33 files changed, 604 insertions, 11 deletions

diff --git a/enigma-swing/src/main/java/cuchaz/enigma/gui/Gui.java b/enigma-swing/src/main/java/cuchaz/enigma/gui/Gui.java
index 12877fe..3a0597e 100644
--- a/enigma-swing/src/main/java/cuchaz/enigma/gui/Gui.java
+++ b/enigma-swing/src/main/java/cuchaz/enigma/gui/Gui.java
@@ -350,6 +350,12 @@ public class Gui {
                 return activeEditor == null ? null : activeEditor.getCursorReference();
         }
 
+        @Nullable
+        public Entry<?> getCursorDeclaration() {
+                EditorPanel activeEditor = this.editorTabbedPane.getActiveEditor();
+                return activeEditor == null ? null : activeEditor.getCursorDeclaration();
+        }
+
         public void startDocChange(EditorPanel editor) {
                 EntryReference<Entry<?>, Entry<?>> cursorReference = editor.getCursorReference();
 
diff --git a/enigma-swing/src/main/java/cuchaz/enigma/gui/GuiController.java b/enigma-swing/src/main/java/cuchaz/enigma/gui/GuiController.java
index a2b3bd9..2c27376 100644
--- a/enigma-swing/src/main/java/cuchaz/enigma/gui/GuiController.java
+++ b/enigma-swing/src/main/java/cuchaz/enigma/gui/GuiController.java
@@ -27,6 +27,7 @@ import java.util.concurrent.ExecutionException;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
+import javax.swing.JEditorPane;
 import javax.swing.JFrame;
 import javax.swing.JOptionPane;
 import javax.swing.SwingUtilities;
@@ -52,12 +53,15 @@ import cuchaz.enigma.api.service.ObfuscationTestService;
 import cuchaz.enigma.api.service.ProjectService;
 import cuchaz.enigma.api.view.GuiView;
 import cuchaz.enigma.api.view.entry.EntryReferenceView;
+import cuchaz.enigma.api.view.entry.EntryView;
 import cuchaz.enigma.classhandle.ClassHandle;
 import cuchaz.enigma.classhandle.ClassHandleProvider;
+import cuchaz.enigma.gui.config.LookAndFeel;
 import cuchaz.enigma.gui.config.NetConfig;
 import cuchaz.enigma.gui.config.UiConfig;
 import cuchaz.enigma.gui.dialog.ProgressDialog;
 import cuchaz.enigma.gui.newabstraction.EntryValidation;
+import cuchaz.enigma.gui.panels.EditorPanel;
 import cuchaz.enigma.gui.stats.StatsGenerator;
 import cuchaz.enigma.gui.stats.StatsMember;
 import cuchaz.enigma.gui.util.History;
@@ -130,6 +134,23 @@ public class GuiController implements ClientPacketHandler, GuiView, DataInvalida
                 return gui.getFrame();
         }
 
+        @Override
+        public float getScale() {
+                return UiConfig.getActiveScaleFactor();
+        }
+
+        @Override
+        public boolean isDarkTheme() {
+                return LookAndFeel.isDarkLaf();
+        }
+
+        @Override
+        public JEditorPane createEditorPane() {
+                JEditorPane editor = new JEditorPane();
+                EditorPanel.customizeEditor(editor);
+                return editor;
+        }
+
         public boolean isDirty() {
                 return project != null && project.getMapper().isDirty();
         }
@@ -349,6 +370,12 @@ public class GuiController implements ClientPacketHandler, GuiView, DataInvalida
                 return gui.getCursorReference();
         }
 
+        @Override
+        @Nullable
+        public EntryView getCursorDeclaration() {
+                return gui.getCursorDeclaration();
+        }
+
         /**
          * Navigates to the declaration with respect to navigation history.
          *
diff --git a/enigma-swing/src/main/java/cuchaz/enigma/gui/config/LookAndFeel.java b/enigma-swing/src/main/java/cuchaz/enigma/gui/config/LookAndFeel.java
index 2088aac..2ac5d74 100644
--- a/enigma-swing/src/main/java/cuchaz/enigma/gui/config/LookAndFeel.java
+++ b/enigma-swing/src/main/java/cuchaz/enigma/gui/config/LookAndFeel.java
@@ -22,6 +22,7 @@ public enum LookAndFeel {
         // the "JVM default" look and feel, get it at the beginning and store it so we can set it later
         private static final javax.swing.LookAndFeel NONE_LAF = UIManager.getLookAndFeel();
         private final boolean needsScaling;
+        private static Boolean isDarkLaf = null;
 
         LookAndFeel(boolean needsScaling) {
                 this.needsScaling = needsScaling;
@@ -52,6 +53,10 @@ public enum LookAndFeel {
         }
 
         public static boolean isDarkLaf() {
+                if (isDarkLaf != null) {
+                        return isDarkLaf;
+                }
+
                 // a bit of a hack because swing doesn't give any API for that, and we need colors that aren't defined in look and feel
                 JPanel panel = new JPanel();
                 panel.setSize(new Dimension(10, 10));
@@ -64,6 +69,6 @@ public enum LookAndFeel {
 
                 // convert the color we got to grayscale
                 int b = (int) (0.3 * c.getRed() + 0.59 * c.getGreen() + 0.11 * c.getBlue());
-                return b < 85;
+                return isDarkLaf = b < 85;
         }
 }
diff --git a/enigma-swing/src/main/java/cuchaz/enigma/gui/elements/GutterIcon.java b/enigma-swing/src/main/java/cuchaz/enigma/gui/elements/GutterIcon.java
new file mode 100644
index 0000000..946591a
--- /dev/null
+++ b/enigma-swing/src/main/java/cuchaz/enigma/gui/elements/GutterIcon.java
@@ -0,0 +1,42 @@
+package cuchaz.enigma.gui.elements;
+
+import java.awt.Cursor;
+import java.awt.event.ComponentAdapter;
+import java.awt.event.ComponentEvent;
+
+import javax.swing.JButton;
+
+import cuchaz.enigma.api.service.GuiService;
+import cuchaz.enigma.gui.util.EnigmaIconImpl;
+import cuchaz.enigma.gui.util.ScaleUtil;
+
+public class GutterIcon extends JButton implements GuiService.GutterMarkerBuilder {
+        private Runnable clickAction = () -> { };
+
+        public GutterIcon(EnigmaIconImpl icon) {
+                super(icon.icon());
+                setContentAreaFilled(false);
+                setCursor(Cursor.getDefaultCursor());
+                addActionListener(e -> clickAction.run());
+
+                addComponentListener(new ComponentAdapter() {
+                        @Override
+                        public void componentResized(ComponentEvent e) {
+                                setIcon(icon.icon().derive(ScaleUtil.invert(getWidth()), ScaleUtil.invert(getHeight())));
+                        }
+                });
+        }
+
+        @Override
+        public GuiService.GutterMarkerBuilder setClickAction(Runnable action) {
+                this.clickAction = action;
+                setCursor(Cursor.getPredefinedCursor(Cursor.HAND_CURSOR));
+                return this;
+        }
+
+        @Override
+        public GuiService.GutterMarkerBuilder setTooltip(String tooltip) {
+                setToolTipText(tooltip);
+                return this;
+        }
+}
diff --git a/enigma-swing/src/main/java/cuchaz/enigma/gui/panels/EditorPanel.java b/enigma-swing/src/main/java/cuchaz/enigma/gui/panels/EditorPanel.java
index 6b341ee..92d1bd7 100644
--- a/enigma-swing/src/main/java/cuchaz/enigma/gui/panels/EditorPanel.java
+++ b/enigma-swing/src/main/java/cuchaz/enigma/gui/panels/EditorPanel.java
@@ -15,6 +15,7 @@ import java.awt.event.MouseAdapter;
 import java.awt.event.MouseEvent;
 import java.util.ArrayList;
 import java.util.Collection;
+import java.util.Comparator;
 import java.util.List;
 import java.util.Map;
 
