System File Chooser: support "approve" callback and system message dialog on macOS (not yet used in SystemFileChooser

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

@@ -18,6 +18,7 @@ package com.formdev.flatlaf.ui;
 
 import java.awt.Rectangle;
 import java.awt.Window;
+import javax.swing.JOptionPane;
 import com.formdev.flatlaf.util.SystemInfo;
 
 /**
@@ -122,5 +123,32 @@ public class FlatNativeMacLibrary
 	public native static String[] showFileChooser( boolean open,
 		String title, String prompt, String message, String filterFieldLabel,
 		String nameFieldLabel, String nameFieldStringValue, String directoryURL,
-		int optionsSet, int optionsClear, int fileTypeIndex, String... fileTypes );
+		int optionsSet, int optionsClear, FileChooserCallback callback,
+		int fileTypeIndex, String... fileTypes );
+
+	/** @since 3.6 */
+	public interface FileChooserCallback {
+		boolean approve( String[] files, long hwndFileDialog );
+	}
+
+	/**
+	 * Shows a macOS alert
+	 * <a href="https://developer.apple.com/documentation/appkit/nsalert?language=objc">NSAlert</a>.
+	 * <p>
+	 * For use in {@link FileChooserCallback} only.
+	 *
+	 * @param hwndParent the parent of the message box
+	 * @param alertStyle type of alert being displayed:
+	 *        {@link JOptionPane#ERROR_MESSAGE}, {@link JOptionPane#INFORMATION_MESSAGE} or
+	 *        {@link JOptionPane#WARNING_MESSAGE}
+	 * @param messageText main message of the alert
+	 * @param informativeText additional information about the alert; shown below of main message; or {@code null}
+	 * @param defaultButton index of the default button, which can be pressed using ENTER key
+	 * @param buttons texts of the buttons; if no buttons given the a default "OK" button is shown
+	 * @return index of pressed button
+	 *
+	 * @since 3.6
+	 */
+	public native static int showMessageDialog( long hwndParent, int alertStyle,
+		String messageText, String informativeText, int defaultButton, String... buttons );
 }

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

@@ -616,8 +616,8 @@ public class SystemFileChooser
 			// show system file dialog
 			return FlatNativeMacLibrary.showFileChooser( open,
 				fc.getDialogTitle(), fc.getApproveButtonText(), null, null, null,
-				nameFieldStringValue, directoryURL,
-				optionsSet, optionsClear, fileTypeIndex, fileTypes.toArray( new String[fileTypes.size()] ) );
+				nameFieldStringValue, directoryURL, optionsSet, optionsClear, null,
+				fileTypeIndex, fileTypes.toArray( new String[fileTypes.size()] ) );
 		}
 	}
 

flatlaf-natives/flatlaf-natives-macos/src/main/headers/JNIUtils.h

@@ -29,15 +29,43 @@
 #endif
 
 
+#define JNI_COCOA_TRY() \
+	@try {
+
+#define JNI_COCOA_CATCH() \
+	} @catch( NSException *ex ) { \
+		NSLog( @"Exception: %@\nReason: %@\nUser Info: %@\nStack: %@", \
+			[ex name], [ex reason], [ex userInfo], [ex callStackSymbols] ); \
+	}
+
 #define JNI_COCOA_ENTER() \
 	@autoreleasepool { \
-		@try {
+		JNI_COCOA_TRY()
 
 #define JNI_COCOA_EXIT() \
-		} @catch( NSException *ex ) { \
- 			NSLog( @"Exception: %@\nReason: %@\nUser Info: %@\nStack: %@", \
- 				[ex name], [ex reason], [ex userInfo], [ex callStackSymbols] ); \
- 		} \
+		JNI_COCOA_CATCH() \
+	}
+
+#define JNI_THREAD_ENTER( jvm, returnValue ) \
+	JNIEnv *env; \
+	bool detach = false; \
+	switch( jvm->GetEnv( (void**) &env, JNI_VERSION_1_6 ) ) { \
+		case JNI_OK: break; \
+		case JNI_EDETACHED: \
+			if( jvm->AttachCurrentThread( (void**) &env, NULL ) != JNI_OK ) \
+				return returnValue; \
+			detach = true; \
+			break; \
+		default: return returnValue; \
+	} \
+	@try {
+
+#define JNI_THREAD_EXIT( jvm ) \
+	} @finally { \
+		if( env->ExceptionCheck() ) \
+			env->ExceptionDescribe(); \
+		if( detach ) \
+			jvm->DetachCurrentThread(); \
 	}
 
