是否可以将整个样式表包装在字符串中并将其应用于特定节点？
使用案例是为PseudoClass添加特定（不可更改的）行为。
我知道我可以使用pane.getStylesheets().add(getClass().getResource("mycss.css").toExternalForm());，但我想知道是否有一些直接嵌入源代码的方法。类似于以下内容：
pane.getStylesheets().add(
".button:ok { -fx-background-color: green; }\n"+
".button:ko { -fx-background-color: red; }");
我通过定义新的URL连接找到了一种实现方法：
private String css;
public void initialize() {
...
// to be done only once.
URL.setURLStreamHandlerFactory(new StringURLStreamHandlerFactory());
...
}
private void updateCss(Node node) {
// can be done multiple times.
css = createCSS();
node.getStylesheets().setAll("internal:"+System.nanoTime()+"stylesheet.css");
}
private class StringURLConnection extends URLConnection {
public StringURLConnection(URL url){
super(url);
}
@Override public void connect() throws IOException {}
@Override public InputStream getInputStream() throws IOException {
return new StringBufferInputStream(css);
}
}
private class StringURLStreamHandlerFactory implements URLStreamHandlerFactory {
URLStreamHandler streamHandler = new URLStreamHandler(){
@Override protected URLConnection openConnection(URL url) throws IOException {
if (url.toString().toLowerCase().endsWith(".css")) {
return new StringURLConnection(url);
}
throw new FileNotFoundException();
}
};
@Override public URLStreamHandler createURLStreamHandler(String protocol) {
if ("internal".equals(protocol)) {
return streamHandler;
}
return null;
}
}
显然，“internal”协议可以是任何（不冲突的）规范字符串，并且（在这个简单的例子中）文件路径完全被忽略。
我使用这个来设置全局.css，所以我不需要记住多个字符串。 它似乎只打开一次流，但我不知道在所有情况下是否都是这样。
随时根据需要复杂化代码；）
此方法的功劳归功于Jasper Potts（请参见此示例）
URLStreamHandlerProvider，它实现了URLStreamHandlerFactory（因此上述代码几乎可以原封不动地使用）; 然后可以注册此类而不会出现“每个进程只有一次调用”的问题，也可以覆盖/替换默认处理程序http、jar等：https://docs.oracle.com/javase/9/docs/api/java/net/spi/URLStreamHandlerProvider.html - CodeClown42IOUtils类，以返回基于String的Stream。但如果需要，这可以很容易地内联或替换为另一个库。/**
* Class that handles the update of the CSS on the scene or any parent.
*
* Since in JavaFX, stylesheets can only be loaded from files or URLs, it implements a handler to create a magic "internal:stylesheet.css" url for our css string
* see : https://github.com/fxexperience/code/blob/master/FXExperienceTools/src/com/fxexperience/tools/caspianstyler/CaspianStylerMainFrame.java
* and : https://dev59.com/kWAf5IYBdhLWcg3wZB6u
*/
public class FXCSSUpdater {
// URL Handler to create magic "internal:stylesheet.css" url for our css string
{
URL.setURLStreamHandlerFactory(new StringURLStreamHandlerFactory());
}
private String css;
private Scene scene;
public FXCSSUpdater(Scene scene) {
this.scene = scene;
}
public void bindCss(StringProperty cssProperty){
cssProperty.addListener(e -> {
this.css = cssProperty.get();
Platform.runLater(()->{
scene.getStylesheets().clear();
scene.getStylesheets().add("internal:stylesheet.css");
});
});
}
public void applyCssToParent(Parent parent){
parent.getStylesheets().clear();
scene.getStylesheets().add("internal:stylesheet.css");
}
/**
* URLConnection implementation that returns the css string property, as a stream, in the getInputStream method.
