一尘不染

通过使用Java Selenium WebDriver和HTML窗口位置

selenium

我将Selenium
WebDriver与java.awt.Robot结合使用,以更好地模拟用户与Web应用程序的交互。是的,我知道可能没有必要,但是我所服务的客户都需要它。

当前,一切运行良好,但是我有一个小问题,就是我似乎找不到找到将Web元素显示在屏幕上位置的好方法。诸如标题栏,菜单栏,导航栏之类的东西都将内容向下推到物理屏幕上(Robot从中获取坐标),但对Selenium报告元素所在的位置没有影响。

当我element.getLocation();在Selenium
WebElement上调用:时,它总是为我提供相对于HTML内容呈现窗格的位置,而不是浏览器窗口本身的位置。

一个更好的示例是:driver.findElement(By.tagName("body")).getLocation();无论窗口的实际屏幕位置如何,始终返回0,0。

现在,我通过在最大化窗口后添加垂直和水平偏移量来破解它,但是不同的浏览器之间这些偏移量并不相同(例如,IE的顶部装饰所占的空间要比Firefox更大),并且每个用户可能会有所不同如果其中添加了书签工具栏,搜索栏等。

是的,我知道我可以在全屏模式下运行,但如果可能的话,我宁愿不运行。

有没有一种方法可以使用WebDriver以可靠的方式获取元素在屏幕上的物理位置?


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2020-06-26

共1个答案

一尘不染

我相信无法获得页面上元素的真实屏幕位置。

我也认为全屏模式是您最好的选择。

就是说,我写了一个RobotCalibration可以检测当前浏览器实际偏移量的类。它会打开一个特制页面,并使用Robot该类单击它。该算法从浏览器的中心开始,然后使用二等分线找到浏览器视口的左上角。

在IE8和FF18上测试。适用于最大化和窗口浏览器。已知问题:如果启用了顶部的书签工具栏,则它可能会单击某些书签,因此会重定向。它可以很容易地处理,但是如果您需要它,我留给您:)。

测试页面:

<!DOCTYPE html>
<html lang="en" onclick="document.getElementById('counter').value++">
<head>
    <meta charset="utf-8" />
    <title>Calibration Test</title>
</head>
<body>
    <img height="1" width="1" style="position: absolute; left: 0; top: 0;"
        onclick="document.getElementById('done').value = 'yep'" />
    <input type="text" id="counter" value="0" />
    <input type="text" id="done" value="nope" />
</body>
</html>

RobotCalibration班。它有点长,所以我建议您将其复制粘贴到您喜欢的IDE中并在其中进行探索:

import java.awt.AWTException;
import java.awt.Dimension;
import java.awt.Point;
import java.awt.Robot;
import java.awt.Toolkit;
import java.awt.event.InputEvent;
import java.nio.file.Paths;

import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.ie.InternetExplorerDriver;

public class RobotCalibration {

    public static Point calibrate(WebDriver driver) {
        return new RobotCalibration(driver).calibrate();
    }

    /** Time for which to wait for the page response. */
    private static final long TIMEOUT = 1000;

    private final WebDriver driver;
    private final Robot r;

    private final Point browserCenter;
    private int leftX;
    private int rightX;
    private int midX;
    private int topY;
    private int bottomY;
    private int midY;

    private RobotCalibration(WebDriver driver) {
        this.driver = driver;
        try {
            driver.manage().window().getSize();
        } catch (UnsupportedOperationException headlessBrowserException) {
            throw new IllegalArgumentException("Calibrating a headless browser makes no sense.", headlessBrowserException);
        }

        try {
            this.r = new Robot();
        } catch (AWTException headlessEnvironmentException) {
            throw new IllegalStateException("Robot won't work on headless environments.", headlessEnvironmentException);
        }

        Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
        org.openqa.selenium.Dimension browserSize = driver.manage().window().getSize();
        org.openqa.selenium.Point browserPos = driver.manage().window().getPosition();

        // a maximized browser returns negative position
        // a maximized browser returns size larger than actual screen size
        // you can't click outside the screen
        leftX = Math.max(0, browserPos.x);
        rightX = Math.min(leftX + browserSize.width, screenSize.width - 1);
        midX = (leftX + rightX) /2;

        topY = Math.max(0, browserPos.y);
        bottomY = Math.min(topY + browserSize.height, screenSize.height - 1);
        midY = (topY + bottomY) /2;

        browserCenter = new Point(midX, midY);
    }

    private Point calibrate() {
        driver.get(Paths.get("files/RobotCalibration.html").toUri().toString());

        // find left border
        while (leftX < rightX) {
            click(midX, midY);
            if (clickWasSuccessful()) {
                rightX = midX;
            } else {
                leftX = midX + 1;
                // close any menu we could have opened
                click(browserCenter.x, browserCenter.y);
            }
            midX = (leftX + rightX) /2;
        }

        // find top border
        while (topY < bottomY) {
            click(midX, midY);
            if (clickWasSuccessful()) {
                bottomY = midY;
            } else {
                topY = midY + 1;
                // close any menu we could have opened
                click(browserCenter.x, browserCenter.y);
            }
            midY = (topY + bottomY) /2;
        }

        if (!isCalibrated()) {
            throw new IllegalStateException("Couldn't calibrate the Robot.");
        }
        return new Point(midX, midY);
    }

    /** clicks on the specified location */
    private void click(int x, int y) {
        r.mouseMove(x, y);
        r.mousePress(InputEvent.BUTTON1_DOWN_MASK);
        r.mouseRelease(InputEvent.BUTTON1_DOWN_MASK);

        // for some reason, my IE8 can't properly register clicks that are close
        // to each other faster than click every half a second
        if (driver instanceof InternetExplorerDriver) {
            sleep(500);
        }
    }

    private static void sleep(int millis) {
        try {
            Thread.sleep(millis);
        } catch (InterruptedException ignored) {
            // nothing to do
        }
    }

    private int counter = 0;
    /** @return whether the click on a page was successful */
    private boolean clickWasSuccessful() {
        counter++;

        long targetTime = System.currentTimeMillis() + TIMEOUT;
        while (System.currentTimeMillis() < targetTime) {
            int pageCounter = Integer.parseInt(driver.findElement(By.id("counter")).getAttribute("value"));
            if (counter == pageCounter) {
                return true;
            }
        }
        return false;
    }

    /** @return whether the top left corner has already been clicked at */
    private boolean isCalibrated() {
        long targetTime = System.currentTimeMillis() + TIMEOUT;
        while (System.currentTimeMillis() < targetTime) {
            if (driver.findElement(By.id("done")).getAttribute("value").equals("yep")) {
                return true;
            }
        }
        return false;
    }

}

用法示例:

WebDriver driver = new InternetExplorerDriver();
Point p = RobotCalibration.calibrate(driver);
System.out.println("Left offset: " + p.x + ", top offset: " + p.y);
driver.quit();

如果有不清楚的地方,请随时提出任何问题。

2020-06-26