 

flatlaf-natives/flatlaf-natives-macos/src/main/headers/com_formdev_flatlaf_ui_FlatNativeMacLibrary.h

@@ -82,10 +82,18 @@ JNIEXPORT jboolean JNICALL Java_com_formdev_flatlaf_ui_FlatNativeMacLibrary_togg
 /*
  * Class:     com_formdev_flatlaf_ui_FlatNativeMacLibrary
  * Method:    showFileChooser
- * Signature: (ZLjava/lang/String;Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;III[Ljava/lang/String;)[Ljava/lang/String;
+ * Signature: (ZLjava/lang/String;Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;IILcom/formdev/flatlaf/ui/FlatNativeMacLibrary/FileChooserCallback;I[Ljava/lang/String;)[Ljava/lang/String;
  */
 JNIEXPORT jobjectArray JNICALL Java_com_formdev_flatlaf_ui_FlatNativeMacLibrary_showFileChooser
-  (JNIEnv *, jclass, jboolean, jstring, jstring, jstring, jstring, jstring, jstring, jstring, jint, jint, jint, jobjectArray);
+  (JNIEnv *, jclass, jboolean, jstring, jstring, jstring, jstring, jstring, jstring, jstring, jint, jint, jobject, jint, jobjectArray);
+
+/*
+ * Class:     com_formdev_flatlaf_ui_FlatNativeMacLibrary
+ * Method:    showMessageDialog
+ * Signature: (JILjava/lang/String;Ljava/lang/String;I[Ljava/lang/String;)I
+ */
+JNIEXPORT jint JNICALL Java_com_formdev_flatlaf_ui_FlatNativeMacLibrary_showMessageDialog
+  (JNIEnv *, jclass, jlong, jint, jstring, jstring, jint, jobjectArray);
 
 #ifdef __cplusplus
 }

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

@@ -26,10 +26,19 @@
  * @since 3.6
  */
 
+// declare internal methods
+static jobjectArray newJavaStringArray( JNIEnv* env, jsize count );
+static jobjectArray urlsToStringArray( JNIEnv* env, NSArray* urls );
+static NSArray* getDialogURLs( NSSavePanel* dialog );
+
 //---- class FileChooserDelegate ----------------------------------------------
 
-@interface FileChooserDelegate : NSObject {
+@interface FileChooserDelegate : NSObject <NSOpenSavePanelDelegate> {
 		NSArray* _filters;
+
+		JavaVM* _jvm;
+		jobject _callback;
+		NSMutableSet* _urlsSet;
 	}
 
 	@property (nonatomic, assign) NSSavePanel* dialog;
@@ -118,6 +127,53 @@
 		_dialog.allowedFileTypes = [fileTypes containsObject:@"*"] ? nil : fileTypes;
 	}
 
+	//---- NSOpenSavePanelDelegate ----
+
+	- (void)initCallback: (JavaVM*)jvm :(jobject)callback {
+		_jvm = jvm;
+		_callback = callback;
+	}
+
+	- (BOOL) panel:(id) sender validateURL:(NSURL*) url error:(NSError**) outError {
+		JNI_COCOA_TRY()
+
+		NSArray* urls = getDialogURLs( sender );
+
+		// if multiple files are selected for opening, then the validateURL method
+		// is invoked for earch file, but our callback should be invoked only once for all files
+		if( urls != NULL && urls.count > 1 ) {
+			if( _urlsSet == NULL ) {
+				// invoked for first selected file --> invoke callback
+				_urlsSet = [NSMutableSet setWithArray:urls];
+				[_urlsSet removeObject:url];
+			} else {
+				// invoked for other selected files --> do not invoke callback
+				[_urlsSet removeObject:url];
+				if( _urlsSet.count == 0 )
+					_urlsSet = NULL;
+				return true;
+			}
+		}
+
+		JNI_THREAD_ENTER( _jvm, true )
+
+		jobjectArray files = urlsToStringArray( env, urls );
+		jlong window = (jlong) sender;
+
+		// invoke callback: boolean approve( String[] files, long hwnd );
+		jclass cls = env->GetObjectClass( _callback );
+		jmethodID approveID = env->GetMethodID( cls, "approve", "([Ljava/lang/String;J)Z" );
+		if( approveID != NULL && !env->CallBooleanMethod( _callback, approveID, files, window ) ) {
+			_urlsSet = NULL;
+			return false; // keep dialog open
+		}
+
+		JNI_THREAD_EXIT( _jvm )
+		JNI_COCOA_CATCH()
+
+		return true;
+	}
+
 @end
 
 //---- helper -----------------------------------------------------------------
@@ -126,9 +182,6 @@
 #define isOptionClear( option ) ((optionsClear & com_formdev_flatlaf_ui_FlatNativeMacLibrary_ ## option) != 0)
 #define isOptionSetOrClear( option ) isOptionSet( option ) || isOptionClear( option )
 
-// declare external methods
-extern NSWindow* getNSWindow( JNIEnv* env, jclass cls, jobject window );
-
 static jobjectArray newJavaStringArray( JNIEnv* env, jsize count ) {
 	jclass stringClass = env->FindClass( "java/lang/String" );
 	return env->NewObjectArray( count, stringClass, NULL );
@@ -182,10 +235,14 @@ JNIEXPORT jobjectArray JNICALL Java_com_formdev_flatlaf_ui_FlatNativeMacLibrary_
 	( JNIEnv* env, jclass cls, jboolean open,
 		jstring title, jstring prompt, jstring message, jstring filterFieldLabel,
 		jstring nameFieldLabel, jstring nameFieldStringValue, jstring directoryURL,
-		jint optionsSet, jint optionsClear, jint fileTypeIndex, jobjectArray fileTypes )
+		jint optionsSet, jint optionsClear, jobject callback, jint fileTypeIndex, jobjectArray fileTypes )
 {
 	JNI_COCOA_ENTER()
 
+	JavaVM* jvm;
+	if( env->GetJavaVM( &jvm ) != JNI_OK )
+		return NULL;
+
 	// convert Java strings to NSString (on Java thread)
 	NSString* nsTitle = JavaToNSString( env, title );
 	NSString* nsPrompt = JavaToNSString( env, prompt );
@@ -198,11 +255,11 @@ JNIEXPORT jobjectArray JNICALL Java_com_formdev_flatlaf_ui_FlatNativeMacLibrary_
 
 	NSArray* urls = NULL;
 	NSArray** purls = &urls;
-	NSURL* url = NULL;
-	NSURL** purl = &url;
 
 	// show file dialog on macOS thread
 	[FlatJNFRunLoop performOnMainThreadWaiting:YES withBlock:^(){
+		JNI_COCOA_TRY()
+
 		NSSavePanel* dialog = open ? [NSOpenPanel openPanel] : [NSSavePanel savePanel];
 
 		if( nsTitle != NULL )
@@ -262,35 +319,108 @@ JNIEXPORT jobjectArray JNICALL Java_com_formdev_flatlaf_ui_FlatNativeMacLibrary_
 				((NSOpenPanel*)dialog).accessoryViewDisclosed = isOptionSet( FC_accessoryViewDisclosed );
 		}
 
+		// initialize callback
+		if( callback != NULL ) {
+			[delegate initCallback :jvm :callback];
+			dialog.delegate = delegate;
+		}
+
 		// show dialog
 		NSModalResponse response = [dialog runModal];
 		[delegate release];
-		if( response != NSModalResponseOK )
+		if( response != NSModalResponseOK ) {
+			*purls = @[];
 			return;
+		}
 
-		if( open )
-			*purls = ((NSOpenPanel*)dialog).URLs;
-		else
-			*purl = dialog.URL;
+		*purls = getDialogURLs( dialog );
+
+		JNI_COCOA_CATCH()
 	}];
 
-	if( url != NULL )
-		urls = @[url];
-
 	if( urls == NULL )
-		return newJavaStringArray( env, 0 );
+		return NULL;
 
