Remove deprecated Observer and Observable usage

With this the RupsEvent and its package was removed. Usages were
replaced with the following:

1. Somewhat global events (like document opened/closed) are now handled
   by IRupsEventListener. Implementers of this interface handle the
   global events and may forward them further in any way they like.

2. Events from PdfObjectPanel were extracted to
   IPdfObjectPanelEventListener interface and now only
   PdfReaderController explicitly handles them. Not quite sure, why they
   were on a somewhat global level originally.

3. Events, like _requests_ (not the aftermath) of stuff, like open/close
   were replaced with direct calls or individual functional listener
   interfaces.

FileCloseAction was inlined into a lambda. There is no real need to have
a full class, when the handler just calls one methods on an object.

FileCompareAction was removed, since it is currently unused and we would
want to reuse PdfFileOpenAction for it in the future, so that MRU also
works there.

Author: Eswcvlad

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

@@ -141,7 +141,6 @@ static IRupsController initApplication(JFrame frame) {
         final RupsTabbedPane rupsTabbedPane = new RupsTabbedPane();
         final RupsController rupsController = new RupsController(screen, rupsTabbedPane);
         final RupsMenuBar rupsMenuBar = new RupsMenuBar(rupsController);
-        rupsController.addObserver(rupsMenuBar);
 
         frame.setDropTarget(new RupsDropTarget(rupsController));
         frame.setJMenuBar(rupsMenuBar);

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

@@ -43,6 +43,7 @@ This file is part of the iText (R) project.
 package com.itextpdf.rups.controller;
 
 import com.itextpdf.rups.model.IPdfFile;
+import com.itextpdf.rups.model.IRupsEventListener;
 
 import java.awt.Component;
 import java.io.File;
@@ -51,7 +52,7 @@ This file is part of the iText (R) project.
  * The controller in charge of the application. To view the specific tab controllers, look at the RupsInstanceController
  * class.
  */
-public interface IRupsController {
+public interface IRupsController extends IRupsEventListener {
 
     /**
      * Returns the main component of RUPS.

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

@@ -48,31 +48,25 @@ This file is part of the iText (R) project.
 import com.itextpdf.kernel.pdf.PdfObject;
 import com.itextpdf.kernel.pdf.PdfStream;
 import com.itextpdf.kernel.utils.CompareTool;
+import com.itextpdf.kernel.utils.CompareTool.CompareResult;
 import com.itextpdf.kernel.utils.objectpathitems.ArrayPathItem;
 import com.itextpdf.kernel.utils.objectpathitems.DictPathItem;
 import com.itextpdf.kernel.utils.objectpathitems.IndirectPathItem;
 import com.itextpdf.kernel.utils.objectpathitems.LocalPathItem;
 import com.itextpdf.kernel.utils.objectpathitems.ObjectPath;
-import com.itextpdf.rups.event.NodeAddArrayChildEvent;
-import com.itextpdf.rups.event.NodeAddDictChildEvent;
-import com.itextpdf.rups.event.NodeDeleteArrayChildEvent;
-import com.itextpdf.rups.event.NodeDeleteDictChildEvent;
-import com.itextpdf.rups.event.OpenPlainTextEvent;
-import com.itextpdf.rups.event.OpenStructureEvent;
-import com.itextpdf.rups.event.RupsEvent;
 import com.itextpdf.rups.io.listeners.PdfTreeNavigationListener;
-import com.itextpdf.rups.model.IPdfFile;
 import com.itextpdf.rups.model.ObjectLoader;
 import com.itextpdf.rups.model.PdfSyntaxParser;
 import com.itextpdf.rups.model.TreeNodeFactory;
 import com.itextpdf.rups.view.DebugView;
-import com.itextpdf.rups.view.IRupsEventHandler;
+import com.itextpdf.rups.model.IRupsEventListener;
 import com.itextpdf.rups.view.Language;
 import com.itextpdf.rups.view.PageSelectionListener;
 import com.itextpdf.rups.view.contextmenu.PdfTreeContextMenu;
 import com.itextpdf.rups.view.contextmenu.PdfTreeContextMenuMouseListener;
 import com.itextpdf.rups.view.icons.IconTreeNode;
 import com.itextpdf.rups.view.itext.FormTree;
+import com.itextpdf.rups.view.itext.IPdfObjectPanelEventListener;
 import com.itextpdf.rups.view.itext.OutlineTree;
 import com.itextpdf.rups.view.itext.PagesTable;
 import com.itextpdf.rups.view.itext.PdfObjectPanel;
@@ -82,27 +76,23 @@ This file is part of the iText (R) project.
 import com.itextpdf.rups.view.itext.SyntaxHighlightedStreamPane;
 import com.itextpdf.rups.view.itext.XRefTable;
 import com.itextpdf.rups.view.itext.treenodes.PdfObjectTreeNode;
-import com.itextpdf.rups.view.itext.treenodes.PdfTrailerTreeNode;
 
