1 files changed, 122 insertions, 47 deletions

diff --git a/extension/src/openvic-extension/classes/GUIListBox.cpp b/extension/src/openvic-extension/classes/GUIListBox.cpp
index f7b8d88..d04ab59 100644
--- a/extension/src/openvic-extension/classes/GUIListBox.cpp
+++ b/extension/src/openvic-extension/classes/GUIListBox.cpp
@@ -12,28 +12,52 @@ using namespace godot;
 
 using OpenVic::Utilities::std_view_to_godot_string;
 
-Error GUIListBox::_calculate_child_arrangement() {
-	ERR_FAIL_NULL_V(gui_listbox, FAILED);
+/* StringNames cannot be constructed until Godot has called StringName::setup(),
+ * so we must use wrapper functions to delay their initialisation. */
+StringName const& GUIListBox::_signal_scroll_index_changed() {
+	static const StringName signal_scroll_index_changed = "scroll_index_changed";
+	return signal_scroll_index_changed;
+}
 
-	const int32_t child_count = get_child_count();
-	const real_t max_height = get_size().height;
+Error GUIListBox::_calculate_max_scroll_index(bool signal) {
+	if (fixed) {
+		if (fixed_item_count <= 0) {
+			max_scroll_index = 0;
+			fixed_visible_items = 0;
+		} else if (fixed_item_height <= 0.0f) {
+			max_scroll_index = fixed_item_count - 1;
+			fixed_visible_items = max_scroll_index;
+		} else {
+			const real_t max_height = get_size().height;
 
-	real_t height = 0.0f, height_under_max_scroll_index = 0.0f;
+			fixed_visible_items = max_height / fixed_item_height;
+			max_scroll_index = fixed_item_count - std::max(fixed_visible_items, 1);
+		}
+	} else {
+		const int32_t child_count = get_child_count();
 
-	children_data.clear();
-	max_scroll_index = 0;
+		if (child_count <= 0) {
+			max_scroll_index = 0;
+		} else {
+			const real_t max_height = get_size().height;
 
-	for (int32_t index = 0; index < child_count; ++index) {
-		Control* child = Object::cast_to<Control>(get_child(index));
-		if (child != nullptr && child != scrollbar && child->is_visible()) {
-			const real_t child_height = child->get_size().height; /* Spacing is ignored */
-			children_data.push_back({ child, height, child_height });
+			real_t height_under_max_scroll_index = 0.0f;
 
-			height += child_height;
-			height_under_max_scroll_index += child_height;
+			max_scroll_index = child_count;
 
-			while (height_under_max_scroll_index > max_height && max_scroll_index + 1 < children_data.size()) {
-				height_under_max_scroll_index -= children_data[max_scroll_index++].height;
+			while (max_scroll_index > 0) {
+				max_scroll_index--;
+				Control* child = Object::cast_to<Control>(get_child(max_scroll_index));
+				if (child != nullptr) {
+					height_under_max_scroll_index += child->get_size().height; /* Spacing is ignored */
+
+					if (height_under_max_scroll_index > max_height) {
+						if (max_scroll_index + 1 < child_count) {
+							max_scroll_index++;
+						}
+						break;
+					}
+				}
 			}
 		}
 	}
@@ -41,28 +65,34 @@ Error GUIListBox::_calculate_child_arrangement() {
 	ERR_FAIL_NULL_V(scrollbar, FAILED);
 
 	scrollbar->set_limits(0, max_scroll_index, false);
-	scrollbar->emit_value_changed();
 	scrollbar->set_visible(max_scroll_index > 0);
 
+	set_scroll_index(scrollbar->get_value(), signal);
+
 	return OK;
 }
 
 Error GUIListBox::_update_child_positions() {
-	ERR_FAIL_NULL_V(gui_listbox, FAILED);
+	const int32_t child_count = get_child_count();
+	const real_t max_height = get_size().height;
 
