindUi();updateUi();}```
接下来看看DestinationAdapter，在这里我们主要看看这几个方法。```
在这里插入代码片
public DestinationAdapter() {getLoaderManager().initLoader(LOADER_ID_PRINTERS_LOADER, null, this);}@Overridepublic Loader<List<PrinterInfo>> onCreateLoader(int id, Bundle args) {if (id == LOADER_ID_PRINTERS_LOADER) {return new FusedPrintersProvider(PrintJobConfigActivity.this);}return null;}@Overridepublic void onLoadFinished(Loader<List<PrinterInfo>> loader,List<PrinterInfo> printers) {// If this is the first load, create the fake PDF printer.// We do this to avoid flicker where the PDF printer is the// only one and as soon as the loader loads the favorites// it gets switched. Not a great user experience.if (mFakePdfPrinter == null) {mCurrentPrinter = mFakePdfPrinter = createFakePdfPrinter();updatePrintAttributes(mCurrentPrinter.getCapabilities());updateUi();}for(int i = 0,length = printers.size();i<length;i++){Log.e("PrintJobConfigActivity", "[ymy]print_index="+i+","+printers.get(i).toString());}// We rearrange the printers if the user selects a printer// not shown in the initial short list. Therefore, we have// to keep the printer order.// No old printers - do not bother keeping their position.if (mPrinters.isEmpty()) {mPrinters.addAll(printers);mEditor.ensureCurrentPrinterSelected();notifyDataSetChanged();return;}// Add the new printers to a map.ArrayMap<PrinterId, PrinterInfo> newPrintersMap =new ArrayMap<PrinterId, PrinterInfo>();final int printerCount = printers.size();for (int i = 0; i < printerCount; i++) {PrinterInfo printer = printers.get(i);newPrintersMap.put(printer.getId(), printer);}List<PrinterInfo> newPrinters = new ArrayList<PrinterInfo>();// Update printers we already have.final int oldPrinterCount = mPrinters.size();for (int i = 0; i < oldPrinterCount; i++) {PrinterId oldPrinterId = mPrinters.get(i).getId();PrinterInfo updatedPrinter = newPrintersMap.remove(oldPrinterId);if (updatedPrinter != null) {newPrinters.add(updatedPrinter);}}// Add the rest of the new printers, i.e. what is left.newPrinters.addAll(newPrintersMap.values());mPrinters.clear();mPrinters.addAll(newPrinters);mEditor.ensureCurrentPrinterSelected();notifyDataSetChanged();}@Overridepublic void onLoaderReset(Loader<List<PrinterInfo>> loader) {mPrinters.clear();notifyDataSetInvalidated();}
```
这几行代码主要是扫描打印机的，在执行完onLoadFinished后如果找到了打印机，就执行adapter的notifyDataSetChanged，在上面postCreate方法里面，我们可以看到mDestinationSpinnerAdapter.registerDataSetObserver注册了数据变化监听，我们看看onChanged方法，前面几行代码是选择第一个打印机为默认打印机，接下来就是判断打印机的状态是否可用，以及打印机属性是否为空，如果两者状态都满足，就执行updateUi方法，updateUi主要是实现一些属性的配置，这个我们不细讲，我们主要关注这几行代码。```
在这里插入代码片
if ((mRangeOptionsSpinner.getSelectedItemPosition() == 1
&& (TextUtils.isEmpty(mPageRangeEditText.getText())|| hasErrors()))||   (mRangeOptionsSpinner.getSelectedItemPosition() == 0&& (!mController.hasPerformedLayout() || hasErrors()))) {mPrintButton.setEnabled(false);} else {mPrintButton.setEnabled(true);}
```
这几行代码主要判断打印机状态等等信息是否正常，打印按钮是否可用，接下来我们去看看打印按钮主要做了什么操作。```
在这里插入代码片
final PrinterInfo printer = (PrinterInfo) mDestinationSpinner.getSelectedItem();
Log.e(LOG_TAG, "[ymy]PrintButton is click--"+printer.toString());
if (printer != null) {mEditor.confirmPrint();mController.update();if (!printer.equals(mDestinationSpinnerAdapter.mFakePdfPrinter)) {mEditor.refreshCurrentPrinter();}
} else {mEditor.cancel();PrintJobConfigActivity.this.finish();}
```
接下来主要操作在mController.update()方法里面，我们就不一一介绍了，大概的流程就是第一步执行mRemotePrintAdapter.layout，接下来handleOnLayoutFinished里面mRemotePrintAdapter.write，接下来handleOnWriteFinished里面的requestCreatePdfFileOrFinish里面执行PrintJobConfigActivity.this.finish()，接下俩我们看看Activity生命周期方法onPause里面。```
在这里插入代码片
if (isFinishing()) {Log.e(LOG_TAG, "onPause");if (mController != null && mController.hasStarted()) {mController.finish();}if (mEditor != null && mEditor.isPrintConfirmed()&& mController != null && mController.isFinished()) {Log.e(LOG_TAG, "setPrintJobState--STATE_QUEUED");mSpoolerProvider.getSpooler().setPrintJobState(mPrintJobId,PrintJobInfo.STATE_QUEUED, null);} else {mSpoolerProvider.getSpooler().setPrintJobState(mPrintJobId,PrintJobInfo.STATE_CANCELED, null);}if (mGeneratingPrintJobDialog != null) {mGeneratingPrintJobDialog.dismiss();mGeneratingPrintJobDialog = null;}mIPrintDocumentAdapter.unlinkToDeath(mDeathRecipient, 0);mSpoolerProvider.destroy();}super.onPause();
```
就是将打印状态修改为STATE_QUEUED，接下来就交给PrintSpoolerService来处理了，这个我们就不看了，有兴趣的自己看。
前面说了这么多，主要是为后面做个铺垫，我们自定义PrintJobService就是根据这个流程来写的，大家有兴趣的话可以自己去看下，我是给PrintjobConfigActivity的方法都打上log，看看他具体是怎么跑的，大家可以试试，有其他更好的方法也可以交流一下。
接下来我们来说下我们的service是怎么实现的，首先我们的service也是放在\frameworks\base\packages\PrintSpooler\src\com\android\printspooler目录下的，这个是为了避免我们调用一些类时找不到，其实我们这个service就是PrintjobConfigActivity的简化版本，删除了一些东西，把activity变成了service而已。我们先从PrintManager.print开始修改。```
在这里插入代码片
public PrintJob print(String printJobName, PrintDocumentAdapter documentAdapter,PrintAttributes attributes) {isPrint = false;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");}final PrintDocumentAdapterDelegate delegate = new PrintDocumentAdapterDelegate((Activity) mContext, documentAdapter);try {final 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 {final PrinterLoader loader = new PrinterLoader((Activity)mContext);loader.getPrinters(new GetPrintersCallBack(){public void receivePrinters(List<PrinterInfo> printers){for(int i = 0,length = printers.size();i<length;i++){PrinterInfo printer = printers.get(i);Log.e("PrintManager", "[ymy]receivePrinters--print_index="+i+","+printer.toString());if(printer.getName().startsWith("L805") && printer.getStatus() == PrinterInfo.STATUS_IDLE && null != printer.getCapabilities() && !isPrint){loader.addHistoricalPrinter(printer);Intent intent = new Intent("android.print.PRINT_JOB_SERVICE");result.putParcelable(KEY_READY_PRINTER, (Parcelable)printer);result.putBinder(EXTRA_PRINT_DOCUMENT_ADAPTER,delegate.asBinder());intent.putExtras(result);mContext.startService(intent);isPrint = true;Log.e(LOG_TAG,"startService");return;}else if(printer.getName().startsWith("L805")){loader.refreshPrinters(printer.getId());}}}});}return new PrintJob(printJob, this);} catch (Exception sie) {Log.e(LOG_TAG, "Couldn't start print job config activity.", sie);}}} catch (RemoteException re) {Log.e(LOG_TAG, "Error creating a print job", re);}return null;
}
```
这我们主要流程是先查找打印机，再将找到的打印机传递到service中，这里我们自定义一个PrintLoader类用来实现查找打印机的功能，
下面是PrinterLoader.java```
在这里插入代码片
package android.print;

import android.content.Context;
import android.app.Activity;
import android.app.LoaderManager;
import android.content.Context;
import android.content.Loader;
import android.os.Bundle;
import android.print.PrinterId;
import android.print.PrinterInfo;
import android.util.ArrayMap;
import android.util.Log;

import java.util.ArrayList;
import java.util.List;

public class PrinterLoader implements LoaderManager.LoaderCallbacks<List>{
private static final int LOADER_ID_PRINTERS_LOADER = 1;
private final List mPrinters = new ArrayList();
private Activity activity;
private GetPrintersCallBack callBack;
public PrinterLoader(Activity activity) {
this.activity = activity;
}

public void getPrinters(GetPrintersCallBack callBack){Log.e("PrinterLoader", "getPrinters");this.callBack = callBack;activity.getLoaderManager().initLoader(LOADER_ID_PRINTERS_LOADER, null, this);
