System File Chooser: implemented native bindings for GtkFileChooserDialog on Linux

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;
+}