@@ -35,10 +36,12 @@ import javax.swing.text.Highlighter.HighlightPainter;
 
 import de.sciss.syntaxpane.DefaultSyntaxKit;
 import de.sciss.syntaxpane.SyntaxDocument;
+import de.sciss.syntaxpane.actions.ActionUtils;
 import org.jetbrains.annotations.Nullable;
 
 import cuchaz.enigma.EnigmaProject;
 import cuchaz.enigma.analysis.EntryReference;
+import cuchaz.enigma.api.service.GuiService;
 import cuchaz.enigma.classhandle.ClassHandle;
 import cuchaz.enigma.classhandle.ClassHandleError;
 import cuchaz.enigma.events.ClassHandleListener;
@@ -50,14 +53,17 @@ import cuchaz.enigma.gui.config.LookAndFeel;
 import cuchaz.enigma.gui.config.Themes;
 import cuchaz.enigma.gui.config.UiConfig;
 import cuchaz.enigma.gui.elements.EditorPopupMenu;
+import cuchaz.enigma.gui.elements.GutterIcon;
 import cuchaz.enigma.gui.events.EditorActionListener;
 import cuchaz.enigma.gui.events.ThemeChangeListener;
 import cuchaz.enigma.gui.highlight.BoxHighlightPainter;
 import cuchaz.enigma.gui.highlight.SelectionHighlightPainter;
+import cuchaz.enigma.gui.util.EnigmaIconImpl;
 import cuchaz.enigma.gui.util.GridBagConstraintsBuilder;
 import cuchaz.enigma.gui.util.ScaleUtil;
 import cuchaz.enigma.source.DecompiledClassSource;
 import cuchaz.enigma.source.RenamableTokenType;
+import cuchaz.enigma.source.SourceIndex;
 import cuchaz.enigma.source.Token;
 import cuchaz.enigma.translation.mapping.EntryRemapper;
 import cuchaz.enigma.translation.mapping.EntryResolver;
@@ -65,12 +71,14 @@ import cuchaz.enigma.translation.mapping.ResolutionStrategy;
 import cuchaz.enigma.translation.representation.entry.ClassEntry;
 import cuchaz.enigma.translation.representation.entry.Entry;
 import cuchaz.enigma.utils.I18n;
+import cuchaz.enigma.utils.Pair;
 import cuchaz.enigma.utils.Result;
 
 public class EditorPanel {
         private final JPanel ui = new JPanel();
         private final JEditorPane editor = new JEditorPane();
         private final JScrollPane editorScrollPane = new JScrollPane(this.editor);
+        private final GutterPanel gutterPanel;
         private final EditorPopupMenu popupMenu;
 
         // progress UI
@@ -109,20 +117,16 @@ public class EditorPanel {
                 this.gui = gui;
                 this.controller = gui.getController();
 
-                this.editor.setEditable(false);
-                this.editor.setSelectionColor(new Color(31, 46, 90));
-                this.editor.setCaret(new BrowserCaret());
+                customizeEditor(this.editor);
                 this.editor.addCaretListener(event -> onCaretMove(event.getDot(), this.mouseIsPressed));
-                this.editor.setCaretColor(UiConfig.getCaretColor());
-                this.editor.setContentType("text/enigma-sources");
-                this.editor.setBackground(UiConfig.getEditorBackgroundColor());
-                DefaultSyntaxKit kit = (DefaultSyntaxKit) this.editor.getEditorKit();
-                kit.toggleComponent(this.editor, "de.sciss.syntaxpane.components.TokenMarker");
 
                 // set unit increment to height of one line, the amount scrolled per
                 // mouse wheel rotation is then controlled by OS settings
                 this.editorScrollPane.getVerticalScrollBar().setUnitIncrement(this.editor.getFontMetrics(this.editor.getFont()).getHeight());
 
+                this.gutterPanel = new GutterPanel(this.editor, (JComponent) this.editorScrollPane.getRowHeader().getView());
+                this.editorScrollPane.setRowHeaderView(this.gutterPanel);
+
                 // init editor popup menu
                 this.popupMenu = new EditorPopupMenu(this, gui);
                 this.editor.setComponentPopupMenu(this.popupMenu.getUi());
@@ -255,6 +259,17 @@ public class EditorPanel {
                 this.ui.putClientProperty(EditorPanel.class, this);
         }
 
+        public static void customizeEditor(JEditorPane editor) {
+                editor.setEditable(false);
+                editor.setSelectionColor(new Color(31, 46, 90));
+                editor.setCaret(new BrowserCaret());
+                editor.setCaretColor(UiConfig.getCaretColor());
+                editor.setContentType("text/enigma-sources");
+                editor.setBackground(UiConfig.getEditorBackgroundColor());
+                DefaultSyntaxKit kit = (DefaultSyntaxKit) editor.getEditorKit();
+                kit.toggleComponent(editor, "de.sciss.syntaxpane.components.TokenMarker");
+        }
+
         @Nullable
         public static EditorPanel byUi(Component ui) {
                 if (ui instanceof JComponent) {
@@ -512,6 +527,7 @@ public class EditorPanel {
                                 this.editor.setCaretPosition(newCaretPos);
                         }
 
+                        addGutterMarkers(source.getIndex());
                         setHighlightedTokens(source.getHighlightedTokens());
                         setCursorReference(getReference(getToken(this.editor.getCaretPosition())));
                 } finally {
@@ -524,6 +540,44 @@ public class EditorPanel {
                 }
         }
 
