fix(gui): load file in background thread and show progress indicator

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

+package jadx.gui.jobs;
+
+import java.util.Collections;
+import java.util.List;
+import java.util.concurrent.Executors;
+import java.util.concurrent.Future;
+import java.util.concurrent.ThreadPoolExecutor;
+import java.util.concurrent.TimeUnit;
+
+import javax.swing.SwingWorker;
+
+import org.jetbrains.annotations.Nullable;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import jadx.gui.ui.MainWindow;
+import jadx.gui.ui.ProgressPanel;
+
+/**
+ * Class for run tasks in background with progress bar indication.
+ * Use instance created in {@link MainWindow}.
+ */
+public class BackgroundExecutor {
+	private static final Logger LOG = LoggerFactory.getLogger(BackgroundExecutor.class);
+
+	private final MainWindow mainWindow;
+	private final ProgressPanel progressPane;
+
+	private ThreadPoolExecutor taskQueueExecutor;
+
+	public BackgroundExecutor(MainWindow mainWindow) {
+		this.mainWindow = mainWindow;
+		this.progressPane = mainWindow.getProgressPane();
+		this.taskQueueExecutor = makeTaskQueueExecutor();
+	}
+
+	public Future<Boolean> execute(IBackgroundTask task) {
+		TaskWorker taskWorker = new TaskWorker(task);
+		taskWorker.init();
+		taskQueueExecutor.execute(taskWorker);
+		return taskWorker;
+	}
+
+	public void cancelAll() {
+		try {
+			taskQueueExecutor.shutdownNow();
+			taskQueueExecutor.awaitTermination(1, TimeUnit.SECONDS);
+		} catch (Exception e) {
+			LOG.error("Error terminating task executor", e);
+		} finally {
+			taskQueueExecutor = makeTaskQueueExecutor();
+		}
+	}
+
+	public void execute(String title, Runnable backgroundRunnable, Runnable onFinishUiRunnable) {
+		execute(new SimpleTask(title, backgroundRunnable, onFinishUiRunnable));
+	}
+
+	public void execute(String title, Runnable backgroundRunnable) {
+		execute(new SimpleTask(title, backgroundRunnable, null));
+	}
+
+	private ThreadPoolExecutor makeTaskQueueExecutor() {
+		return (ThreadPoolExecutor) Executors.newFixedThreadPool(1);
+	}
+
+	private final class TaskWorker extends SwingWorker<Boolean, Void> {
+		private final IBackgroundTask task;
+		private long jobsCount;
+
+		public TaskWorker(IBackgroundTask task) {
+			this.task = task;
+		}
+
+		public void init() {
+			addPropertyChangeListener(progressPane);
+			progressPane.reset();
+		}
+
+		@Override
+		protected Boolean doInBackground() throws Exception {
+			progressPane.changeLabel(this, task.getTitle() + ':');
+			progressPane.changeCancelBtnVisible(this, task.canBeCanceled());
+			progressPane.changeVisibility(this, true);
+
+			List<Runnable> jobs = task.scheduleJobs();
+			jobsCount = jobs.size();
+			if (jobsCount == 1) {
+				jobs.get(0).run();
+				return true;
+			}
+			int threadsCount = mainWindow.getSettings().getThreadsCount();
+			if (threadsCount == 1) {
+				return runInCurrentThread(jobs);
+			}
+			return runInExecutor(jobs, threadsCount);
+		}
+
+		private boolean runInCurrentThread(List<Runnable> jobs) {
+			int k = 0;
+			for (Runnable job : jobs) {
+				job.run();
+				k++;
+				setProgress(calcProgress(k));
+				if (isCancelled()) {
+					return false;
+				}
+			}
+			return true;
+		}
+
+		private boolean runInExecutor(List<Runnable> jobs, int threadsCount) throws InterruptedException {
+			ThreadPoolExecutor executor = (ThreadPoolExecutor) Executors.newFixedThreadPool(threadsCount);
+			for (Runnable job : jobs) {
+				executor.execute(job);
+			}
+			executor.shutdown();
+			return waitTermination(executor);
+		}
+
+		private boolean waitTermination(ThreadPoolExecutor executor) throws InterruptedException {
+			while (true) {
+				if (executor.isTerminated()) {
+					return true;
+				}
+				if (isCancelled()) {
+					executor.shutdownNow();
+					progressPane.changeLabel(this, task.getTitle() + " (Canceling):");
+					// force termination
+					executor.awaitTermination(5, TimeUnit.SECONDS);
+					return false;
+				}
+				setProgress(calcProgress(executor.getCompletedTaskCount()));
+				Thread.sleep(500);
+			}
+		}
+
+		private int calcProgress(long done) {
+			return Math.round(done * 100 / (float) jobsCount);
+		}
+
+		@Override
+		protected void done() {
+			progressPane.setVisible(false);
+			task.onFinish();
+		}
+	}
+
+	private static final class SimpleTask implements IBackgroundTask {
+		private final String title;
+		private final Runnable runnable;
+		private final Runnable onFinish;
+
+		public SimpleTask(String title, Runnable runnable, @Nullable Runnable onFinish) {
+			this.title = title;
+			this.runnable = runnable;
+			this.onFinish = onFinish;
+		}
+
+		@Override
+		public String getTitle() {
+			return title;
+		}
+
+		@Override
+		public List<Runnable> scheduleJobs() {
+			return Collections.singletonList(runnable);
+		}
+
+		@Override
+		public boolean canBeCanceled() {
+			return false;
+		}
+
+		@Override
+		public void onFinish() {
+			if (onFinish != null) {
+				onFinish.run();
+			}
+		}
+	}
+}