 import java.awt.Color;
 import java.awt.event.KeyListener;
-import java.util.Observable;
-import java.util.Observer;
 import java.util.Stack;
 import java.util.function.Consumer;
 import javax.swing.JPanel;
 import javax.swing.JScrollPane;
 import javax.swing.JTabbedPane;
 import javax.swing.event.ChangeEvent;
-import javax.swing.event.ChangeListener;
 import javax.swing.event.TreeSelectionListener;
 import javax.swing.tree.DefaultTreeModel;
 import javax.swing.tree.TreePath;
 
 /**
  * Controls the components that get their content from iText's PdfReader.
  */
-public class PdfReaderController extends Observable implements Observer {
+public class PdfReaderController implements IPdfObjectPanelEventListener, IRupsEventListener {
 
     /**
      * Treeview of the PDF file.
@@ -155,9 +145,9 @@ public class PdfReaderController extends Observable implements Observer {
      */
     protected PlainText text;
 
-    private Stack<IconTreeNode> highlights = new Stack<>();
+    private final Stack<IconTreeNode> highlights = new Stack<>();
 
-    private PdfSyntaxParser parser = new PdfSyntaxParser();
+    private final PdfSyntaxParser parser = new PdfSyntaxParser();
 
     /**
      * Constructs the PdfReaderController.
@@ -175,20 +165,13 @@ public PdfReaderController(TreeSelectionListener treeSelectionListener,
         final PdfTreeContextMenu menu = new PdfTreeContextMenu(pdfTree);
         pdfTree.setComponentPopupMenu(menu);
         pdfTree.addMouseListener(new PdfTreeContextMenuMouseListener(menu, pdfTree));
-        addObserver(pdfTree);
 
         pages = new PagesTable(this, pageSelectionListener);
-        addObserver(pages);
         outlines = new OutlineTree(this);
-        addObserver(outlines);
         structure = new StructureTree(this);
-        addObserver(structure);
         form = new FormTree(this);
-        addObserver(form);
         xref = new XRefTable(this);
-        addObserver(xref);
         text = new PlainText();
-        addObserver(text);
 
         navigationTabs = new JTabbedPane();
         final String pagesString = Language.PAGES.getString();
@@ -205,27 +188,22 @@ public PdfReaderController(TreeSelectionListener treeSelectionListener,
                 Language.XREF_DESCRIPTION.getString());
         navigationTabs.addTab(Language.PLAINTEXT.getString(), null, new JScrollPane(text),
                 Language.PLAINTEXT_DESCRIPTION.getString());
-        navigationTabs.addChangeListener(new ChangeListener() {
-            public void stateChanged(ChangeEvent e) {
-                if (navigationTabs.getSelectedIndex() != -1) {
-                    final String title = navigationTabs.getTitleAt(navigationTabs.getSelectedIndex());
-
-                    if (Language.STRUCTURE.getString().equals(title)) {
-                        structure.update(PdfReaderController.this, new OpenStructureEvent());
-                    } else if (Language.PLAINTEXT.getString().equals(title)) {
-                        text.update(PdfReaderController.this, new OpenPlainTextEvent());
-                    } else {
-                        // Intentionally empty
-                    }
+        navigationTabs.addChangeListener((ChangeEvent e) -> {
+            if (navigationTabs.getSelectedIndex() != -1) {
+                final String title = navigationTabs.getTitleAt(navigationTabs.getSelectedIndex());
+
+                if (Language.STRUCTURE.getString().equals(title)) {
+                    structure.openStructure();
+                } else if (Language.PLAINTEXT.getString().equals(title)) {
+                    text.openPlainText();
                 }
+                // No special handling for other tabs
             }
         });
 
