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How to use ScreenshotState.ScreenshotComparisonError class of io.appium.java_client package

Best io.appium code snippet using io.appium.java_client.ScreenshotState.ScreenshotComparisonError

ScreenshotState.java

Source:ScreenshotState.java

1package utils;2import io.appium.java_client.ComparesImages;3import static com.google.common.base.Preconditions.checkNotNull;4import static java.util.Optional.ofNullable;5import java.awt.image.BufferedImage;6import java.io.ByteArrayOutputStream;7import java.io.IOException;8import java.time.Duration;9import java.time.LocalDateTime;10import java.util.Base64;11import java.util.function.Function;12import java.util.function.Supplier;13import javax.imageio.ImageIO;14public class ScreenshotState {15    private static final Duration DEFAULT_INTERVAL_MS = Duration.ofMillis(500);16    private BufferedImage previousScreenshot;17    private final Supplier<BufferedImage> stateProvider;18    private final ComparesImages comparator;19    private Duration comparisonInterval = DEFAULT_INTERVAL_MS;20    /**21     * The class constructor accepts two arguments. The first one is image comparator, the second22     * parameter is lambda function, that provides the screenshot of the necessary23     * screen area to be verified for similarity.24     * This lambda method is NOT called upon class creation.25     * One has to invoke {@link #remember()} method in order to call it.26     *27     * <p>Examples of provider function with Appium driver:28     * <code>29     * () -&gt; {30     * final byte[] srcImage = ((TakesScreenshot) driver).getScreenshotAs(OutputType.BYTES);31     * return ImageIO.read(new ByteArrayInputStream(srcImage));32     * }33     * </code>34     * or35     * <code>36     * () -&gt; {37     * final byte[] srcImage = ((TakesScreenshot) driver).getScreenshotAs(OutputType.BYTES);38     * final BufferedImage screenshot = ImageIO.read(new ByteArrayInputStream(srcImage));39     * final WebElement element = driver.findElement(locator);40     * // Can be simplified in Selenium 3.0+ by using getRect method of WebElement interface41     * final Point elementLocation = element.getLocation();42     * final Dimension elementSize = element.getSize();43     * return screenshot.getSubimage(44     * new Rectangle(elementLocation.x, elementLocation.y, elementSize.width, elementSize.height);45     * }46     * </code>47     *48     * @param comparator image comparator49     * @param stateProvider lambda function, which returns a screenshot for further comparison50     */51    public ScreenshotState(ComparesImages comparator, Supplier<BufferedImage> stateProvider) {52        this.comparator = checkNotNull(comparator);53        this.stateProvider = stateProvider;54    }55    public ScreenshotState(ComparesImages comparator) {56        this(comparator, null);57    }58    /**59     * Gets the interval value in ms between similarity verification rounds in <em>verify*</em> methods.60     *61     * @return current interval value in ms62     */63    public Duration getComparisonInterval() {64        return comparisonInterval;65    }66    /**67     * Sets the interval between similarity verification rounds in <em>verify*</em> methods.68     *69     * @param comparisonInterval interval value. 500 ms by default70     * @return self instance for chaining71     */72    public ScreenshotState setComparisonInterval(Duration comparisonInterval) {73        this.comparisonInterval = comparisonInterval;74        return this;75    }76    /**77     * Call this method to save the initial screenshot state.78     * It is mandatory to call before any <em>verify*</em> method is invoked.79     *80     * @return self instance for chaining81     */82    public ScreenshotState remember() {83        this.previousScreenshot = stateProvider.get();84        return this;85    }86    /**87     * This method allows to pass a custom bitmap for further comparison88     * instead of taking one using screenshot provider function. This might89     * be useful in some advanced cases.90     *91     * @param customInitialState valid bitmap92     * @return self instance for chaining93     */94    public ScreenshotState remember(BufferedImage customInitialState) {95        this.previousScreenshot = checkNotNull(customInitialState);96        return this;97    }98    public static class ScreenshotComparisonError extends RuntimeException {99        private static final long serialVersionUID = -7011854909939194466L;100        ScreenshotComparisonError(Throwable