File comparison in Android

You can visually compare pages. This resolution independent comparison allows you to quickly spot differences between pages.

There are two main ways to integrate the out-of-box UI components in your application:

1. Standalone activity
2. Comparison options dialog

Standalone activity

The DiffActivity is a standalone component that handles from picking two files to generating the comparison result.

1. Define the activity

Storage Permission

Please follow the latest Android best practices and guidelines outlined here

XML

<activity android:name="com.pdftron.pdf.controls.DiffActivity" android:configChanges="keyboardHidden|orientation|screenSize|screenLayout|smallestScreenSize" android:theme="@style/PDFTronAppTheme" android:windowSoftInputMode="adjustPan" />

1. Show the activity

Java

DiffActivity.open(this);

Kotlin

DiffActivity.open(this)

Comparison options dialog

If you have your own viewer already and only want to show the comparison options in your application, the DiffOptionsDialogFragment can be used.

Java

public void show(final Context context, FragmentManager fragmentManager, final ArrayList<Uri> files) {
    DiffOptionsDialogFragment fragment = DiffOptionsDialogFragment.newInstance(
        files.get(0), files.get(1)
    );
    fragment.setStyle(DialogFragment.STYLE_NORMAL, R.style.PDFTronAppTheme);
    fragment.setDiffOptionsDialogListener(new DiffOptionsDialogFragment.DiffOptionsDialogListener() {
        @Override
        public void onDiffOptionsConfirmed(int color1, int color2, int blendMode) {
            compareFiles(context, files, color1, color2, blendMode);
        }
    });
    fragment.show(fragmentManager, DiffOptionsDialogFragment.TAG);
}

Kotlin

fun show(context: Context, fragmentManager: FragmentManager, files: ArrayList<Uri>) {
    val fragment = DiffOptionsDialogFragment.newInstance(
            files[0], files[1]
    )
    fragment.setStyle(DialogFragment.STYLE_NORMAL, R.style.PDFTronAppTheme)
    fragment.setDiffOptionsDialogListener { color1, color2, blendMode -> compareFiles(context, files, color1, color2, blendMode) }
    fragment.show(fragmentManager, DiffOptionsDialogFragment.TAG)
}

where compareFile is:

Java

private final CompositeDisposable mDisposable = new CompositeDisposable();

private void compareFiles(Context context, ArrayList<Uri> files, int color1, int color2, int blendMode) {
    mDisposable.add(DiffUtils.compareFiles(context, files, color1, color2, blendMode)
        .subscribeOn(Schedulers.io())
        .observeOn(AndroidSchedulers.mainThread())
        .subscribe(new Consumer<Uri>() {
            @Override
            public void accept(Uri uri) throws Exception {
                // do something with the output
            }
        }, new Consumer<Throwable>() {
            @Override
            public void accept(Throwable throwable) throws Exception {

            }
        }));
}

Kotlin

private val mDisposable = CompositeDisposable()

private fun compareFiles(context: Context, files: ArrayList<Uri>, color1: Int, color2: Int, blendMode: Int) {
    mDisposable.add(DiffUtils.compareFiles(context, files, color1, color2, blendMode)
            .subscribeOn(Schedulers.io())
            .observeOn(AndroidSchedulers.mainThread())
            .subscribe({
                // do something with the output
            }, { }))
}

AsyncTask pattern can be used instead of Disposable pattern if desired.