1. Printing Framework
android.print

2. The gist of it

3. The gist of it
PrintManager

4. Prerequisites

SDK platform 19

SDK build-tools 19 or later

Something to print with

A Google Cloud Print Ready printer

A printer shared through Google Cloud Print

Print to PDF

5. ApiDemos

[sdk]/sampes/android-19/legacy/ApiDemos

6. PrintManager
PrintManager printManager = (PrintManager)
context.getSystemService(Context.PRINT_SERVICE);
PrintJob printJob = printManager.print(
printJobName, documentAdapter, attributes);
Name for the print job
(shown to the user)
Default print job attributes
Adapter that emits the document

7. PrintDocumentAdapter
Web pages
PrintDocumentAdapter documentAdapter =
// Directly from an existing WebView
webView.createPrintDocumentAdapter();

8. PrintDocumentAdapter
Web pages
// Create a WebView and start printing when its ready
WebView webView = new WebView(context);
webView.setWebViewClient(new WebViewClient() {
@Override
public void onPageFinished(
WebView webView, String url) {
// Print to it as before
PrintDocumentAdapter documentAdapter =
webView.createPrintDocumentAdapter();
}
});
webView.loadUrl(url);

9. PrintDocumentAdapter
Custom documents
PrintDocumentAdapter documentAdapter =
// Define a custom print adapter
new MyPrintDocumentAdapter(context);

10. Custom Print Adapters
Events:

onStart()


Print process has begun.
onLayout()



A print setting has changed and the layout of the pages needs to be computed.
Must return expected number of pages.
onWrite()


Render printed pages into a file.
onFinish()

Print process has ended.

11. Custom Print Adapters
onLayout()
public void onLayout(
final PrintAttributes oldAttributes,
final PrintAttributes newAttributes,
final CancellationSignal cancellationSignal,
final LayoutResultCallback callback,
final Bundle metadata) {
CONTRACT
onLayoutFinished(
PrintDocumentInfo, boolean)
}
onLayoutCancelled()
onLayoutFailed(CharSequence)

12. Custom Print Adapters
onLayout()

Create a document for printing:
PrintedPdfDocument document =
new PrintedPdfDocument(context, newAttributes);

Compute the number of pages using PrintAttributes

Return print information to the print framework:
PrintDocumentInfo info = new PrintDocumentInfo
.Builder("print_output.pdf")
.setContentType(
PrintDocumentInfo.CONTENT_TYPE_DOCUMENT)
.setPageCount(pages);
.build();
callback.onLayoutFinished(info, true);

Wait for the print framework to invoke onWrite()

13. Custom Print Adapters
onWrite()
public void onWrite(
final PageRange[] pages,
final ParcelFileDescriptor destination,
final CancellationSignal cancellationSignal,
final WriteResultCallback callback) {
CONTRACT
onWriteFinished(PageRange[])
}
onWriteCancelled()
onWriteFailed(CharSequence)

14. Custom Print Adapters
onWrite()

Start writing a page:
Page page = document.startPage(pageNumber);

Draw onto the page canvas:
page.getCanvas();


Note that elements are specified in points (1/72 inch)
Finish writing the page:
document.finishPage(page);

Inform WriteResultCallback of the PageRange[] printed

15. Custom Print Adapters
Caveats
If you need a screen context, remember that the printer and screen densities differ!

Obtain the printer density:
printerDensity = Math.max(
newAttributes.getResolution().getHorizontalDpi(),
newAttributes.getResolution().getVerticalDpi());

Create a new Context to cope with a different Configuration:
Configuration configuration = new Configuration();
configuration.densityDpi = printerDensity;
printContext = createConfigurationContext(
configuration);

Use this context for creating new views:
View view = new LinearLayout(printContext);
view.draw(page.getCanvas());

16. PrintHelper
PrintHelper printHelper = new PrintHelper(context);
// Instruct how the content should scale
printHelper.setScaleMode(PrintHelper.SCALE_MODE_FIT);
// Get the bitmap for the ImageView's drawable
Bitmap bitmap = ((BitmapDrawable)
mImageView.getDrawable()).getBitmap();
// Print the bitmap
printHelper.printBitmap("Print Bitmap", bitmap);

17. Happy printing!