-	if (children_data.empty()) {
-		return OK;
-	}
+	real_t height = 0.0f;
 
-	const real_t max_height = get_size().height;
-	const real_t scroll_pos = children_data[scroll_index].start_pos;
+	const int32_t child_scroll_index = fixed ? 0 : scroll_index;
 
-	for (int32_t index = 0; index < children_data.size(); ++index) {
-		child_data_t const& data = children_data[index];
-		if (index < scroll_index || data.start_pos + data.height > scroll_pos + max_height) {
-			data.child->set_position({ 0.0f, max_height + 10.0f });
-		} else {
-			data.child->set_position({ 0.0f, data.start_pos - scroll_pos });
+	for (int32_t index = 0; index < child_count; ++index) {
+		Control* child = Object::cast_to<Control>(get_child(index));
+
+		if (child != nullptr) {
+			if (index < child_scroll_index) {
+				child->hide();
+			} else {
+				child->set_position({ 0.0f, height });
+
+				height += child->get_size().height; /* Spacing is ignored */
+
+				child->set_visible(height <= max_height);
+			}
 		}
 	}
 
@@ -71,28 +101,36 @@ Error GUIListBox::_update_child_positions() {
 
 void GUIListBox::_bind_methods() {
 	OV_BIND_METHOD(GUIListBox::clear);
-	OV_BIND_METHOD(GUIListBox::clear_children);
+	OV_BIND_METHOD(GUIListBox::clear_children, { "remaining_child_count" }, DEFVAL(0));
 
 	OV_BIND_METHOD(GUIListBox::get_scroll_index);
-	OV_BIND_METHOD(GUIListBox::set_scroll_index, { "new_scroll_index" });
+	OV_BIND_METHOD(GUIListBox::set_scroll_index, { "new_scroll_index", "signal" }, DEFVAL(true));
 	OV_BIND_METHOD(GUIListBox::get_max_scroll_index);
 
+	OV_BIND_METHOD(GUIListBox::is_fixed);
+	OV_BIND_METHOD(GUIListBox::get_fixed_item_count);
+	OV_BIND_METHOD(GUIListBox::get_fixed_visible_items);
+	OV_BIND_METHOD(GUIListBox::get_fixed_item_height);
+	OV_BIND_METHOD(GUIListBox::set_fixed, { "item_count", "item_height", "signal" }, DEFVAL(true));
+	OV_BIND_METHOD(GUIListBox::unset_fixed, { "signal" }, DEFVAL(true));
+
 	OV_BIND_METHOD(GUIListBox::get_gui_listbox_name);
 	OV_BIND_METHOD(GUIListBox::get_scrollbar);
+
+	ADD_SIGNAL(MethodInfo(_signal_scroll_index_changed(), PropertyInfo(Variant::INT, "value")));
 }
 
 void GUIListBox::_notification(int what) {
 	switch (what) {
 	case NOTIFICATION_SORT_CHILDREN: {
-		_calculate_child_arrangement();
+		_calculate_max_scroll_index(!fixed);
 	} break;
 	}
 }
 
 GUIListBox::GUIListBox()
-  : gui_listbox { nullptr }, scrollbar { nullptr }, children_data {}, scroll_index { 0 }, max_scroll_index { 0 } {
-	set_clip_contents(true);
-}
+  : gui_listbox { nullptr }, scrollbar { nullptr }, scroll_index { 0 }, max_scroll_index { 0 },
+	fixed { false }, fixed_item_count { 0 }, fixed_visible_items { 0 }, fixed_item_height { 0.0f } {}
 
 Vector2 GUIListBox::_get_minimum_size() const {
 	if (gui_listbox != nullptr) {
@@ -111,14 +149,18 @@ Vector2 GUIListBox::_get_minimum_size() const {
 void GUIListBox::_gui_input(godot::Ref<godot::InputEvent> const& event) {
 	ERR_FAIL_NULL(event);
 
