Investigate RSyntaxTextArea for RUPS

pom.xml

@@ -81,6 +81,8 @@
     <itext.version>9.1.0</itext.version>
     <jackson.version>2.18.3</jackson.version>
     <logback.version>1.5.18</logback.version>
+    <rsyntaxtextarea.version>3.6.0</rsyntaxtextarea.version>
+    <rstaui.version>3.3.1</rstaui.version>
 
     <!-- Test dependencies -->
     <junit-jupiter-api.version>5.12.0</junit-jupiter-api.version>
@@ -134,6 +136,16 @@
       <artifactId>flatlaf</artifactId>
       <version>${flatlaf.version}</version>
     </dependency>
+    <dependency>
+      <groupId>com.fifesoft</groupId>
+      <artifactId>rsyntaxtextarea</artifactId>
+      <version>${rsyntaxtextarea.version}</version>
+    </dependency>
+    <dependency>
+      <groupId>com.fifesoft</groupId>
+      <artifactId>rstaui</artifactId>
+      <version>${rstaui.version}</version>
+    </dependency>
     <dependency>
       <groupId>com.itextpdf</groupId>
       <artifactId>pdftest</artifactId>

src/main/java/com/itextpdf/rups/Rups.java

@@ -62,6 +62,7 @@ This file is part of the iText (R) project.
 import java.io.IOException;
 import java.io.InputStream;
 import java.util.List;
+import java.util.Locale;
 import java.util.Properties;
 import javax.swing.JFrame;
 import javax.swing.SwingUtilities;
@@ -94,6 +95,13 @@ public static void showBriefMessage(String message) {
      */
     public static void startNewApplication(final List<File> files) {
         SwingUtilities.invokeLater(() -> {
+            /*
+             * While we get the locale explicitly for our localized strings,
+             * some of the 3rd party Swings components use the default locale
+             * for string (ex. RSyntaxTextArea). So we need to change the
+             * default locale for everything to look consistent.
+             */
+            Locale.setDefault(RupsConfiguration.INSTANCE.getUserLocale());
             setLookandFeel();
             final IRupsController rupsController = initApplication(new JFrame());
             setOpenFileHandler(

src/main/java/com/itextpdf/rups/controller/PdfReaderController.java

@@ -72,8 +72,8 @@ This file is part of the iText (R) project.
 import com.itextpdf.rups.view.itext.PdfObjectPanel;
 import com.itextpdf.rups.view.itext.PdfTree;
 import com.itextpdf.rups.view.itext.PlainText;
+import com.itextpdf.rups.view.itext.stream.StreamPane;
 import com.itextpdf.rups.view.itext.StructureTree;
-import com.itextpdf.rups.view.itext.SyntaxHighlightedStreamPane;
 import com.itextpdf.rups.view.itext.XRefTable;
 import com.itextpdf.rups.view.itext.treenodes.PdfObjectTreeNode;
 
@@ -135,7 +135,7 @@ public class PdfReaderController implements IPdfObjectPanelEventListener, IRupsE
     /**
      * A panel that will show a stream.
      */
-    protected SyntaxHighlightedStreamPane streamPane;
+    protected StreamPane streamPane;
 
     /**
      * The factory producing tree nodes.
@@ -205,7 +205,7 @@ public PdfReaderController(TreeSelectionListener treeSelectionListener,
 
         objectPanel = new PdfObjectPanel();
         objectPanel.addEventListener(this);
-        streamPane = new SyntaxHighlightedStreamPane(this);
+        streamPane = new StreamPane(this);
         JScrollPane debug = new JScrollPane(DebugView.getInstance().getTextArea());
         editorTabs = new JTabbedPane();
         editorTabs.addTab(Language.STREAM.getString(), null, streamPane, Language.STREAM.getString());
@@ -255,16 +255,6 @@ public JTabbedPane getEditorTabs() {
         return editorTabs;
     }
 