         objectPanel = new PdfObjectPanel();
-        addObserver(objectPanel);
-        objectPanel.addObserver(this);
+        objectPanel.addEventListener(this);
         streamPane = new SyntaxHighlightedStreamPane(this);
-        addObserver(streamPane);
         JScrollPane debug = new JScrollPane(DebugView.getInstance().getTextArea());
         editorTabs = new JTabbedPane();
         editorTabs.addTab(Language.STREAM.getString(), null, streamPane, Language.STREAM.getString());
@@ -289,79 +267,6 @@ public PdfSyntaxParser getParser() {
         return parser;
     }
 
-    /**
-     * @see java.util.Observer#update(java.util.Observable, java.lang.Object)
-     */
-    public void update(Observable observable, Object obj) {
-        if (observable != null && obj instanceof RupsEvent) {
-            RupsEvent event = (RupsEvent) obj;
-            switch (event.getType()) {
-                case RupsEvent.COMPARE_POST_EVENT:
-                    highlightChanges((CompareTool.CompareResult) event.getContent());
-                    pdfTree.repaint();
-                    break;
-                case RupsEvent.OPEN_DOCUMENT_POST_EVENT:
-                    final ObjectLoader loader = (ObjectLoader) event.getContent();
-                    final IPdfFile pdfFile = loader.getFile();
-                    nodes = loader.getNodes();
-                    final PdfTrailerTreeNode root = pdfTree.getRoot();
-                    root.setTrailer(pdfFile.getPdfDocument().getTrailer());
-                    root.setUserObject(String.format(Language.PDF_OBJECT_TREE.getString(), loader.getLoaderName()));
-                    nodes.expandNode(root);
-                    navigationTabs.setSelectedIndex(0);
-                    streamPane.setEditable(pdfFile.isOpenedAsOwner());
-                    objectPanel.setEditable(pdfFile.isOpenedAsOwner());
-                    setChanged();
-                    super.notifyObservers(event);
-                    break;
-                case RupsEvent.TREE_NODE_CLICKED_EVENT:
-                    PdfObjectTreeNode node = (PdfObjectTreeNode) event.getContent();
-                    nodes.expandNode(node);
-
-                    if (node.isRecursive()) {
-                        boolean keyboardNav = false;
-
-                        KeyListener[] listeners = pdfTree.getKeyListeners();
-
-                        for (KeyListener listener : listeners) {
-                            if (listener instanceof PdfTreeNavigationListener) {
-                                keyboardNav = ((PdfTreeNavigationListener) listener).isLastActionKeyboardNavigation();
-                            }
-                        }
-
-                        if (!keyboardNav) {
-                            pdfTree.selectNode(node.getAncestor());
-                            return;
-                        }
-                    }
-                    render(node);
-                    break;
-                case RupsEvent.NODE_DELETE_DICT_CHILD_EVENT:
-                    deleteTreeNodeDictChild(((NodeDeleteDictChildEvent.Content) event.getContent()).parent,
-                            ((NodeDeleteDictChildEvent.Content) event.getContent()).key);
-                    break;
-                case RupsEvent.NODE_ADD_DICT_CHILD_EVENT:
-                    addTreeNodeDictChild(((NodeAddDictChildEvent.Content) event.getContent()).parent,
-                            ((NodeAddDictChildEvent.Content) event.getContent()).key,
-                            ((NodeAddDictChildEvent.Content) event.getContent()).index);
-                    break;
-                case RupsEvent.NODE_ADD_ARRAY_CHILD_EVENT:
-                    addTreeNodeArrayChild(((NodeAddArrayChildEvent.Content) event.getContent()).parent,
-                            ((NodeAddArrayChildEvent.Content) event.getContent()).index);
-                    break;
-                case RupsEvent.NODE_DELETE_ARRAY_CHILD_EVENT:
-                    deleteTreeChild(((NodeDeleteArrayChildEvent.Content) event.getContent()).parent,
-                            ((NodeDeleteArrayChildEvent.Content) event.getContent()).index);
-                    break;
-                case RupsEvent.POST_NEW_INDIRECT_OBJECT_EVENT:
-                    nodes.addNewIndirectObject((PdfObject) event.getContent());
-                    setChanged();
-                    notifyObservers(event);
-                    break;
-            }
-        }
-    }
-
     /**
      * Selects a node in the PdfTree.
      *
@@ -491,13 +396,75 @@ public int addTreeNodeChild(PdfObjectTreeNode parent, PdfObjectTreeNode child, i
         return index;
     }
 
