System File Chooser: implemented native bindings for GtkFileChooserDialog on Linux

2025-12-06 22:10:54 +03:00 · 2025-01-03 16:22:07 +01:00
parent 63272a03cf
commit 2b810addd8
10 changed files with 848 additions and 10 deletions
--- a/.github/workflows/natives.yml
+++ b/.github/workflows/natives.yml
@@ -32,6 +32,10 @@ jobs:

            - uses: gradle/actions/wrapper-validation@v4

+            - name: install libgtk-3-dev
+              if: matrix.os == 'ubuntu'
+              run: sudo apt install libgtk-3-dev
+
            - name: Setup Java 11
              uses: actions/setup-java@v4
              with:
--- a/flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatNativeLinuxLibrary.java
+++ b/flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatNativeLinuxLibrary.java
@@ -34,9 +34,9 @@ import com.formdev.flatlaf.util.SystemInfo;
 * @author Karl Tauber
 * @since 2.5
 */
-class FlatNativeLinuxLibrary
+public class FlatNativeLinuxLibrary
 {
-	private static int API_VERSION_LINUX = 3001;
+	private static int API_VERSION_LINUX = 3002;

 	/**
 	 * Checks whether native library is loaded/available.
@@ -44,7 +44,7 @@ class FlatNativeLinuxLibrary
 	 * <b>Note</b>: It is required to invoke this method before invoking any other
 	 *              method of this class. Otherwise, the native library may not be loaded.
 	 */
-	static boolean isLoaded() {
+	public static boolean isLoaded() {
 		return SystemInfo.isLinux && FlatNativeLibrary.isLoaded( API_VERSION_LINUX );
 	}

@@ -115,4 +115,48 @@ class FlatNativeLinuxLibrary
 		return (window instanceof JFrame && JFrame.isDefaultLookAndFeelDecorated() && ((JFrame)window).isUndecorated()) ||
 			(window instanceof JDialog && JDialog.isDefaultLookAndFeelDecorated() && ((JDialog)window).isUndecorated());
 	}
+
+
+	/**
+	 * https://docs.gtk.org/gtk3/iface.FileChooser.html#properties
+	 *
+	 * @since 3.6
+	 */
+	public static final int
+		FC_select_folder					= 1 << 0,
+		FC_select_multiple					= 1 << 1,
+		FC_show_hidden						= 1 << 2,
+		FC_local_only						= 1 << 3,  // default
+		FC_do_overwrite_confirmation		= 1 << 4,  // GTK 3 only; removed and always-on in GTK 4
+		FC_create_folders					= 1 << 5;  // default for Save
+
+	/**
+	 * Shows the Linux system file dialog
+	 * <a href="https://docs.gtk.org/gtk3/class.FileChooserDialog.html">GtkFileChooserDialog</a>.
+	 * <p>
+	 * <b>Note:</b> This method blocks the current thread until the user closes
+	 * the file dialog. It is highly recommended to invoke it from a new thread
+	 * to avoid blocking the AWT event dispatching thread.
+	 *
+	 * @param open if {@code true}, shows the open dialog; if {@code false}, shows the save dialog
+	 * @param title text displayed in dialog title; or {@code null}
+	 * @param okButtonLabel text displayed in default button; or {@code null}
+	 * @param currentName user-editable filename currently shown in the filename field in save dialog; or {@code null}
+	 * @param currentFolder current directory shown in the dialog; or {@code null}
+	 * @param optionsSet options to set; see {@code FOS_*} constants
+	 * @param optionsClear options to clear; see {@code FOS_*} constants
+	 * @param fileTypeIndex the file type that appears as selected (zero-based)
+	 * @param fileTypes file types that the dialog can open or save.
+	 *        Two or more strings and {@code null} are required for each filter.
+	 *        First string is the display name of the filter shown in the combobox (e.g. "Text Files").
+	 *        Subsequent strings are the filter patterns (e.g. "*.txt" or "*").
+	 *        {@code null} is required to mark end of filter.
+	 * @return file path(s) that the user selected; an empty array if canceled;
+	 *         or {@code null} on failures (no dialog shown)
+	 *
+	 * @since 3.6
+	 */
+	public native static String[] showFileChooser( boolean open,
+		String title, String okButtonLabel, String currentName, String currentFolder,
+		int optionsSet, int optionsClear, int fileTypeIndex, String... fileTypes );
 }
--- a/flatlaf-natives/flatlaf-natives-linux/README.md
+++ b/flatlaf-natives/flatlaf-natives-linux/README.md
@@ -24,16 +24,25 @@ To build the library on Linux, some packages needs to be installed.
 ### Ubuntu

 `build-essential` contains GCC and development tools. `libxt-dev` contains the
-X11 toolkit development headers.
+X11 toolkit development headers. `libgtk-3-dev` contains the GTK toolkit
+development headers.

 ~~~
 sudo apt update
-sudo apt install build-essential libxt-dev
+sudo apt install build-essential libxt-dev libgtk-3-dev
+~~~
+
+
+### Fedora
+
+~~~
+sudo dnf group install c-development
+sudo dnf install libXt-devel gtk3-devel
 ~~~


 ### CentOS

 ~~~
-sudo yum install libXt-devel
+sudo yum install libXt-devel gtk3-devel
 ~~~
--- a/flatlaf-natives/flatlaf-natives-linux/build.gradle.kts
+++ b/flatlaf-natives/flatlaf-natives-linux/build.gradle.kts
@@ -52,7 +52,17 @@ tasks {

 		includes.from(
 			"${javaHome}/include",
-			"${javaHome}/include/linux"
+			"${javaHome}/include/linux",
+
+			// for GTK
+			"/usr/include/gtk-3.0",
+			"/usr/include/glib-2.0",
+			"/usr/lib/x86_64-linux-gnu/glib-2.0/include",
+			"/usr/include/gdk-pixbuf-2.0",
+			"/usr/include/atk-1.0",
+			"/usr/include/cairo",
+			"/usr/include/pango-1.0",
+			"/usr/include/harfbuzz",
 		)

 		compilerArgs.addAll( toolChain.map {
@@ -75,7 +85,7 @@ tasks {

 		linkerArgs.addAll( toolChain.map {
 			when( it ) {
-				is Gcc, is Clang -> listOf( "-L${jawtPath}", "-l${jawt}" )
+				is Gcc, is Clang -> listOf( "-L${jawtPath}", "-l${jawt}", "-lgtk-3" )
 				else -> emptyList()
 			}
 		} )
--- a/flatlaf-natives/flatlaf-natives-linux/src/main/cpp/ApiVersion.cpp
+++ b/flatlaf-natives/flatlaf-natives-linux/src/main/cpp/ApiVersion.cpp
@@ -24,7 +24,7 @@

 // increase this version if changing API or functionality of native library
 // also update version in Java class com.formdev.flatlaf.ui.FlatNativeLinuxLibrary
-#define API_VERSION_LINUX		3001
+#define API_VERSION_LINUX		3002


 //---- JNI methods ------------------------------------------------------------
--- a/flatlaf-natives/flatlaf-natives-linux/src/main/cpp/GtkFileChooser.cpp
+++ b/flatlaf-natives/flatlaf-natives-linux/src/main/cpp/GtkFileChooser.cpp
@@ -0,0 +1,177 @@
+/*
+ * Copyright 2025 FormDev Software GmbH
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <jawt.h>
+#include <linux/jawt_md.h>
+#include <gtk/gtk.h>
+#include <gdk/gdkx.h>
+#include <glib/gi18n.h>
+#include "com_formdev_flatlaf_ui_FlatNativeLinuxLibrary.h"
+
+/**
+ * @author Karl Tauber
+ * @since 3.6
+ */
+
+//---- class AutoReleaseStringUTF8 --------------------------------------------
+
+class AutoReleaseStringUTF8 {
+	JNIEnv* env;
+	jstring javaString;
+	const char* chars;
+
+public:
+	AutoReleaseStringUTF8( JNIEnv* _env, jstring _javaString ) {
+		env = _env;
+		javaString = _javaString;
+		chars = (javaString != NULL) ? env->GetStringUTFChars( javaString, NULL ) : NULL;
+	}
+	~AutoReleaseStringUTF8() {
+		if( chars != NULL )
+			env->ReleaseStringUTFChars( javaString, chars );
+	}
+	operator const gchar*() { return chars; }
+};
+
+//---- helper -----------------------------------------------------------------
+
+#define isOptionSet( option ) ((optionsSet & com_formdev_flatlaf_ui_FlatNativeLinuxLibrary_ ## option) != 0)
+#define isOptionClear( option ) ((optionsClear & com_formdev_flatlaf_ui_FlatNativeLinuxLibrary_ ## option) != 0)
+#define isOptionSetOrClear( option ) isOptionSet( option ) || isOptionClear( option )
+
+jobjectArray newJavaStringArray( JNIEnv* env, jsize count ) {
+	jclass stringClass = env->FindClass( "java/lang/String" );
+	return env->NewObjectArray( count, stringClass, NULL );
+}
+
+void initFilters( GtkFileChooser* chooser, JNIEnv* env, jint fileTypeIndex, jobjectArray fileTypes ) {
+	jint length = env->GetArrayLength( fileTypes );
+	if( length <= 0 )
+		return;
+
+	GtkFileFilter* filter = NULL;
+	int filterIndex = 0;
+	for( int i = 0; i < length; i++ ) {
+		jstring jstr = (jstring) env->GetObjectArrayElement( fileTypes, i );
+		if( jstr == NULL ) {
+			if( filter != NULL ) {
+				gtk_file_chooser_add_filter( chooser, filter );
+				if( fileTypeIndex == filterIndex )
+					gtk_file_chooser_set_filter( chooser, filter );
+				filter = NULL;
+				filterIndex++;
+			}
+			continue;
+		}
+
+		AutoReleaseStringUTF8 str( env, jstr );
+		if( filter == NULL ) {
+			filter = gtk_file_filter_new();
+			gtk_file_filter_set_name( filter, str );
+		} else
+			gtk_file_filter_add_pattern( filter, str );