 	// convert URLs to Java string array
-	jsize count = urls.count;
+	return urlsToStringArray( env, urls );
+
+	JNI_COCOA_EXIT()
+}
+
+static NSArray* getDialogURLs( NSSavePanel* dialog ) {
+	if( [dialog isKindOfClass:[NSOpenPanel class]] )
+		return static_cast<NSOpenPanel*>(dialog).URLs;
+
+	NSURL* url = dialog.URL;
+	// use '[[NSArray alloc] initWithObject:url]' here because '@[url]' crashes on macOS 10.14
+	return (url != NULL) ? [[NSArray alloc] initWithObject:url] : @[];
+}
+
+static jobjectArray urlsToStringArray( JNIEnv* env, NSArray* urls ) {
+	jsize count = (urls != NULL) ? urls.count : 0;
 	jobjectArray array = newJavaStringArray( env, count );
 	for( int i = 0; i < count; i++ ) {
 		jstring filename = NormalizedPathJavaFromNSString( env, [urls[i] path] );
 		env->SetObjectArrayElement( array, i, filename );
 		env->DeleteLocalRef( filename );
 	}
-
 	return array;
+}
+
+extern "C"
+JNIEXPORT jint JNICALL Java_com_formdev_flatlaf_ui_FlatNativeMacLibrary_showMessageDialog
+	( JNIEnv* env, jclass cls, jlong hwndParent, jint alertStyle, jstring messageText, jstring informativeText,
+		jint defaultButton, jobjectArray buttons )
+{
+	JNI_COCOA_ENTER()
+
+	// convert Java strings to NSString (on Java thread)
+	NSString* nsMessageText = JavaToNSString( env, messageText );
+	NSString* nsInformativeText = JavaToNSString( env, informativeText );
+
+	jint buttonCount = env->GetArrayLength( buttons );
+	NSMutableArray* nsButtons = [NSMutableArray array];
+	for( int i = 0; i < buttonCount; i++ ) {
+		NSString* nsButton = JavaToNSString( env, (jstring) env->GetObjectArrayElement( buttons, i ) );
+		[nsButtons addObject:nsButton];
+	}
+
+	jint result = -1;
+	jint* presult = &result;
+
+	// show alert on macOS thread
+	[FlatJNFRunLoop performOnMainThreadWaiting:YES withBlock:^(){
+		NSAlert* alert = [[NSAlert alloc] init];
+
+		// use empty string because if alert.messageText is not set it displays "Alert"
+		alert.messageText = (nsMessageText != NULL) ? nsMessageText : @"";
+		if( nsInformativeText != NULL )
+			alert.informativeText = nsInformativeText;
+
+		// alert style
+		switch( alertStyle ) {
+			case /* JOptionPane.ERROR_MESSAGE */       0: alert.alertStyle = NSAlertStyleCritical; break;
+			default:
+			case /* JOptionPane.INFORMATION_MESSAGE */ 1: alert.alertStyle = NSAlertStyleInformational; break;
+			case /* JOptionPane.WARNING_MESSAGE */     2: alert.alertStyle = NSAlertStyleWarning; break;
+		}
+
+		// add buttons
+		for( int i = 0; i < nsButtons.count; i++ ) {
+			NSButton* b = [alert addButtonWithTitle:nsButtons[i]];
+			if( i == defaultButton )
+				alert.window.defaultButtonCell = b.cell;
+		}
+
+		// show alert
+		NSInteger response = [alert runModal];
+
+		// if no buttons added, which shows a single OK button, the response is 0 when clicking OK
+		// if buttons added, response is 1000+buttonIndex
+		*presult = MAX( response - NSAlertFirstButtonReturn, 0 );
+	}];
+
+	return result;
 
 	JNI_COCOA_EXIT()
 }
-

flatlaf-testing/src/main/java/com/formdev/flatlaf/testing/FlatSystemFileChooserMacTest.java

@@ -59,7 +59,7 @@ public class FlatSystemFileChooserMacTest
 			}
 
 			FlatTestFrame frame = FlatTestFrame.create( args, "FlatSystemFileChooserMacTest" );
-			addListeners( frame );
+//			addListeners( frame );
 			frame.showFrame( FlatSystemFileChooserMacTest::new );
 		} );
 	}
@@ -133,11 +133,24 @@ public class FlatSystemFileChooserMacTest
 		}
 		int fileTypeIndex = fileTypeIndexSlider.getValue();
 
