feat(gui): save tree expansions in project (PR #605)

jadx-core/src/main/java/jadx/api/JavaClass.java

@@ -68,7 +68,7 @@ public synchronized void unload() {
 		cls.unload();
 	}
 
-	ClassNode getClassNode() {
+	public ClassNode getClassNode() {
 		return cls;
 	}
 

jadx-gui/src/main/java/jadx/gui/settings/JadxProject.java

@@ -3,7 +3,9 @@
 import java.io.BufferedWriter;
 import java.nio.file.Files;
 import java.nio.file.Path;
+import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Iterator;
 import java.util.List;
 
 import org.slf4j.Logger;
@@ -29,6 +31,8 @@ public class JadxProject {
 	private transient String name = "New Project";
 	private transient Path projectPath;
 	private List<Path> filesPath;
+	private List<String[]> treeExpansions = new ArrayList<>();
+
 	private transient boolean saved;
 	private transient boolean initial = true;
 
@@ -63,6 +67,24 @@ public void setFilePath(Path filePath) {
 		}
 	}
 
+	public List<String[]> getTreeExpansions() {
+		return treeExpansions;
+	}
+
+	public void addTreeExpansion(String[] expansion) {
+		treeExpansions.add(expansion);
+		changed();
+	}
+
+	public void removeTreeExpansion(String[] expansion) {
+		for (Iterator<String[]> it = treeExpansions.iterator(); it.hasNext(); ) {
+			if (Arrays.equals(it.next(), expansion)) {
+				it.remove();
+			}
+		}
+		changed();
+	}
+
 	private void changed() {
 		if (settings.isAutoSaveProject()) {
 			save();

jadx-gui/src/main/java/jadx/gui/ui/MainWindow.java

@@ -23,7 +23,9 @@
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.Paths;
+import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.List;
 import java.util.Locale;
 import java.util.Timer;
 import java.util.TimerTask;
@@ -130,6 +132,7 @@ public class MainWindow extends JFrame {
 	private JRoot treeRoot;
 	private TabbedPane tabbedPane;
 	private HeapUsageBar heapUsageBar;
+	private transient boolean treeReloading;
 
 	private boolean isFlattenPackage;
 	private JToggleButton flatPkgButton;
@@ -431,8 +434,34 @@ private void initTree() {
 	}
 
 	private void reloadTree() {
+		treeReloading = true;
+
 		treeModel.reload();
-		tree.expandRow(1);
+		List<String[]> treeExpansions = project.getTreeExpansions();
+		if (!treeExpansions.isEmpty()) {
+			expand(treeRoot, treeExpansions);
+		} else {
+			tree.expandRow(1);
+		}
+
+		treeReloading = false;
+	}
+
+	private void expand(TreeNode node, List<String[]> treeExpansions) {
+		TreeNode[] pathNodes = treeModel.getPathToRoot(node);
+		if (pathNodes == null) {
+			return;
+		}
+		TreePath path = new TreePath(pathNodes);
+		for (String[] expansion : treeExpansions) {
+			if (Arrays.equals(expansion, getPathExpansion(path))) {
+				tree.expandPath(path);
+				break;
+			}
+		}
+		for (int i = node.getChildCount() - 1; i >= 0; i--) {
+			expand(node.getChildAt(i), treeExpansions);
+		}
 	}
 
 	private void toggleFlattenPackage() {
@@ -824,11 +853,18 @@ public void treeWillExpand(TreeExpansionEvent event) {
 				if (node instanceof JLoadableNode) {
 					((JLoadableNode) node).loadNode();
 				}
+				if (!treeReloading) {
+					project.addTreeExpansion(getPathExpansion(event.getPath()));
+					update();
+				}
 			}
 
 			@Override
 			public void treeWillCollapse(TreeExpansionEvent event) {
-				// ignore
+				if (!treeReloading) {
+					project.removeTreeExpansion(getPathExpansion(event.getPath()));
+					update();
+				}
 			}
 		});
 
@@ -851,6 +887,36 @@ public void treeWillCollapse(TreeExpansionEvent event) {
 		setTitle(DEFAULT_TITLE);
 	}
 
+	private static String[] getPathExpansion(TreePath path) {
+		List<String> pathList = new ArrayList<>();
+		while (path != null) {
+			Object node = path.getLastPathComponent();
+			String name;
+			if (node instanceof JClass) {
+				name = ((JClass) node).getCls().getClassNode().getClassInfo().getFullName();
+			}
+			else {
+				name = node.toString();
+			}
+			pathList.add(name);
+			path = path.getParentPath();
+		}
+		return pathList.toArray(new String[pathList.size()]);
+	}
+
+	public static void getExpandedPaths(JTree tree, TreePath path, List<TreePath> list) {
+		if (tree.isExpanded(path)) {
+			list.add(path);
+
+			TreeNode node = (TreeNode) path.getLastPathComponent();
+			for (int i = node.getChildCount() - 1; i >= 0; i--) {
+				TreeNode n = node.getChildAt(i);
+				TreePath child = path.pathByAddingChild(n);
+				getExpandedPaths(tree, child, list);
+			}
+		}
+	}
+
 	public void setLocationAndPosition() {
 		if (this.settings.loadWindowPos(this)) {
 			return;

jadx-gui/src/main/java/jadx/gui/utils/PathTypeAdapter.java

@@ -9,7 +9,7 @@
 import com.google.gson.stream.JsonToken;
 import com.google.gson.stream.JsonWriter;
 
-public class PathTypeAdapter  {
+public class PathTypeAdapter {
 
 	private static TypeAdapter<Path> SINGLETON;