+	}
+}
+
+static void handle_response( GtkWidget* dialog, gint responseId, gpointer data ) {
+	if( responseId == GTK_RESPONSE_ACCEPT )
+		*((GSList**)data) = gtk_file_chooser_get_filenames( GTK_FILE_CHOOSER( dialog ) );
+
+	gtk_widget_hide( dialog );
+	gtk_widget_destroy( dialog );
+	gtk_main_quit();
+}
+
+//---- JNI methods ------------------------------------------------------------
+
+extern "C"
+JNIEXPORT jobjectArray JNICALL Java_com_formdev_flatlaf_ui_FlatNativeLinuxLibrary_showFileChooser
+	( JNIEnv* env, jclass cls, jboolean open,
+		jstring title, jstring okButtonLabel, jstring currentName, jstring currentFolder,
+		jint optionsSet, jint optionsClear, jint fileTypeIndex, jobjectArray fileTypes )
+{
+	// initialize GTK
+	if( !gtk_init_check( NULL, NULL ) )
+		return NULL;
+
+	// convert Java strings to C strings
+	AutoReleaseStringUTF8 ctitle( env, title );
+	AutoReleaseStringUTF8 cokButtonLabel( env, okButtonLabel );
+	AutoReleaseStringUTF8 ccurrentName( env, currentName );
+	AutoReleaseStringUTF8 ccurrentFolder( env, currentFolder );
+
+	// create GTK file chooser dialog
+	// https://docs.gtk.org/gtk3/class.FileChooserDialog.html
+	bool selectFolder = isOptionSet( FC_select_folder );
+	bool multiSelect = isOptionSet( FC_select_multiple );
+	GtkWidget* dialog = gtk_file_chooser_dialog_new(
+		(ctitle != NULL) ? ctitle
+			: (open ? (selectFolder ? (multiSelect ? _("Select Folders") : _("Select Folder"))
+				: (multiSelect ? _("Open Files") : _("Open File"))) : _("Save File")),
+		NULL, // can not use AWT X11 window as parent because GtkWindow is required
+		open ? (selectFolder ? GTK_FILE_CHOOSER_ACTION_SELECT_FOLDER : GTK_FILE_CHOOSER_ACTION_OPEN)
+			: GTK_FILE_CHOOSER_ACTION_SAVE,
+		_("_Cancel"), GTK_RESPONSE_CANCEL,
+		(cokButtonLabel != NULL) ? cokButtonLabel : (open ? _("_Open") : _("_Save")), GTK_RESPONSE_ACCEPT,
+		NULL ); // marks end of buttons
+	GtkFileChooser* chooser = GTK_FILE_CHOOSER( dialog );
+
+	if( !open && ccurrentName != NULL )
+		gtk_file_chooser_set_current_name( chooser, ccurrentName );
+	if( ccurrentFolder != NULL )
+		gtk_file_chooser_set_current_folder( chooser, ccurrentFolder );
+
+	if( isOptionSetOrClear( FC_select_multiple ) )
+		gtk_file_chooser_set_select_multiple( chooser, isOptionSet( FC_select_multiple ) );
+	if( isOptionSetOrClear( FC_show_hidden ) )
+		gtk_file_chooser_set_show_hidden( chooser, isOptionSet( FC_show_hidden ) );
+	if( isOptionSetOrClear( FC_local_only ) )
+		gtk_file_chooser_set_local_only( chooser, isOptionSet( FC_local_only ) );
+	if( isOptionSetOrClear( FC_do_overwrite_confirmation ) )
+		gtk_file_chooser_set_do_overwrite_confirmation( chooser, isOptionSet( FC_do_overwrite_confirmation ) );
+	if( isOptionSetOrClear( FC_create_folders ) )
+		gtk_file_chooser_set_create_folders( chooser, isOptionSet( FC_create_folders ) );
+
+	initFilters( chooser, env, fileTypeIndex, fileTypes );
+
+	gtk_window_set_modal( GTK_WINDOW( dialog ), true );
+
+	// show dialog
+	// (similar to what's done in sun_awt_X11_GtkFileDialogPeer.c)
+	GSList* fileList = NULL;
+    g_signal_connect( dialog, "response", G_CALLBACK( handle_response ), &fileList );
+	gtk_widget_show( dialog );
+	gtk_main();
+
+	// canceled?
+	if( fileList == NULL )
+		return newJavaStringArray( env, 0 );
+
+	// convert GSList to Java string array
+	guint count = g_slist_length( fileList );
+	jobjectArray array = newJavaStringArray( env, count );
+	GSList* it = fileList;
+	for( int i = 0; i < count; i++, it = it->next ) {
+		gchar* path = (gchar*) it->data;
+		jstring jpath = env->NewStringUTF( path );
+		g_free( path );
+
+		env->SetObjectArrayElement( array, i, jpath );
+		env->DeleteLocalRef( jpath );
+	}
+	g_slist_free( fileList );
+	return array;
+}
--- a/flatlaf-natives/flatlaf-natives-linux/src/main/cpp/X11WmUtils.cpp
+++ b/flatlaf-natives/flatlaf-natives-linux/src/main/cpp/X11WmUtils.cpp
@@ -36,7 +36,7 @@ Window getWindowHandle( JNIEnv* env, JAWT* awt, jobject window, Display** displa
 /**
 * Send _NET_WM_MOVERESIZE to window to initiate moving or resizing.
