implement right-to-left

engine/node.cpp

@@ -46,11 +46,14 @@ void Node::async_end()
     App::I.async_end();
 }
 
-void Node::watch(std::function<void(Node*)> observer)
+void Node::watch(std::function<bool(Node*)> observer)
 {
-    observer(this);
-    for (auto& c : m_children)
-        c->watch(observer);
+    bool cont = observer(this);
+    if (cont)
+    {
+        for (auto& c : m_children)
+            c->watch(observer);
+    }
 }
 
 void Node::destroy()
@@ -532,6 +535,11 @@ void Node::SetAspectRatio(float ar)
     YGNodeStyleSetAspectRatio(y_node, ar);
 }
 
+void Node::SetRTL(YGDirection dir)
+{
+    YGNodeStyleSetDirection(y_node, dir);
+}
+
 glm::vec2 Node::GetPosition()
 {
     return{ YGNodeLayoutGetLeft(y_node), YGNodeLayoutGetTop(y_node) };
@@ -552,6 +560,11 @@ glm::vec2 Node::GetSize()
     return{ GetWidth(), GetHeight() };
 }
 
+YGDirection Node::GetRTL()
+{
+    return YGNodeStyleGetDirection(y_node);
+}
+
 void Node::restore_context()
 {
     for (auto& c : m_children)
@@ -809,6 +822,17 @@ void Node::parse_attributes(kAttribute ka, const tinyxml2::XMLAttribute* attr)
     case kAttribute::AspectRatio:
         YGNodeStyleSetAspectRatio(y_node, attr->FloatValue());
         break;
+    case kAttribute::RTL:
+        if (strcmp("rtl", attr->Value()) == 0)
+            SetRTL(YGDirectionRTL);
+        else if (strcmp("ltr", attr->Value()) == 0)
+            SetRTL(YGDirectionLTR);
+        else if (strcmp("inherit", attr->Value()) == 0)
+            SetRTL(YGDirectionInherit);
+        else
+        {
+            LOG("Attribute %s for RTL unrecognized", attr->Value());
+        }
     default:
         break;
     }