Allow all ColorPicker Shapes to expand horizontally

Co-authored-by: Tomasz Chabora <[email protected]>

Author: WhalesState

scene/gui/color_picker.cpp

@@ -2162,7 +2162,7 @@ ColorPicker::ColorPicker() {
 	internal_margin->add_child(real_vbox);
 
 	shape_container = memnew(HBoxContainer);
-	shape_container->set_v_size_flags(SIZE_SHRINK_BEGIN);
+	shape_container->set_alignment(ALIGNMENT_CENTER);
 	real_vbox->add_child(shape_container);
 
 	sample_hbc = memnew(HBoxContainer);

scene/gui/color_picker_shape.cpp

@@ -322,6 +322,7 @@ void ColorPickerShapeRectangle::_hue_slider_draw() {
 
 void ColorPickerShapeRectangle::_initialize_controls() {
 	sv_square = memnew(Control);
+	sv_square->set_h_size_flags(Control::SIZE_EXPAND_FILL);
 	color_picker->shape_container->add_child(sv_square);
 	sv_square->connect(SceneStringName(gui_input), callable_mp(this, &ColorPickerShapeRectangle::_sv_square_input));
 	sv_square->connect(SceneStringName(draw), callable_mp(this, &ColorPickerShapeRectangle::_sv_square_draw));
@@ -358,6 +359,7 @@ void ColorPickerShapeRectangle::grab_focus() {
 
 void ColorPickerShapeOKHSRectangle::_initialize_controls() {
 	rectangle_margin = memnew(MarginContainer);
+	rectangle_margin->set_h_size_flags(Control::SIZE_EXPAND_FILL);
 	color_picker->shape_container->add_child(rectangle_margin);
 
 	Ref<ShaderMaterial> material;