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

@@ -2,7 +2,9 @@ package jadx.gui.jobs;
 
 import java.util.concurrent.Future;
 
-import javax.swing.*;
+import javax.swing.JOptionPane;
+import javax.swing.SwingUtilities;
+import javax.swing.SwingWorker;
 
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -13,6 +15,9 @@ import jadx.gui.utils.NLS;
 import jadx.gui.utils.UiUtils;
 import jadx.gui.utils.search.TextSearchIndex;
 
+/**
+ * Deprecated. Use {@link BackgroundExecutor} instead.
+ */
 public class BackgroundWorker extends SwingWorker<Void, Void> {
 	private static final Logger LOG = LoggerFactory.getLogger(BackgroundWorker.class);
 

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

@@ -2,6 +2,7 @@ package jadx.gui.jobs;
 
 import jadx.api.JavaClass;
 import jadx.gui.JadxWrapper;
+import jadx.gui.utils.NLS;
 
 public class DecompileJob extends BackgroundJob {
 
@@ -9,6 +10,7 @@ public class DecompileJob extends BackgroundJob {
 		super(wrapper, threadsCount);
 	}
 
+	@Override
 	protected void runJob() {
 		for (final JavaClass cls : wrapper.getIncludedClasses()) {
 			addTask(cls::decompile);
@@ -17,6 +19,6 @@ public class DecompileJob extends BackgroundJob {
 
 	@Override
 	public String getInfoString() {
-		return "Decompiling: ";
+		return NLS.str("progress.decompile");
 	}
 }

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

+package jadx.gui.jobs;
+
+import java.util.List;
+
+public interface IBackgroundTask {
+
+	String getTitle();
+
+	List<Runnable> scheduleJobs();
+
+	void onFinish();
+
+	boolean canBeCanceled();
+}

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

@@ -13,6 +13,7 @@ import jadx.gui.utils.CacheObject;
 import jadx.gui.utils.CodeLinesInfo;
 import jadx.gui.utils.CodeUsageInfo;
 import jadx.gui.utils.JNodeCache;
+import jadx.gui.utils.NLS;
 import jadx.gui.utils.UiUtils;
 import jadx.gui.utils.search.StringRef;
 import jadx.gui.utils.search.TextSearchIndex;
@@ -27,6 +28,7 @@ public class IndexJob extends BackgroundJob {
 		this.cache = cache;
 	}
 
+	@Override
 	protected void runJob() {
 		JNodeCache nodeCache = cache.getNodeCache();
 		final TextSearchIndex index = new TextSearchIndex(nodeCache);
@@ -66,6 +68,6 @@ public class IndexJob extends BackgroundJob {
 
 	@Override
 	public String getInfoString() {
-		return "Indexing: ";
+		return NLS.str("progress.index");
 	}
 }

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

@@ -78,6 +78,7 @@ import jadx.api.JavaClass;
 import jadx.api.JavaNode;
 import jadx.api.ResourceFile;
 import jadx.gui.JadxWrapper;
+import jadx.gui.jobs.BackgroundExecutor;
 import jadx.gui.jobs.BackgroundWorker;
 import jadx.gui.jobs.DecompileJob;
 import jadx.gui.jobs.IndexJob;
@@ -156,6 +157,7 @@ public class MainWindow extends JFrame {
 	private transient Link updateLink;
 	private transient ProgressPanel progressPane;
 	private transient BackgroundWorker backgroundWorker;
+	private transient BackgroundExecutor backgroundExecutor;
 	private transient Theme editorTheme;
 
 	public MainWindow(JadxSettings settings) {
@@ -172,6 +174,8 @@ public class MainWindow extends JFrame {
 		loadSettings();
 		checkForUpdate();
 		newProject();
+
+		this.backgroundExecutor = new BackgroundExecutor(this);
 	}
 
 	public void init() {
@@ -252,14 +256,6 @@ public class MainWindow extends JFrame {
 		clearTree();
 	}
 