-    public void reset() {
+    @Override
+    public void handleCloseDocument() {
         nodes = null;
-        setChanged();
-        forAllComponents(IRupsEventHandler::handleCloseDocument);
+        forAllComponents(IRupsEventListener::handleCloseDocument);
+    }
+
+    @Override
+    public void handleOpenDocument(ObjectLoader loader) {
+        nodes = loader.getNodes();
+        navigationTabs.setSelectedIndex(0);
+        forAllComponents(c -> c.handleOpenDocument(loader));
+    }
+
+    @Override
+    public void handleNewIndirectObject(PdfObject object) {
+        nodes.addNewIndirectObject(object);
+        forAllComponents(c -> c.handleNewIndirectObject(object));
+    }
+
+    @Override
+    public void handleCompare(CompareResult result) {
+        highlightChanges(result);
+        pdfTree.repaint();
+    }
+
+    @Override
+    public void handlePdfTreeNodeClicked(PdfObjectTreeNode node) {
+        nodes.expandNode(node);
+
+        if (node.isRecursive()) {
+            boolean keyboardNav = false;
+
+            KeyListener[] listeners = pdfTree.getKeyListeners();
+
+            for (KeyListener listener : listeners) {
+                if (listener instanceof PdfTreeNavigationListener) {
+                    keyboardNav = ((PdfTreeNavigationListener) listener).isLastActionKeyboardNavigation();
+                }
+            }
+
+            if (!keyboardNav) {
+                pdfTree.selectNode(node.getAncestor());
+                return;
+            }
+        }
+        render(node);
+    }
+
+    @Override
+    public void handleArrayChildAdded(PdfObject value, PdfObjectTreeNode parent, int index) {
+        addTreeNodeArrayChild(parent, index);
+    }
+
+    @Override
+    public void handleArrayChildDeleted(PdfObjectTreeNode parent, int index) {
+        deleteTreeChild(parent, index);
+    }
+
+    @Override
+    public void handleDictChildAdded(PdfObject value, PdfObjectTreeNode parent, PdfName key, int index) {
+        addTreeNodeDictChild(parent, key, index);
+    }
+
+    @Override
+    public void handleDictChildDeleted(PdfObjectTreeNode parent, PdfName key) {
+        deleteTreeNodeDictChild(parent, key);
     }
 
-    private void forAllComponents(Consumer<IRupsEventHandler> func) {
+    private void forAllComponents(Consumer<IRupsEventListener> func) {
         func.accept(pdfTree);
         func.accept(pages);
         func.accept(outlines);