}public void refreshPrinters(PrinterId printerId){Log.e("PrinterLoader", "refreshPrinters");PrintersProvider printersLoader = (PrintersProvider)(Loader<?>) activity.getLoaderManager().getLoader(LOADER_ID_PRINTERS_LOADER);if (printersLoader != null){printersLoader.setTrackedPrinter(printerId);}
}public void addHistoricalPrinter(PrinterInfo printer){Log.e("PrinterLoader", "refreshPrinters");PrintersProvider printersLoader = (PrintersProvider)(Loader<?>) activity.getLoaderManager().getLoader(LOADER_ID_PRINTERS_LOADER);if (printersLoader != null){printersLoader.addHistoricalPrinter(printer);}
}@Override
public Loader<List<PrinterInfo>> onCreateLoader(int id, Bundle args) {if (id == LOADER_ID_PRINTERS_LOADER) {return new PrintersProvider(activity);}return null;
}@Override
public void onLoadFinished(Loader<List<PrinterInfo>> loader, List<PrinterInfo> printers) {for(int i = 0,length = printers.size();i<length;i++){Log.e("PrinterLoader", "[ymy]print_index="+i+","+printers.get(i).toString());}if (mPrinters.isEmpty()) {callBack.receivePrinters(printers);return;}// Add the new printers to a map.ArrayMap<PrinterId, PrinterInfo> newPrintersMap =new ArrayMap<PrinterId, PrinterInfo>();final int printerCount = printers.size();for (int i = 0; i < printerCount; i++) {PrinterInfo printer = printers.get(i);newPrintersMap.put(printer.getId(), printer);}List<PrinterInfo> newPrinters = new ArrayList<PrinterInfo>();// Update printers we already have.final int oldPrinterCount = mPrinters.size();for (int i = 0; i < oldPrinterCount; i++) {PrinterId oldPrinterId = mPrinters.get(i).getId();PrinterInfo updatedPrinter = newPrintersMap.remove(oldPrinterId);if (updatedPrinter != null) {newPrinters.add(updatedPrinter);}}// Add the rest of the new printers, i.e. what is left.newPrinters.addAll(newPrintersMap.values());callBack.receivePrinters(newPrinters);
}@Override
public void onLoaderReset(Loader<List<PrinterInfo>> loader) {}

}

```

这里主要是仿造PrintJobConfigActivity.DestinationAdapter里面的查找打印机方法来的，里面的PrintersProvider类就是直接copyframeworks\base\packages\PrintSpooler\src\com\android\printspooler\FusedPrintersProvider.java文件来的，是为了能在外面调用这个类，里面什么代码都没改，就改了个包名和类名，具体代码在下面。

在这里插入代码片
package android.print;import android.content.ComponentName;
import android.content.Context;
import android.content.Loader;
import android.content.pm.ServiceInfo;
import android.os.AsyncTask;
import android.print.PrintManager;
import android.print.PrinterDiscoverySession;
import android.print.PrinterDiscoverySession.OnPrintersChangeListener;
import android.print.PrinterId;
import android.print.PrinterInfo;
import android.printservice.PrintServiceInfo;
import android.util.ArrayMap;
import android.util.ArraySet;
import android.util.AtomicFile;
import android.util.Log;
import android.util.Slog;
import android.util.Xml;import com.android.internal.util.FastXmlSerializer;import org.xmlpull.v1.XmlPullParser;
import org.xmlpull.v1.XmlPullParserException;
import org.xmlpull.v1.XmlSerializer;import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.Set;import libcore.io.IoUtils;/*** This class is responsible for loading printers by doing discovery* and merging the discovered printers with the previously used ones.*/
public class PrintersProvider extends Loader<List<PrinterInfo>> {private static final String LOG_TAG = "PrintersProvider";private static final boolean DEBUG = true;private static final double WEIGHT_DECAY_COEFFICIENT = 0.95f;private static final int MAX_HISTORY_LENGTH = 50;private static final int MAX_FAVORITE_PRINTER_COUNT = 4;private final List<PrinterInfo> mPrinters =new ArrayList<PrinterInfo>();private final List<PrinterInfo> mFavoritePrinters =new ArrayList<PrinterInfo>();private final PersistenceManager mPersistenceManager;private PrinterDiscoverySession mDiscoverySession;private PrinterId mTrackedPrinter;private boolean mPrintersUpdatedBefore;public PrintersProvider(Context context) {super(context);mPersistenceManager = new PersistenceManager(context);}public void addHistoricalPrinter(PrinterInfo printer) {mPersistenceManager.addPrinterAndWritePrinterHistory(printer);}private void computeAndDeliverResult(ArrayMap<PrinterId, PrinterInfo> discoveredPrinters,ArrayMap<PrinterId, PrinterInfo> favoritePrinters) {List<PrinterInfo> printers = new ArrayList<PrinterInfo>();// Add the updated favorite printers.final int favoritePrinterCount = favoritePrinters.size();for (int i = 0; i < favoritePrinterCount; i++) {PrinterInfo favoritePrinter = favoritePrinters.valueAt(i);PrinterInfo updatedPrinter = discoveredPrinters.remove(favoritePrinter.getId());if (updatedPrinter != null) {printers.add(updatedPrinter);} else {printers.add(favoritePrinter);}}// Add other updated printers.final int printerCount = mPrinters.size();for (int i = 0; i < printerCount; i++) {PrinterInfo printer = mPrinters.get(i);PrinterInfo updatedPrinter = discoveredPrinters.remove(printer.getId());if (updatedPrinter != null) {printers.add(updatedPrinter);}}// Add the new printers, i.e. what is left.printers.addAll(discoveredPrinters.values());// Update the list of printers.mPrinters.clear();mPrinters.addAll(printers);if (isStarted()) {// If stated deliver the new printers.deliverResult(printers);} else {// Otherwise, take a note for the change.onContentChanged();}}@Overrideprotected void onStartLoading() {if (DEBUG) {Log.i(LOG_TAG, "onStartLoading() " + PrintersProvider.this.hashCode());}// The contract is that if we already have a valid,// result the we have to deliver it immediately.if (!mPrinters.isEmpty()) {deliverResult(new ArrayList<PrinterInfo>(mPrinters));}// Always load the data to ensure discovery period is// started and to make sure obsolete printers are updated.onForceLoad();}@Overrideprotected void onStopLoading() {if (DEBUG) {Log.i(LOG_TAG, "onStopLoading() " + PrintersProvider.this.hashCode());}onCancelLoad();}@Overrideprotected void onForceLoad() {if (DEBUG) {Log.i(LOG_TAG, "onForceLoad() " + PrintersProvider.this.hashCode());}loadInternal();}private void loadInternal() {if (mDiscoverySession == null) {PrintManager printManager = (PrintManager) getContext().getSystemService(Context.PRINT_SERVICE);mDiscoverySession = printManager.createPrinterDiscoverySession();mPersistenceManager.readPrinterHistory();} else if (mPersistenceManager.isHistoryChanged()) {mPersistenceManager.readPrinterHistory();}if (mPersistenceManager.isReadHistoryCompleted()&& !mDiscoverySession.isPrinterDiscoveryStarted()) {mDiscoverySession.setOnPrintersChangeListener(new OnPrintersChangeListener() {@Overridepublic void onPrintersChanged() {if (DEBUG) {Log.i(LOG_TAG, "onPrintersChanged() count:"+ mDiscoverySession.getPrinters().size()+ " " + PrintersProvider.this.hashCode());}updatePrinters(mDiscoverySession.getPrinters(), mFavoritePrinters);}});final int favoriteCount = mFavoritePrinters.size();List<PrinterId> printerIds = new ArrayList<PrinterId>(favoriteCount);for (int i = 0; i < favoriteCount; i++) {printerIds.add(mFavoritePrinters.get(i).getId());}mDiscoverySession.startPrinterDisovery(printerIds);List<PrinterInfo> printers = mDiscoverySession.getPrinters();if (!printers.isEmpty()) {updatePrinters(printers, mFavoritePrinters);}}}private void updatePrinters(List<PrinterInfo> printers, List<PrinterInfo> favoritePrinters) {for(int