 *
- * https://specifications.freedesktop.org/wm-spec/wm-spec-latest.html#idm45446104441728
+ * https://specifications.freedesktop.org/wm-spec/latest/ar01s04.html#id-1.5.4
 * https://gitlab.gnome.org/GNOME/gtk/-/blob/main/gdk/x11/gdksurface-x11.c#L3841-3881
 */
 extern "C"
--- a/flatlaf-natives/flatlaf-natives-linux/src/main/headers/com_formdev_flatlaf_ui_FlatNativeLinuxLibrary.h
+++ b/flatlaf-natives/flatlaf-natives-linux/src/main/headers/com_formdev_flatlaf_ui_FlatNativeLinuxLibrary.h
@@ -9,6 +9,18 @@ extern "C" {
 #endif
 #undef com_formdev_flatlaf_ui_FlatNativeLinuxLibrary_MOVE
 #define com_formdev_flatlaf_ui_FlatNativeLinuxLibrary_MOVE 8L
+#undef com_formdev_flatlaf_ui_FlatNativeLinuxLibrary_FC_select_folder
+#define com_formdev_flatlaf_ui_FlatNativeLinuxLibrary_FC_select_folder 1L
+#undef com_formdev_flatlaf_ui_FlatNativeLinuxLibrary_FC_select_multiple
+#define com_formdev_flatlaf_ui_FlatNativeLinuxLibrary_FC_select_multiple 2L
+#undef com_formdev_flatlaf_ui_FlatNativeLinuxLibrary_FC_show_hidden
+#define com_formdev_flatlaf_ui_FlatNativeLinuxLibrary_FC_show_hidden 4L
+#undef com_formdev_flatlaf_ui_FlatNativeLinuxLibrary_FC_local_only
+#define com_formdev_flatlaf_ui_FlatNativeLinuxLibrary_FC_local_only 8L
+#undef com_formdev_flatlaf_ui_FlatNativeLinuxLibrary_FC_do_overwrite_confirmation
+#define com_formdev_flatlaf_ui_FlatNativeLinuxLibrary_FC_do_overwrite_confirmation 16L
+#undef com_formdev_flatlaf_ui_FlatNativeLinuxLibrary_FC_create_folders
+#define com_formdev_flatlaf_ui_FlatNativeLinuxLibrary_FC_create_folders 32L
 /*
 * Class:     com_formdev_flatlaf_ui_FlatNativeLinuxLibrary
 * Method:    xMoveOrResizeWindow
@@ -25,6 +37,14 @@ JNIEXPORT jboolean JNICALL Java_com_formdev_flatlaf_ui_FlatNativeLinuxLibrary_xM
 JNIEXPORT jboolean JNICALL Java_com_formdev_flatlaf_ui_FlatNativeLinuxLibrary_xShowWindowMenu
  (JNIEnv *, jclass, jobject, jint, jint);

+/*
+ * Class:     com_formdev_flatlaf_ui_FlatNativeLinuxLibrary
+ * Method:    showFileChooser
+ * Signature: (ZLjava/lang/String;Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;III[Ljava/lang/String;)[Ljava/lang/String;
+ */
+JNIEXPORT jobjectArray JNICALL Java_com_formdev_flatlaf_ui_FlatNativeLinuxLibrary_showFileChooser
+  (JNIEnv *, jclass, jboolean, jstring, jstring, jstring, jstring, jint, jint, jint, jobjectArray);
+
 #ifdef __cplusplus
 }
 #endif
--- a/flatlaf-testing/src/main/java/com/formdev/flatlaf/testing/FlatSystemFileChooserLinuxTest.java
+++ b/flatlaf-testing/src/main/java/com/formdev/flatlaf/testing/FlatSystemFileChooserLinuxTest.java
@@ -0,0 +1,392 @@
+/*
+ * Copyright 2025 FormDev Software GmbH
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.formdev.flatlaf.testing;
+
+import static com.formdev.flatlaf.ui.FlatNativeLinuxLibrary.*;
+import java.awt.EventQueue;
+import java.awt.SecondaryLoop;
+import java.awt.Toolkit;
+import java.awt.Window;
+import java.awt.event.WindowEvent;
+import java.awt.event.WindowFocusListener;
+import java.awt.event.WindowListener;
+import java.awt.event.WindowStateListener;
+import java.util.Arrays;
+import java.util.concurrent.atomic.AtomicInteger;
+import javax.swing.*;
+import com.formdev.flatlaf.extras.components.*;
+import com.formdev.flatlaf.extras.components.FlatTriStateCheckBox.State;
+import com.formdev.flatlaf.ui.FlatNativeLinuxLibrary;
+import net.miginfocom.swing.*;
+
+/**
+ * @author Karl Tauber
+ */
+public class FlatSystemFileChooserLinuxTest
+	extends FlatTestPanel
+{
+	public static void main( String[] args ) {
+		SwingUtilities.invokeLater( () -> {
+			if( !FlatNativeLinuxLibrary.isLoaded() ) {
+				JOptionPane.showMessageDialog( null, "FlatLaf native library not loaded" );
+				return;
+			}
+
+			FlatTestFrame frame = FlatTestFrame.create( args, "FlatSystemFileChooserLinuxTest" );
+			addListeners( frame );
+			frame.showFrame( FlatSystemFileChooserLinuxTest::new );
+		} );
+	}
+
+	FlatSystemFileChooserLinuxTest() {
+		initComponents();
+
+		fileTypesField.setSelectedItem( null );
+	}
+
+	private void open() {
+		openOrSave( true, false );
+	}
+
+	private void save() {
+		openOrSave( false, false );
+	}
+
+	private void openDirect() {
+		openOrSave( true, true );
+	}
+
+	private void saveDirect() {
+		openOrSave( false, true );
+	}
+
+	private void openOrSave( boolean open, boolean direct ) {
+		String title = n( titleField.getText() );
+		String okButtonLabel = n( okButtonLabelField.getText() );