+        private void addGutterMarkers(SourceIndex sourceIndex) {
+                List<GuiService> services = this.gui.getController().enigma.getServices().get(GuiService.TYPE);
+
+                if (services.isEmpty()) {
+                        return;
+                }
+
+                this.gutterPanel.clearMarkers();
+
+                List<Pair<Entry<?>, Token>> declarationTokens = new ArrayList<>();
+
+                for (Entry<?> declaration : sourceIndex.declarations()) {
+                        declarationTokens.add(new Pair<>(declaration, sourceIndex.getDeclarationToken(declaration)));
+                }
+
+                declarationTokens.sort(Comparator.comparing(pair -> pair.b));
+
+                for (Pair<Entry<?>, Token> declaration : declarationTokens) {
+                        int lineNumber;
+
+                        try {
+                                lineNumber = ActionUtils.getLineNumber(this.editor, declaration.b.start);
+                        } catch (BadLocationException e) {
+                                continue;
+                        }
+
+                        for (GuiService service : services) {
+                                service.addGutterMarkers(this.gui.getController(), declaration.a, (icon, alignment) -> {
+                                        GutterIcon button = new GutterIcon((EnigmaIconImpl) icon);
+                                        this.gutterPanel.addMarker(lineNumber, alignment, button);
+                                        return button;
+                                });
+                        }
+                }
+
+                this.editor.revalidate();
+        }
+
         public void setHighlightedTokens(Map<RenamableTokenType, ? extends Collection<Token>> tokens) {
                 // remove any old highlighters
                 this.editor.getHighlighter().removeAllHighlights();
@@ -565,10 +619,23 @@ public class EditorPanel {
                 }
         }
 
+        @Nullable
         public EntryReference<Entry<?>, Entry<?>> getCursorReference() {
                 return this.cursorReference;
         }
 