-	private void clearTree() {
-		tabbedPane.closeAllTabs();
-		resetCache();
-		treeRoot = null;
-		treeModel.setRoot(treeRoot);
-		treeModel.reload();
-	}
-
 	private void saveProject() {
 		if (project.getProjectPath() == null) {
 			saveProjectAs();
@@ -310,13 +306,15 @@ public class MainWindow extends JFrame {
 			openProject(path);
 		} else {
 			project.setFilePath(path);
-			tabbedPane.closeAllTabs();
-			resetCache();
-			wrapper.openFile(path.toFile());
-			deobfToggleBtn.setSelected(settings.isDeobfuscationOn());
-			initTree();
-			update();
-			runBackgroundJobs();
+			clearTree();
+			backgroundExecutor.execute(NLS.str("progress.load"),
+					() -> wrapper.openFile(path.toFile()),
+					() -> {
+						deobfToggleBtn.setSelected(settings.isDeobfuscationOn());
+						initTree();
+						update();
+						runBackgroundJobs();
+					});
 		}
 	}
 
@@ -398,6 +396,7 @@ public class MainWindow extends JFrame {
 	}
 
 	public synchronized void cancelBackgroundJobs() {
+		backgroundExecutor.cancelAll();
 		if (backgroundWorker != null) {
 			backgroundWorker.stop();
 			backgroundWorker = new BackgroundWorker(cacheObject, progressPane);
@@ -492,6 +491,14 @@ public class MainWindow extends JFrame {
 		reloadTree();
 	}
 
+	private void clearTree() {
+		tabbedPane.closeAllTabs();
+		resetCache();
+		treeRoot = null;
+		treeModel.setRoot(treeRoot);
+		treeModel.reload();
+	}
+
 	private void reloadTree() {
 		treeReloading = true;
 
@@ -1101,6 +1108,10 @@ public class MainWindow extends JFrame {
 		return backgroundWorker;
 	}
 
+	public ProgressPanel getProgressPane() {
+		return progressPane;
+	}
+
 	private class RecentProjectsMenuListener implements MenuListener {
 		private final JMenu recentProjects;
 

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

 package jadx.gui.ui;
 
-import java.awt.*;
+import java.awt.Dimension;
 import java.beans.PropertyChangeEvent;
 import java.beans.PropertyChangeListener;
 
-import javax.swing.*;
+import javax.swing.BorderFactory;
+import javax.swing.BoxLayout;
+import javax.swing.Icon;
+import javax.swing.JButton;
+import javax.swing.JLabel;
+import javax.swing.JPanel;
+import javax.swing.JProgressBar;
+import javax.swing.SwingWorker;
 
 import jadx.gui.utils.UiUtils;
 
@@ -16,8 +23,12 @@ public class ProgressPanel extends JPanel implements PropertyChangeListener {
 
 	private final JProgressBar progressBar;
 	private final JLabel progressLabel;
+	private final JButton cancelButton;
+	private final boolean showCancelButton;
 
 	public ProgressPanel(final MainWindow mainWindow, boolean showCancelButton) {
+		this.showCancelButton = showCancelButton;
+
 		progressLabel = new JLabel();
 		progressBar = new JProgressBar(0, 100);
 		progressBar.setIndeterminate(true);
@@ -30,28 +41,47 @@ public class ProgressPanel extends JPanel implements PropertyChangeListener {
 		add(progressLabel);
 		add(progressBar);
 
-		if (showCancelButton) {
-			JButton cancelButton = new JButton(ICON_CANCEL);
-			cancelButton.setPreferredSize(new Dimension(ICON_CANCEL.getIconWidth(), ICON_CANCEL.getIconHeight()));
-			cancelButton.setToolTipText("Cancel background jobs");
-			cancelButton.setBorderPainted(false);
-			cancelButton.setFocusPainted(false);
-			cancelButton.setContentAreaFilled(false);
-			cancelButton.addActionListener(e -> mainWindow.cancelBackgroundJobs());
-			add(cancelButton);
-		}
+		cancelButton = new JButton(ICON_CANCEL);
+		cancelButton.setPreferredSize(new Dimension(ICON_CANCEL.getIconWidth(), ICON_CANCEL.getIconHeight()));
+		cancelButton.setToolTipText("Cancel background jobs");
+		cancelButton.setBorderPainted(false);
+		cancelButton.setFocusPainted(false);
+		cancelButton.setContentAreaFilled(false);
+		cancelButton.addActionListener(e -> mainWindow.cancelBackgroundJobs());
+		cancelButton.setVisible(showCancelButton);
+		add(cancelButton);
+	}
+
+	public void reset() {
+		cancelButton.setVisible(showCancelButton);
+		progressBar.setIndeterminate(true);
+		progressBar.setValue(0);
+		progressBar.setString("");
+		progressBar.setStringPainted(true);
 	}
 