+	if (scrollbar == nullptr) {
+		return;
+	}
+
 	Ref<InputEventMouseButton> mb = event;
 
 	if (mb.is_valid()) {
 		if (mb->is_pressed()) {
 			if (mb->get_button_index() == MouseButton::MOUSE_BUTTON_WHEEL_UP) {
-				set_scroll_index(scroll_index - 1);
+				scrollbar->decrement_value();
 			} else if (mb->get_button_index() == MouseButton::MOUSE_BUTTON_WHEEL_DOWN) {
-				set_scroll_index(scroll_index + 1);
+				scrollbar->increment_value();
 			} else {
 				return;
 			}
@@ -129,9 +171,14 @@ void GUIListBox::_gui_input(godot::Ref<godot::InputEvent> const& event) {
 
 void GUIListBox::clear() {
 	gui_listbox = nullptr;
-	children_data.clear();
 	scroll_index = 0;
 	max_scroll_index = 0;
+
+	fixed = false;
+	fixed_item_count = 0;
+	fixed_visible_items = 0;
+	fixed_item_height = 0.0f;
+
 	clear_children();
 	if (scrollbar != nullptr) {
 		remove_child(scrollbar);
@@ -139,27 +186,55 @@ void GUIListBox::clear() {
 	}
 }
 
-void GUIListBox::clear_children() {
-	int32_t child_count = get_child_count();
-	while (child_count > 0) {
-		Node* child = get_child(--child_count);
-		if (child != scrollbar) {
-			remove_child(child);
-		}
+void GUIListBox::clear_children(int32_t remaining_child_count) {
+	ERR_FAIL_COND(remaining_child_count < 0);
+
+	int32_t child_index = get_child_count();
+
+	while (child_index > remaining_child_count) {
+		remove_child(get_child(--child_index));
 	}
+
 	if (scrollbar != nullptr) {
 		scrollbar->set_value(0);
 	}
 }
 
-void GUIListBox::set_scroll_index(int32_t new_scroll_index) {
+void GUIListBox::set_scroll_index(int32_t new_scroll_index, bool signal) {
+	const int32_t old_scroll_index = scroll_index;
+
 	scroll_index = std::clamp(new_scroll_index, 0, max_scroll_index);
+
 	if (scrollbar != nullptr && scrollbar->get_value() != scroll_index) {
 		scrollbar->set_value(scroll_index, false);
 	}
+
+	if (signal && scroll_index != old_scroll_index) {
+		emit_signal(_signal_scroll_index_changed(), scroll_index);
+	}
+
 	_update_child_positions();
 }
 
+Error GUIListBox::set_fixed(int32_t item_count, real_t item_height, bool signal) {
+	fixed = true;
+
+	fixed_item_count = item_count;
+	fixed_item_height = item_height;
+
+	return _calculate_max_scroll_index(signal);
+}
+
+Error GUIListBox::unset_fixed(bool signal) {
+	ERR_FAIL_COND_V(!fixed, FAILED);
+
+	fixed = false;
+	fixed_item_count = 0;
+	fixed_item_height = 0.0f;
+
+	return _calculate_max_scroll_index(signal);
+}
+
 Error GUIListBox::set_gui_listbox(GUI::ListBox const* new_gui_listbox) {
 	if (gui_listbox == new_gui_listbox) {
 		return OK;
@@ -192,7 +267,7 @@ Error GUIListBox::set_gui_listbox(GUI::ListBox const* new_gui_listbox) {
 		if (scrollbar_control != nullptr) {
 			scrollbar = Object::cast_to<GUIScrollbar>(scrollbar_control);
 			if (scrollbar != nullptr) {
-				add_child(scrollbar);
+				add_child(scrollbar, false, INTERNAL_MODE_FRONT);
 
 				const Size2 size = Utilities::to_godot_fvec2(gui_listbox->get_size());
 				scrollbar->set_position({ size.width, 0.0f });