i = 0,length = printers.size();i<length;i++){Log.i(LOG_TAG, "[ymy]updatePrinters--printers="+i+","+printers.get(i).toString());}for(int i = 0,length = favoritePrinters.size();i<length;i++){Log.i(LOG_TAG, "[ymy]updatePrinters--favoritePrinters="+i+","+favoritePrinters.get(i).toString());}if (mPrintersUpdatedBefore && mPrinters.equals(printers)&& mFavoritePrinters.equals(favoritePrinters)) {return;}mPrintersUpdatedBefore = true;ArrayMap<PrinterId, PrinterInfo> printersMap =new ArrayMap<PrinterId, PrinterInfo>();final int printerCount = printers.size();for (int i = 0; i < printerCount; i++) {PrinterInfo printer = printers.get(i);printersMap.put(printer.getId(), printer);}ArrayMap<PrinterId, PrinterInfo> favoritePrintersMap =new ArrayMap<PrinterId, PrinterInfo>();final int favoritePrinterCount = favoritePrinters.size();for (int i = 0; i < favoritePrinterCount; i++) {PrinterInfo favoritePrinter = favoritePrinters.get(i);favoritePrintersMap.put(favoritePrinter.getId(), favoritePrinter);}computeAndDeliverResult(printersMap, favoritePrintersMap);}@Overrideprotected boolean onCancelLoad() {if (DEBUG) {Log.i(LOG_TAG, "onCancelLoad() " + PrintersProvider.this.hashCode());}return cancelInternal();}private boolean cancelInternal() {if (mDiscoverySession != null&& mDiscoverySession.isPrinterDiscoveryStarted()) {if (mTrackedPrinter != null) {mDiscoverySession.stopPrinterStateTracking(mTrackedPrinter);mTrackedPrinter = null;}mDiscoverySession.stopPrinterDiscovery();return true;} else if (mPersistenceManager.isReadHistoryInProgress()) {return mPersistenceManager.stopReadPrinterHistory();}return false;}@Overrideprotected void onReset() {if (DEBUG) {Log.i(LOG_TAG, "onReset() " + PrintersProvider.this.hashCode());}onStopLoading();mPrinters.clear();if (mDiscoverySession != null) {mDiscoverySession.destroy();mDiscoverySession = null;}}@Overrideprotected void onAbandon() {if (DEBUG) {Log.i(LOG_TAG, "onAbandon() " + PrintersProvider.this.hashCode());}onStopLoading();}public void setTrackedPrinter(PrinterId printerId) {Log.i(LOG_TAG, "[ymy]setTrackedPrinter");if (isStarted() && mDiscoverySession != null&& mDiscoverySession.isPrinterDiscoveryStarted()) {if (mTrackedPrinter != null) {if (mTrackedPrinter.equals(printerId)) {return;}mDiscoverySession.stopPrinterStateTracking(mTrackedPrinter);}mTrackedPrinter = printerId;mDiscoverySession.startPrinterStateTracking(printerId);}}public boolean isFavoritePrinter(PrinterId printerId) {final int printerCount = mFavoritePrinters.size();for (int i = 0; i < printerCount; i++) {PrinterInfo favoritePritner = mFavoritePrinters.get(i);if (favoritePritner.getId().equals(printerId)) {return true;}}return false;}public void forgetFavoritePrinter(PrinterId printerId) {List<PrinterInfo> newFavoritePrinters = null;// Remove the printer from the favorites.final int favoritePrinterCount = mFavoritePrinters.size();for (int i = 0; i < favoritePrinterCount; i++) {PrinterInfo favoritePrinter = mFavoritePrinters.get(i);if (favoritePrinter.getId().equals(printerId)) {newFavoritePrinters = new ArrayList<PrinterInfo>();newFavoritePrinters.addAll(mPrinters);newFavoritePrinters.remove(i);break;}}// If we removed a favorite printer, we have work to do.if (newFavoritePrinters != null) {// Remove the printer from history and persist the latter.mPersistenceManager.removeHistoricalPrinterAndWritePrinterHistory(printerId);// Recompute and deliver the printers.updatePrinters(mDiscoverySession.getPrinters(), newFavoritePrinters);}}private final class PersistenceManager {private static final String PERSIST_FILE_NAME = "printer_history.xml";private static final String TAG_PRINTERS = "printers";private static final String TAG_PRINTER = "printer";private static final String TAG_PRINTER_ID = "printerId";private static final String ATTR_LOCAL_ID = "localId";private static final String ATTR_SERVICE_NAME = "serviceName";private static final String ATTR_NAME = "name";private static final String ATTR_DESCRIPTION = "description";private static final String ATTR_STATUS = "status";private final AtomicFile mStatePersistFile;private List<PrinterInfo> mHistoricalPrinters = new ArrayList<PrinterInfo>();private boolean mReadHistoryCompleted;private boolean mReadHistoryInProgress;private ReadTask mReadTask;private volatile long mLastReadHistoryTimestamp;private PersistenceManager(Context context) {mStatePersistFile = new AtomicFile(new File(context.getFilesDir(),PERSIST_FILE_NAME));}public boolean isReadHistoryInProgress() {return mReadHistoryInProgress;}public boolean isReadHistoryCompleted() {return mReadHistoryCompleted;}public boolean stopReadPrinterHistory() {final boolean cancelled = mReadTask.cancel(true);mReadTask = null;return cancelled;}public void readPrinterHistory() {if (DEBUG) {Log.i(LOG_TAG, "read history started "+ PrintersProvider.this.hashCode());}mReadHistoryInProgress = true;mReadTask = new ReadTask();mReadTask.executeOnExecutor(AsyncTask.SERIAL_EXECUTOR, (Void[]) null);}@SuppressWarnings("unchecked")public void addPrinterAndWritePrinterHistory(PrinterInfo printer) {if (mHistoricalPrinters.size() >= MAX_HISTORY_LENGTH) {mHistoricalPrinters.remove(0);}mHistoricalPrinters.add(printer);new WriteTask().executeOnExecutor(AsyncTask.SERIAL_EXECUTOR,new ArrayList<PrinterInfo>(mHistoricalPrinters));}@SuppressWarnings("unchecked")public void removeHistoricalPrinterAndWritePrinterHistory(PrinterId printerId) {boolean writeHistory = false;final int printerCount = mHistoricalPrinters.size();for (int i = printerCount - 1; i >= 0; i--) {PrinterInfo historicalPrinter = mHistoricalPrinters.get(i);if (historicalPrinter.getId().equals(printerId)) {mHistoricalPrinters.remove(i);writeHistory = true;}}if (writeHistory) {new WriteTask().executeOnExecutor(AsyncTask.SERIAL_EXECUTOR,new ArrayList<PrinterInfo>(mHistoricalPrinters));}}public boolean isHistoryChanged() {return mLastReadHistoryTimestamp != mStatePersistFile.getBaseFile().lastModified();}private List<PrinterInfo> computeFavoritePrinters(List<PrinterInfo> printers) {Map<PrinterId, PrinterRecord> recordMap =new ArrayMap<PrinterId, PrinterRecord>();// Recompute the weights.float currentWeight = 1.0f;final int printerCount = printers.size();for (int i = printerCount - 1; i >= 0; i--) {PrinterInfo printer = printers.get(i);// Aggregate weight for the same printerPrinterRecord record = recordMap.get(printer.getId());if (record == null) {record = new PrinterRecord(printer);recordMap.put(printer.getId(), record);}record.weight += currentWeight;currentWeight *= WEIGHT_DECAY_COEFFICIENT;}// Soft the favorite printers.List<PrinterRecord> favoriteRecords = new ArrayList<PrinterRecord>(recordMap.values());Collections.sort(favoriteRecords);// Write the favorites to the output.final int favoriteCount = Math.min(favoriteRecords.size(),MAX_FAVORITE_PRINTER_COUNT);List<PrinterInfo> favoritePrinters = new ArrayList<PrinterInfo>(favoriteCount);for (int i = 0; i < favoriteCount; i++) {PrinterInfo printer = favoriteRecords.get(i).printer;favoritePrinters.add(printer);}return favoritePrinters;}private final class PrinterRecord implements Comparable<PrinterRecord> {public final PrinterInfo printer;public float weight;public PrinterRecord(PrinterInfo printer) {this.printer = printer;}@Overridepublic int compareTo(PrinterRecord