add 'onfocus' ui event & optimize container:add

src/graphics/ui/elements/Container.cpp

@@ -71,6 +71,10 @@ void Container::mouseRelease(int x, int y) {
 }
 
 void Container::act(float delta) {
+    if (mustRefresh) {
+        refresh();
+        mustRefresh = false;
+    }
     for (const auto& node : nodes) {
         if (node->isVisible()) {
             node->act(delta);
@@ -162,7 +166,7 @@ void Container::add(const std::shared_ptr<UINode>& node) {
     nodes.push_back(node);
     node->setParent(this);
     node->reposition();
-    refresh();
+    mustRefresh = true;
 }
 
 void Container::add(const std::shared_ptr<UINode>& node, glm::vec2 pos) {
@@ -202,7 +206,6 @@ void Container::listenInterval(float interval, ontimeout callback, int repeat) {
 
 void Container::setSize(glm::vec2 size) {
     if (size == getSize()) {
-        refresh();
         return;
     }
     UINode::setSize(size);

src/graphics/ui/elements/Container.hpp

@@ -9,6 +9,7 @@
 namespace gui {
     class Container : public UINode, public ::util::ObjectsKeeper {
         int prevScrollY = -1;
+        bool mustRefresh = true;
     protected:
         std::vector<std::shared_ptr<UINode>> nodes;
         std::vector<IntervalEvent> intervalEvents;

src/graphics/ui/elements/UINode.cpp

@@ -74,6 +74,11 @@ UINode* UINode::listenDoubleClick(const onaction& action) {
     return this;
 }
 
+UINode* UINode::listenFocus(const onaction& action) {
+    focusCallbacks.listen(action);
+    return this;
+}
+
 UINode* UINode::listenDefocus(const onaction& action) {
     defocusCallbacks.listen(action);
     return this;
@@ -101,6 +106,11 @@ bool UINode::isPressed() const {
     return pressed;
 }
 
+void UINode::onFocus() {
+    focused = true;
+    focusCallbacks.notify(gui);
+}
+
 void UINode::defocus() {
     focused = false;
     defocusCallbacks.notify(gui);

src/graphics/ui/elements/UINode.hpp

@@ -114,6 +114,8 @@ namespace gui {
         ActionsSet actions;
         /// @brief 'ondoubleclick' callbacks
         ActionsSet doubleClickCallbacks;
+        /// @brief 'onfocus' callbacks
+        ActionsSet focusCallbacks;
         /// @brief 'ondefocus' callbacks
         ActionsSet defocusCallbacks;
         /// @brief element tooltip text
@@ -173,9 +175,10 @@ namespace gui {
 
         virtual UINode* listenAction(const onaction& action);
         virtual UINode* listenDoubleClick(const onaction& action);
+        virtual UINode* listenFocus(const onaction& action);
         virtual UINode* listenDefocus(const onaction& action);
 
-        virtual void onFocus() {focused = true;}
+        virtual void onFocus();
         virtual void doubleClick(int x, int y);
         virtual void click(int x, int y);
         virtual void clicked(Mousecode button) {}