+		String currentName = n( currentNameField.getText() );
+		String currentFolder = n( currentFolderField.getText() );
+		AtomicInteger optionsSet = new AtomicInteger();
+		AtomicInteger optionsClear = new AtomicInteger();
+
+		o( FC_select_folder, select_folderCheckBox, optionsSet, optionsClear );
+		o( FC_select_multiple, select_multipleCheckBox, optionsSet, optionsClear );
+		o( FC_show_hidden, show_hiddenCheckBox, optionsSet, optionsClear );
+		o( FC_local_only, local_onlyCheckBox, optionsSet, optionsClear );
+		o( FC_do_overwrite_confirmation, do_overwrite_confirmationCheckBox, optionsSet, optionsClear );
+		o( FC_create_folders, create_foldersCheckBox, optionsSet, optionsClear );
+
+		String fileTypesStr = n( (String) fileTypesField.getSelectedItem() );
+		String[] fileTypes = {};
+		if( fileTypesStr != null ) {
+			if( !fileTypesStr.endsWith( ",null" ) )
+				fileTypesStr += ",null";
+			fileTypes = fileTypesStr.trim().split( "[,]+" );
+			for( int i = 0; i < fileTypes.length; i++ ) {
+				if( "null".equals( fileTypes[i] ) )
+					fileTypes[i] = null;
+			}
+		}
+		int fileTypeIndex = fileTypeIndexSlider.getValue();
+
+		if( direct ) {
+			String[] files = FlatNativeLinuxLibrary.showFileChooser( open,
+				title, okButtonLabel, currentName, currentFolder,
+				optionsSet.get(), optionsClear.get(), fileTypeIndex, fileTypes );
+
+			filesField.setText( (files != null) ? Arrays.toString( files ).replace( ',', '\n' ) : "null" );
+		} else {
+			SecondaryLoop secondaryLoop = Toolkit.getDefaultToolkit().getSystemEventQueue().createSecondaryLoop();
+
+			String[] fileTypes2 = fileTypes;
+			new Thread( () -> {
+				String[] files = FlatNativeLinuxLibrary.showFileChooser( open,
+					title, okButtonLabel, currentName, currentFolder,
+					optionsSet.get(), optionsClear.get(), fileTypeIndex, fileTypes2 );
+
+				System.out.println( "    secondaryLoop.exit() returned " + secondaryLoop.exit() );
+
+				EventQueue.invokeLater( () -> {
+					filesField.setText( (files != null) ? Arrays.toString( files ).replace( ',', '\n' ) : "null" );
+				} );
+			} ).start();
+
+			System.out.println( "---- enter secondary loop ----" );
+			System.out.println( "---- secondary loop exited (secondaryLoop.enter() returned " + secondaryLoop.enter() + ") ----" );
+		}
+	}
+
+	private static String n( String s ) {
+		return s != null && !s.isEmpty() ? s : null;
+	}
+
+	private static void o( int option, FlatTriStateCheckBox checkBox, AtomicInteger optionsSet, AtomicInteger optionsClear ) {
+		if( checkBox.getState() == State.SELECTED )
+			optionsSet.set( optionsSet.get() | option );
+		else if( checkBox.getState() == State.UNSELECTED )
+			optionsClear.set( optionsClear.get() | option );
+	}
+
+	private static void addListeners( Window w ) {
+		w.addWindowListener( new WindowListener() {
+			@Override
+			public void windowOpened( WindowEvent e ) {
+				System.out.println( e );
+			}
+
+			@Override
+			public void windowIconified( WindowEvent e ) {
+				System.out.println( e );
+			}
+
+			@Override
+			public void windowDeiconified( WindowEvent e ) {
+				System.out.println( e );
+			}
+
+			@Override
+			public void windowDeactivated( WindowEvent e ) {
+				System.out.println( e );
+			}
+
+			@Override
+			public void windowClosing( WindowEvent e ) {
+				System.out.println( e );
+			}
+
+			@Override
+			public void windowClosed( WindowEvent e ) {
+				System.out.println( e );
+			}
+
+			@Override
+			public void windowActivated( WindowEvent e ) {
+				System.out.println( e );
+			}
+		} );
+		w.addWindowStateListener( new WindowStateListener() {
+			@Override
+			public void windowStateChanged( WindowEvent e ) {
+				System.out.println( e );
+			}
+		} );
+		w.addWindowFocusListener( new WindowFocusListener() {
+			@Override
+			public void windowLostFocus( WindowEvent e ) {
+				System.out.println( e );
+			}
+
+			@Override
+			public void windowGainedFocus( WindowEvent e ) {
+				System.out.println( e );
+			}
+		} );
+	}
+
+	private void initComponents() {
+		// JFormDesigner - Component initialization - DO NOT MODIFY  //GEN-BEGIN:initComponents
+		titleLabel = new JLabel();
+		titleField = new JTextField();
+		panel1 = new JPanel();
+		select_folderCheckBox = new FlatTriStateCheckBox();
+		select_multipleCheckBox = new FlatTriStateCheckBox();
+		do_overwrite_confirmationCheckBox = new FlatTriStateCheckBox();
+		create_foldersCheckBox = new FlatTriStateCheckBox();
