System File Chooser: support macOS in class SystemFileChooser

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatNativeMacLibrary.java

@@ -72,7 +72,7 @@ public class FlatNativeMacLibrary
 
 	/** @since 3.6 */
 	public static final int
-		// NSOpenPanel
+		// NSOpenPanel (extends NSSavePanel)
 		FC_canChooseFiles					= 1 << 0,  // default
 		FC_canChooseDirectories				= 1 << 1,
 		FC_resolvesAliases					= 1 << 2,  // default
@@ -105,7 +105,8 @@ public class FlatNativeMacLibrary
 	 * @param optionsSet options to set; see {@code FC_*} constants
 	 * @param optionsClear options to clear; see {@code FC_*} constants
 	 * @param allowedFileTypes allowed filename extensions (e.g. "txt")
-	 * @return file path(s) that the user selected, or {@code null} if canceled
+	 * @return file path(s) that the user selected; an empty array if canceled;
+	 *         or {@code null} on failures (no dialog shown)
 	 *
 	 * @since 3.6
 	 */

flatlaf-core/src/main/java/com/formdev/flatlaf/util/SystemFileChooser.java

@@ -31,6 +31,7 @@ import javax.swing.UIManager;
 import javax.swing.filechooser.FileSystemView;
 import com.formdev.flatlaf.FlatSystemProperties;
 import com.formdev.flatlaf.ui.FlatNativeLinuxLibrary;
+import com.formdev.flatlaf.ui.FlatNativeMacLibrary;
 import com.formdev.flatlaf.ui.FlatNativeWindowsLibrary;
 
 /**
@@ -61,7 +62,11 @@ import com.formdev.flatlaf.ui.FlatNativeWindowsLibrary;
  *       If user selects "Yes", the file chooser closes. If user selects "No", the file chooser stays open.
  *       It is not possible to customize that question dialog.
  *   <li><b>Save File</b> dialog does not support multi-selection.
+ *   <li>For selection mode {@link #DIRECTORIES_ONLY}, dialog type {@link #SAVE_DIALOG} is ignored.
+ *       Operating system file dialogs support folder selection only in "Open" dialogs.
  *   <li>{@link JFileChooser#FILES_AND_DIRECTORIES} is not supported.
+ *   <li>{@link #getSelectedFiles()} returns selected file also in single selection mode.
+ *       {@link JFileChooser#getSelectedFiles()} only in multi selection mode.
  * </ul>
  *
  * @author Karl Tauber
@@ -289,6 +294,8 @@ public class SystemFileChooser
 
 		if( SystemInfo.isWindows_10_orLater && FlatNativeWindowsLibrary.isLoaded() )
 			return new WindowsFileChooserProvider();
+		else if( SystemInfo.isMacOS && FlatNativeMacLibrary.isLoaded() )
+			return new MacFileChooserProvider();
 		else if( SystemInfo.isLinux && FlatNativeLinuxLibrary.isLoaded() )
 			return new LinuxFileChooserProvider();
 		else // unknown platform or FlatLaf native library not loaded
@@ -413,7 +420,52 @@ public class SystemFileChooser
 		}
 	}
 
-	//---- class LinuxFileChooserProvider -----------------------------------..
+	//---- class MacFileChooserProvider ---------------------------------------
+
+	private static class MacFileChooserProvider
+		extends SystemFileChooserProvider
+	{
+		@Override
+		String[] showSystemDialog( Window owner, SystemFileChooser fc ) {
+			boolean open = (fc.getDialogType() == OPEN_DIALOG);
+			String nameFieldStringValue = null;
+			String directoryURL = null;
+
+			// paths
+			File currentDirectory = fc.getCurrentDirectory();
+			File selectedFile = fc.getSelectedFile();
+			if( selectedFile != null ) {
+				if( selectedFile.isDirectory() )
+					directoryURL = selectedFile.getAbsolutePath();
+				else {
+					nameFieldStringValue = selectedFile.getName();
+					directoryURL = selectedFile.getParent();
+				}
+			} else if( currentDirectory != null )
+				directoryURL = currentDirectory.getAbsolutePath();
+
+			// options
+			int optionsSet = 0;
+			int optionsClear = 0;
+			if( fc.isDirectorySelectionEnabled() ) {
+				optionsSet |= FlatNativeMacLibrary.FC_canChooseDirectories;
+				optionsClear |= FlatNativeMacLibrary.FC_canChooseFiles;
+				open = true;
+			}
+			if( fc.isMultiSelectionEnabled() )
+				optionsSet |= FlatNativeMacLibrary.FC_allowsMultipleSelection;
+			if( !fc.isFileHidingEnabled() )
+				optionsSet |= FlatNativeMacLibrary.FC_showsHiddenFiles;
+
+			// show system file dialog
+			return FlatNativeMacLibrary.showFileChooser( open,
+				fc.getDialogTitle(), fc.getApproveButtonText(), null, null,
+				nameFieldStringValue, directoryURL,
+				optionsSet, optionsClear );
+		}
+	}
+
+	//---- class LinuxFileChooserProvider -------------------------------------
 
 	private static class LinuxFileChooserProvider
 		extends SystemFileChooserProvider

flatlaf-natives/flatlaf-natives-macos/src/main/objcpp/MacFileChooser.mm

@@ -23,15 +23,23 @@
 
 /**
  * @author Karl Tauber
+ * @since 3.6
  */
 
+//---- helper -----------------------------------------------------------------
+
 #define isOptionSet( option ) ((optionsSet & com_formdev_flatlaf_ui_FlatNativeMacLibrary_ ## option) != 0)
 #define isOptionClear( option ) ((optionsClear & com_formdev_flatlaf_ui_FlatNativeMacLibrary_ ## option) != 0)
 #define isOptionSetOrClear( option ) isOptionSet( option ) || isOptionClear( option )
 
-// declare internal methods
+// declare methods
 NSWindow* getNSWindow( JNIEnv* env, jclass cls, jobject window );
 
+jobjectArray newJavaStringArray( JNIEnv* env, jsize count ) {
+	jclass stringClass = env->FindClass( "java/lang/String" );
+	return env->NewObjectArray( count, stringClass, NULL );
+}
+
 //---- JNI methods ------------------------------------------------------------
 
 extern "C"
@@ -135,19 +143,18 @@ JNIEXPORT jobjectArray JNICALL Java_com_formdev_flatlaf_ui_FlatNativeMacLibrary_
 		urls = @[url];
 
 	if( urls == NULL )
-		return NULL;
+		return newJavaStringArray( env, 0 );
 
 	// convert URLs to Java string array
 	jsize count = urls.count;
-	jclass stringClass = env->FindClass( "java/lang/String" );
-	jobjectArray result = env->NewObjectArray( count, stringClass, NULL );
+	jobjectArray array = newJavaStringArray( env, count );
 	for( int i = 0; i < count; i++ ) {
 		jstring filename = NormalizedPathJavaFromNSString( env, [urls[i] path] );
-		env->SetObjectArrayElement( result, i, filename );
+		env->SetObjectArrayElement( array, i, filename );
 		env->DeleteLocalRef( filename );
 	}
 
-	return result;
+	return array;
 
 	JNI_COCOA_EXIT()
 }