+        @Nullable
+        public Entry<?> getCursorDeclaration() {
+                int pos = this.editor.getCaretPosition();
+                Token token = getToken(pos);
+
+                if (token == null) {
+                        return null;
+                }
+
+                return this.source.getIndex().getDeclaration(token);
+        }
+
         public void showReference(EntryReference<Entry<?>, Entry<?>> reference) {
                 if (this.mode == DisplayMode.SUCCESS) {
                         showReference0(reference);
diff --git a/enigma-swing/src/main/java/cuchaz/enigma/gui/panels/GutterPanel.java b/enigma-swing/src/main/java/cuchaz/enigma/gui/panels/GutterPanel.java
new file mode 100644
index 0000000..28636a1
--- /dev/null
+++ b/enigma-swing/src/main/java/cuchaz/enigma/gui/panels/GutterPanel.java
@@ -0,0 +1,238 @@
+package cuchaz.enigma.gui.panels;
+
+import java.awt.Color;
+import java.awt.Component;
+import java.awt.Container;
+import java.awt.Dimension;
+import java.awt.FlowLayout;
+import java.awt.FontMetrics;
+import java.awt.Graphics;
+import java.awt.Insets;
+import java.awt.LayoutManager2;
+import java.beans.PropertyChangeEvent;
+import java.beans.PropertyChangeListener;
+import java.util.HashMap;
+import java.util.Map;
+
+import javax.swing.BorderFactory;
+import javax.swing.JComponent;
+import javax.swing.JEditorPane;
+import javax.swing.JPanel;
+import javax.swing.SwingUtilities;
+import javax.swing.event.CaretEvent;
+import javax.swing.event.CaretListener;
+import javax.swing.event.DocumentEvent;
+import javax.swing.event.DocumentListener;
+import javax.swing.text.BadLocationException;
+
+import de.sciss.syntaxpane.actions.ActionUtils;
+
+import cuchaz.enigma.api.service.GuiService;
+import cuchaz.enigma.gui.config.UiConfig;
+
+public class GutterPanel extends JPanel {
+        private final JPanel markerPanel;
+
+        public GutterPanel(JEditorPane editor, JComponent lineNumbers) {
+                markerPanel = new MarkerPanel(editor);
+
+                setLayout(new FlowLayout(FlowLayout.LEFT, 0, 0));
+                add(lineNumbers);
+                add(markerPanel);
+
+                setBackground(UiConfig.getLineNumbersBackgroundColor());
+                setForeground(UiConfig.getLineNumbersForegroundColor());
+                markerPanel.setBackground(UiConfig.getLineNumbersBackgroundColor());
+                markerPanel.setForeground(UiConfig.getLineNumbersForegroundColor());
+                setBorder(lineNumbers.getBorder());
+                lineNumbers.setBorder(null);
+        }
+
+        public void clearMarkers() {
+                markerPanel.removeAll();
+        }
+
+        public void addMarker(int line, GuiService.GutterMarkerAlignment alignment, Component marker) {
+                markerPanel.add(marker, new MarkerLayout.Constraint(line, alignment));
+        }
+
+        private static class MarkerPanel extends JPanel implements CaretListener, DocumentListener, PropertyChangeListener {
+                private final JEditorPane editor;
+                private final Color currentLineColor = UiConfig.getLineNumbersSelectedColor();
+
+                private MarkerPanel(JEditorPane editor) {
+                        this.editor = editor;
+                        setLayout(new MarkerLayout());
+
+                        Insets editorInsets = editor.getInsets();
+
+                        if (editorInsets.top != 0 || editorInsets.bottom != 0) {
+                                setBorder(BorderFactory.createEmptyBorder(editorInsets.top, 0, editorInsets.bottom, 0));
+                        }
+
+                        setFont(editor.getFont());
+
+                        editor.addCaretListener(this);
+                        editor.getDocument().addDocumentListener(this);
+                        editor.addPropertyChangeListener(this);
+                }
+
+                @Override
+                protected void paintComponent(Graphics g) {
+                        super.paintComponent(g);
+
+                        int currentLine;
+
+                        try {
+                                currentLine = ActionUtils.getLineNumber(editor, editor.getCaretPosition());
+                        } catch (BadLocationException ex) {
+                                return; // no valid caret -> nothing to draw
+                        }
+
+                        FontMetrics fm = getFontMetrics(getFont());
+                        int lh = fm.getHeight();
+                        Insets insets = getInsets();
+
+                        int y = currentLine * lh;
+
+                        g.setColor(currentLineColor);
+                        g.fillRect(0, y, getWidth(), lh);
+                }
+
+                @Override
+                public void propertyChange(PropertyChangeEvent evt) {
+                        if (evt.getPropertyName().equals("document")) {
+                                repaint();
+                        }
+                }
+
+                @Override
+                public void caretUpdate(CaretEvent e) {
+                        repaint();
+                }
+
+                @Override
+                public void insertUpdate(DocumentEvent e) {
+                        documentChanged();
+                }
+
+                @Override
+                public void removeUpdate(DocumentEvent e) {
+                        documentChanged();
+                }
+
+                @Override
+                public void changedUpdate(DocumentEvent e) {
+                        documentChanged();
+                }
+
+                private void documentChanged() {
+                        SwingUtilities.invokeLater(this::repaint);
+                }
+        }
+
+        private static class MarkerLayout implements LayoutManager2 {
+                private static final int GAP = 2;
+                private static final int HUGE_HEIGHT = 0x100000; // taken from LineNumbersRuler
+
+                private final Map<Component, Constraint> constraints = new HashMap<>();
+
+                @Override
+                public void addLayoutComponent(Component comp, Object constraints) {
+                        this.constraints.put(comp, (Constraint) constraints);
+                }
+
+                @Override
+                public Dimension maximumLayoutSize(Container target) {
+                        return preferredLayoutSize(target);
+                }
+
+                @Override
+                public float getLayoutAlignmentX(Container target) {
+                        return 0.5f;
+                }
+
+                @Override
+                public float getLayoutAlignmentY(Container target) {
+                        return 0.5f;
+                }
+
+                @Override
+                public void invalidateLayout(Container target) {
+                }
+
+                @Override
+                public void addLayoutComponent(String name, Component comp) {
+                }
+
+                @Override
+                public void removeLayoutComponent(Component comp) {
+                        constraints.remove(comp);
+                }
+
+                @Override
+                public Dimension preferredLayoutSize(Container parent) {
+                        synchronized (parent.getTreeLock()) {
+                                Insets insets = parent.getInsets();
+
+                                if (constraints.isEmpty()) {
+                                        return new Dimension(insets.left + insets.right, HUGE_HEIGHT);
+                                }
+
+                                Map<Integer, Integer> leftCount = new HashMap<>();
+                                Map<Integer, Integer> rightCount = new HashMap<>();
+
+                                for (Constraint constraint : constraints.values()) {
+                                        switch (constraint.alignment) {
+                                        case LEFT -> leftCount.merge(constraint.line, 1, Integer::sum);
+                                        case RIGHT -> rightCount.merge(constraint.line, 1, Integer::sum);
+                                        }
+                                }
+
+                                int maxLeft = leftCount.values().stream().mapToInt(Integer::intValue).max().orElse(0);
+                                int maxRight = rightCount.values().stream().mapToInt(Integer::intValue).max().orElse(0);
+
+                                int lineHeight = parent.getFontMetrics(parent.getFont()).getHeight();
+                                return new Dimension(
+                                                GAP + insets.left + insets.right + (maxLeft + maxRight) * lineHeight,
+                                                HUGE_HEIGHT
+                                );
+                        }
+                }
+
+                @Override
+                public Dimension minimumLayoutSize(Container parent) {
+                        return preferredLayoutSize(parent);
+                }
+
+                @Override
+                public void layoutContainer(Container parent) {
+                        synchronized (parent.getTreeLock()) {
+                                Map<Integer, Integer> leftCount = new HashMap<>();
+                                Map<Integer, Integer> rightCount = new HashMap<>();
+
+                                int lineHeight = parent.getFontMetrics(parent.getFont()).getHeight();
+
+                                int numComponents = parent.getComponentCount();
+
+                                for (int i = 0; i < numComponents; i++) {
+                                        Component comp = parent.getComponent(i);
+                                        Constraint constraint = constraints.get(comp);
+
+                                        if (constraint == null) {
+                                                continue;
+                                        }
+
+                                        int left = switch (constraint.alignment) {
+                                        case LEFT -> GAP + (leftCount.merge(constraint.line, 1, Integer::sum) - 1) * lineHeight + GAP / 2;
+                                        case RIGHT -> parent.getWidth() - rightCount.merge(constraint.line, 1, Integer::sum) * lineHeight + GAP / 2;
+                                        };
+                                        comp.setBounds(left, constraint.line * lineHeight + GAP / 2, lineHeight - GAP, lineHeight - GAP);
+                                }
+                        }
+                }
+
+                private record Constraint(int line, GuiService.GutterMarkerAlignment alignment) {
+                }
+        }
+}
diff --git a/enigma-swing/src/main/java/cuchaz/enigma/gui/util/EnigmaIconImpl.java b/enigma-swing/src/main/java/cuchaz/enigma/gui/util/EnigmaIconImpl.java
new file mode 100644
index 0000000..8e07df3
--- /dev/null
+++ b/enigma-swing/src/main/java/cuchaz/enigma/gui/util/EnigmaIconImpl.java
@@ -0,0 +1,8 @@
+package cuchaz.enigma.gui.util;
+
+import com.formdev.flatlaf.extras.FlatSVGIcon;
+
+import cuchaz.enigma.api.EnigmaIcon;
+
+public record EnigmaIconImpl(FlatSVGIcon icon) implements EnigmaIcon {
+}
diff --git a/enigma-swing/src/main/java/cuchaz/enigma/gui/util/IconLoadingServiceImpl.java b/enigma-swing/src/main/java/cuchaz/enigma/gui/util/IconLoadingServiceImpl.java
new file mode 100644
index 0000000..e948f5a
--- /dev/null
+++ b/enigma-swing/src/main/java/cuchaz/enigma/gui/util/IconLoadingServiceImpl.java
@@ -0,0 +1,16 @@
+package cuchaz.enigma.gui.util;
+
+import java.io.IOException;
+import java.io.InputStream;
+
+import com.formdev.flatlaf.extras.FlatSVGIcon;
+
+import cuchaz.enigma.api.EnigmaIcon;
+import cuchaz.enigma.utils.IconLoadingService;
+
+public class IconLoadingServiceImpl implements IconLoadingService {
+        @Override
+        public EnigmaIcon loadIcon(InputStream in) throws IOException {
+                return new EnigmaIconImpl(new FlatSVGIcon(in));
+        }
+}
diff --git a/enigma-swing/src/main/resources/META-INF/services/cuchaz.enigma.utils.IconLoadingService b/enigma-swing/src/main/resources/META-INF/services/cuchaz.enigma.utils.IconLoadingService
new file mode 100644
index 0000000..649dfd0
--- /dev/null
+++ b/enigma-swing/src/main/resources/META-INF/services/cuchaz.enigma.utils.IconLoadingService
@@ -0,0 +1 @@
+cuchaz.enigma.gui.util.IconLoadingServiceImpl
diff --git a/enigma/src/main/java/cuchaz/enigma/EnigmaProject.java b/enigma/src/main/java/cuchaz/enigma/EnigmaProject.java
index 348e640..5242385 100644
--- a/enigma/src/main/java/cuchaz/enigma/EnigmaProject.java
+++ b/enigma/src/main/java/cuchaz/enigma/EnigmaProject.java
@@ -410,6 +410,11 @@ public class EnigmaProject implements ProjectView {
         }
 
