A few adjustments to file/dir open dialogs

editor/editor_file_dialog.cpp

@@ -197,6 +197,9 @@ Vector<String> EditorFileDialog::get_selected_files() const {
 void EditorFileDialog::update_dir() {
 
 	dir->set_text(dir_access->get_current_dir());
+
+	// Disable "Open" button only when we in selecting file(s) mode or open dir mode.
+	get_ok()->set_disabled(_is_open_should_be_disabled());
 }
 
 void EditorFileDialog::_dir_entered(String p_dir) {
@@ -452,6 +455,28 @@ void EditorFileDialog::_item_selected(int p_item) {
 		file->set_text(d["name"]);
 		_request_single_thumbnail(get_current_dir().plus_file(get_current_file()));
 	}
+
+	get_ok()->set_disabled(_is_open_should_be_disabled());
+}
+
+void EditorFileDialog::_items_clear_selection() {
+
+	item_list->unselect_all();
+
+	// If nothing is selected, then block Open button.
+	switch (mode) {
+
+		case MODE_OPEN_FILE:
+		case MODE_OPEN_FILES:
+			get_ok()->set_text(TTR("Open"));
+			get_ok()->set_disabled(item_list->is_anything_selected() == false);
+			break;
+
+		case MODE_OPEN_DIR:
+			get_ok()->set_disabled(false);
+			get_ok()->set_text(TTR("Select Current Folder"));
+			break;
+	}
 }
 
 void EditorFileDialog::_push_history() {
@@ -487,6 +512,26 @@ void EditorFileDialog::_item_dc_selected(int p_item) {
 	}
 }
 
+bool EditorFileDialog::_is_open_should_be_disabled() {
+
+	if (mode == MODE_OPEN_ANY || mode == MODE_SAVE_FILE)
+		return false;
+
+	Vector<int> items = item_list->get_selected_items();
+	if (items.size() == 0)
+		return true;
+
+	for (int i = 0; i < items.size(); i++) {
+
+		Dictionary d = item_list->get_item_metadata(items.get(i));
+
+		if (((mode == MODE_OPEN_FILE || mode == MODE_OPEN_FILES) && d["dir"]) || (mode == MODE_OPEN_DIR && !d["dir"]))
+			return true;
+	}
+
+	return false;
+}
+
 void EditorFileDialog::update_file_list() {
 
 	int thumbnail_size = EditorSettings::get_singleton()->get("filesystem/file_dialog/thumbnail_size");
@@ -681,6 +726,7 @@ void EditorFileDialog::update_file_list() {
 	favorite->set_pressed(false);
 	fav_up->set_disabled(true);
 	fav_down->set_disabled(true);
+	get_ok()->set_disabled(_is_open_should_be_disabled());
 	for (int i = 0; i < favorites->get_item_count(); i++) {
 		if (favorites->get_item_metadata(i) == base_dir) {
 			favorites->select(i);
@@ -1139,6 +1185,7 @@ void EditorFileDialog::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("_unhandled_input"), &EditorFileDialog::_unhandled_input);
 
 	ClassDB::bind_method(D_METHOD("_item_selected"), &EditorFileDialog::_item_selected);
+	ClassDB::bind_method(D_METHOD("_items_clear_selection"), &EditorFileDialog::_items_clear_selection);
 	ClassDB::bind_method(D_METHOD("_item_db_selected"), &EditorFileDialog::_item_dc_selected);
 	ClassDB::bind_method(D_METHOD("_dir_entered"), &EditorFileDialog::_dir_entered);
 	ClassDB::bind_method(D_METHOD("_file_entered"), &EditorFileDialog::_file_entered);
@@ -1415,6 +1462,7 @@ EditorFileDialog::EditorFileDialog() {
 	//cancel->connect("pressed", this,"_cancel_pressed");
 	item_list->connect("item_selected", this, "_item_selected", varray(), CONNECT_DEFERRED);
 	item_list->connect("item_activated", this, "_item_db_selected", varray());
+	item_list->connect("nothing_selected", this, "_items_clear_selection");
 	dir->connect("text_entered", this, "_dir_entered");
 	file->connect("text_entered", this, "_file_entered");
 	filter->connect("item_selected", this, "_filter_selected");

editor/editor_file_dialog.h

@@ -143,6 +143,7 @@ class EditorFileDialog : public ConfirmationDialog {
 	void _recent_selected(int p_idx);
 
 	void _item_selected(int p_item);
+	void _items_clear_selection();
 	void _item_dc_selected(int p_item);
 
 	void _select_drive(int p_idx);
@@ -172,6 +173,8 @@ class EditorFileDialog : public ConfirmationDialog {
 
 	void _unhandled_input(const Ref<InputEvent> &p_event);
 
+	bool _is_open_should_be_disabled();
+
 protected:
 	void _notification(int p_what);
 	static void _bind_methods();

scene/gui/file_dialog.cpp

@@ -85,6 +85,10 @@ void FileDialog::_unhandled_input(const Ref<InputEvent> &p_event) {
 
 					invalidate();
 				} break;
+				case KEY_BACKSPACE: {
+
+					_dir_entered("..");
+				} break;
 				default: { handled = false; }
 			}
 
@@ -189,7 +193,7 @@ void FileDialog::_action_pressed() {
 		TreeItem *item = tree->get_selected();
 		if (item) {
 			Dictionary d = item->get_metadata(0);
-			if (d["dir"]) {
+			if (d["dir"] && d["name"] != "..") {
 				path = path.plus_file(d["name"]);
 			}
 		}
@@ -272,6 +276,26 @@ void FileDialog::_cancel_pressed() {
 	hide();
 }
 
+bool FileDialog::_is_open_should_be_disabled() {
+
+	if (mode == MODE_OPEN_ANY || mode == MODE_SAVE_FILE)
+		return false;
+
+	TreeItem *ti = tree->get_selected();
+	// We have something that we can't select?
+	if (!ti)
+		return true;
+
+	Dictionary d = ti->get_metadata(0);
+
+	// Opening a file, but selected a folder? Forbidden.
+	if (((mode == MODE_OPEN_FILE || mode == MODE_OPEN_FILES) && d["dir"]) || // Flipped case, also forbidden.
+			(mode == MODE_OPEN_DIR && !d["dir"]))
+		return true;
+
+	return false;
+}
+
 void FileDialog::_tree_selected() {
 
 	TreeItem *ti = tree->get_selected();
@@ -283,6 +307,8 @@ void FileDialog::_tree_selected() {
 
 		file->set_text(d["name"]);
 	}
+
+	get_ok()->set_disabled(_is_open_should_be_disabled());
 }
 
 void FileDialog::_tree_dc_selected() {
@@ -563,7 +589,7 @@ void FileDialog::set_mode(Mode p_mode) {
 			makedir->hide();
 			break;
 		case MODE_OPEN_DIR:
-			get_ok()->set_text(RTR("Open"));
+			get_ok()->set_text(RTR("Select Current Folder"));
 			set_title(RTR("Open a Directory"));
 			makedir->show();
 			break;

scene/gui/file_dialog.h

@@ -33,7 +33,6 @@
 #include "box_container.h"
 #include "os/dir_access.h"
 #include "scene/gui/dialogs.h"
-#include "scene/gui/dialogs.h"
 #include "scene/gui/line_edit.h"
 #include "scene/gui/option_button.h"
 #include "scene/gui/tool_button.h"
@@ -117,6 +116,8 @@ class FileDialog : public ConfirmationDialog {
 
 	void _unhandled_input(const Ref<InputEvent> &p_event);
 
+	bool _is_open_should_be_disabled();
+
 	virtual void _post_popup();
 
 protected: