1 files changed, 80 insertions, 13 deletions

diff --git a/scene/gui/flow_container.cpp b/scene/gui/flow_container.cpp
index 30b694da76..44c5ec62f8 100644
--- a/scene/gui/flow_container.cpp
+++ b/scene/gui/flow_container.cpp
@@ -44,9 +44,6 @@ void FlowContainer::_resort() {
 		return;
 	}
 
-	int separation_horizontal = get_theme_constant(SNAME("h_separation"));
-	int separation_vertical = get_theme_constant(SNAME("v_separation"));
-
 	bool rtl = is_layout_rtl();
 
 	HashMap<Control *, Size2i> children_minsize_cache;
@@ -74,14 +71,14 @@ void FlowContainer::_resort() {
 
 		if (vertical) { /* VERTICAL */
 			if (children_in_current_line > 0) {
-				ofs.y += separation_vertical;
+				ofs.y += theme_cache.v_separation;
 			}
 			if (ofs.y + child_msc.y > current_container_size) {
-				line_length = ofs.y - separation_vertical;
+				line_length = ofs.y - theme_cache.v_separation;
 				lines_data.push_back(_LineData{ children_in_current_line, line_height, line_length, current_container_size - line_length, line_stretch_ratio_total });
 
 				// Move in new column (vertical line).
-				ofs.x += line_height + separation_horizontal;
+				ofs.x += line_height + theme_cache.h_separation;
 				ofs.y = 0;
 				line_height = 0;
 				line_stretch_ratio_total = 0;
@@ -96,14 +93,14 @@ void FlowContainer::_resort() {
 
 		} else { /* HORIZONTAL */
 			if (children_in_current_line > 0) {
-				ofs.x += separation_horizontal;
+				ofs.x += theme_cache.h_separation;
 			}
 			if (ofs.x + child_msc.x > current_container_size) {
-				line_length = ofs.x - separation_horizontal;
+				line_length = ofs.x - theme_cache.h_separation;
 				lines_data.push_back(_LineData{ children_in_current_line, line_height, line_length, current_container_size - line_length, line_stretch_ratio_total });
 
 				// Move in new line.
-				ofs.y += line_height + separation_vertical;
+				ofs.y += line_height + theme_cache.v_separation;
 				ofs.x = 0;
 				line_height = 0;
 				line_stretch_ratio_total = 0;
@@ -146,15 +143,37 @@ void FlowContainer::_resort() {
 			current_line_idx++;
 			child_idx_in_line = 0;
 			if (vertical) {
-				ofs.x += line_data.min_line_height + separation_horizontal;
+				ofs.x += line_data.min_line_height + theme_cache.h_separation;
 				ofs.y = 0;
 			} else {
 				ofs.x = 0;
-				ofs.y += line_data.min_line_height + separation_vertical;
+				ofs.y += line_data.min_line_height + theme_cache.v_separation;
 			}
 			line_data = lines_data[current_line_idx];
 		}
 
+		// The first child of each line adds the offset caused by the alignment,
+		// but only if the line doesn't contain a child that expands.
+		if (child_idx_in_line == 0 && Math::is_equal_approx(line_data.stretch_ratio_total, 0)) {
+			int alignment_ofs = 0;
+			switch (alignment) {
+				case ALIGNMENT_CENTER:
+					alignment_ofs = line_data.stretch_avail / 2;
+					break;
+				case ALIGNMENT_END:
+					alignment_ofs = line_data.stretch_avail;
+					break;
+				default:
+					break;
+			}
+
+			if (vertical) { /* VERTICAL */
+				ofs.y += alignment_ofs;
+			} else { /* HORIZONTAL */
+				ofs.x += alignment_ofs;
+			}
+		}
+
 		if (vertical) { /* VERTICAL */
 			if (child->get_h_size_flags() & (SIZE_FILL | SIZE_SHRINK_CENTER | SIZE_SHRINK_END)) {
 				child_size.width = line_data.min_line_height;
@@ -184,9 +203,9 @@ void FlowContainer::_resort() {
 		fit_child_in_rect(child, child_rect);
 
 		if (vertical) { /* VERTICAL */
-			ofs.y += child_size.height + separation_vertical;
+			ofs.y += child_size.height + theme_cache.v_separation;
 		} else { /* HORIZONTAL */
-			ofs.x += child_size.width + separation_horizontal;
+			ofs.x += child_size.width + theme_cache.h_separation;
 		}
 
 		child_idx_in_line++;
@@ -250,6 +269,13 @@ Vector<int> FlowContainer::get_allowed_size_flags_vertical() const {
 	return flags;
 }
 
+void FlowContainer::_update_theme_item_cache() {
+	Container::_update_theme_item_cache();
+
+	theme_cache.h_separation = get_theme_constant(SNAME("h_separation"));
+	theme_cache.v_separation = get_theme_constant(SNAME("v_separation"));
+}
+
 void FlowContainer::_notification(int p_what) {
 	switch (p_what) {
 		case NOTIFICATION_SORT_CHILDREN: {
@@ -268,14 +294,55 @@ void FlowContainer::_notification(int p_what) {
 	}
 }
 
+void FlowContainer::_validate_property(PropertyInfo &p_property) const {
+	if (is_fixed && p_property.name == "vertical") {
+		p_property.usage = PROPERTY_USAGE_NONE;
+	}
+}
+
 int FlowContainer::get_line_count() const {
 	return cached_line_count;
 }
 
+void FlowContainer::set_alignment(AlignmentMode p_alignment) {
+	if (alignment == p_alignment) {
+		return;
+	}
+	alignment = p_alignment;
+	_resort();
+}
+
+FlowContainer::AlignmentMode FlowContainer::get_alignment() const {
+	return alignment;
+}
+
+void FlowContainer::set_vertical(bool p_vertical) {
+	ERR_FAIL_COND_MSG(is_fixed, "Can't change orientation of " + get_class() + ".");
+	vertical = p_vertical;
+	update_minimum_size();
+	_resort();
+}
+
+bool FlowContainer::is_vertical() const {
+	return vertical;
+}
+
 FlowContainer::FlowContainer(bool p_vertical) {
 	vertical = p_vertical;
 }
 
 void FlowContainer::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("get_line_count"), &FlowContainer::get_line_count);
+
+	ClassDB::bind_method(D_METHOD("set_alignment", "alignment"), &FlowContainer::set_alignment);
+	ClassDB::bind_method(D_METHOD("get_alignment"), &FlowContainer::get_alignment);
+	ClassDB::bind_method(D_METHOD("set_vertical", "vertical"), &FlowContainer::set_vertical);
+	ClassDB::bind_method(D_METHOD("is_vertical"), &FlowContainer::is_vertical);
+
+	BIND_ENUM_CONSTANT(ALIGNMENT_BEGIN);
+	BIND_ENUM_CONSTANT(ALIGNMENT_CENTER);
+	BIND_ENUM_CONSTANT(ALIGNMENT_END);
+
+	ADD_PROPERTY(PropertyInfo(Variant::INT, "alignment", PROPERTY_HINT_ENUM, "Begin,Center,End"), "set_alignment", "get_alignment");
+	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "vertical"), "set_vertical", "is_vertical");
 }