         @Override
+        public Collection<String> getProjectAndLibraryClasses() {
+                return classProvider.getClassNames();
+        }
+
+        @Override
         @Nullable
         public ClassNode getBytecode(String className) {
                 return classProvider.get(className);
diff --git a/enigma/src/main/java/cuchaz/enigma/analysis/index/BridgeMethodIndex.java b/enigma/src/main/java/cuchaz/enigma/analysis/index/BridgeMethodIndex.java
index adb48ba..b852b5f 100644
--- a/enigma/src/main/java/cuchaz/enigma/analysis/index/BridgeMethodIndex.java
+++ b/enigma/src/main/java/cuchaz/enigma/analysis/index/BridgeMethodIndex.java
@@ -10,6 +10,8 @@ import java.util.concurrent.ConcurrentMap;
 
 import org.jetbrains.annotations.Nullable;
 
+import cuchaz.enigma.api.view.entry.MethodEntryView;
+import cuchaz.enigma.api.view.index.BridgeMethodIndexView;
 import cuchaz.enigma.translation.representation.AccessFlags;
 import cuchaz.enigma.translation.representation.MethodDescriptor;
 import cuchaz.enigma.translation.representation.TypeDescriptor;
@@ -17,7 +19,7 @@ import cuchaz.enigma.translation.representation.entry.ClassEntry;
 import cuchaz.enigma.translation.representation.entry.MethodDefEntry;
 import cuchaz.enigma.translation.representation.entry.MethodEntry;
 
-public class BridgeMethodIndex implements JarIndexer {
+public class BridgeMethodIndex implements JarIndexer, BridgeMethodIndexView {
         private final EntryIndex entryIndex;
         private final InheritanceIndex inheritanceIndex;
         private final ReferenceIndex referenceIndex;
@@ -154,6 +156,18 @@ public class BridgeMethodIndex implements JarIndexer {
                 return bridgeToSpecialized.get(bridge);
         }
 
+        @Override
+        @Nullable
+        public MethodEntryView getBridgeFromSpecialized(MethodEntryView specialized) {
+                return getBridgeFromSpecialized((MethodEntry) specialized);
+        }
+
+        @Override
+        @Nullable
+        public MethodEntryView getSpecializedFromBridge(MethodEntryView bridge) {
+                return getSpecializedFromBridge((MethodEntry) bridge);
+        }
+
         /** Includes "renamed specialized -> bridge" entries. */
         public Map<MethodEntry, MethodEntry> getSpecializedToBridge() {
                 return Collections.unmodifiableMap(specializedToBridge);
diff --git a/enigma/src/main/java/cuchaz/enigma/analysis/index/JarIndex.java b/enigma/src/main/java/cuchaz/enigma/analysis/index/JarIndex.java
index 5c5e2c3..242d750 100644
--- a/enigma/src/main/java/cuchaz/enigma/analysis/index/JarIndex.java
+++ b/enigma/src/main/java/cuchaz/enigma/analysis/index/JarIndex.java
@@ -204,6 +204,7 @@ public class JarIndex implements JarIndexer, JarIndexView {
                 return referenceIndex;
         }
 
+        @Override
         public BridgeMethodIndex getBridgeMethodIndex() {
                 return bridgeMethodIndex;
         }
diff --git a/enigma/src/main/java/cuchaz/enigma/api/DataInvalidationEvent.java b/enigma/src/main/java/cuchaz/enigma/api/DataInvalidationEvent.java
index 812ad39..9396eff 100644
--- a/enigma/src/main/java/cuchaz/enigma/api/DataInvalidationEvent.java
+++ b/enigma/src/main/java/cuchaz/enigma/api/DataInvalidationEvent.java
@@ -2,8 +2,10 @@ package cuchaz.enigma.api;
 
 import java.util.Collection;
 
+import org.jetbrains.annotations.ApiStatus;
 import org.jetbrains.annotations.Nullable;
 
+@ApiStatus.NonExtendable
 public interface DataInvalidationEvent {
         /**
          * The classes for which the invalidation applies, or {@code null} if the invalidation applies to all classes.
diff --git a/enigma/src/main/java/cuchaz/enigma/api/EnigmaIcon.java b/enigma/src/main/java/cuchaz/enigma/api/EnigmaIcon.java
new file mode 100644
index 0000000..4a4bd0e
--- /dev/null
+++ b/enigma/src/main/java/cuchaz/enigma/api/EnigmaIcon.java
@@ -0,0 +1,39 @@
+package cuchaz.enigma.api;
+
+import java.io.IOException;
+import java.io.InputStream;
+
+import org.jetbrains.annotations.ApiStatus;
+
+import cuchaz.enigma.utils.IconLoadingService;
+
+@ApiStatus.NonExtendable
+public interface EnigmaIcon {
+        /**
+         * Loads an icon resource from the given SVG resource path.
+         *
+         * @param resource the path to the resource to be loaded
+         * @return The loaded icon
+         * @throws IOException if the resource could not be found or an error occurred while reading it
+         */
+        static EnigmaIcon loadResource(String resource) throws IOException {
+                try (InputStream in = Thread.currentThread().getContextClassLoader().getResourceAsStream(resource)) {
+                        if (in == null) {
+                                throw new IOException("Could not find resource: " + resource);
+                        }
+
+                        return load(in);
+                }
+        }
+
+        /**
+         * Loads an icon in SVG format from the given input stream.
+         *
+         * @param in the input stream to load from
+         * @return The loaded icon
+         * @throws IOException if the stream throws an error
+         */
+        static EnigmaIcon load(InputStream in) throws IOException {
+                return IconLoadingService.INSTANCE.loadIcon(in);
+        }
+}
diff --git a/enigma/src/main/java/cuchaz/enigma/api/service/GuiService.java b/enigma/src/main/java/cuchaz/enigma/api/service/GuiService.java
index b00b94d..53b566f 100644
--- a/enigma/src/main/java/cuchaz/enigma/api/service/GuiService.java
+++ b/enigma/src/main/java/cuchaz/enigma/api/service/GuiService.java
@@ -5,7 +5,9 @@ import java.util.function.Supplier;
 
 import javax.swing.KeyStroke;
 
+import cuchaz.enigma.api.EnigmaIcon;
 import cuchaz.enigma.api.view.GuiView;
+import cuchaz.enigma.api.view.entry.EntryView;
 
 public interface GuiService extends EnigmaService {
         EnigmaServiceType<GuiService> TYPE = EnigmaServiceType.create("gui");
@@ -16,6 +18,9 @@ public interface GuiService extends EnigmaService {
         default void addToEditorContextMenu(GuiView gui, MenuRegistrar registrar) {
         }
 