+		FlatNativeMacLibrary.FileChooserCallback callback = (files, hwndFileDialog) -> {
+			System.out.println( "  -- callback " + hwndFileDialog + "  " + Arrays.toString( files ) );
+			if( showMessageDialogOnOKCheckBox.isSelected() ) {
+				int result = FlatNativeMacLibrary.showMessageDialog( hwndFileDialog,
+					JOptionPane.INFORMATION_MESSAGE,
+					"primary text", "secondary text", 0, "Yes", "No" );
+				System.out.println( "     result   " + result );
+				if( result != 0 )
+					return false;
+			}
+			return true;
+		};
+
 		if( direct ) {
 			String[] files = FlatNativeMacLibrary.showFileChooser( open,
 				title, prompt, message, filterFieldLabel,
 				nameFieldLabel, nameFieldStringValue, directoryURL,
-				optionsSet.get(), optionsClear.get(), fileTypeIndex, fileTypes );
+				optionsSet.get(), optionsClear.get(), callback, fileTypeIndex, fileTypes );
 
 			filesField.setText( (files != null) ? Arrays.toString( files ).replace( ',', '\n' ) : "null" );
 		} else {
@@ -148,7 +161,7 @@ public class FlatSystemFileChooserMacTest
 				String[] files = FlatNativeMacLibrary.showFileChooser( open,
 					title, prompt, message, filterFieldLabel,
 					nameFieldLabel, nameFieldStringValue, directoryURL,
-					optionsSet.get(), optionsClear.get(), fileTypeIndex, fileTypes2 );
+					optionsSet.get(), optionsClear.get(), callback, fileTypeIndex, fileTypes2 );
 
 				System.out.println( "    secondaryLoop.exit() returned " + secondaryLoop.exit() );
 
@@ -173,6 +186,7 @@ public class FlatSystemFileChooserMacTest
 			optionsClear.set( optionsClear.get() | option );
 	}
 
+	@SuppressWarnings( "unused" )
 	private static void addListeners( Window w ) {
 		w.addWindowListener( new WindowListener() {
 			@Override
@@ -270,6 +284,7 @@ public class FlatSystemFileChooserMacTest
 		saveButton = new JButton();
 		openDirectButton = new JButton();
 		saveDirectButton = new JButton();
+		showMessageDialogOnOKCheckBox = new JCheckBox();
 		filesScrollPane = new JScrollPane();
 		filesField = new JTextArea();
 
@@ -468,6 +483,10 @@ public class FlatSystemFileChooserMacTest
 		saveDirectButton.addActionListener(e -> saveDirect());
 		add(saveDirectButton, "cell 0 10 3 1");
 
+		//---- showMessageDialogOnOKCheckBox ----
+		showMessageDialogOnOKCheckBox.setText("show message dialog on OK");
+		add(showMessageDialogOnOKCheckBox, "cell 0 10 3 1");
+
 		//======== filesScrollPane ========
 		{
 
@@ -519,6 +538,7 @@ public class FlatSystemFileChooserMacTest
 	private JButton saveButton;
 	private JButton openDirectButton;
 	private JButton saveDirectButton;
+	private JCheckBox showMessageDialogOnOKCheckBox;
 	private JScrollPane filesScrollPane;
 	private JTextArea filesField;
 	// JFormDesigner - End of variables declaration  //GEN-END:variables

flatlaf-testing/src/main/java/com/formdev/flatlaf/testing/FlatSystemFileChooserMacTest.jfd

@@ -257,6 +257,12 @@ new FormModel {
 			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
 				"value": "cell 0 10 3 1"
 			} )
+			add( new FormComponent( "javax.swing.JCheckBox" ) {
+				name: "showMessageDialogOnOKCheckBox"
+				"text": "show message dialog on OK"
+			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+				"value": "cell 0 10 3 1"
+			} )
 			add( new FormContainer( "javax.swing.JScrollPane", new FormLayoutManager( class javax.swing.JScrollPane ) ) {
 				name: "filesScrollPane"
 				add( new FormComponent( "javax.swing.JTextArea" ) {