reason) {101            super(reason);102        }103        ScreenshotComparisonError(String message) {104            super(message);105        }106    }107    public static class ScreenshotComparisonTimeout extends RuntimeException {108        private static final long serialVersionUID = 6336247721154252476L;109        private final double currentScore;110        ScreenshotComparisonTimeout(String message, double currentScore) {111            super(message);112            this.currentScore = currentScore;113        }114        public double getCurrentScore() {115            return currentScore;116        }117    }118    private ScreenshotState checkState(Function<Double, Boolean> checkerFunc, Duration timeout) {119        final LocalDateTime started = LocalDateTime.now();120        double score;121        do {122            final BufferedImage currentState = stateProvider.get();123            score = getOverlapScore(ofNullable(this.previousScreenshot)124                    .orElseThrow(() -> new ScreenshotComparisonError("Initial screenshot state is not set. "125                            + "Nothing to compare")), currentState);126            if (checkerFunc.apply(score)) {127                return this;128            }129            try {130                Thread.sleep(comparisonInterval.toMillis());131            } catch (InterruptedException e) {132                throw new ScreenshotComparisonError(e);133            }134        }135        while (Duration.between(started, LocalDateTime.now()).compareTo(timeout) <= 0);136        throw new ScreenshotComparisonTimeout(137                String.format("Screenshot comparison timed out after %s ms. Actual similarity score: %.5f",138                        timeout.toMillis(), score), score);139    }140    /**141     * Verifies whether the state of the screenshot provided by stateProvider lambda function142     * is changed within the given timeout.143     *144     * @param timeout  timeout value145     * @param minScore the value in range (0.0, 1.0)146     * @return self instance for chaining147     * @throws ScreenshotComparisonTimeout if the calculated score is still148     *                                     greater or equal to the given score after timeout happens149     * @throws ScreenshotComparisonError   if {@link #remember()} method has not been invoked yet150     */151    public ScreenshotState verifyChanged(Duration timeout, double minScore) {152        return checkState((x) -> x < minScore, timeout);153    }154    /**155     * Verifies whether the state of the screenshot provided by stateProvider lambda function156     * is not changed within the given timeout.157     *158     * @param timeout   timeout value159     * @param minScore  the value in range (0.0, 1.0)160     * @return self instance for chaining161     * @throws ScreenshotComparisonTimeout if the calculated score is still162     *                                     less than the given score after timeout happens163     * @throws ScreenshotComparisonError   if {@link #remember()} method has not been invoked yet164     */165    public ScreenshotState verifyNotChanged(Duration timeout, double minScore) {166        return checkState((x) -> x >= minScore, timeout);167    }168    /**169     * Compares two valid java bitmaps and calculates similarity score between them.170     * Both images are expected to be of the same size/resolution. The method171     * implicitly invokes {@link ComparesImages#getImagesSimilarity(byte[], byte[])}.172     *173     * @param refImage   reference image174     * @param tplImage   template175     * @return similarity score value in range (-1.0, 1.0]. 1.0 is returned if the images are equal176     * @throws ScreenshotComparisonError if provided images are not valid or have177     *                                   different resolution178     */179    public double getOverlapScore(BufferedImage refImage, BufferedImage tplImage) {180        try (ByteArrayOutputStream img1 = new ByteArrayOutputStream();181             ByteArrayOutputStream img2 = new ByteArrayOutputStream()) {182            ImageIO.write(refImage, "png", img1);183            ImageIO.write(tplImage, "png", img2);184            return comparator185                    .getImagesSimilarity(Base64.getEncoder().encode(img1.toByteArray()),186                            Base64.getEncoder().encode(img2.toByteArray()))187                    .getScore();188        } catch (IOException e) {189            throw new ScreenshotComparisonError(e);190        }191    }192}...