Implement Animation Libraries

* Instead of containing single animations, AnimationPlayer now contains libraries.
* Libraries, in turn, contain the animations.

This paves the way for implementing the possibility of importing scenes as animation libraries, finally allowing to import animations separate from the 3D models.

Missing (will be done on separate PRs):

* Make it possible to import scenes (dae/fbx/gltf) as animation libraries.
* Make it possible for AnimationTree to import animation libraries on its own, so it does not rely on AnimationPlayer for everything.

1 files changed, 40 insertions, 7 deletions

diff --git a/scene/gui/option_button.cpp b/scene/gui/option_button.cpp
index 1e8a149e11..307696c44a 100644
--- a/scene/gui/option_button.cpp
+++ b/scene/gui/option_button.cpp
@@ -203,16 +203,18 @@ void OptionButton::pressed() {
 }
 
 void OptionButton::add_icon_item(const Ref<Texture2D> &p_icon, const String &p_label, int p_id) {
+	bool first_selectable = !has_selectable_items();
 	popup->add_icon_radio_check_item(p_icon, p_label, p_id);
-	if (popup->get_item_count() == 1) {
-		select(0);
+	if (first_selectable) {
+		select(get_item_count() - 1);
 	}
 }
 
 void OptionButton::add_item(const String &p_label, int p_id) {
+	bool first_selectable = !has_selectable_items();
 	popup->add_radio_check_item(p_label, p_id);
-	if (popup->get_item_count() == 1) {
-		select(0);
+	if (first_selectable) {
+		select(get_item_count() - 1);
 	}
 }
 
@@ -280,6 +282,9 @@ bool OptionButton::is_item_disabled(int p_idx) const {
 	return popup->is_item_disabled(p_idx);
 }
 
+bool OptionButton::is_item_separator(int p_idx) const {
+	return popup->is_item_separator(p_idx);
+}
 void OptionButton::set_item_count(int p_count) {
 	ERR_FAIL_COND(p_count < 0);
 
@@ -299,12 +304,37 @@ void OptionButton::set_item_count(int p_count) {
 	notify_property_list_changed();
 }
 
+bool OptionButton::has_selectable_items() const {
+	for (int i = 0; i < get_item_count(); i++) {
+		if (!is_item_disabled(i) && !is_item_separator(i)) {
+			return true;
+		}
+	}
+	return false;
+}
+int OptionButton::get_selectable_item(bool p_from_last) const {
+	if (!p_from_last) {
+		for (int i = 0; i < get_item_count(); i++) {
+			if (!is_item_disabled(i) && !is_item_separator(i)) {
+				return i;
+			}
+		}
+	} else {
+		for (int i = get_item_count() - 1; i >= 0; i++) {
+			if (!is_item_disabled(i) && !is_item_separator(i)) {
+				return i;
+			}
+		}
+	}
+	return -1;
+}
+
 int OptionButton::get_item_count() const {
 	return popup->get_item_count();
 }
 
-void OptionButton::add_separator() {
-	popup->add_separator();
+void OptionButton::add_separator(const String &p_text) {
+	popup->add_separator(p_text);
 }
 
 void OptionButton::clear() {
@@ -407,7 +437,8 @@ void OptionButton::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("get_item_metadata", "idx"), &OptionButton::get_item_metadata);
 	ClassDB::bind_method(D_METHOD("get_item_tooltip", "idx"), &OptionButton::get_item_tooltip);
 	ClassDB::bind_method(D_METHOD("is_item_disabled", "idx"), &OptionButton::is_item_disabled);
-	ClassDB::bind_method(D_METHOD("add_separator"), &OptionButton::add_separator);
+	ClassDB::bind_method(D_METHOD("is_item_separator", "idx"), &OptionButton::is_item_separator);
+	ClassDB::bind_method(D_METHOD("add_separator", "text"), &OptionButton::add_separator, DEFVAL(String()));
 	ClassDB::bind_method(D_METHOD("clear"), &OptionButton::clear);
 	ClassDB::bind_method(D_METHOD("select", "idx"), &OptionButton::select);
 	ClassDB::bind_method(D_METHOD("get_selected"), &OptionButton::get_selected);
@@ -420,6 +451,8 @@ void OptionButton::_bind_methods() {
 
 	ClassDB::bind_method(D_METHOD("set_item_count", "count"), &OptionButton::set_item_count);
 	ClassDB::bind_method(D_METHOD("get_item_count"), &OptionButton::get_item_count);
+	ClassDB::bind_method(D_METHOD("has_selectable_items"), &OptionButton::has_selectable_items);
+	ClassDB::bind_method(D_METHOD("get_selectable_item", "from_last"), &OptionButton::get_selectable_item, DEFVAL(false));
 
 	// "selected" property must come after "item_count", otherwise GH-10213 occurs.
 	ADD_ARRAY_COUNT("Items", "item_count", "set_item_count", "get_item_count", "popup/item_");