fix(gui): resolve various minor issues

jadx-gui/src/main/java/jadx/gui/jobs/BackgroundExecutor.java

@@ -145,11 +145,12 @@ public class BackgroundExecutor {
 					task.onDone(this);
 					// treat UI task operations as part of the task to not mix with others
 					UiUtils.uiRunAndWait(() -> {
-						progressPane.setVisible(false);
 						task.onFinish(this);
+						progressPane.setVisible(false);
 					});
 				} finally {
 					taskComplete(id);
+					progressPane.changeVisibility(this, false);
 				}
 			}
 			return status;
@@ -230,13 +231,13 @@ public class BackgroundExecutor {
 			// force termination
 			task.cancel();
 			executor.shutdown();
-			if (executor.awaitTermination(5, TimeUnit.SECONDS)) {
+			if (executor.awaitTermination(2, TimeUnit.SECONDS)) {
 				LOG.debug("Task cancel complete");
 				return;
 			}
 			LOG.debug("Forcing tasks cancel");
 			executor.shutdownNow();
-			boolean complete = executor.awaitTermination(30, TimeUnit.SECONDS);
+			boolean complete = executor.awaitTermination(5, TimeUnit.SECONDS);
 			LOG.debug("Forced task cancel status: {}",
 					complete ? "success" : "fail, still active: " + executor.getActiveCount());
 		}

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

@@ -356,6 +356,10 @@ public abstract class AbstractCodeArea extends RSyntaxTextArea {
 		return null;
 	}
 
+	public boolean isDisposed() {
+		return node == null;
+	}
+
 	public void dispose() {
 		// code area reference can still be used somewhere in UI objects,
 		// reset node reference to allow to GC jadx objects tree
@@ -363,6 +367,10 @@ public abstract class AbstractCodeArea extends RSyntaxTextArea {
 		contentPanel = null;
 
 		// also clear internals
+		setIgnoreRepaint(true);
+		setText("");
+		setEnabled(false);
+		setSyntaxEditingStyle(SYNTAX_STYLE_NONE);
 		setLinkGenerator(null);
 		for (MouseListener mouseListener : getMouseListeners()) {
 			removeMouseListener(mouseListener);

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

@@ -165,10 +165,15 @@ public final class ClassCodeContentPanel extends AbstractCodeContentPanel implem
 		} catch (Exception e) {
 			LOG.debug("Failed to restore view position: {}", viewState.getViewPoint(), e);
 		}
+		int caretPos = viewState.getCaretPos();
 		try {
-			activePanel.getCodeArea().setCaretPosition(viewState.getCaretPos());
+			AbstractCodeArea codeArea = activePanel.getCodeArea();
+			int codeLen = codeArea.getDocument().getLength();
+			if (caretPos >= 0 && caretPos < codeLen) {
+				codeArea.setCaretPosition(caretPos);
+			}
 		} catch (Exception e) {
-			LOG.debug("Failed to restore caret position: {}", viewState.getCaretPos(), e);
+			LOG.debug("Failed to restore caret position: {}", caretPos, e);
 		}
 	}
 

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

@@ -85,6 +85,10 @@ public final class CodeArea extends AbstractCodeArea {
 	@Override
 	public ICodeInfo getCodeInfo() {
 		if (cachedCodeInfo == null) {
+			if (isDisposed()) {
+				LOG.debug("CodeArea used after dispose!");
+				return ICodeInfo.EMPTY;
+			}
 			cachedCodeInfo = Objects.requireNonNull(node.getCodeInfo());
 		}
 		return cachedCodeInfo;

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

@@ -29,9 +29,12 @@ public final class JadxTokenMaker extends JavaTokenMaker {
 
 	@Override
 	public Token getTokenList(Segment text, int initialTokenType, int startOffset) {
+		if (codeArea.isDisposed()) {
+			return new TokenImpl();
+		}
 		try {
 			Token tokens = super.getTokenList(text, initialTokenType, startOffset);
-			if (tokens.getType() != TokenTypes.NULL) {
+			if (tokens != null && tokens.getType() != TokenTypes.NULL) {
 				processTokens(tokens);
 			}
 			return tokens;