+        default void addGutterMarkers(GuiView gui, EntryView entry, GutterMarkerAdder gutter) {
+        }
+
         interface MenuRegistrar {
                 void addSeparator();
 
@@ -31,4 +36,17 @@ public interface GuiService extends EnigmaService {
                 MenuItemBuilder setEnabledWhen(BooleanSupplier condition);
                 MenuItemBuilder setAction(Runnable action);
         }
+
+        interface GutterMarkerAdder {
+                GutterMarkerBuilder addMarker(EnigmaIcon icon, GutterMarkerAlignment alignment);
+        }
+
+        interface GutterMarkerBuilder {
+                GutterMarkerBuilder setClickAction(Runnable action);
+                GutterMarkerBuilder setTooltip(String tooltip);
+        }
+
+        enum GutterMarkerAlignment {
+                LEFT, RIGHT
+        }
 }
diff --git a/enigma/src/main/java/cuchaz/enigma/api/view/GuiView.java b/enigma/src/main/java/cuchaz/enigma/api/view/GuiView.java
index 519a8ce..1d91573 100644
--- a/enigma/src/main/java/cuchaz/enigma/api/view/GuiView.java
+++ b/enigma/src/main/java/cuchaz/enigma/api/view/GuiView.java
@@ -1,11 +1,15 @@
 package cuchaz.enigma.api.view;
 
+import javax.swing.JEditorPane;
 import javax.swing.JFrame;
 
+import org.jetbrains.annotations.ApiStatus;
 import org.jetbrains.annotations.Nullable;
 
 import cuchaz.enigma.api.view.entry.EntryReferenceView;
+import cuchaz.enigma.api.view.entry.EntryView;
 
+@ApiStatus.NonExtendable
 public interface GuiView {
         @Nullable
         ProjectView getProject();
@@ -13,5 +17,14 @@ public interface GuiView {
         @Nullable
         EntryReferenceView getCursorReference();
 
+        @Nullable
+        EntryView getCursorDeclaration();
+
         JFrame getFrame();
+
+        float getScale();
+
+        boolean isDarkTheme();
+
+        JEditorPane createEditorPane();
 }
diff --git a/enigma/src/main/java/cuchaz/enigma/api/view/ProjectView.java b/enigma/src/main/java/cuchaz/enigma/api/view/ProjectView.java
index b72e1c3..c8cb384 100644
--- a/enigma/src/main/java/cuchaz/enigma/api/view/ProjectView.java
+++ b/enigma/src/main/java/cuchaz/enigma/api/view/ProjectView.java
@@ -3,6 +3,7 @@ package cuchaz.enigma.api.view;
 import java.util.Collection;
 import java.util.List;
 
+import org.jetbrains.annotations.ApiStatus;
 import org.jetbrains.annotations.Nullable;
 import org.objectweb.asm.tree.ClassNode;
 
@@ -11,6 +12,7 @@ import cuchaz.enigma.api.DataInvalidationListener;
 import cuchaz.enigma.api.view.entry.EntryView;
 import cuchaz.enigma.api.view.index.JarIndexView;
 
+@ApiStatus.NonExtendable
 public interface ProjectView {
         <T extends EntryView> T deobfuscate(T entry);
 
@@ -25,6 +27,8 @@ public interface ProjectView {
 
         Collection<String> getProjectClasses();
 
+        Collection<String> getProjectAndLibraryClasses();
+
         @Nullable
         ClassNode getBytecode(String className);
 
diff --git a/enigma/src/main/java/cuchaz/enigma/api/view/entry/ClassDefEntryView.java b/enigma/src/main/java/cuchaz/enigma/api/view/entry/ClassDefEntryView.java
index 7cb1829..1fb6a7f 100644
--- a/enigma/src/main/java/cuchaz/enigma/api/view/entry/ClassDefEntryView.java
+++ b/enigma/src/main/java/cuchaz/enigma/api/view/entry/ClassDefEntryView.java
@@ -1,7 +1,9 @@
 package cuchaz.enigma.api.view.entry;
 
+import org.jetbrains.annotations.ApiStatus;
 import org.jetbrains.annotations.Nullable;
 
+@ApiStatus.NonExtendable
 public interface ClassDefEntryView extends ClassEntryView, DefEntryView {
         @Nullable
         ClassEntryView getSuperClass();
diff --git a/enigma/src/main/java/cuchaz/enigma/api/view/entry/ClassEntryView.java b/enigma/src/main/java/cuchaz/enigma/api/view/entry/ClassEntryView.java
index 085188b..330920b 100644
--- a/enigma/src/main/java/cuchaz/enigma/api/view/entry/ClassEntryView.java
+++ b/enigma/src/main/java/cuchaz/enigma/api/view/entry/ClassEntryView.java
@@ -1,7 +1,10 @@
 package cuchaz.enigma.api.view.entry;
 
+import org.jetbrains.annotations.ApiStatus;
+
 import cuchaz.enigma.translation.representation.entry.ClassEntry;
 
+@ApiStatus.NonExtendable
 public interface ClassEntryView extends EntryView {
         ClassEntryView getParent();
 
diff --git a/enigma/src/main/java/cuchaz/enigma/api/view/entry/DefEntryView.java b/enigma/src/main/java/cuchaz/enigma/api/view/entry/DefEntryView.java
index bf246fb..a52e685 100644
--- a/enigma/src/main/java/cuchaz/enigma/api/view/entry/DefEntryView.java
+++ b/enigma/src/main/java/cuchaz/enigma/api/view/entry/DefEntryView.java
@@ -1,5 +1,8 @@
 package cuchaz.enigma.api.view.entry;
 
+import org.jetbrains.annotations.ApiStatus;
+
+@ApiStatus.NonExtendable
 public interface DefEntryView {
         int getAccessFlags();
 }
diff --git a/enigma/src/main/java/cuchaz/enigma/api/view/entry/EntryReferenceView.java b/enigma/src/main/java/cuchaz/enigma/api/view/entry/EntryReferenceView.java
index d49aa1e..6ca87ab 100644
--- a/enigma/src/main/java/cuchaz/enigma/api/view/entry/EntryReferenceView.java
+++ b/enigma/src/main/java/cuchaz/enigma/api/view/entry/EntryReferenceView.java
@@ -1,5 +1,8 @@
 package cuchaz.enigma.api.view.entry;
 
+import org.jetbrains.annotations.ApiStatus;
+
+@ApiStatus.NonExtendable
 public interface EntryReferenceView {
         EntryView getEntry();
 }
diff --git a/enigma/src/main/java/cuchaz/enigma/api/view/entry/EntryView.java b/enigma/src/main/java/cuchaz/enigma/api/view/entry/EntryView.java
index 2dad562..963c1e7 100644
--- a/enigma/src/main/java/cuchaz/enigma/api/view/entry/EntryView.java
+++ b/enigma/src/main/java/cuchaz/enigma/api/view/entry/EntryView.java
@@ -1,7 +1,9 @@
 package cuchaz.enigma.api.view.entry;
 