+		show_hiddenCheckBox = new FlatTriStateCheckBox();
+		local_onlyCheckBox = new FlatTriStateCheckBox();
+		okButtonLabelLabel = new JLabel();
+		okButtonLabelField = new JTextField();
+		currentNameLabel = new JLabel();
+		currentNameField = new JTextField();
+		currentFolderLabel = new JLabel();
+		currentFolderField = new JTextField();
+		fileTypesLabel = new JLabel();
+		fileTypesField = new JComboBox<>();
+		fileTypeIndexLabel = new JLabel();
+		fileTypeIndexSlider = new JSlider();
+		openButton = new JButton();
+		saveButton = new JButton();
+		openDirectButton = new JButton();
+		saveDirectButton = new JButton();
+		filesScrollPane = new JScrollPane();
+		filesField = new JTextArea();
+
+		//======== this ========
+		setLayout(new MigLayout(
+			"ltr,insets dialog,hidemode 3",
+			// columns
+			"[left]" +
+			"[grow,fill]" +
+			"[fill]",
+			// rows
+			"[]" +
+			"[]" +
+			"[]" +
+			"[]" +
+			"[]" +
+			"[]" +
+			"[]" +
+			"[grow,fill]"));
+
+		//---- titleLabel ----
+		titleLabel.setText("title");
+		add(titleLabel, "cell 0 0");
+		add(titleField, "cell 1 0");
+
+		//======== panel1 ========
+		{
+			panel1.setLayout(new MigLayout(
+				"insets 2,hidemode 3",
+				// columns
+				"[left]",
+				// rows
+				"[]0" +
+				"[]0" +
+				"[]0" +
+				"[]0" +
+				"[]0" +
+				"[]"));
+
+			//---- select_folderCheckBox ----
+			select_folderCheckBox.setText("select_folder");
+			select_folderCheckBox.setAllowIndeterminate(false);
+			select_folderCheckBox.setState(FlatTriStateCheckBox.State.UNSELECTED);
+			panel1.add(select_folderCheckBox, "cell 0 0");
+
+			//---- select_multipleCheckBox ----
+			select_multipleCheckBox.setText("select_multiple");
+			select_multipleCheckBox.setState(FlatTriStateCheckBox.State.UNSELECTED);
+			select_multipleCheckBox.setAllowIndeterminate(false);
+			panel1.add(select_multipleCheckBox, "cell 0 1");
+
+			//---- do_overwrite_confirmationCheckBox ----
+			do_overwrite_confirmationCheckBox.setText("do_overwrite_confirmation");
+			panel1.add(do_overwrite_confirmationCheckBox, "cell 0 2");
+
+			//---- create_foldersCheckBox ----
+			create_foldersCheckBox.setText("create_folders");
+			panel1.add(create_foldersCheckBox, "cell 0 3");
+
+			//---- show_hiddenCheckBox ----
+			show_hiddenCheckBox.setText("show_hidden");
+			panel1.add(show_hiddenCheckBox, "cell 0 4");
+
+			//---- local_onlyCheckBox ----
+			local_onlyCheckBox.setText("local_only");
+			panel1.add(local_onlyCheckBox, "cell 0 5");
+		}
+		add(panel1, "cell 2 0 1 6,aligny top,growy 0");
+
+		//---- okButtonLabelLabel ----
+		okButtonLabelLabel.setText("okButtonLabel");
+		add(okButtonLabelLabel, "cell 0 1");
+		add(okButtonLabelField, "cell 1 1");
+
+		//---- currentNameLabel ----
+		currentNameLabel.setText("currentName");
+		add(currentNameLabel, "cell 0 2");
+		add(currentNameField, "cell 1 2");
+
+		//---- currentFolderLabel ----
+		currentFolderLabel.setText("currentFolder");
+		add(currentFolderLabel, "cell 0 3");
+		add(currentFolderField, "cell 1 3");
+
+		//---- fileTypesLabel ----
+		fileTypesLabel.setText("fileTypes");
+		add(fileTypesLabel, "cell 0 4");
+
+		//---- fileTypesField ----
+		fileTypesField.setEditable(true);
+		fileTypesField.setModel(new DefaultComboBoxModel<>(new String[] {
+			"Text Files,*.txt,null",
+			"All Files,*,null",
+			"Text Files,*.txt,null,PDF Files,*.pdf,null,All Files,*,null",
+			"Text and PDF Files,*.txt,*.pdf,null"
+		}));
+		add(fileTypesField, "cell 1 4");
+
+		//---- fileTypeIndexLabel ----
+		fileTypeIndexLabel.setText("fileTypeIndex");
+		add(fileTypeIndexLabel, "cell 0 5");
+
+		//---- fileTypeIndexSlider ----
+		fileTypeIndexSlider.setMaximum(10);
+		fileTypeIndexSlider.setMajorTickSpacing(1);
+		fileTypeIndexSlider.setValue(0);
+		fileTypeIndexSlider.setPaintLabels(true);
+		fileTypeIndexSlider.setSnapToTicks(true);
+		add(fileTypeIndexSlider, "cell 1 5");
+
+		//---- openButton ----
+		openButton.setText("Open...");
+		openButton.addActionListener(e -> open());
+		add(openButton, "cell 0 6 3 1");
+
+		//---- saveButton ----
+		saveButton.setText("Save...");
+		saveButton.addActionListener(e -> save());
+		add(saveButton, "cell 0 6 3 1");
+
+		//---- openDirectButton ----
+		openDirectButton.setText("Open (no-thread)...");
+		openDirectButton.addActionListener(e -> openDirect());
+		add(openDirectButton, "cell 0 6 3 1");
+
+		//---- saveDirectButton ----
+		saveDirectButton.setText("Save (no-thread)...");
