ExportDialog: Validate path before allowing export

Otherwise one could quite easily end up with the exported game
being hidden files named ".x86_64" and ".pck" for example.

Also improved the default filename logic a bit to also include
extension, and never fallback to an empty string.

Also fixed being able to click "Export project" without selecting
a preset.

editor/project_export.cpp

@@ -723,6 +723,25 @@ void ProjectExportDialog::_open_export_template_manager() {
 	hide();
 }
 
+void ProjectExportDialog::_validate_export_path(const String &p_path) {
+	// Disable export via OK button or Enter key if LineEdit has an empty filename
+	bool invalid_path = (p_path.get_file().get_basename() == "");
+
+	// Check if state change before needlessly messing with signals
+	if (invalid_path && export_project->get_ok()->is_disabled())
+		return;
+	if (!invalid_path && !export_project->get_ok()->is_disabled())
+		return;
+
+	if (invalid_path) {
+		export_project->get_ok()->set_disabled(true);
+		export_project->get_line_edit()->disconnect("text_entered", export_project, "_file_entered");
+	} else {
+		export_project->get_ok()->set_disabled(false);
+		export_project->get_line_edit()->connect("text_entered", export_project, "_file_entered");
+	}
+}
+
 void ProjectExportDialog::_export_project() {
 
 	Ref<EditorExportPreset> current = EditorExport::get_singleton()->get_export_preset(presets->get_current());
@@ -732,12 +751,19 @@ void ProjectExportDialog::_export_project() {
 
 	export_project->set_access(FileDialog::ACCESS_FILESYSTEM);
 	export_project->clear_filters();
-	export_project->set_current_file(default_filename);
 
 	String extension = platform->get_binary_extension(current);
-
 	if (extension != String()) {
 		export_project->add_filter("*." + extension + " ; " + platform->get_name() + " Export");
+		export_project->set_current_file(default_filename + "." + extension);
+	} else {
+		export_project->set_current_file(default_filename);
+	}
+
+	// Ensure that signal is connected if previous attempt left it disconnected with _validate_export_path
+	if (!export_project->get_line_edit()->is_connected("text_entered", export_project, "_file_entered")) {
+		export_project->get_ok()->set_disabled(false);
+		export_project->get_line_edit()->connect("text_entered", export_project, "_file_entered");
 	}
 
 	export_project->set_mode(FileDialog::MODE_SAVE_FILE);
@@ -746,7 +772,7 @@ void ProjectExportDialog::_export_project() {
 
 void ProjectExportDialog::_export_project_to_path(const String &p_path) {
 	// Save this name for use in future exports (but drop the file extension)
-	default_filename = p_path.get_basename().get_file();
+	default_filename = p_path.get_file().get_basename();
 	EditorSettings::get_singleton()->set_project_metadata("export_options", "default_filename", default_filename);
 
 	Ref<EditorExportPreset> current = EditorExport::get_singleton()->get_export_preset(presets->get_current());
@@ -785,11 +811,13 @@ void ProjectExportDialog::_bind_methods() {
 	ClassDB::bind_method("_export_pck_zip", &ProjectExportDialog::_export_pck_zip);
 	ClassDB::bind_method("_export_pck_zip_selected", &ProjectExportDialog::_export_pck_zip_selected);
 	ClassDB::bind_method("_open_export_template_manager", &ProjectExportDialog::_open_export_template_manager);
+	ClassDB::bind_method("_validate_export_path", &ProjectExportDialog::_validate_export_path);
 	ClassDB::bind_method("_export_project", &ProjectExportDialog::_export_project);
 	ClassDB::bind_method("_export_project_to_path", &ProjectExportDialog::_export_project_to_path);
 	ClassDB::bind_method("_custom_features_changed", &ProjectExportDialog::_custom_features_changed);
 	ClassDB::bind_method("_tab_changed", &ProjectExportDialog::_tab_changed);
 }
+
 ProjectExportDialog::ProjectExportDialog() {
 
 	set_title(TTR("Export"));
@@ -942,6 +970,9 @@ ProjectExportDialog::ProjectExportDialog() {
 	get_cancel()->set_text(TTR("Close"));
 	get_ok()->set_text(TTR("Export PCK/Zip"));
 	export_button = add_button(TTR("Export Project"), !OS::get_singleton()->get_swap_ok_cancel(), "export");
+	export_button->connect("pressed", this, "_export_project");
+	// Disable initially before we select a valid preset
+	export_button->set_disabled(true);
 
 	export_pck_zip = memnew(FileDialog);
 	export_pck_zip->add_filter("*.zip ; ZIP File");
@@ -981,7 +1012,7 @@ ProjectExportDialog::ProjectExportDialog() {
 	export_project->set_access(FileDialog::ACCESS_FILESYSTEM);
 	add_child(export_project);
 	export_project->connect("file_selected", this, "_export_project_to_path");
-	export_button->connect("pressed", this, "_export_project");
+	export_project->get_line_edit()->connect("text_changed", this, "_validate_export_path");
 
 	export_debug = memnew(CheckButton);
 	export_debug->set_text(TTR("Export With Debug"));
@@ -997,10 +1028,14 @@ ProjectExportDialog::ProjectExportDialog() {
 
 	editor_icons = "EditorIcons";
 
-	default_filename = EditorSettings::get_singleton()->get_project_metadata("export_options", "default_filename", String());
-
+	default_filename = EditorSettings::get_singleton()->get_project_metadata("export_options", "default_filename", "");
+	// If no default set, use project name
 	if (default_filename == "") {
+		// If no project name defined, use a sane default
 		default_filename = ProjectSettings::get_singleton()->get("application/config/name");
+		if (default_filename == "") {
+			default_filename = "UnnamedProject";
+		}
 	}
 }
 

editor/project_export.h

@@ -136,6 +136,7 @@ private:
 	void _export_pck_zip();
 	void _export_pck_zip_selected(const String &p_path);
 
+	void _validate_export_path(const String &p_path);
 	void _export_project();
 	void _export_project_to_path(const String &p_path);