PrintManager

Class Overview

System level service for accessing the printing capabilities of the platform.

To obtain a handle to the print manager do the following:

 PrintManager printManager =
         (PrintManager) context.getSystemService(Context.PRINT_SERVICE);
 

Print mechanics

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 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.

Print jobs

Print jobs are started by calling the 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.

Print jobs can be in created, queued, started, blocked, completed, failed, and 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.

An applications can query the print spooler for current print jobs it created but not print jobs created by other applications.

Summary

[Expand] Inherited Methods

From class java.lang.Object Object clone() Creates and returns a copy of this Object. boolean equals(Object o) Compares this instance with the specified object and indicates if they are equal. void finalize() Invoked when the garbage collector has detected that this instance is no longer reachable. final Class<?> getClass() Returns the unique instance of Class that represents this object's class. int hashCode() Returns an integer hash code for this object. final void notify() Causes a thread which is waiting on this object's monitor (by means of calling one of the wait() methods) to be woken up. final void notifyAll() Causes all threads which are waiting on this object's monitor (by means of calling one of the wait() methods) to be woken up. String toString() Returns a string containing a concise, human-readable description of this object. final void wait() Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object. final void wait(long millis, int nanos) Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object or until the specified timeout expires. final void wait(long millis) Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object or until the specified timeout expires.