*/
private class StringURLConnection extends URLConnection {
public StringURLConnection(URL url){
super(url);
}
@Override
public void connect() throws IOException {}
@Override public InputStream getInputStream() throws IOException {
return IOUtils.toInputStream(css);
}
}
/**
* URL Handler to create magic "internal:stylesheet.css" url for our css string
*/
private class StringURLStreamHandlerFactory implements URLStreamHandlerFactory {
URLStreamHandler streamHandler = new URLStreamHandler(){
@Override
protected URLConnection openConnection(URL url) throws IOException {
if (url.toString().toLowerCase().endsWith(".css")) {
return new StringURLConnection(url);
}
throw new FileNotFoundException();
}
};
@Override
public URLStreamHandler createURLStreamHandler(String protocol) {
if ("internal".equals(protocol)) {
return streamHandler;
}
return null;
}
}
}
使用方法：
StringProperty cssProp = new SimpleStringProperty(".root {-fx-background-color : red}");
FXCSSUpdater updater = new FXCSSUpdater(scene);
updater.bindCss(cssProp);
//new style will be applied to the scene automatically
cssProp.set(".root {-fx-background-color : green}");
//manually apply css to another node
cssUpdater.applyCssToParent(((Parent)popover.getSkin().getNode()));
IOUtils 是什么？ - Eugene KartoyevHandler extends URLStreamHandler的类，并更新系统属性java.protocol.handler.pkgs，将其指向该类的包，减去最后的包后缀。因此，com.fu.css将把属性设置为com.fu，然后所有css:my/path请求都将路由到此处理程序。package xapi.jre.ui.css;
import xapi.collect.X_Collect;
import xapi.collect.api.CollectionOptions;
import xapi.collect.api.StringTo;
import xapi.fu.Out1;
import xapi.io.X_IO;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.net.URLConnection;
import java.net.URLStreamHandler;
import java.nio.charset.Charset;
/**
* I abhor the name of this class,
* but it must be called "Handler" in order for java.net.URL to be able to find us.
*
* It sucks, but it's not our api, and it's the only way to get dynamic stylesheets in JavaFx,
* short of overriding the url stream handler directly (and this can only be done once in a single
* JVM, and as framework-level code, it is unacceptable to prevent clients from choosing to
* override the stream handler themselves).
*
* Created by James X. Nelson (james @wetheinter.net) on 8/21/16.
*/
public class Handler extends URLStreamHandler {
private static final StringTo<Out1<String>> dynamicFiles;
static {
// Ensure that we are registered as a url protocol handler for css:/path css files.
String was = System.getProperty("java.protocol.handler.pkgs", "");
System.setProperty("java.protocol.handler.pkgs", Handler.class.getPackage().getName().replace(".css", "") +
(was.isEmpty() ? "" : "|" + was ));
dynamicFiles = X_Collect.newStringMap(Out1.class,
CollectionOptions.asConcurrent(true)
.mutable(true)
.insertionOrdered(false)
.build());
}
public static void registerStyleSheet(String path, Out1<String> contents) {
dynamicFiles.put(path, contents);
}
@Override
protected URLConnection openConnection(URL u) throws IOException {
final String path = u.getPath();
final Out1<String> file = dynamicFiles.get(path);
return new StringURLConnection(u, file);
}
private static class StringURLConnection extends URLConnection {
private final Out1<String> contents;
public StringURLConnection(URL url, Out1<String> contents){
super(url);
this.contents = contents;
}
@Override
public void connect() throws IOException {}
@Override public InputStream getInputStream() throws IOException {
return X_IO.toStream(contents.out1(), Charset.defaultCharset().name());
}
}
}
scene.getStylesheets().add("data:text/css;base64," + Base64.getEncoder().encodeToString("* { -fx-color: red; }".getBytes(StandardCharsets.UTF_8)));
在JavaFX 17中，它将会直接工作。