-    /**
-     * Getter for the object that holds the TextPane
-     * with the content stream of a PdfStream object.
-     *
-     * @return a SyntaxHighlightedStreamPane
-     */
-    public SyntaxHighlightedStreamPane getStreamPane() {
-        return streamPane;
-    }
-
     public PdfSyntaxParser getParser() {
         return parser;
     }

src/main/java/com/itextpdf/rups/model/PdfStreamUtil.java

@@ -0,0 +1,94 @@
+/*
+    This file is part of the iText (R) project.
+    Copyright (c) 1998-2025 Apryse Group NV
+    Authors: Apryse Software.
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License version 3
+    as published by the Free Software Foundation with the addition of the
+    following permission added to Section 15 as permitted in Section 7(a):
+    FOR ANY PART OF THE COVERED WORK IN WHICH THE COPYRIGHT IS OWNED BY
+    APRYSE GROUP. APRYSE GROUP DISCLAIMS THE WARRANTY OF NON INFRINGEMENT
+    OF THIRD PARTY RIGHTS
+
+    This program is distributed in the hope that it will be useful, but
+    WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+    or FITNESS FOR A PARTICULAR PURPOSE.
+    See the GNU Affero General Public License for more details.
+    You should have received a copy of the GNU Affero General Public License
+    along with this program; if not, see http://www.gnu.org/licenses or write to
+    the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+    Boston, MA, 02110-1301 USA, or download the license from the following URL:
+    http://itextpdf.com/terms-of-use/
+
+    The interactive user interfaces in modified source and object code versions
+    of this program must display Appropriate Legal Notices, as required under
+    Section 5 of the GNU Affero General Public License.
+
+    In accordance with Section 7(b) of the GNU Affero General Public License,
+    a covered work must retain the producer line in every PDF that is created
+    or manipulated using iText.
+
+    You can be released from the requirements of the license by purchasing
+    a commercial license. Buying such a license is mandatory as soon as you
+    develop commercial activities involving the iText software without
+    disclosing the source code of your own applications.
+    These activities include: offering paid services to customers as an ASP,
+    serving PDFs on the fly in a web application, shipping iText with a closed
+    source product.
+
+    For more information, please contact iText Software Corp. at this
+    address: [email protected]
+ */
+package com.itextpdf.rups.model;
+
+import com.itextpdf.kernel.pdf.PdfName;
+import com.itextpdf.kernel.pdf.PdfStream;
+import com.itextpdf.kernel.pdf.xobject.PdfImageXObject;
+import com.itextpdf.rups.view.Language;
+
+import java.awt.image.BufferedImage;
+import java.io.IOException;
+
+/**
+ * Static utility class for getting information on PDF streams.
+ */
+public final class PdfStreamUtil {
+    private PdfStreamUtil() {
+        // static class
+    }
+
+    public static BufferedImage getAsImage(PdfStream stream) {
+        if (!isImage(stream)) {
+            return null;
+        }
+        final PdfImageXObject xObject = new PdfImageXObject(stream);
+        try {
+            return xObject.getBufferedImage();
+        } catch (IOException e) {
+            LoggerHelper.warn(Language.ERROR_PARSING_IMAGE.getString(), e, PdfStreamUtil.class);
+            return null;
+        }
+    }
+
+    public static boolean isImage(PdfStream stream) {
+        /*
+         * We will consider stream being an image, if it has /Width and
+         * /Height number fields present and /Subtype is /Image.
+         *
+         * This could skip thumbnail images, as those do not require the
+         * /Subtype field being there.
+         */
+        return PdfName.Image.equals(stream.getAsName(PdfName.Subtype))
+                && (stream.getAsNumber(PdfName.Width) != null)
+                && (stream.getAsNumber(PdfName.Height) != null);
+    }
+
+    public static boolean isFont(PdfStream stream) {
+        /*
+         * For now just checking, that there is a /Length1 field present. It
+         * is required for Type 1 and TrueType fonts.
+         */
+        return stream.containsKey(PdfName.Length1);
+    }
+}