我已在 Web 引擎中加载本地 html 文件。我需要在网页视图页面中搜索并突出显示给定的字符串。
有什么办法可以做到吗？
如果您不介意使用反射，则可以在 Java 代码中本地完成。
WebEngine 有一个类型为 WebPage 的私有字段页面，该页面又具有此方法，它完全可以实现您想要的功能：
// Find in page
public boolean find(String stringToFind, boolean forward, boolean wrap, boolean matchCase) {
// ...
}
因此要访问此 find() 方法，您必须执行以下操作：
WebView webView = new WebView();
WebEngine engine = webView.getEngine();
try {
Field pageField = engine.getClass().getDeclaredField("page");
pageField.setAccessible(true);
WebPage page = (com.sun.webkit.WebPage) pageField.get(engine);
page.find("query", true, true, false);
} catch(Exception e) { /* log error could not access page */ }
参加派对已经太晚了，但请检查一下这个组件。它可以使用搜索栏突出显示文本并再次删除突出显示：
package com.wedasoft.wedasoftFxCustomNodes.htmlViewer;
import javafx.geometry.Insets;
import javafx.scene.control.Button;
import javafx.scene.control.TextField;
import javafx.scene.input.KeyCode;
import javafx.scene.layout.BorderPane;
import javafx.scene.layout.HBox;
import javafx.scene.layout.Priority;
import javafx.scene.web.WebEngine;
import javafx.scene.web.WebView;
import lombok.Getter;
import java.net.URL;
@Getter
public class HtmlViewer extends BorderPane {
private final WebView webView;
private final TextField searchTextField;
private final JavascriptBridge javascriptBridge;
private final Button searchButton;
private final Button selectPreviousSearchResultButton;
private final Button selectNextSearchResultButton;
private final Button resetButton;
private int selectedSearchResultIndex;
public HtmlViewer(URL url) {
webView = new WebView();
webView.setMaxHeight(Integer.MAX_VALUE);
webView.setMaxWidth(Integer.MAX_VALUE);
webView.getEngine().setJavaScriptEnabled(true);
setCenter(webView);
searchTextField = new TextField();
searchTextField.setPromptText("Search...");
searchTextField.setMinWidth(0);
searchTextField.setMinHeight(0);
javascriptBridge = new JavascriptBridge(webView);
searchButton = new Button("Search");
searchButton.setMinWidth(0);
searchButton.setMinHeight(0);
searchButton.setOnAction(e -> onSearchButtonClick());
selectPreviousSearchResultButton = new Button("/\\");
selectPreviousSearchResultButton.setOnAction(e -> onSelectPreviousSearchResultButtonClick());
selectNextSearchResultButton = new Button("\\/");
selectNextSearchResultButton.setOnAction(e -> onSelectNextSearchResultButtonClick());
resetButton = new Button("Reset");
resetButton.setMinWidth(0);
resetButton.setMinHeight(0);
resetButton.setOnAction(e -> onResetButtonClick());
HBox searchBar = new HBox(
searchTextField,
searchButton,
selectPreviousSearchResultButton,
selectNextSearchResultButton,
resetButton);
HBox.setHgrow(searchTextField, Priority.ALWAYS);
searchBar.setMinHeight(0);
searchBar.setMaxWidth(Double.MAX_VALUE);
searchBar.setSpacing(5);
searchBar.setPadding(new Insets(5, 5, 5, 5));
setTop(searchBar);
loadHtmlByUrl(url);
setOnKeyReleased(e -> {
if (e.getCode() == KeyCode.ENTER) onSearchButtonClick();
if (e.getCode() == KeyCode.F && e.isControlDown()) onSearchShortcutClick();
});
}
private void onSelectNextSearchResultButtonClick() {
selectedSearchResultIndex = javascriptBridge.selectNextSearchResultAndReturnNewIndex(selectedSearchResultIndex);
}
private void onSelectPreviousSearchResultButtonClick() {
selectedSearchResultIndex = javascriptBridge.selectPreviousSearchResultAndReturnNewIndex(selectedSearchResultIndex);
}
public void loadHtmlByUrl(URL url) {
webView.getEngine().load(url.toExternalForm());
selectedSearchResultIndex = -1;
}
private void onSearchShortcutClick() {
webView.requestFocus();
searchTextField.requestFocus();
}
private void onSearchButtonClick() {
javascriptBridge.removeHighlightings();
if (searchTextField.getText().trim().isBlank()) {
return;
}
javascriptBridge.highlightText(searchTextField.getText());
selectedSearchResultIndex = -1;
onSelectNextSearchResultButtonClick();
}
private void onResetButtonClick() {
javascriptBridge.removeHighlightings();
selectedSearchResultIndex = -1;
searchTextField.setText("");
}
@SuppressWarnings("unused")
private String getCurrentHtmlOfWebViewDocument() {
return javascriptBridge.getDomAsHtmlString();
}
private static class JavascriptBridge {
private final WebEngine webEngine;
private final String nodeContainingHighlightings;
private final boolean caseInSensitive;
private final String cssClassUsedForHighlighting;
public JavascriptBridge(final WebView webView) {
this.webEngine = webView.getEngine();
this.nodeContainingHighlightings = "document.body";
this.caseInSensitive = true;
this.cssClassUsedForHighlighting = "wedasoft-highlighted";
}
void highlightText(String textToHighlight) {
final String javascript = String.format("""
/**
* @param {string} elem Element to search for keywords in
* @param {string[]} keywords Keywords to highlight
* @param {boolean} caseInSensitive Differenciate between capital and lowercase letters
* @param {string} cssClass Class to apply to the highlighted keyword
*/
function highlightInsideElement(elem, keywords, caseInSensitive = true, cssClass) {
const flags = caseInSensitive ? 'gi' : 'g';
// Sort longer matches first to avoid
// highlighting keywords within keywords.