 	@Override
 	public void propertyChange(PropertyChangeEvent evt) {
-		if ("progress".equals(evt.getPropertyName())) {
-			int progress = (Integer) evt.getNewValue();
-			progressBar.setIndeterminate(false);
-			progressBar.setValue(progress);
-			progressBar.setString(progress + "%");
-			progressBar.setStringPainted(true);
-		} else if ("label".equals(evt.getPropertyName())) {
-			setLabel((String) evt.getNewValue());
+		switch (evt.getPropertyName()) {
+			case "progress":
+				int progress = (Integer) evt.getNewValue();
+				progressBar.setIndeterminate(false);
+				progressBar.setValue(progress);
+				progressBar.setString(progress + "%");
+				progressBar.setStringPainted(true);
+				break;
+
+			case "label":
+				setLabel((String) evt.getNewValue());
+				break;
+
+			case "visible":
+				setVisible(((Boolean) evt.getNewValue()));
+				break;
+
+			case "cancel-visible":
+				cancelButton.setVisible(((Boolean) evt.getNewValue()));
+				break;
 		}
 	}
 
@@ -66,4 +96,12 @@ public class ProgressPanel extends JPanel implements PropertyChangeListener {
 	public void changeLabel(SwingWorker<?, ?> task, String label) {
 		task.firePropertyChange("label", null, label);
 	}
+
+	public void changeVisibility(SwingWorker<?, ?> task, boolean visible) {
+		task.firePropertyChange("visible", null, visible);
+	}
+
+	public void changeCancelBtnVisible(SwingWorker<?, ?> task, boolean visible) {
+		task.firePropertyChange("cancel-visible", null, visible);
+	}
 }

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

@@ -62,6 +62,14 @@ public class NLS {
 		LANG_LOCALES_MAP.put(locale, bundle);
 	}
 
+	public static String str(String key) {
+		try {
+			return localizedMessagesMap.getString(key);
+		} catch (Exception e) {
+			return FALLBACK_MESSAGES_MAP.getString(key);
+		}
+	}
+
 	public static String str(String key, Object... parameters) {
 		String value;
 		try {

jadx-gui/src/main/resources/i18n/Messages_de_DE.properties

@@ -32,6 +32,10 @@ tree.sources_title=Quellcode
 tree.resources_title=Ressourcen
 tree.loading=Laden…
 
+progress.load=Laden
+progress.decompile=Decompiling
+progress.index=Indexing
+
 error_dialog.title=Fehler
 
 search.previous=Zurück
@@ -133,7 +137,7 @@ msg.project_error_title=Fehler
 msg.project_error=Projekt konnte nicht geladen werden
 msg.rename_disabled_title=Umbenennen deaktiviert
 msg.rename_disabled=Einige der Umbenennungseinstellungen sind deaktiviert, bitte beachten Sie dies.
-msg.cmd_select_class_error=Klasse\n%s auswählen nicht möglich\nSie existiert nicht. 
+msg.cmd_select_class_error=Klasse\n%s auswählen nicht möglich\nSie existiert nicht.
 
 popup.undo=Rückgängig
 popup.redo=Wiederholen

jadx-gui/src/main/resources/i18n/Messages_en_US.properties

@@ -32,6 +32,10 @@ tree.sources_title=Source code
 tree.resources_title=Resources
 tree.loading=Loading...
 
+progress.load=Loading
+progress.decompile=Decompiling
+progress.index=Indexing
+
 error_dialog.title=Error
 
 search.previous=Previous
@@ -133,7 +137,7 @@ msg.project_error_title=Error
 msg.project_error=Project could not be loaded
 msg.rename_disabled_title=Rename disabled
 msg.rename_disabled=Some of rename settings are disabled, please take this into consideration
-msg.cmd_select_class_error=Failed to select the class\n%s\nThe class does not exist. 
+msg.cmd_select_class_error=Failed to select the class\n%s\nThe class does not exist.
 
 popup.undo=Undo
 popup.redo=Redo

jadx-gui/src/main/resources/i18n/Messages_es_ES.properties

@@ -32,6 +32,10 @@ tree.sources_title=Código fuente
 tree.resources_title=Recursos
 tree.loading=Cargando...
 
+progress.load=Cargando
+progress.decompile=Decompiling
+progress.index=Indexing
+
 #error_dialog.title=
 
 search.previous=Anterior

jadx-gui/src/main/resources/i18n/Messages_zh_CN.properties

@@ -32,6 +32,10 @@ tree.sources_title=源代码
 tree.resources_title=资源文件
 tree.loading=稍等...
 
+progress.load=稍等
+progress.decompile=Decompiling
+progress.index=Indexing
+
 error_dialog.title=错误
 
 search.previous=上一个