+import org.jetbrains.annotations.ApiStatus;
 import org.jetbrains.annotations.Nullable;
 
+@ApiStatus.NonExtendable
 public interface EntryView {
         /**
          * Returns the default name of this entry.
diff --git a/enigma/src/main/java/cuchaz/enigma/api/view/entry/FieldEntryView.java b/enigma/src/main/java/cuchaz/enigma/api/view/entry/FieldEntryView.java
index ae44458..bf22814 100644
--- a/enigma/src/main/java/cuchaz/enigma/api/view/entry/FieldEntryView.java
+++ b/enigma/src/main/java/cuchaz/enigma/api/view/entry/FieldEntryView.java
@@ -1,9 +1,12 @@
 package cuchaz.enigma.api.view.entry;
 
+import org.jetbrains.annotations.ApiStatus;
+
 import cuchaz.enigma.translation.representation.TypeDescriptor;
 import cuchaz.enigma.translation.representation.entry.ClassEntry;
 import cuchaz.enigma.translation.representation.entry.FieldEntry;
 
+@ApiStatus.NonExtendable
 public interface FieldEntryView extends EntryView {
         String getDescriptor();
 
diff --git a/enigma/src/main/java/cuchaz/enigma/api/view/entry/LocalVariableDefEntryView.java b/enigma/src/main/java/cuchaz/enigma/api/view/entry/LocalVariableDefEntryView.java
index d091560..32e0af3 100644
--- a/enigma/src/main/java/cuchaz/enigma/api/view/entry/LocalVariableDefEntryView.java
+++ b/enigma/src/main/java/cuchaz/enigma/api/view/entry/LocalVariableDefEntryView.java
@@ -1,5 +1,8 @@
 package cuchaz.enigma.api.view.entry;
 
+import org.jetbrains.annotations.ApiStatus;
+
+@ApiStatus.NonExtendable
 public interface LocalVariableDefEntryView extends LocalVariableEntryView {
         String getDescriptor();
 }
diff --git a/enigma/src/main/java/cuchaz/enigma/api/view/entry/LocalVariableEntryView.java b/enigma/src/main/java/cuchaz/enigma/api/view/entry/LocalVariableEntryView.java
index 391bc0f..b4728b5 100644
--- a/enigma/src/main/java/cuchaz/enigma/api/view/entry/LocalVariableEntryView.java
+++ b/enigma/src/main/java/cuchaz/enigma/api/view/entry/LocalVariableEntryView.java
@@ -1,9 +1,19 @@
 package cuchaz.enigma.api.view.entry;
 
+import org.jetbrains.annotations.ApiStatus;
+
+import cuchaz.enigma.translation.representation.entry.LocalVariableEntry;
+import cuchaz.enigma.translation.representation.entry.MethodEntry;
+
+@ApiStatus.NonExtendable
 public interface LocalVariableEntryView extends EntryView {
         int getIndex();
 
         boolean isArgument();
 
         MethodEntryView getParent();
+
+        static LocalVariableEntryView create(MethodEntryView parent, int index, String name, boolean argument) {
+                return new LocalVariableEntry((MethodEntry) parent, index, name, argument, null);
+        }
 }
diff --git a/enigma/src/main/java/cuchaz/enigma/api/view/entry/MethodEntryView.java b/enigma/src/main/java/cuchaz/enigma/api/view/entry/MethodEntryView.java
index 7d7fcd2..3020afa 100644
--- a/enigma/src/main/java/cuchaz/enigma/api/view/entry/MethodEntryView.java
+++ b/enigma/src/main/java/cuchaz/enigma/api/view/entry/MethodEntryView.java
@@ -1,9 +1,12 @@
 package cuchaz.enigma.api.view.entry;
 
+import org.jetbrains.annotations.ApiStatus;
+
 import cuchaz.enigma.translation.representation.MethodDescriptor;
 import cuchaz.enigma.translation.representation.entry.ClassEntry;
 import cuchaz.enigma.translation.representation.entry.MethodEntry;
 
+@ApiStatus.NonExtendable
 public interface MethodEntryView extends EntryView {
         String getDescriptor();
 
diff --git a/enigma/src/main/java/cuchaz/enigma/api/view/index/BridgeMethodIndexView.java b/enigma/src/main/java/cuchaz/enigma/api/view/index/BridgeMethodIndexView.java
new file mode 100644
index 0000000..c07be88
--- /dev/null
+++ b/enigma/src/main/java/cuchaz/enigma/api/view/index/BridgeMethodIndexView.java
@@ -0,0 +1,15 @@
+package cuchaz.enigma.api.view.index;
+
+import org.jetbrains.annotations.ApiStatus;
+import org.jetbrains.annotations.Nullable;
+
+import cuchaz.enigma.api.view.entry.MethodEntryView;
+
+@ApiStatus.NonExtendable
+public interface BridgeMethodIndexView {
+        @Nullable
+        MethodEntryView getBridgeFromSpecialized(MethodEntryView specialized);
+
+        @Nullable
+        MethodEntryView getSpecializedFromBridge(MethodEntryView bridge);
+}
diff --git a/enigma/src/main/java/cuchaz/enigma/api/view/index/EntryIndexView.java b/enigma/src/main/java/cuchaz/enigma/api/view/index/EntryIndexView.java
index 56bf70e..9b4fbaf 100644
--- a/enigma/src/main/java/cuchaz/enigma/api/view/index/EntryIndexView.java
+++ b/enigma/src/main/java/cuchaz/enigma/api/view/index/EntryIndexView.java
@@ -2,10 +2,13 @@ package cuchaz.enigma.api.view.index;
 
 import java.util.Collection;
 
+import org.jetbrains.annotations.ApiStatus;
+
 import cuchaz.enigma.api.view.entry.ClassDefEntryView;
 import cuchaz.enigma.api.view.entry.ClassEntryView;
 import cuchaz.enigma.api.view.entry.EntryView;
 
+@ApiStatus.NonExtendable
 public interface EntryIndexView {
         boolean hasEntry(EntryView entry);
         int getAccess(EntryView entry);
diff --git a/enigma/src/main/java/cuchaz/enigma/api/view/index/InheritanceIndexView.java b/enigma/src/main/java/cuchaz/enigma/api/view/index/InheritanceIndexView.java
index a016d11..a156155 100644
--- a/enigma/src/main/java/cuchaz/enigma/api/view/index/InheritanceIndexView.java
+++ b/enigma/src/main/java/cuchaz/enigma/api/view/index/InheritanceIndexView.java
@@ -2,8 +2,11 @@ package cuchaz.enigma.api.view.index;
 
 import java.util.Collection;
 