another) {return Float.floatToIntBits(another.weight) - Float.floatToIntBits(weight);}}private final class ReadTask extends AsyncTask<Void, Void, List<PrinterInfo>> {@Overrideprotected List<PrinterInfo> doInBackground(Void... args) {return doReadPrinterHistory();}@Overrideprotected void onPostExecute(List<PrinterInfo> printers) {if (DEBUG) {Log.i(LOG_TAG, "read history completed "+ PrintersProvider.this.hashCode()+"-printers.size()="+printers.size());}for(int i = 0,length = printers.size();i<length;i++){Log.i(LOG_TAG, "[ymy]print_index="+i+","+printers.get(i).toString());}// Ignore printer records whose target services are not enabled.PrintManager printManager = (PrintManager) getContext().getSystemService(Context.PRINT_SERVICE);List<PrintServiceInfo> services = printManager.getEnabledPrintServices();Set<ComponentName> enabledComponents = new ArraySet<ComponentName>();final int installedServiceCount = services.size();for (int i = 0; i < installedServiceCount; i++) {ServiceInfo serviceInfo = services.get(i).getResolveInfo().serviceInfo;ComponentName componentName = new ComponentName(serviceInfo.packageName, serviceInfo.name);enabledComponents.add(componentName);}final int printerCount = printers.size();for (int i = printerCount - 1; i >= 0; i--) {ComponentName printerServiceName = printers.get(i).getId().getServiceName();if (!enabledComponents.contains(printerServiceName)) {printers.remove(i);}}// Store the filtered list.mHistoricalPrinters = printers;// Compute the favorite printers.mFavoritePrinters.clear();mFavoritePrinters.addAll(computeFavoritePrinters(mHistoricalPrinters));mReadHistoryInProgress = false;mReadHistoryCompleted = true;// Deliver the printers.updatePrinters(mDiscoverySession.getPrinters(), mHistoricalPrinters);// Loading the available printers if needed.loadInternal();// We are done.mReadTask = null;}private List<PrinterInfo> doReadPrinterHistory() {FileInputStream in = null;try {in = mStatePersistFile.openRead();} catch (FileNotFoundException fnfe) {if (DEBUG) {Log.i(LOG_TAG, "No existing printer history "+ PrintersProvider.this.hashCode());}return new ArrayList<PrinterInfo>();}try {List<PrinterInfo> printers = new ArrayList<PrinterInfo>();XmlPullParser parser = Xml.newPullParser();parser.setInput(in, null);parseState(parser, printers);// Take a note which version of the history was read.mLastReadHistoryTimestamp = mStatePersistFile.getBaseFile().lastModified();return printers;} catch (IllegalStateException ise) {Slog.w(LOG_TAG, "Failed parsing ", ise);} catch (NullPointerException npe) {Slog.w(LOG_TAG, "Failed parsing ", npe);} catch (NumberFormatException nfe) {Slog.w(LOG_TAG, "Failed parsing ", nfe);} catch (XmlPullParserException xppe) {Slog.w(LOG_TAG, "Failed parsing ", xppe);} catch (IOException ioe) {Slog.w(LOG_TAG, "Failed parsing ", ioe);} catch (IndexOutOfBoundsException iobe) {Slog.w(LOG_TAG, "Failed parsing ", iobe);} finally {IoUtils.closeQuietly(in);}return Collections.emptyList();}private void parseState(XmlPullParser parser, List<PrinterInfo> outPrinters)throws IOException, XmlPullParserException {parser.next();skipEmptyTextTags(parser);expect(parser, XmlPullParser.START_TAG, TAG_PRINTERS);parser.next();while (parsePrinter(parser, outPrinters)) {// Be nice and respond to cancellationif (isCancelled()) {return;}parser.next();}skipEmptyTextTags(parser);expect(parser, XmlPullParser.END_TAG, TAG_PRINTERS);}private boolean parsePrinter(XmlPullParser parser, List<PrinterInfo> outPrinters)throws IOException, XmlPullParserException {skipEmptyTextTags(parser);if (!accept(parser, XmlPullParser.START_TAG, TAG_PRINTER)) {return false;}String name = parser.getAttributeValue(null, ATTR_NAME);String description = parser.getAttributeValue(null, ATTR_DESCRIPTION);final int status = Integer.parseInt(parser.getAttributeValue(null, ATTR_STATUS));parser.next();skipEmptyTextTags(parser);expect(parser, XmlPullParser.START_TAG, TAG_PRINTER_ID);String localId = parser.getAttributeValue(null, ATTR_LOCAL_ID);ComponentName service = ComponentName.unflattenFromString(parser.getAttributeValue(null, ATTR_SERVICE_NAME));PrinterId printerId =  new PrinterId(service, localId);parser.next();skipEmptyTextTags(parser);expect(parser, XmlPullParser.END_TAG, TAG_PRINTER_ID);parser.next();PrinterInfo.Builder builder = new PrinterInfo.Builder(printerId, name, status);builder.setDescription(description);PrinterInfo printer = builder.build();outPrinters.add(printer);if (DEBUG) {Log.i(LOG_TAG, "[RESTORED] " + printer);}skipEmptyTextTags(parser);expect(parser, XmlPullParser.END_TAG, TAG_PRINTER);return true;}private void expect(XmlPullParser parser, int type, String tag)throws IOException, XmlPullParserException {if (!accept(parser, type, tag)) {throw new XmlPullParserException("Exepected event: " + type+ " and tag: " + tag + " but got event: " + parser.getEventType()+ " and tag:" + parser.getName());}}private void skipEmptyTextTags(XmlPullParser parser)throws IOException, XmlPullParserException {while (accept(parser, XmlPullParser.TEXT, null)&& "\n".equals(parser.getText())) {parser.next();}}private boolean accept(XmlPullParser parser, int type, String tag)throws IOException, XmlPullParserException {if (parser.getEventType() != type) {return false;}if (tag != null) {if (!tag.equals(parser.getName())) {return false;}} else if (parser.getName() != null) {return false;}return true;}};private final class WriteTask extends AsyncTask<List<PrinterInfo>, Void, Void> {@Overrideprotected Void doInBackground(List<PrinterInfo>... printers) {doWritePrinterHistory(printers[0]);return null;}private void doWritePrinterHistory(List<PrinterInfo> printers) {FileOutputStream out = null;try {out = mStatePersistFile.startWrite();XmlSerializer serializer = new FastXmlSerializer();serializer.setOutput(out, "utf-8");serializer.startDocument(null, true);serializer.startTag(null, TAG_PRINTERS);final int printerCount = printers.size();for (int i = 0; i < printerCount; i++) {PrinterInfo printer = printers.get(i);serializer.startTag(null, TAG_PRINTER);serializer.attribute(null, ATTR_NAME, printer.getName());// Historical printers are always stored as unavailable.serializer.attribute(null, ATTR_STATUS, String.valueOf(PrinterInfo.STATUS_UNAVAILABLE));String description = printer.getDescription();if (description != null) {serializer.attribute(null, ATTR_DESCRIPTION, description);}PrinterId printerId = printer.getId();serializer.startTag(null, TAG_PRINTER_ID);serializer.attribute(null, ATTR_LOCAL_ID, printerId.getLocalId());serializer.attribute(null, ATTR_SERVICE_NAME, printerId.getServiceName().flattenToString());serializer.endTag(null, TAG_PRINTER_ID);serializer.endTag(null, TAG_PRINTER);if (DEBUG) {Log.i(LOG_TAG, "[PERSISTED] " + printer);}}serializer.endTag(null, TAG_PRINTERS);serializer.endDocument();mStatePersistFile.finishWrite(out);if (DEBUG) {Log.i(LOG_TAG, "[PERSIST END]");}} catch (IOException ioe) {Slog.w(LOG_TAG, "Failed to write printer history, restoring backup.", ioe);mStatePersistFile.failWrite(out);} finally {IoUtils.closeQuietly(out);}}};}
}

在PrinterLoader中找到打印机，我们回调到PrintManger.print方法中我们GetPrintersCallBack自定义的回调中，选择我们自己的打印机，接下来我们将打印机信息和打印任务信息传递到PrintJobService中，action自己定义的，在frameworks\base\packages\PrintSpooler\AndroidManifest.xml中注册```
在这里插入代码片
