[WIP] Implement ByImage locator

pom.xml

@@ -96,6 +96,12 @@
             <version>2.14.2</version>
         </dependency>
 
+        <dependency>
+            <groupId>org.openpnp</groupId>
+            <artifactId>opencv</artifactId>
+            <version>[4.7.0,)</version>
+        </dependency>
+
         <dependency>
             <groupId>org.testng</groupId>
             <artifactId>testng</artifactId>

src/main/java/aquality/selenium/elements/interfaces/ByImage.java

@@ -0,0 +1,87 @@
+package aquality.selenium.elements.interfaces;
+
+import aquality.selenium.browser.AqualityServices;
+import org.opencv.core.Core;
+import org.opencv.core.Mat;
+import org.opencv.core.MatOfByte;
+import org.opencv.core.Point;
+import org.opencv.imgcodecs.Imgcodecs;
+import org.opencv.imgproc.Imgproc;
+import org.openqa.selenium.*;
+
+import java.io.File;
+import java.util.ArrayList;
+import java.util.List;
+
+public class ByImage extends By {
+    private static boolean wasLibraryLoaded = false;
+    private final Mat template;
+
+    private static void loadLibrary() {
+        if (!wasLibraryLoaded) {
+            nu.pattern.OpenCV.loadShared();
+            System.loadLibrary(org.opencv.core.Core.NATIVE_LIBRARY_NAME);
+            wasLibraryLoaded = true;
+        }
+    }
+
+    public ByImage(File file) {
+        loadLibrary();
+        this.template = Imgcodecs.imread(file.getAbsolutePath(), Imgcodecs.IMREAD_UNCHANGED);
+    }
+
+    public ByImage(byte[] bytes) {
+        loadLibrary();
+        this.template = Imgcodecs.imdecode(new MatOfByte(bytes), Imgcodecs.IMREAD_UNCHANGED);
+    }
+
+    @Override
+    public List<WebElement> findElements(SearchContext context) {
+        byte[] screenshotBytes = getScreenshot(context);
+        Mat source = Imgcodecs.imdecode(new MatOfByte(screenshotBytes), Imgcodecs.IMREAD_UNCHANGED);
+        Mat result = new Mat();
+        Imgproc.matchTemplate(source, template, result, Imgproc.TM_CCOEFF_NORMED);
+
+        float threshold = 1 - AqualityServices.getConfiguration().getVisualizationConfiguration().getDefaultThreshold();
+        Core.MinMaxLocResult minMaxLoc = Core.minMaxLoc(result);
+
+        if (minMaxLoc.maxVal < threshold) {
+            AqualityServices.getLogger().warn(String.format("No elements found by image [%s]", template));
+            return new ArrayList<>(0);
+        }
+
+        return getElementsOnPoint(minMaxLoc.maxLoc, context);
+    }
+
+    private List<WebElement> getElementsOnPoint(Point matchLocation, SearchContext context) {
+        int centerX = (int)(matchLocation.x + (template.width() / 2));
+        int centerY = (int)(matchLocation.y + (template.height() / 2));
+
+        JavascriptExecutor js;
+        if (!(context instanceof JavascriptExecutor)) {
+            AqualityServices.getLogger().debug("Current search context doesn't support executing scripts. " +
+                    "Will take browser js executor instead");
+            js = AqualityServices.getBrowser().getDriver();
+        }
+        else {
+            js = (JavascriptExecutor) context;
+        }
+
+        //noinspection unchecked
+        return (List<WebElement>) js.executeScript("return document.elementsFromPoint(arguments[0], arguments[1]);", centerX, centerY);
+    }
+
+    private byte[] getScreenshot(SearchContext context) {
+        byte[] screenshotBytes;
+
+        if (!(context instanceof TakesScreenshot)) {
+            AqualityServices.getLogger().debug("Current search context doesn't support taking screenshots. " +
+                    "Will take browser screenshot instead");
+            screenshotBytes = AqualityServices.getBrowser().getScreenshot();
+        } else {
+            screenshotBytes = ((TakesScreenshot) context).getScreenshotAs(OutputType.BYTES);
+        }
+
+        return screenshotBytes;
+    }
+}