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Version: 3.2.0

Customizing the captured bitmap

In some instances, it may be useful to modify or customize the captured Bitmap. For example, you may wish to annotate the screenshot with certain diagnostic information, print the name of the test, or add a watermark.

You can leverage the TestifyConfiguration.captureMethod configuration function property for this purpose.

To configure a custom capture method, provide a function that conforms to the CaptureMethod signature. A CaptureMethod returns a Bitmap from the provided Activity and View.

typealias CaptureMethod = (activity: Activity, targetView: View?) -> Bitmap?
tip

Testify provides 3 built-in capture methods as well as a Fullscreen capture method extension which may provide the functionality you need without requiring you to write your own.

Within the body of the CaptureMethod, you can use any mechanism you'd like to create or modify the Bitmap. The only requirement is that you return a valid Bitmap. Testify provides a variety of useful helper functions, classes and extension methods that you can use to build your own capture method.

Available ScreenshotUtility helper functions​

  • createBitmapFromActivity: Capture a Bitmap from the given Activity and save it to the screenshots directory.
  • deleteBitmap: Delete the File specified by Destination.
  • loadBaselineBitmapForComparison: Load a baseline Bitmap from the androidTest assets directory.
  • loadBitmapFromFile: Decode the file specified by a path into a Bitmap.
  • preferredBitmapOptions: The default, preferred BitmapFactory.Options to use when decoding a Bitmap.
  • saveBitmapToDestination: Write the given Bitmap to the Destination file.

Wordmark example​

In this example, we add the wordmark Testify and the test name to the bottom of the captured image. We use the ScreenshotUtility function createBitmapFromDrawingCache() to capture a Bitmap from the provided activity. The, we wrap the Bitmap in a Canvas and use the canvas' drawText method to render text on the bitmap.

@ScreenshotInstrumentation
@Test
fun captureMethodExample() {
    rule
        .configure {
            captureMethod = { activity, targetView ->
                /* Return a Bitmap */
                createBitmapFromDrawingCache(activity, targetView).apply {
                    /* Wrap the Bitmap in a Canvas so we can draw on it */
                    Canvas(this).apply {
                        /* Add a wordmark to the captured image */
                        val textPaint = Paint().apply {
                            color = Color.BLACK
                            textSize = 50f
                            isAntiAlias = true
                        }
                        this.drawText(
                            "<<Testify ${getInstrumentation().testDescription.methodName}>>",
                            50f,
                            2000f,
                            textPaint
                        )
                    }
                }
            }
        }
        .assertSame()
}