<serviceandroid:name=".PrintSpoolerService"android:exported="true"android:permission="android.permission.BIND_PRINT_SPOOLER_SERVICE"></service>
```
接下来我们来看看PrintJobService.java的实现```
在这里插入代码片/** 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 com.android.printspooler;import android.app.Service;import android.app.LoaderManager;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.content.Loader;
import android.content.ServiceConnection;
import android.content.pm.PackageInfo;
import android.content.pm.PackageManager.NameNotFoundException;
import android.content.pm.ResolveInfo;
import android.content.pm.ServiceInfo;
import android.database.DataSetObserver;
import android.graphics.Rect;
import android.graphics.drawable.Drawable;
import android.net.Uri;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.Handler;
import android.os.IBinder;
import android.os.IBinder.DeathRecipient;
import android.os.Looper;
import android.os.Message;
import android.os.RemoteException;
import android.print.ILayoutResultCallback;
import android.print.IPrintDocumentAdapter;
import android.print.IPrintDocumentAdapterObserver;
import android.print.IWriteResultCallback;
import android.print.PageRange;
import android.print.PrintAttributes;
import android.print.PrintAttributes.Margins;
import android.print.PrintAttributes.MediaSize;
import android.print.PrintAttributes.Resolution;
import android.print.PrintDocumentAdapter;
import android.print.PrintDocumentInfo;
import android.print.PrintJobId;
import android.print.PrintJobInfo;
import android.print.PrintManager;
import android.print.PrinterCapabilitiesInfo;
import android.print.PrinterId;
import android.print.PrinterInfo;
import android.printservice.PrintService;
import android.printservice.PrintServiceInfo;
import android.provider.DocumentsContract;
import android.text.Editable;
import android.text.TextUtils;
import android.util.ArrayMap;
import android.util.AttributeSet;
import android.util.Log;import com.android.printspooler.MediaSizeUtils.MediaSizeComparator;import libcore.io.IoUtils;import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.lang.ref.WeakReference;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.regex.Matcher;
import java.util.regex.Pattern;/*** Activity for configuring a print job.*/
public class PrintJobService extends Service {private static final String LOG_TAG = "PrintJobService";private static final boolean DEBUG = true;public static final String INTENT_EXTRA_PRINTER_ID = "INTENT_EXTRA_PRINTER_ID";private static final int LOADER_ID_PRINTERS_LOADER = 1;private static final int ORIENTATION_PORTRAIT = 0;private static final int ORIENTATION_LANDSCAPE = 1;private static final int DEST_ADAPTER_MAX_ITEM_COUNT = 9;private static final int DEST_ADAPTER_ITEM_ID_SAVE_AS_PDF = Integer.MAX_VALUE;private static final int DEST_ADAPTER_ITEM_ID_ALL_PRINTERS = Integer.MAX_VALUE - 1;private static final int ACTIVITY_REQUEST_CREATE_FILE = 1;private static final int ACTIVITY_REQUEST_SELECT_PRINTER = 2;private static final int ACTIVITY_POPULATE_ADVANCED_PRINT_OPTIONS = 3;private static final int CONTROLLER_STATE_FINISHED = 1;private static final int CONTROLLER_STATE_FAILED = 2;private static final int CONTROLLER_STATE_CANCELLED = 3;private static final int CONTROLLER_STATE_INITIALIZED = 4;private static final int CONTROLLER_STATE_STARTED = 5;private static final int CONTROLLER_STATE_LAYOUT_STARTED = 6;private static final int CONTROLLER_STATE_LAYOUT_COMPLETED = 7;private static final int CONTROLLER_STATE_WRITE_STARTED = 8;private static final int CONTROLLER_STATE_WRITE_COMPLETED = 9;private static final int EDITOR_STATE_INITIALIZED = 1;private static final int EDITOR_STATE_CONFIRMED_PRINT = 2;private static final int EDITOR_STATE_CANCELLED = 3;private static final int MIN_COPIES = 1;private static final String MIN_COPIES_STRING = String.valueOf(MIN_COPIES);private static final Pattern PATTERN_DIGITS = Pattern.compile("[\\d]+");private static final Pattern PATTERN_ESCAPE_SPECIAL_CHARS = Pattern.compile("(?=[]\\[+&|!(){}^\"~*?:\\\\])");private static final Pattern PATTERN_PAGE_RANGE = Pattern.compile("[\\s]*[0-9]*[\\s]*[\\-]?[\\s]*[0-9]*[\\s]*?(([,])"+ "[\\s]*[0-9]*[\\s]*[\\-]?[\\s]*[0-9]*[\\s]*|[\\s]*)+");public static final PageRange[] ALL_PAGES_ARRAY = new PageRange[] {PageRange.ALL_PAGES};private final PrintAttributes mOldPrintAttributes = new PrintAttributes.Builder().build();private final PrintAttributes mCurrPrintAttributes = new PrintAttributes.Builder().build();private final DeathRecipient mDeathRecipient = new DeathRecipient() {@Overridepublic void binderDied() {PrintJobService.this.finish();}};private Editor mEditor;private Document mDocument;private PrintController mController;private PrintJobId mPrintJobId;private IBinder mIPrintDocumentAdapter;private PrintSpoolerProvider mSpoolerProvider;private String mCallingPackageName;private boolean isPrint = false;private PrinterInfo mCurrentPrinter;public void finish(){super.stopSelf();}@Overridepublic IBinder onBind(Intent intent) {// TODO Auto-generated method stubreturn null;}/*** 服务启动的时候调用*/@Overridepublic int onStartCommand(Intent intent, int flags, int startId) {Log.e(LOG_TAG,"onStartCommand");// TODO Auto-generated method stubBundle extras = intent.getExtras();PrintJobInfo printJob = extras.getParcelable(PrintManager.EXTRA_PRINT_JOB);mCurrentPrinter = extras.getParcelable("ready_printer");if (printJob == null) {throw new IllegalArgumentException("printJob cannot be null");}mPrintJobId = printJob.getId();mIPrintDocumentAdapter = extras.getBinder(PrintManager.EXTRA_PRINT_DOCUMENT_ADAPTER);if (mIPrintDocumentAdapter == null) {throw new IllegalArgumentException("PrintDocumentAdapter cannot be null");}try {IPrintDocumentAdapter.Stub.asInterface(mIPrintDocumentAdapter).setObserver(new PrintDocumentAdapterObserver(this));} catch (RemoteException re) {finish();}PrintAttributes attributes = printJob.getAttributes();if (attributes != null) {mCurrPrintAttributes.copyFrom(attributes);}mCallingPackageName = extras.getString(DocumentsContract.EXTRA_PACKAGE_NAME);try {mIPrintDocumentAdapter.linkToDeath(mDeathRecipient, 0);} catch (RemoteException re) {finish();}mDocument = new Document();mEditor = new Editor();mSpoolerProvider = new PrintSpoolerProvider(this,new Runnable() {@Overridepublic void run() {// We got the spooler so unleash the UI.mController = new PrintController(new RemotePrintDocumentAdapter(IPrintDocumentAdapter.Stub.asInterface(mIPrintDocumentAdapter),mSpoolerProvider.getSpooler().generateFileForPrintJob(mPrintJobId)));mController.initialize();mEditor.initialize();mEditor.postCreate();}});return super.onStartCommand(intent, flags, startId);}@Overridepublic void onDestroy() {Log.e(LOG_TAG,"onDestroy");if (mController != null && mController.hasStarted()) {mController.finish();}if (mEditor != null && mEditor.isPrintConfirmed()&& mController != null && mController.isFinished()) {Log.e(LOG_TAG,"setPrintJobState--STATE_QUEUED");mSpoolerProvider.getSpooler().setPrintJobState(mPrintJobId,PrintJobInfo.STATE_QUEUED, null);} else {mSpoolerProvider.getSpooler().setPrintJobState(mPrintJobId,PrintJobInfo.STATE_CANCELED, null);}mIPrintDocumentAdapter.unlinkToDeath(mDeathRecipient, 0);mSpoolerProvider.destroy();}private boolean