public
final
class
PdfRenderer
extends Object
implements
AutoCloseable
| java.lang.Object | |
| ↳ | android.graphics.pdf.PdfRenderer |
This class enables rendering a PDF document. This class is not thread safe.
If you want to render a PDF, you create a renderer and for every page you want to render, you open the page, render it, and close the page. After you are done with rendering, you close the renderer. After the renderer is closed it should not be used anymore. Note that the pages are rendered one by one, i.e. you can have only a single page opened at any given time.
A typical use of the APIs to render a PDF looks like this:
Developers
// create a new renderer
PdfRenderer renderer = new PdfRenderer(getSeekableFileDescriptor());
// let us just render all pages
final int pageCount = renderer.getPageCount();
for (int i = 0; i < pageCount; i++) {
Page page = renderer.openPage(i);
// say we render for showing on the screen
page.render(mBitmap, null, null, Page.RENDER_MODE_FOR_DISPLAY);
// do stuff with the bitmap
// close the page
page.close();
}
// close the renderer
renderer.close();
If you are using this class to rasterize a PDF for printing or show a print preview, it is recommended that you respect the following contract in order to provide a consistent user experience when seeing a preview and printing, i.e. the user sees a preview that is the same as the printout.
shouldScaleForPrinting().
PrintAttributes
as the application is responsible to render it such that the margins are respected.
See also:
Nested classes | |
|---|---|
class |
PdfRenderer.Page
This class represents a PDF document page for rendering. |
Public constructors | |
|---|---|
PdfRenderer(ParcelFileDescriptor input)
Creates a new instance. |
|
Public methods | |
|---|---|
void
|
close()
Closes this renderer. |
int
|
getPageCount()
Gets the number of pages in the document. |
PdfRenderer.Page
|
openPage(int index)
Opens a page for rendering. |
boolean
|
shouldScaleForPrinting()
Gets whether the document prefers to be scaled for printing. |
Protected methods | |
|---|---|
void
|
finalize()
Called by the garbage collector on an object when garbage collection determines that there are no more references to the object. |
Inherited methods | |
|---|---|
 From
class
java.lang.Object
| |
From
interface
java.lang.AutoCloseable
| |
PdfRenderer (ParcelFileDescriptor input)
Creates a new instance.
Note: The provided file descriptor must be seekable, i.e. its data being randomly accessed, e.g. pointing to a file.
Note: This class takes ownership of the passed in file descriptor and is responsible for closing it when the renderer is closed.
If the file is from an untrusted source it is recommended to run the renderer in a separate, isolated process with minimal permissions to limit the impact of security exploits.
| Parameters | |
|---|---|
input |
ParcelFileDescriptor:
Seekable file descriptor to read from. |
| Throws | |
|---|---|
IOException |
If an error occurs while reading the file. |
SecurityException |
If the file requires a password or the security scheme is not supported. |
void close ()
Closes this renderer. You should not use this instance after this method is called.
int getPageCount ()
Gets the number of pages in the document.
| Returns | |
|---|---|
int |
The page count. |
PdfRenderer.Page openPage (int index)
Opens a page for rendering.
| Parameters | |
|---|---|
index |
int:
The page index. |
| Returns | |
|---|---|
PdfRenderer.Page |
A page that can be rendered. |
See also:
boolean shouldScaleForPrinting ()
Gets whether the document prefers to be scaled for printing. You should take this info account if the document is rendered for printing and the target media size differs from the page size.
| Returns | |
|---|---|
boolean |
If to scale the document. |
void finalize ()
Called by the garbage collector on an object when garbage collection
determines that there are no more references to the object.
A subclass overrides the finalize method to dispose of
system resources or to perform other cleanup.
The general contract of finalize is that it is invoked
if and when the JavaTM virtual
machine has determined that there is no longer any
means by which this object can be accessed by any thread that has
not yet died, except as a result of an action taken by the
finalization of some other object or class which is ready to be
finalized. The finalize method may take any action, including
making this object available again to other threads; the usual purpose
of finalize, however, is to perform cleanup actions before
the object is irrevocably discarded. For example, the finalize method
for an object that represents an input/output connection might perform
explicit I/O transactions to break the connection before the object is
permanently discarded.
The finalize method of class Object performs no
special action; it simply returns normally. Subclasses of
Object may override this definition.
The Java programming language does not guarantee which thread will
invoke the finalize method for any given object. It is
guaranteed, however, that the thread that invokes finalize will not
be holding any user-visible synchronization locks when finalize is
invoked. If an uncaught exception is thrown by the finalize method,
the exception is ignored and finalization of that object terminates.
After the finalize method has been invoked for an object, no
further action is taken until the Java virtual machine has again
determined that there is no longer any means by which this object can
be accessed by any thread that has not yet died, including possible
actions by other objects or classes which are ready to be finalized,
at which point the object may be discarded.
The finalize method is never invoked more than once by a Java
virtual machine for any given object.
Any exception thrown by the finalize method causes
the finalization of this object to be halted, but is otherwise
ignored.
| Throws | |
|---|---|
Throwable |
|