+		saveDirectButton.addActionListener(e -> saveDirect());
+		add(saveDirectButton, "cell 0 6 3 1");
+
+		//======== filesScrollPane ========
+		{
+
+			//---- filesField ----
+			filesField.setRows(8);
+			filesScrollPane.setViewportView(filesField);
+		}
+		add(filesScrollPane, "cell 0 7 3 1,growx");
+		// JFormDesigner - End of component initialization  //GEN-END:initComponents
+	}
+
+	// JFormDesigner - Variables declaration - DO NOT MODIFY  //GEN-BEGIN:variables
+	private JLabel titleLabel;
+	private JTextField titleField;
+	private JPanel panel1;
+	private FlatTriStateCheckBox select_folderCheckBox;
+	private FlatTriStateCheckBox select_multipleCheckBox;
+	private FlatTriStateCheckBox do_overwrite_confirmationCheckBox;
+	private FlatTriStateCheckBox create_foldersCheckBox;
+	private FlatTriStateCheckBox show_hiddenCheckBox;
+	private FlatTriStateCheckBox local_onlyCheckBox;
+	private JLabel okButtonLabelLabel;
+	private JTextField okButtonLabelField;
+	private JLabel currentNameLabel;
+	private JTextField currentNameField;
+	private JLabel currentFolderLabel;
+	private JTextField currentFolderField;
+	private JLabel fileTypesLabel;
+	private JComboBox<String> fileTypesField;
+	private JLabel fileTypeIndexLabel;
+	private JSlider fileTypeIndexSlider;
+	private JButton openButton;
+	private JButton saveButton;
+	private JButton openDirectButton;
+	private JButton saveDirectButton;
+	private JScrollPane filesScrollPane;
+	private JTextArea filesField;
+	// JFormDesigner - End of variables declaration  //GEN-END:variables
+}
--- a/flatlaf-testing/src/main/java/com/formdev/flatlaf/testing/FlatSystemFileChooserLinuxTest.jfd
+++ b/flatlaf-testing/src/main/java/com/formdev/flatlaf/testing/FlatSystemFileChooserLinuxTest.jfd
@@ -0,0 +1,182 @@
+JFDML JFormDesigner: "8.3" encoding: "UTF-8"
+
+new FormModel {
+	contentType: "form/swing"
+	root: new FormRoot {
+		add( new FormContainer( "com.formdev.flatlaf.testing.FlatTestPanel", new FormLayoutManager( class net.miginfocom.swing.MigLayout ) {
+			"$layoutConstraints": "ltr,insets dialog,hidemode 3"
+			"$columnConstraints": "[left][grow,fill][fill]"
+			"$rowConstraints": "[][][][][][][][grow,fill]"
+		} ) {
+			name: "this"
+			add( new FormComponent( "javax.swing.JLabel" ) {
+				name: "titleLabel"
+				"text": "title"
+			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+				"value": "cell 0 0"
+			} )
+			add( new FormComponent( "javax.swing.JTextField" ) {
+				name: "titleField"
+			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+				"value": "cell 1 0"
+			} )
+			add( new FormContainer( "javax.swing.JPanel", new FormLayoutManager( class net.miginfocom.swing.MigLayout ) {
+				"$layoutConstraints": "insets 2,hidemode 3"
+				"$columnConstraints": "[left]"
+				"$rowConstraints": "[]0[]0[]0[]0[]0[]"
+			} ) {
+				name: "panel1"
+				add( new FormComponent( "com.formdev.flatlaf.extras.components.FlatTriStateCheckBox" ) {
+					name: "select_folderCheckBox"
+					"text": "select_folder"
+					"allowIndeterminate": false
+					"state": enum com.formdev.flatlaf.extras.components.FlatTriStateCheckBox$State UNSELECTED
+				}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+					"value": "cell 0 0"
+				} )
+				add( new FormComponent( "com.formdev.flatlaf.extras.components.FlatTriStateCheckBox" ) {
+					name: "select_multipleCheckBox"
+					"text": "select_multiple"
+					"state": enum com.formdev.flatlaf.extras.components.FlatTriStateCheckBox$State UNSELECTED
+					"allowIndeterminate": false
+				}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+					"value": "cell 0 1"
+				} )
+				add( new FormComponent( "com.formdev.flatlaf.extras.components.FlatTriStateCheckBox" ) {
+					name: "do_overwrite_confirmationCheckBox"
+					"text": "do_overwrite_confirmation"
+				}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+					"value": "cell 0 2"
+				} )
+				add( new FormComponent( "com.formdev.flatlaf.extras.components.FlatTriStateCheckBox" ) {
+					name: "create_foldersCheckBox"
+					"text": "create_folders"
+				}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+					"value": "cell 0 3"
+				} )
+				add( new FormComponent( "com.formdev.flatlaf.extras.components.FlatTriStateCheckBox" ) {
+					name: "show_hiddenCheckBox"
+					"text": "show_hidden"
+				}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+					"value": "cell 0 4"
+				} )