keywords.sort((a, b) => b.length - a.length);
Array.from(elem.childNodes).forEach(child => {
const keywordRegex = RegExp(keywords.join('|'), flags);
if (child.nodeType !== 3) { // not a text node
highlightInsideElement(child, keywords, caseInSensitive, cssClass);
} else if (keywordRegex.test(child.textContent)) {
const frag = document.createDocumentFragment();
let lastIdx = 0;
child.textContent.replace(keywordRegex, (match, idx) => {
const part = document.createTextNode(child.textContent.slice(lastIdx, idx));
const highlighted = document.createElement('span');
highlighted.textContent = match;
highlighted.classList.add(cssClass);
highlighted.style.background='yellow';
frag.appendChild(part);
frag.appendChild(highlighted);
lastIdx = idx + match.length;
});
const end = document.createTextNode(child.textContent.slice(lastIdx));
frag.appendChild(end);
child.parentNode.replaceChild(frag, child);
}
});
}
highlightInsideElement(%s, ['%s'], %s, '%s');""",
nodeContainingHighlightings,
textToHighlight,
caseInSensitive,
cssClassUsedForHighlighting);
webEngine.executeScript(javascript);
}
void removeHighlightings() {
final String javascript = String.format("""
/**
* @param {string} nodeToRemoveHighlightingsIn Node to remove highlights from.
* @param {string} cssClass Class used for highlighting.
*/
function removeHighlightings(nodeToRemoveHighlightingsIn, cssClass) {
Array.from(nodeToRemoveHighlightingsIn.querySelectorAll(`.${cssClass}`)).forEach(span => {
const parent = span.parentNode;
parent.replaceChild(document.createTextNode(span.textContent), span);
parent.normalize();
});
}
removeHighlightings(%s, '%s');""",
nodeContainingHighlightings,
cssClassUsedForHighlighting);
webEngine.executeScript(javascript);
}
Integer selectNextSearchResultAndReturnNewIndex(int selectedSearchResultIndex) {
return selectSearchResultAndReturnNewIndex(true, selectedSearchResultIndex);
}
Integer selectPreviousSearchResultAndReturnNewIndex(int selectedSearchResultIndex) {
return selectSearchResultAndReturnNewIndex(false, selectedSearchResultIndex);
}
Integer selectSearchResultAndReturnNewIndex(boolean scrollToNextResult, int selectedSearchResultIndex) {
final String javascript = String.format("""
/**
* @param {string} cssClass The css class used for highlighting and to scroll to.
* @param selectedSearchResultIndex {number} The index of the current 'selected' search result.
* @param scrollToNext {boolean} True for scrolling to the next search result, false for the previous one.
* @returns {number} The new current index of the selected search result.
*/
function scrollToSearchResult(cssClass, selectedSearchResultIndex, scrollToNext = true) {
function scrollToResultAndMark(allResults, newResultIndex) {
for (let result of allResults) {
result.style.background = 'yellow';
}
allResults[newResultIndex].scrollIntoView(true);
allResults[newResultIndex].style.background = '#FF9632';
return newResultIndex;
}
let allResults = document.querySelectorAll('.' + cssClass);
if (allResults.length === 0) {
return -1;
}
if (selectedSearchResultIndex === -1) {
let firstIndex = 0;
return scrollToResultAndMark(allResults, firstIndex);
}
if (scrollToNext) {
if (selectedSearchResultIndex < allResults.length - 1) {
let nextIndex = selectedSearchResultIndex + 1;
return scrollToResultAndMark(allResults, nextIndex);
} else {
let firstIndex = 0;
return scrollToResultAndMark(allResults, firstIndex);
}
} else {
if (selectedSearchResultIndex > 0) {
let previousIndex = selectedSearchResultIndex - 1;
return scrollToResultAndMark(allResults, previousIndex);
} else {
let lastIndex = allResults.length - 1;
return scrollToResultAndMark(allResults, lastIndex);
}
}
}
scrollToSearchResult('%s', %s, %s);""",
cssClassUsedForHighlighting,
selectedSearchResultIndex,
scrollToNextResult);
return (int) webEngine.executeScript(javascript);
}
String getDomAsHtmlString() {
final String javascript = "document.documentElement.outerHTML";
return (String) webEngine.executeScript(javascript);
}
}
}