Auto save PDF annotations on Android

Nutrient will save “dirty” (changed/created/deleted) annotations when their fragment lifecycle onStop() method is called. In practice, this means that saving will be performed when:

The application goes into the background.
A configuration change occurs (for example, change of device orientation, change of locale, added keyboard).
The application is fully covered by another Activity.

Each time, onDocumentSaved() is called on DocumentListener.

Manual saving

Saving can always be triggered by calling saveIfModifiedAsync() from the main thread:

/** Manually saving inside the activity. **/
fun saveDocument() {
    // Won't save if the document inside `PdfFragment` is `null`.
    val document : PdfDocument = pdfFragment.document ?: return

    document.saveIfModifiedAsync()
        .observeOn(AndroidSchedulers.mainThread())
        .subscribe(object : DisposableSingleObserver<Boolean>() {
            override fun onError(e : Throwable) {
                /** Saving has failed. The exception holds additional failure details. **/
                Toast.makeText(context, "Failed to save the document!", Toast.LENGTH_SHORT).show()
            }

            override fun onSuccess(saved : Boolean) {
                if (saved) {
                    /** Changes were saved successfully! **/
                    Toast.makeText(context, "Saved successfully!", Toast.LENGTH_SHORT).show()
                } else {
                    /** There was nothing to save. **/
                    Toast.makeText(context, "There were no changes in the file.", Toast.LENGTH_SHORT).show()
                }
            }
        })
}

/** Manually saving inside the activity. **/
PdfDocument document = getPdfFragment().getDocument();
if (document == null) {
    // No document loaded.
    return;
}
document.saveIfModifiedAsync()
        .observeOn(AndroidSchedulers.mainThread())
        .subscribe(new DisposableSingleObserver<Boolean>() {
             @Override
             public void onError(Throwable e) {
                 /** Saving has failed. The exception holds additional failure details. **/
                Toast.makeText(context, "Failed to save the document!", Toast.LENGTH_SHORT).show();
             }

             @Override
             public void onSuccess(Boolean saved) {
                 if (saved) {
                     /** Changes were saved successfully! **/
                     Toast.makeText(context, "Saved successfully!", Toast.LENGTH_SHORT).show();
                 } else {
                    /** There was nothing to save. **/
                     Toast.makeText(context, "There were no changes in the file.", Toast.LENGTH_SHORT).show();
                 }
             }
        });

Save calls on PdfDocument are synchronized and can be called from the main or background threads. Remember that save() and saveIfModified() calls run on the current thread and should never be called from the main thread. Use saveAsync() or saveIfModifiedAsync() instead.

To disable automatic saving of a document by Nutrient, set autosaveEnabled(false) when building PdfConfiguration or PdfActivityConfiguration.