getStylesheets 是 Parent 中唯一与样式表相关的方法，它只接受“链接到样式表的字符串 URL”，而不是样式表本身。它返回一个通用的 ObservableList，因此其返回值没有针对不同类型的特殊方法；只有一个通用的 add。这与 getResource 返回 URL 一致，而 toExternalForm() 只是返回该 URL 对象的字符串版本。getStylesheets的文档中链接的CSS参考指南中说：
样式表URL可以是绝对URL或相对URL。
首先尝试一个非常简单的数据URI以查看它是否有效。您可以使用此在线工具生成一个数据URI。如果Java接受数据URI，则只需要将包含CSS的字符串包装在一些方法调用中，将字符串转换为数据URI，类似于以下内容：
pane.getStylesheets().add(new DataURI(
".button:ok { -fx-background-color: green; }\n"+
".button:ko { -fx-background-color: red; }").toString());
类 DataURI 是假设的。如果JavaFX接受手动生成的数据URI，则您将不得不自己找到提供该DataURI类的库；我相信这样的库在某个地方存在。
还有一种方法可以将内联CSS指定为String，以用于特定Node，这几乎是您要寻找的内容。 它在CSS参考指南中提到：
stylesheets变量指定的URL加载。如果场景图包含控件，则会加载默认用户代理样式表。内联样式通过节点的setStyle API指定。内联样式类似于HTML元素的style="..."属性。
然而，听起来它不支持CSS中的选择器，只支持规则 - 因此，与其说.red { color: red; }，你只能写color: red;，它将应用于该Node的所有子元素。这听起来不是你想要的。因此，数据URI是你唯一的希望。
我使用了这个样式：
”.root{
-fx-font-family: "Muli";
-fx-font-weight: lighter;
-fx-font-size: 35pt;
-fx-padding: 0;
-fx-spacing: 0;
}
data:text/css;charset=utf-8,.root%7B%0D%0A%20%20%20%20-fx-font-family%3A%20%22Muli%22%3B%0D%0A%20%20%20%20-fx-font-weight%3A%20lighter%3B%0D%0A%20%20%20%20-fx-font-size%3A%2035pt%3B%0D%0A%20%20%20%20-fx-padding%3A%200%3B%0D%0A%20%20%20%20-fx-spacing%3A%200%3B%0D%0A%7D
scene.getStylesheets().add("data:text/css;charset=utf-8,.root%7B%0D%0A%20%20%20%20-fx-font-family%3A%20%22Muli%22%3B%0D%0A%20%20%20%20-fx-font-weight%3A%20lighter%3B%0D%0A%20%20%20%20-fx-font-size%3A%2035pt%3B%0D%0A%20%20%20%20-fx-padding%3A%200%3B%0D%0A%20%20%20%20-fx-spacing%3A%200%3B%0D%0A%7D");
janv. 07, 2015 12:02:03 PM com.sun.javafx.css.StyleManager loadStylesheetUnPrivileged
AVERTISSEMENT: Resource "data:text/css;charset=utf-8,%23header%7B%0D%0A%20%20%20%20-fx-background-color%3A%23002D27%3B%0D%0A%20%20%20%20-fx-font-size%3A%2035pt%3B%0D%0A%20%20%20%20-fx-text-fill%3A%20%23fff%3B%0D%0A%7D" not found.
css:/blah URL的支持，这些URL映射到任何您想要的内容，而无需覆盖默认的流工厂。 - Ajaxpackage com.stackoverflow.handler.util;
import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;
public class HandlerUtil {
private HandlerUtil() {/* Please do not instantiate. */}
public synchronized static String register(final Class clazz) {
final String className = clazz.getName();
/*
* There must be at least one '.' in the Package Name.
*/
final int dotLast = className.lastIndexOf('.');
final int dotLastButOne = className.lastIndexOf('.', dotLast - 1);
System.out.println("Class Name............................: " + className);
System.out.println("dotLast...............................: " + dotLast);
System.out.println("dotLastButOne.........................: " + dotLastButOne);
/*
* Split the Package Name in two.:
* - the part BEFORE the final '.' ("SuperPackage" Key for the Protocol Handler)
* - the part AFTER the final '.' (the Protocol Name, which MUST be unique)
* (Unique, because otherwise new URL("protocol:...") may find the Protocol in another SuperPackage)
*/
final String ourSuperPackage;
final String protocolName;
try {
ourSuperPackage = className.substring(0, dotLastButOne);
protocolName = className.substring( dotLastButOne + 1, dotLast);
}
catch (final StringIndexOutOfBoundsException e) {
throw new IllegalArgumentException("Full Classname must contain at least 2 dots. Class=" + className);
}
System.out.println("PROTOCOL_NAME.........................: " + protocolName);
/*
* Get the List of registered Handler "SuperPackages"...
*/
final String handlerProperty = "java.protocol.handler.pkgs";
final char sepBar = '|';
final String handlerPackageList = System.getProperty(handlerProperty, "").trim();
/*
* Precede & append '|' to both List & New Entry to facilitate Pre-Existence check...
*/
final String sepListSep = sepBar + handlerPackageList + sepBar;
final String sepNewSep = sepBar + ourSuperPackage + sepBar;
/*
* Only append our "SuperPackage" Name to the List if it's not already present...
