fix(gui): fix variable usage & caret position after rename (#1099) (PR #1103)

Co-authored-by: tobias <tobias.hotmail.com>

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

@@ -448,7 +448,7 @@ public final class JadxDecompiler implements Closeable {
 		}
 		if (obj instanceof VariableNode) {
 			VariableNode varNode = (VariableNode) obj;
-			return new JavaVariable(getJavaClassByNode(varNode.getClassNode()), varNode);
+			return new JavaVariable(getJavaClassByNode(varNode.getClassNode().getTopParentClass()), varNode);
 		}
 		throw new JadxRuntimeException("Unexpected node type: " + obj);
 	}

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

@@ -55,6 +55,9 @@ public class JavaVariable implements JavaNode {
 
 	@Override
 	public boolean equals(Object obj) {
-		return node.equals(obj);
+		if (obj instanceof JavaVariable) {
+			return node.equals(((JavaVariable) obj).getVariableNode());
+		}
+		return false;
 	}
 }

jadx-core/src/main/java/jadx/core/codegen/InsnGen.java

@@ -92,7 +92,6 @@ public class InsnGen {
 			if (codeVar != null) {
 				VariableNode node = mth.getVariable(codeVar.getIndex());
 				if (node != null) {
-					node.useVar(code, codeVar);
 					code.attachAnnotation(node);
 				}
 			}
@@ -653,7 +652,6 @@ public class InsnGen {
 		if (insn.isSuper()) {
 			code.add("super");
 		} else if (insn.isThis()) {
-			code.attachAnnotation(mth.getParentClass());
 			code.add("this");
 		} else {
 			code.add("new ");

jadx-core/src/main/java/jadx/core/dex/nodes/MethodNode.java

@@ -110,15 +110,6 @@ public class MethodNode extends NotificationAttrNode implements IMethodDetails,
 		return null;
 	}
 
-	public VariableNode getVariable(int index, VarKind varType) {
-		for (VariableNode variable : variables) {
-			if (variable.getVarKind() == varType && variable.getIndex() == index) {
-				return variable;
-			}
-		}
-		return null;
-	}
-
 	public VariableNode declareVar(VisibleVar var, NameGen nameGen, VarKind varKind) {
 		if (var instanceof CodeVar) {
 			if (((CodeVar) var).isThis()) {
@@ -127,14 +118,11 @@ public class MethodNode extends NotificationAttrNode implements IMethodDetails,
 		}
 		VariableNode varNode;
 		int index = var.getIndex();
-		if (index == -1) {
+		if (index > -1) {
+			varNode = getVariable(var.getIndex());
+		} else {
 			index = variables.size();
 			var.setIndex(index);
-			varNode = null;
-		} else {
-			varNode = getVariable(var.getIndex());
-		}
-		if (varNode == null) {
 			String name = mthInfo.getVariableName(VariableNode.makeVarIndex(index, varKind));
 			if (name != null) {
 				var.setName(name); // set name with user renamed previously.

jadx-core/src/main/java/jadx/core/dex/nodes/VariableNode.java

@@ -1,9 +1,7 @@
 package jadx.core.dex.nodes;
 
-import jadx.core.codegen.CodeWriter;
 import jadx.core.dex.attributes.nodes.LineAttrNode;
 import jadx.core.dex.instructions.args.ArgType;
-import jadx.core.dex.instructions.args.CodeVar;
 import jadx.core.utils.exceptions.JadxRuntimeException;
 
 public class VariableNode extends LineAttrNode {
@@ -56,17 +54,6 @@ public class VariableNode extends LineAttrNode {
 		return index;
 	}
 
-	public void addUsage(int line, int offset, int codeOffset) {
-	}
-
-	public void useVar(CodeWriter code, CodeVar codeVar) {
-		if (!codeVar.isThis()) { // TODO: add usage
-			// IdentifierVisitor.VariableNode node = codeVar.getVariableNode();
-			// node.addUsage(code.getLine(), code.getOffset(), code.bufLength());
-			// code.attachAnnotation(node);
-		}
-	}
-
 	public String getRenameKey() {
 		return mth.getMethodInfo().getRawFullId() + VAR_SEPARATOR + makeVarIndex(index, varKind);
 	}

jadx-gui/src/main/java/jadx/gui/ui/codearea/CodePanel.java

@@ -12,6 +12,9 @@ import javax.swing.JPopupMenu.Separator;
 import javax.swing.border.EmptyBorder;
 import javax.swing.event.PopupMenuEvent;
 import javax.swing.event.PopupMenuListener;
+import javax.swing.text.BadLocationException;
+
+import org.fife.ui.rsyntaxtextarea.Token;
 
 import jadx.api.ICodeInfo;
 import jadx.core.utils.StringUtils;
@@ -146,12 +149,67 @@ public class CodePanel extends JPanel {
 	}
 
 	public void refresh() {
-		JViewport viewport = getCodeScrollPane().getViewport();
-		Point viewPosition = viewport.getViewPosition();
+		int line;
+		int lineCount;
+		int tokenIndex;
+		int pos = codeArea.getCaretPosition();
+		try {
+			// after rename the change of document is undetectable, so
+			// use Token offset to calculate the new caret position.
+			line = codeArea.getLineOfOffset(pos);
+			Token token = codeArea.getTokenListForLine(line);
+			tokenIndex = getTokenIndexByOffset(token, pos);
+		} catch (BadLocationException e) {
+			e.printStackTrace();
+			tokenIndex = 0;
+			line = codeArea.getLineCount() - 1;
+		}
+		lineCount = codeArea.getLineCount();
 		codeArea.refresh();
 		initLineNumbers();
+		int lineDiff = codeArea.getLineCount() - lineCount;
+		if (lineDiff > 0) {
+			lineDiff--;
+		} else if (lineDiff < 0) {
+			lineDiff++;
+		}
+		Token token = codeArea.getTokenListForLine(line + lineDiff);
+		int newPos = getOffsetOfTokenByIndex(tokenIndex, token);
 		SwingUtilities.invokeLater(() -> {
-			viewport.setViewPosition(viewPosition);
+			if (newPos != -1) {
+				codeArea.scrollToPos(newPos);
+			} else {
+				codeArea.scrollToLine(codeArea.getLineCount() - 1);
+			}
 		});
 	}
+
+	private int getTokenIndexByOffset(Token token, int offset) {
+		if (token != null) {
+			int index = 1;
+			while (token.getEndOffset() < offset) {
+				token = token.getNextToken();
+				if (token == null) {
+					index = 0;
+					break;
+				}
+				index++;
+			}
+			return index;
+		}
+		return -1;
+	}
+
+	private int getOffsetOfTokenByIndex(int index, Token token) {
+		if (token != null) {
+			for (int i = 0; i < index; i++) {
+				token = token.getNextToken();
+				if (token == null) {
+					return -1;
+				}
+			}
+			return token.getOffset();
+		}
+		return -1;
+	}
 }