+import org.jetbrains.annotations.ApiStatus;
+
 import cuchaz.enigma.api.view.entry.ClassEntryView;
 
+@ApiStatus.NonExtendable
 public interface InheritanceIndexView {
         Collection<? extends ClassEntryView> getParents(ClassEntryView entry);
         Collection<? extends ClassEntryView> getChildren(ClassEntryView entry);
diff --git a/enigma/src/main/java/cuchaz/enigma/api/view/index/JarIndexView.java b/enigma/src/main/java/cuchaz/enigma/api/view/index/JarIndexView.java
index 069b115..b723267 100644
--- a/enigma/src/main/java/cuchaz/enigma/api/view/index/JarIndexView.java
+++ b/enigma/src/main/java/cuchaz/enigma/api/view/index/JarIndexView.java
@@ -1,7 +1,11 @@
 package cuchaz.enigma.api.view.index;
 
+import org.jetbrains.annotations.ApiStatus;
+
+@ApiStatus.NonExtendable
 public interface JarIndexView {
         EntryIndexView getEntryIndex();
         InheritanceIndexView getInheritanceIndex();
         ReferenceIndexView getReferenceIndex();
+        BridgeMethodIndexView getBridgeMethodIndex();
 }
diff --git a/enigma/src/main/java/cuchaz/enigma/api/view/index/ReferenceIndexView.java b/enigma/src/main/java/cuchaz/enigma/api/view/index/ReferenceIndexView.java
index 00ab84e..7c0653f 100644
--- a/enigma/src/main/java/cuchaz/enigma/api/view/index/ReferenceIndexView.java
+++ b/enigma/src/main/java/cuchaz/enigma/api/view/index/ReferenceIndexView.java
@@ -2,11 +2,14 @@ package cuchaz.enigma.api.view.index;
 
 import java.util.Collection;
 
+import org.jetbrains.annotations.ApiStatus;
+
 import cuchaz.enigma.api.view.entry.ClassEntryView;
 import cuchaz.enigma.api.view.entry.EntryReferenceView;
 import cuchaz.enigma.api.view.entry.FieldEntryView;
 import cuchaz.enigma.api.view.entry.MethodEntryView;
 
+@ApiStatus.NonExtendable
 public interface ReferenceIndexView {
         Collection<? extends MethodEntryView> getMethodsReferencedBy(MethodEntryView entry);
         Collection<? extends EntryReferenceView> getReferencesToClass(ClassEntryView entry);
diff --git a/enigma/src/main/java/cuchaz/enigma/source/SourceIndex.java b/enigma/src/main/java/cuchaz/enigma/source/SourceIndex.java
index fec20e2..51636e3 100644
--- a/enigma/src/main/java/cuchaz/enigma/source/SourceIndex.java
+++ b/enigma/src/main/java/cuchaz/enigma/source/SourceIndex.java
@@ -7,6 +7,8 @@ import java.util.List;
 import java.util.Map;
 import java.util.TreeMap;
 
+import org.jetbrains.annotations.Nullable;
+
 import cuchaz.enigma.analysis.EntryReference;
 import cuchaz.enigma.translation.mapping.EntryResolver;
 import cuchaz.enigma.translation.mapping.ResolutionStrategy;
@@ -17,11 +19,13 @@ public class SourceIndex {
         private List<Integer> lineOffsets;
         private final TreeMap<Token, EntryReference<Entry<?>, Entry<?>>> tokenToReference;
         private final Map<EntryReference<Entry<?>, Entry<?>>, Collection<Token>> referenceToTokens;
+        private final TreeMap<Token, Entry<?>> tokenToDeclaration;
         private final Map<Entry<?>, Token> declarationToToken;
 
         public SourceIndex() {
                 tokenToReference = new TreeMap<>();
                 referenceToTokens = new HashMap<>();
+                tokenToDeclaration = new TreeMap<>();
                 declarationToToken = new HashMap<>();
         }
 
@@ -80,6 +84,11 @@ public class SourceIndex {
                 return declarationToToken.get(entry);
         }
 
+        @Nullable
+        public Entry<?> getDeclaration(Token token) {
+                return tokenToDeclaration.get(token);
+        }
+
         public void addDeclaration(Token token, Entry<?> deobfEntry) {
                 if (token != null) {
                         EntryReference<Entry<?>, Entry<?>> reference = new EntryReference<>(deobfEntry, token.text);
@@ -88,6 +97,7 @@ public class SourceIndex {
                                         .add(token);
                         referenceToTokens.computeIfAbsent(EntryReference.declaration(deobfEntry, token.text), key -> new ArrayList<>())
                                         .add(token);
+                        tokenToDeclaration.put(token, deobfEntry);
                         declarationToToken.put(deobfEntry, token);
                 }
         }
@@ -108,6 +118,7 @@ public class SourceIndex {
                 return tokenToReference.keySet();
         }
 
+        @Nullable
         public Token getReferenceToken(int pos) {
                 Token token = tokenToReference.floorKey(new Token(pos, pos, null));
 
@@ -153,7 +164,9 @@ public class SourceIndex {
                 SourceIndex remapped = new SourceIndex(result.getSource());
 
                 for (Map.Entry<Entry<?>, Token> entry : declarationToToken.entrySet()) {
-                        remapped.declarationToToken.put(entry.getKey(), result.getRemappedToken(entry.getValue()));
+                        Token remappedToken = result.getRemappedToken(entry.getValue());
+                        remapped.declarationToToken.put(entry.getKey(), remappedToken);
+                        remapped.tokenToDeclaration.put(remappedToken, entry.getKey());
                 }
 
                 for (Map.Entry<EntryReference<Entry<?>, Entry<?>>, Collection<Token>> entry : referenceToTokens.entrySet()) {
diff --git a/enigma/src/main/java/cuchaz/enigma/utils/IconLoadingService.java b/enigma/src/main/java/cuchaz/enigma/utils/IconLoadingService.java
new file mode 100644
index 0000000..0e66fba
--- /dev/null
+++ b/enigma/src/main/java/cuchaz/enigma/utils/IconLoadingService.java
@@ -0,0 +1,14 @@
+package cuchaz.enigma.utils;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.ServiceLoader;
+
+import cuchaz.enigma.api.EnigmaIcon;
+
+public interface IconLoadingService {
+        IconLoadingService INSTANCE = ServiceLoader.load(IconLoadingService.class).findFirst()
+                        .orElseThrow(() -> new IllegalStateException("Trying to load icon on headless Enigma"));
+
+        EnigmaIcon loadIcon(InputStream in) throws IOException;
+}