*/
if (sepListSep.indexOf(sepNewSep) < 0) {
final String updatedList;
if (handlerPackageList.length() == 0) {
updatedList = ourSuperPackage;
} else {
updatedList = handlerPackageList + sepBar + ourSuperPackage;
}
System.out.println("Updated handlerPackageList............: " + updatedList);
System.setProperty(handlerProperty, updatedList);
}
return protocolName;
}
public static void main(final String[] args) throws MalformedURLException, IOException {
testProtocol(com.stackoverflow.handler.reverse.Handler.PROTOCOL_NAME, "path/reverseme");
testProtocol(com.stackoverflow.handler.dubble .Handler.PROTOCOL_NAME, "path/doubleme");
testProtocol("unregisteredProtocol", "path/unregistered");
}
private static void testProtocol(final String protocol, final String path) throws MalformedURLException, IOException {
final URLConnection urlConnection = new URL(protocol + ':' + path).openConnection();
; urlConnection.connect();
System.out.println("[main] urlConnection..................: " + urlConnection.getClass());
System.out.println("[main] urlInputStream.................: " + new String(readBytes(urlConnection)));
}
private static byte[] readBytes(final URLConnection urlConnection) throws IOException {
final byte[] bytes = new byte[8192];
final int byteCount = urlConnection.getInputStream(/* ByteArrayInputStream for our test Protocols */).read(bytes);
final byte[] bytesCopy = new byte[byteCount];
System.arraycopy(bytes, 0, bytesCopy, 0, byteCount);
return bytesCopy;
}
}
package com.stackoverflow.handler.dubble;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.net.URLConnection;
public final class DoubleURLConnection extends URLConnection {
protected DoubleURLConnection(final URL url) {
super(url);
System.out.println("DublURLConnection.new.................: " + url);
}
public void connect() throws IOException {
System.out.println("DublURLConnection.connect.............:");
}
public InputStream getInputStream() throws IOException {
System.out.println("DublURLConnection.getInputStream......:");
final String urlString = this.getURL().toString();
return new ByteArrayInputStream(("DUBL_" + urlString + '_' + urlString + "_DUBL").getBytes());
}
}
package com.stackoverflow.handler.dubble;
import java.io.IOException;
import java.net.URL;
import java.net.URLConnection;
import java.net.URLStreamHandler;
import com.stackoverflow.handler.util.HandlerUtil;
/**
* This Class MUST be called "Handler".
*/
public final class Handler extends URLStreamHandler {
/**
* Explicitly register the Protocol.<br>
* This is not necessary if you reference the Protocol Name via
* {@link #PROTOCOL_NAME}.
*/
public static void register() {
}
/**
* The Protocol Name for this Handler.<br>
* (which, when referenced, will implicitly register the Protocol)
*/
public static final String PROTOCOL_NAME = HandlerUtil.register(DoubleURLConnection.class);
protected URLConnection openConnection(final URL url) throws IOException {
System.out.println("DUBL Handler.openConnection.(URL).....: " + url);
System.out.println("DUBL Handler.openConnection.(Protocol): " + url.getProtocol());
// System.out.println("DUBL Handler.openConnection.(Path)....: " + url.getPath());
return new DoubleURLConnection(url);
}
}
package com.stackoverflow.handler.reverse;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.net.URLConnection;
public final class ReverseURLConnection extends URLConnection {
protected ReverseURLConnection(final URL url) {
super(url);
System.out.println("RvrsURLConnection.new.................: " + url);
}
public void connect() throws IOException {
System.out.println("RvrsURLConnection.connect.............:");
}
public InputStream getInputStream() throws IOException {
System.out.println("RvrsURLConnection.getInputStream......:");
final StringBuffer sbd = new StringBuffer();
final char[] urlChars = this.getURL().toString().toCharArray();
for (int i=0; i < urlChars.length ; i++) {
sbd.insert(0, urlChars[i]);
}
return new ByteArrayInputStream(sbd.toString().getBytes());
}
}
package com.stackoverflow.handler.reverse;
import java.io.IOException;
import java.net.URL;
import java.net.URLConnection;
import java.net.URLStreamHandler;
import com.stackoverflow.handler.util.HandlerUtil;
/**
* This Class MUST be called "Handler".
*/
public final class Handler extends URLStreamHandler {
/**
* Explicitly register the Protocol.<br>
* This is not necessary if you reference the Protocol Name via
* {@link #PROTOCOL_NAME}.
*/
public static void register() {
}
/**
* The Protocol Name for this Handler.<br>
* (which, when referenced, will implicitly register the Protocol)
*/
public static final String PROTOCOL_NAME = HandlerUtil.register(ReverseURLConnection.class);
protected URLConnection openConnection(final URL url) throws IOException {
System.out.println("Handler.openConnection.(URL)..........: " + url);
System.out.println("Handler.openConnection.(Protocol).....: " + url.getProtocol());
// System.out.println("Handler.openConnection.(Path).........: " + url.getPath());
return new ReverseURLConnection(url);
}
}