+				add( new FormComponent( "com.formdev.flatlaf.extras.components.FlatTriStateCheckBox" ) {
+					name: "local_onlyCheckBox"
+					"text": "local_only"
+				}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+					"value": "cell 0 5"
+				} )
+			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+				"value": "cell 2 0 1 6,aligny top,growy 0"
+			} )
+			add( new FormComponent( "javax.swing.JLabel" ) {
+				name: "okButtonLabelLabel"
+				"text": "okButtonLabel"
+			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+				"value": "cell 0 1"
+			} )
+			add( new FormComponent( "javax.swing.JTextField" ) {
+				name: "okButtonLabelField"
+			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+				"value": "cell 1 1"
+			} )
+			add( new FormComponent( "javax.swing.JLabel" ) {
+				name: "currentNameLabel"
+				"text": "currentName"
+			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+				"value": "cell 0 2"
+			} )
+			add( new FormComponent( "javax.swing.JTextField" ) {
+				name: "currentNameField"
+			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+				"value": "cell 1 2"
+			} )
+			add( new FormComponent( "javax.swing.JLabel" ) {
+				name: "currentFolderLabel"
+				"text": "currentFolder"
+			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+				"value": "cell 0 3"
+			} )
+			add( new FormComponent( "javax.swing.JTextField" ) {
+				name: "currentFolderField"
+			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+				"value": "cell 1 3"
+			} )
+			add( new FormComponent( "javax.swing.JLabel" ) {
+				name: "fileTypesLabel"
+				"text": "fileTypes"
+			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+				"value": "cell 0 4"
+			} )
+			add( new FormComponent( "javax.swing.JComboBox" ) {
+				name: "fileTypesField"
+				"editable": true
+				"model": new javax.swing.DefaultComboBoxModel {
+					selectedItem: "Text Files,*.txt,null"
+					addElement( "Text Files,*.txt,null" )
+					addElement( "All Files,*,null" )
+					addElement( "Text Files,*.txt,null,PDF Files,*.pdf,null,All Files,*,null" )
+					addElement( "Text and PDF Files,*.txt,*.pdf,null" )
+				}
+			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+				"value": "cell 1 4"
+			} )
+			add( new FormComponent( "javax.swing.JLabel" ) {
+				name: "fileTypeIndexLabel"
+				"text": "fileTypeIndex"
+			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+				"value": "cell 0 5"
+			} )
+			add( new FormComponent( "javax.swing.JSlider" ) {
+				name: "fileTypeIndexSlider"
+				"maximum": 10
+				"majorTickSpacing": 1
+				"value": 0
+				"paintLabels": true
+				"snapToTicks": true
+			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+				"value": "cell 1 5"
+			} )
+			add( new FormComponent( "javax.swing.JButton" ) {
+				name: "openButton"
+				"text": "Open..."
+				addEvent( new FormEvent( "java.awt.event.ActionListener", "actionPerformed", "open", false ) )
+			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+				"value": "cell 0 6 3 1"
+			} )
+			add( new FormComponent( "javax.swing.JButton" ) {
+				name: "saveButton"
+				"text": "Save..."
+				addEvent( new FormEvent( "java.awt.event.ActionListener", "actionPerformed", "save", false ) )
+			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+				"value": "cell 0 6 3 1"
+			} )
+			add( new FormComponent( "javax.swing.JButton" ) {
+				name: "openDirectButton"
+				"text": "Open (no-thread)..."
+				addEvent( new FormEvent( "java.awt.event.ActionListener", "actionPerformed", "openDirect", false ) )
+			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+				"value": "cell 0 6 3 1"
+			} )
+			add( new FormComponent( "javax.swing.JButton" ) {
+				name: "saveDirectButton"
+				"text": "Save (no-thread)..."
+				addEvent( new FormEvent( "java.awt.event.ActionListener", "actionPerformed", "saveDirect", false ) )
+			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+				"value": "cell 0 6 3 1"
+			} )
+			add( new FormContainer( "javax.swing.JScrollPane", new FormLayoutManager( class javax.swing.JScrollPane ) ) {
+				name: "filesScrollPane"
+				add( new FormComponent( "javax.swing.JTextArea" ) {
+					name: "filesField"
+					"rows": 8
+				} )
+			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+				"value": "cell 0 7 3 1,growx"
+			} )
+		}, new FormLayoutConstraints( null ) {
+			"location": new java.awt.Point( 0, 0 )
+			"size": new java.awt.Dimension( 690, 630 )
+		} )
+	}
+}