printAttributesChanged() {return !mOldPrintAttributes.equals(mCurrPrintAttributes);}private class PrintController {private final AtomicInteger mRequestCounter = new AtomicInteger();private final RemotePrintDocumentAdapter mRemotePrintAdapter;private final Bundle mMetadata;private final ControllerHandler mHandler;private final LayoutResultCallback mLayoutResultCallback;private final WriteResultCallback mWriteResultCallback;private int mControllerState = CONTROLLER_STATE_INITIALIZED;private boolean mHasStarted;private PageRange[] mRequestedPages;public PrintController(RemotePrintDocumentAdapter adapter) {mRemotePrintAdapter = adapter;mMetadata = new Bundle();mHandler = new ControllerHandler(getMainLooper());mLayoutResultCallback = new LayoutResultCallback(mHandler);mWriteResultCallback = new WriteResultCallback(mHandler);}public void initialize() {mHasStarted = false;mControllerState = CONTROLLER_STATE_INITIALIZED;}public void cancel() {if (isWorking()) {mRemotePrintAdapter.cancel();}mControllerState = CONTROLLER_STATE_CANCELLED;}public boolean isCancelled() {return (mControllerState == CONTROLLER_STATE_CANCELLED);}public boolean isFinished() {return (mControllerState == CONTROLLER_STATE_FINISHED);}public boolean hasStarted() {return mHasStarted;}public boolean hasPerformedLayout() {return mControllerState >= CONTROLLER_STATE_LAYOUT_COMPLETED;}public boolean isPerformingLayout() {return mControllerState == CONTROLLER_STATE_LAYOUT_STARTED;}public boolean isWorking() {return mControllerState == CONTROLLER_STATE_LAYOUT_STARTED|| mControllerState == CONTROLLER_STATE_WRITE_STARTED;}public void start() {Log.e(LOG_TAG, "PrintController-start");mControllerState = CONTROLLER_STATE_STARTED;mHasStarted = true;mRemotePrintAdapter.start();}public void update() {if (!mController.hasStarted()) {mController.start();}// If the print attributes are the same and we are performing// a layout, then we have to wait for it to completed which will// trigger writing of the necessary pages.final boolean printAttributesChanged = printAttributesChanged();if (!printAttributesChanged && isPerformingLayout()) {return;}// If print is confirmed we always do a layout since the previous// ones were for preview and this one is for printing.if (!printAttributesChanged && !mEditor.isPrintConfirmed()) {if (mDocument.info == null) {// We are waiting for the result of a layout, so do nothing.return;}// If the attributes didn't change and we have done a layout, then// we do not do a layout but may have to ask the app to write some// pages. Hence, pretend layout completed and nothing changed, so// we handle writing as usual.handleOnLayoutFinished(mDocument.info, false, mRequestCounter.get());} else {mSpoolerProvider.getSpooler().setPrintJobAttributesNoPersistence(mPrintJobId, mCurrPrintAttributes);mMetadata.putBoolean(PrintDocumentAdapter.EXTRA_PRINT_PREVIEW,!mEditor.isPrintConfirmed());mControllerState = CONTROLLER_STATE_LAYOUT_STARTED;Log.e(LOG_TAG, "PrintController-CONTROLLER_STATE_LAYOUT_STARTED");mRemotePrintAdapter.layout(mOldPrintAttributes, mCurrPrintAttributes,mLayoutResultCallback, mMetadata, mRequestCounter.incrementAndGet());mOldPrintAttributes.copyFrom(mCurrPrintAttributes);}}public void finish() {mControllerState = CONTROLLER_STATE_FINISHED;mRemotePrintAdapter.finish();}private void handleOnLayoutFinished(PrintDocumentInfo info,boolean layoutChanged, int sequence) {if (mRequestCounter.get() != sequence) {return;}if (isCancelled()) {if (mEditor.isDone()) {PrintJobService.this.finish();}return;}Log.e(LOG_TAG, "PrintController-CONTROLLER_STATE_LAYOUT_COMPLETED");mControllerState = CONTROLLER_STATE_LAYOUT_COMPLETED;// For layout purposes we care only whether the type or the page// count changed. We still do not have the size since we did not// call write. We use "layoutChanged" set by the application to// know whether something else changed about the document.final boolean infoChanged = !equalsIgnoreSize(info, mDocument.info);Log.e(LOG_TAG, "PrintController-infoChanged="+infoChanged+",layoutChanged="+layoutChanged);// If the info changed, we update the document and the print job.if (infoChanged) {mDocument.info = info;// Set the info.mSpoolerProvider.getSpooler().setPrintJobPrintDocumentInfoNoPersistence(mPrintJobId, info);}// If the document info or the layout changed, then// drop the pages since we have to fetch them again.if (infoChanged || layoutChanged) {mDocument.pages = null;mSpoolerProvider.getSpooler().setPrintJobPagesNoPersistence(mPrintJobId, null);}// No pages means that the user selected an invalid range while we// were doing a layout or the layout returned a document info for// which the selected range is invalid. In such a case we do not// write anything and wait for the user to fix the range which will// trigger an update.mRequestedPages = mEditor.getRequestedPages();if (mRequestedPages == null || mRequestedPages.length == 0) {Log.e(LOG_TAG, "PrintController-mRequestedPages == null || mRequestedPages.length == 0");if (mEditor.isDone()) {PrintJobService.this.finish();}return;} else {// If print is not confirmed we just ask for the first of the// selected pages to emulate a behavior that shows preview// increasing the chances that apps will implement the APIs// correctly.if (!mEditor.isPrintConfirmed()) {if (ALL_PAGES_ARRAY.equals(mRequestedPages)) {mRequestedPages = new PageRange[] {new PageRange(0, 0)};} else {final int firstPage = mRequestedPages[0].getStart();mRequestedPages = new PageRange[] {new PageRange(firstPage, firstPage)};}}}// If the info and the layout did not change and we already have// the requested pages, then nothing else to do.if (!infoChanged && !layoutChanged&& PageRangeUtils.contains(mDocument.pages, mRequestedPages)) {// Nothing interesting changed and we have all requested pages.// Then update the print jobs's pages as we will not do a write// and we usually update the pages in the write complete callback.Log.e(LOG_TAG, "PrintController-PageRangeUtils.contains(mDocument.pages, mRequestedPages)");updatePrintJobPages(mDocument.pages, mRequestedPages);if (mEditor.isDone()) {requestFinish();}return;}Log.e(LOG_TAG, "PrintController-CONTROLLER_STATE_WRITE_STARTED");// Request a write of the pages of interest.mControllerState = CONTROLLER_STATE_WRITE_STARTED;mRemotePrintAdapter.write(mRequestedPages, mWriteResultCallback,mRequestCounter.incrementAndGet());}private void handleOnLayoutFailed(final CharSequence error, int sequence) {if (mRequestCounter.get() != sequence) {return;}Log.e(LOG_TAG, "PrintController-CONTROLLER_STATE_FAILED");mControllerState = CONTROLLER_STATE_FAILED;}private void handleOnWriteFinished(PageRange[] pages, int sequence) {if (mRequestCounter.get() != sequence) {return;}if (isCancelled()) {if (mEditor.isDone()) {PrintJobService.this.finish();}return;}Log.e(LOG_TAG, "PrintController-CONTROLLER_STATE_WRITE_COMPLETED");mControllerState = CONTROLLER_STATE_WRITE_COMPLETED;// Update the document size.File file = mSpoolerProvider.getSpooler().generateFileForPrintJob(mPrintJobId);mDocument.info.setDataSize(file.length());// Update the print job with the updated info.mSpoolerProvider.getSpooler().setPrintJobPrintDocumentInfoNoPersistence(mPrintJobId, mDocument.info);// Update which pages we have fetched.mDocument.pages = PageRangeUtils.normalize(pages);if (DEBUG) {Log.i(LOG_TAG, "Requested: " + Arrays.toString(mRequestedPages)+ " and got: " + Arrays.toString(mDocument.pages));}updatePrintJobPages(mDocument.pages, mRequestedPages);if (mEditor.isDone()) {requestFinish();}}private void updatePrintJobPages(PageRange[] writtenPages, PageRange[] requestedPages) {// Adjust the print job pages based on what was requested and written.