introduce HtmlPage#getStyleSheets()

Author: rbri

src/main/java/org/htmlunit/WebWindowImpl.java

@@ -32,10 +32,7 @@
 import org.htmlunit.css.CssStyleSheet;
 import org.htmlunit.css.ElementCssStyleDeclaration;
 import org.htmlunit.html.DomElement;
-import org.htmlunit.html.HtmlElement;
-import org.htmlunit.html.HtmlLink;
 import org.htmlunit.html.HtmlPage;
-import org.htmlunit.html.HtmlStyle;
 import org.htmlunit.javascript.HtmlUnitScriptable;
 import org.htmlunit.javascript.background.BackgroundJavaScriptFactory;
 import org.htmlunit.javascript.background.JavaScriptJobManager;
@@ -413,15 +410,7 @@ else if (getWebClient().getBrowserVersion().hasFeature(JS_WINDOW_COMPUTED_STYLE_
 
             if (webClient.getOptions().isCssEnabled()) {
                 final boolean trace = LOG.isTraceEnabled();
-                for (final HtmlElement htmlElement : htmlPage.getHtmlElementDescendants()) {
-                    CssStyleSheet cssStyleSheet = null;
-                    if (htmlElement instanceof HtmlStyle) {
-                        cssStyleSheet = ((HtmlStyle) htmlElement).getSheet();
-                    }
-                    else if (htmlElement instanceof HtmlLink) {
-                        cssStyleSheet = ((HtmlLink) htmlElement).getSheet();
-                    }
-
+                for (final CssStyleSheet cssStyleSheet : htmlPage.getStyleSheets()) {
                     if (cssStyleSheet != null
                             && cssStyleSheet.isEnabled()
                             && cssStyleSheet.isActive()) {

src/main/java/org/htmlunit/html/HtmlPage.java

@@ -79,6 +79,7 @@
 import org.htmlunit.corejs.javascript.ScriptableObject;
 import org.htmlunit.corejs.javascript.Undefined;
 import org.htmlunit.css.ComputedCssStyleDeclaration;
+import org.htmlunit.css.CssStyleSheet;
 import org.htmlunit.html.FrameWindow.PageDenied;
 import org.htmlunit.html.impl.SelectableTextInput;
 import org.htmlunit.html.impl.SimpleRange;
@@ -2713,6 +2714,29 @@ public void putStyleIntoCache(final DomElement element, final String normalizedP
         getCssPropertiesCache().put(element, normalizedPseudo, style);
     }
 
+    /**
+     * <span style="color:red">INTERNAL API - SUBJECT TO CHANGE AT ANY TIME - USE AT YOUR OWN RISK.</span><br>
+     *
+     * @return a list of all styles from this page (&lt;style&gt; and &lt;link rel=stylesheet&gt;).
+     * This returns an empty list if css support is disabled in the web client options.
+     */
+    public List<CssStyleSheet> getStyleSheets() {
+        final List<CssStyleSheet> styles = new ArrayList<>();
+        if (getWebClient().getOptions().isCssEnabled()) {
+            for (final HtmlElement htmlElement : getHtmlElementDescendants()) {
+                if (htmlElement instanceof HtmlStyle) {
+                    styles.add(((HtmlStyle) htmlElement).getSheet());
+                    continue;
+                }
+
+                if (htmlElement instanceof HtmlLink) {
+                    styles.add(((HtmlLink) htmlElement).getSheet());
+                }
+            }
+        }
+        return styles;
+    }
+
     /**
      * @return the CSSPropertiesCache for this page
      */