// The cases are ordered in the most expected to the least expected.Log.e(LOG_TAG, "PrintController-updatePrintJobPages");if (Arrays.equals(writtenPages, requestedPages)) {// We got a document with exactly the pages we wanted. Hence,// the printer has to print all pages in the data.mSpoolerProvider.getSpooler().setPrintJobPagesNoPersistence(mPrintJobId,ALL_PAGES_ARRAY);} else if (Arrays.equals(writtenPages, ALL_PAGES_ARRAY)) {// We requested specific pages but got all of them. Hence,// the printer has to print only the requested pages.mSpoolerProvider.getSpooler().setPrintJobPagesNoPersistence(mPrintJobId,requestedPages);} else if (PageRangeUtils.contains(writtenPages, requestedPages)) {// We requested specific pages and got more but not all pages.// Hence, we have to offset appropriately the printed pages to// be based off the start of the written ones instead of zero.// The written pages are always non-null and not empty.final int offset = -writtenPages[0].getStart();PageRange[] offsetPages = Arrays.copyOf(requestedPages, requestedPages.length);PageRangeUtils.offset(offsetPages, offset);mSpoolerProvider.getSpooler().setPrintJobPagesNoPersistence(mPrintJobId,offsetPages);} else if (Arrays.equals(requestedPages, ALL_PAGES_ARRAY)&& writtenPages.length == 1 && writtenPages[0].getStart() == 0&& writtenPages[0].getEnd() == mDocument.info.getPageCount() - 1) {// We requested all pages via the special constant and got all// of them as an explicit enumeration. Hence, the printer has// to print only the requested pages.mSpoolerProvider.getSpooler().setPrintJobPagesNoPersistence(mPrintJobId,writtenPages);} else {// We did not get the pages we requested, then the application// misbehaves, so we fail quickly.mControllerState = CONTROLLER_STATE_FAILED;Log.e(LOG_TAG, "Received invalid pages from the app");}}private void requestFinish() {Log.e(LOG_TAG, "PrintController-requestFinish");PrintJobService.this.finish();}private void handleOnWriteFailed(final CharSequence error, int sequence) {if (mRequestCounter.get() != sequence) {return;}Log.e(LOG_TAG, "PrintController-CONTROLLER_STATE_FAILED");mControllerState = CONTROLLER_STATE_FAILED;}private boolean equalsIgnoreSize(PrintDocumentInfo lhs, PrintDocumentInfo rhs) {if (lhs == rhs) {return true;}if (lhs == null) {if (rhs != null) {return false;}} else {if (rhs == null) {return false;}if (lhs.getContentType() != rhs.getContentType()|| lhs.getPageCount() != rhs.getPageCount()) {return false;}}return true;}private final class ControllerHandler extends Handler {public static final int MSG_ON_LAYOUT_FINISHED = 1;public static final int MSG_ON_LAYOUT_FAILED = 2;public static final int MSG_ON_WRITE_FINISHED = 3;public static final int MSG_ON_WRITE_FAILED = 4;public ControllerHandler(Looper looper) {super(looper, null, false);}@Overridepublic void handleMessage(Message message) {switch (message.what) {case MSG_ON_LAYOUT_FINISHED: {PrintDocumentInfo info = (PrintDocumentInfo) message.obj;final boolean changed = (message.arg1 == 1);final int sequence = message.arg2;handleOnLayoutFinished(info, changed, sequence);} break;case MSG_ON_LAYOUT_FAILED: {CharSequence error = (CharSequence) message.obj;final int sequence = message.arg1;handleOnLayoutFailed(error, sequence);} break;case MSG_ON_WRITE_FINISHED: {PageRange[] pages = (PageRange[]) message.obj;final int sequence = message.arg1;handleOnWriteFinished(pages, sequence);} break;case MSG_ON_WRITE_FAILED: {CharSequence error = (CharSequence) message.obj;final int sequence = message.arg1;handleOnWriteFailed(error, sequence);} break;}}}}private static final class LayoutResultCallback extends ILayoutResultCallback.Stub {private final WeakReference<PrintController.ControllerHandler> mWeakHandler;public LayoutResultCallback(PrintController.ControllerHandler handler) {mWeakHandler = new WeakReference<PrintController.ControllerHandler>(handler);}@Overridepublic void onLayoutFinished(PrintDocumentInfo info, boolean changed, int sequence) {Handler handler = mWeakHandler.get();if (handler != null) {handler.obtainMessage(PrintController.ControllerHandler.MSG_ON_LAYOUT_FINISHED,changed ? 1 : 0, sequence, info).sendToTarget();}}@Overridepublic void onLayoutFailed(CharSequence error, int sequence) {Handler handler = mWeakHandler.get();if (handler != null) {handler.obtainMessage(PrintController.ControllerHandler.MSG_ON_LAYOUT_FAILED,sequence, 0, error).sendToTarget();}}}private static final class WriteResultCallback extends IWriteResultCallback.Stub {private final WeakReference<PrintController.ControllerHandler> mWeakHandler;public WriteResultCallback(PrintController.ControllerHandler handler) {mWeakHandler = new WeakReference<PrintController.ControllerHandler>(handler);}@Overridepublic void onWriteFinished(PageRange[] pages, int sequence) {Handler handler = mWeakHandler.get();if (handler != null) {handler.obtainMessage(PrintController.ControllerHandler.MSG_ON_WRITE_FINISHED,sequence, 0, pages).sendToTarget();}}@Overridepublic void onWriteFailed(CharSequence error, int sequence) {Handler handler = mWeakHandler.get();if (handler != null) {handler.obtainMessage(PrintController.ControllerHandler.MSG_ON_WRITE_FAILED,sequence, 0, error).sendToTarget();}}}private void writePrintJobDataAndFinish(final Uri uri) {new AsyncTask<Void, Void, Void>() {@Overrideprotected Void doInBackground(Void... params) {InputStream in = null;OutputStream out = null;try {PrintJobInfo printJob = mSpoolerProvider.getSpooler().getPrintJobInfo(mPrintJobId, PrintManager.APP_ID_ANY);if (printJob == null) {return null;}File file = mSpoolerProvider.getSpooler().generateFileForPrintJob(mPrintJobId);in = new FileInputStream(file);out = getContentResolver().openOutputStream(uri);final byte[] buffer = new byte[8192];while (true) {final int readByteCount = in.read(buffer);if (readByteCount < 0) {break;}out.write(buffer, 0, readByteCount);}} catch (FileNotFoundException fnfe) {Log.e(LOG_TAG, "Error writing print job data!", fnfe);} catch (IOException ioe) {Log.e(LOG_TAG, "Error writing print job data!", ioe);} finally {IoUtils.closeQuietly(in);IoUtils.closeQuietly(out);}return null;}@Overridepublic void onPostExecute(Void result) {mEditor.cancel();PrintJobService.this.finish();}}.executeOnExecutor(AsyncTask.SERIAL_EXECUTOR, (Void[]) null);}private final class Editor {private PrinterId mNextPrinterId;private MediaSizeComparator mMediaSizeComparator;private void updatePrintAttributes(PrinterCapabilitiesInfo capabilities) {Log.e(LOG_TAG, "updatePrintAttributes");PrintAttributes defaults = capabilities.getDefaults();// Sort the media sizes based on the current locale.List<MediaSize> sortedMediaSizes = new ArrayList<MediaSize>(capabilities.getMediaSizes());Collections.sort(sortedMediaSizes, mMediaSizeComparator);// Media size.MediaSize currMediaSize = mCurrPrintAttributes.getMediaSize();if (currMediaSize == null) {mCurrPrintAttributes.setMediaSize(defaults.getMediaSize());} else {MediaSize currMediaSizePortrait = currMediaSize.asPortrait();final int mediaSizeCount = sortedMediaSizes.size();for (int i = 0; i < mediaSizeCount; i++) {MediaSize mediaSize = sortedMediaSizes.get(i);if (currMediaSizePortrait.equals(mediaSize.asPortrait())) {mCurrPrintAttributes.setMediaSize(currMediaSize);break;}}}// Color mode.final int colorMode = mCurrPrintAttributes.getColorMode();if ((capabilities.getColorModes() & colorMode) == 0) {mCurrPrintAttributes.setColorMode(colorMode);}// ResolutionResolution resolution = mCurrPrintAttributes.getResolution();if (resolution == null || !capabilities.getResolutions().contains(resolution)) {mCurrPrintAttributes.setResolution(defaults.getResolution());}// Margins.Margins margins = mCurrPrintAttributes.getMinMargins();if (margins == null) {mCurrPrintAttributes.setMinMargins(defaults.getMinMargins());} else {Margins minMargins = capabilities.getMinMargins();if (margins.getLeftMils() < minMargins.getLeftMils()|| margins.getTopMils() < minMargins.getTopMils()|| margins.getRightMils() > minMargins.getRightMils()|| margins.getBottomMils() > minMargins.getBottomMils()) {mCurrPrintAttributes.setMinMargins(defaults.getMinMargins());}}}private int mEditorState;private boolean mIgnoreNextDestinationChange;private int mOldMediaSizeSelectionIndex;private int mOldColorModeSelectionIndex;private boolean mIgnoreNextOrientationChange;private boolean mIgnoreNextRangeOptionChange;private boolean mIgnoreNextCopiesChange;private boolean mIgnoreNextRangeChange;private boolean mIgnoreNextMediaSizeChange;private boolean mIgnoreNextColorChange;private boolean mFavoritePrinterSelected;public Editor() {}public void postCreate() {// Destination.mMediaSizeComparator = new MediaSizeComparator(PrintJobService.this);updatePrintAttributes(mCurrentPrinter.getCapabilities());mSpoolerProvider.getSpooler().setPrintJobPrinterNoPersistence(mPrintJobId, mCurrentPrinter);printButtonClick();}public void reselectCurrentPrinter() {Log.d(LOG_TAG, "reselectCurrentPrinter");}public void addCurrentPrinterToHistory() {}private void printButtonClick() {Log.e(LOG_TAG, "[ymy]printButtonClick--"+mCurrentPrinter.toString());mController.update();if (mCurrentPrinter != null) {isPrint = true;new Handler().postDelayed(new Runnable(){@Overridepublic void run() {mEditor.confirmPrint();mController.update();} }, 5000);} else {mEditor.cancel();PrintJobService.this.finish();}}public void initialize() {mEditorState = EDITOR_STATE_INITIALIZED;}public boolean isCancelled() {return mEditorState == EDITOR_STATE_CANCELLED;}public void cancel() {mEditorState = EDITOR_STATE_CANCELLED;mController.cancel();}public boolean isDone() {return isPrintConfirmed() || isCancelled();}public boolean isPrintConfirmed() {return mEditorState == EDITOR_STATE_CONFIRMED_PRINT;}public void confirmPrint() {Log.e(LOG_TAG, "confirmPrint");addCurrentPrinterToHistory();mEditorState = EDITOR_STATE_CONFIRMED_PRINT;}public PageRange[] getRequestedPages() {if (hasErrors()) {return null;}return ALL_PAGES_ARRAY;}private boolean hasErrors() {return false;}}private static final class Document {public PrintDocumentInfo info;public PageRange[] pages;}private static final class PageRangeUtils {private static final Comparator<PageRange> sComparator = new Comparator<PageRange>() {@Overridepublic int compare(PageRange lhs, PageRange rhs) {return lhs.getStart() - rhs.getStart();}};private PageRangeUtils() {throw new UnsupportedOperationException();}public static boolean contains(PageRange[] ourRanges, PageRange[] otherRanges) {if (ourRanges == null || otherRanges == null) {return false;}if (ourRanges.length == 1&& PageRange.ALL_PAGES.equals(ourRanges[0])) {return true;}ourRanges = normalize(ourRanges);otherRanges = normalize(otherRanges);// Note that the code below relies on the ranges being normalized// which is they contain monotonically increasing non-intersecting// subranges whose start is less that or equal to the end.int otherRangeIdx = 0;final int ourRangeCount = ourRanges.length;final int otherRangeCount = otherRanges.length;for (int ourRangeIdx = 0; ourRangeIdx < ourRangeCount; ourRangeIdx++) {PageRange ourRange = ourRanges[ourRangeIdx];for (; otherRangeIdx < otherRangeCount; otherRangeIdx++) {PageRange otherRange = otherRanges[otherRangeIdx];if (otherRange.getStart() > ourRange.getEnd()) {break;}if (otherRange.getStart() < ourRange.getStart()|| otherRange.getEnd() > ourRange.getEnd()) {return false;}}}if (otherRangeIdx < otherRangeCount) {return false;}return true;}public static PageRange[] normalize(PageRange[] pageRanges) {if (pageRanges == null) {return null;}final int oldRangeCount = pageRanges.length;if (oldRangeCount <= 1) {return pageRanges;}Arrays.sort(pageRanges, sComparator);int newRangeCount = 1;for (int i = 0; i < oldRangeCount - 1; i++) {newRangeCount++;PageRange currentRange = pageRanges[i];PageRange nextRange = pageRanges[i + 1];if (currentRange.getEnd() + 1 >= nextRange.getStart()) {newRangeCount--;pageRanges[i] = null;pageRanges[i + 1] = new PageRange(currentRange.getStart(),Math.max(currentRange.getEnd(), nextRange.getEnd()));}}if (newRangeCount == oldRangeCount) {return pageRanges;}return Arrays.copyOfRange(pageRanges, oldRangeCount - newRangeCount,oldRangeCount);}public static void offset(PageRange[] pageRanges, int offset) {if (offset == 0) {return;}final int pageRangeCount = pageRanges.length;for (int i = 0; i < pageRangeCount; i++) {final int start = pageRanges[i].getStart() + offset;final int end = pageRanges[i].getEnd() + offset;pageRanges[i] = new PageRange(start, end);}}}private static final class PrintSpoolerProvider implements ServiceConnection {private final Context mContext;private final Runnable mCallback;private PrintSpoolerService mSpooler;public PrintSpoolerProvider(Context context, Runnable callback) {mContext = context;mCallback = callback;Intent intent = new Intent(mContext, PrintSpoolerService.class);mContext.bindService(intent, this, 0);}public PrintSpoolerService getSpooler() {return mSpooler;}public void destroy() {if (mSpooler != null) {mContext.unbindService(this);}}@Overridepublic void onServiceConnected(ComponentName name, IBinder service) {mSpooler = ((PrintSpoolerService.PrintSpooler) service).getService();if (mSpooler != null) {mCallback.run();}}@Overridepublic void onServiceDisconnected(ComponentName name) {/* do noting - we are in the same process */}}private static final class PrintDocumentAdapterObserverextends IPrintDocumentAdapterObserver.Stub {private final WeakReference<PrintJobService> mWeakService;public PrintDocumentAdapterObserver(PrintJobService service) {mWeakService = new WeakReference<PrintJobService>(service);}@Overridepublic void onDestroy() {final PrintJobService service = mWeakService.get();if (service != null) {service.mController.mHandler.post(new Runnable() {@Overridepublic void run() {if (service.mController != null) {service.mController.cancel();}if (service.mEditor != null) {service.mEditor.cancel();}service.finish();}});}}}
}```
接下来的实现主要在onStartCommand,这个实现主要是跟之前的onCreate方法大概相同，接下来是mEditor.postCreate方法，这里实现方式跟之前大概相同，只是没有了查找打印机流程，这里就不细说了，大家自己看吧，注意这些流程是在Android4.4实现的，其他版本没试过，应该大概相似吧。

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