Modify selection requirement

include/ftxui/dom/elements.hpp

@@ -122,7 +122,9 @@ Decorator selectionStyle(std::function<void(Pixel&)> style);
 // --- Layout is
 // Horizontal, Vertical or stacked set of elements.
 Element hbox(Elements);
+Element hbox(Elements, int);
 Element vbox(Elements);
+Element vbox(Elements, int);
 Element dbox(Elements);
 Element flexbox(Elements, FlexboxConfig config = FlexboxConfig());
 Element gridbox(std::vector<Elements> lines);

include/ftxui/dom/requirement.hpp

@@ -20,12 +20,7 @@ struct Requirement {
   int flex_shrink_y = 0;
 
   // Focus management to support the frame/focus/select element.
-  enum Selection {
-    NORMAL = 0,
-    SELECTED = 1,
-    FOCUSED = 2,
-  };
-  Selection selection = NORMAL;
+  bool is_selected = false;
   Box selected_box;
 };
 

src/ftxui/component/container.cpp

@@ -107,7 +107,7 @@ class VerticalContainer : public ContainerBase {
     if (elements.empty()) {
       return text("Empty container") | reflect(box_);
     }
-    return vbox(std::move(elements)) | reflect(box_);
+    return vbox(std::move(elements), *selector_) | reflect(box_);
   }
 
   bool EventHandler(Event event) override {
@@ -191,7 +191,7 @@ class HorizontalContainer : public ContainerBase {
     if (elements.empty()) {
       return text("Empty container");
     }
-    return hbox(std::move(elements));
+    return hbox(std::move(elements), *selector_);
   }
 
   bool EventHandler(Event event) override {
@@ -334,7 +334,7 @@ Component Vertical(Components children) {
 ///   children_2,
 ///   children_3,
 ///   children_4,
-/// });
+/// }, &selected_children);
 /// ```
 Component Vertical(Components children, int* selector) {
   return std::make_shared<VerticalContainer>(std::move(children), selector);
@@ -355,7 +355,7 @@ Component Vertical(Components children, int* selector) {
 ///   children_2,
 ///   children_3,
 ///   children_4,
-/// }, &selected_children);
+/// });
 /// ```
 Component Horizontal(Components children) {
   return Horizontal(std::move(children), nullptr);

src/ftxui/dom/dbox.cpp

@@ -27,7 +27,7 @@ class DBox : public Node {
     requirement_.flex_grow_y = 0;
     requirement_.flex_shrink_x = 0;
     requirement_.flex_shrink_y = 0;
-    requirement_.selection = Requirement::NORMAL;
+    requirement_.is_selected = false;
     for (auto& child : children_) {
       child->ComputeRequirement();
       requirement_.min_x =
@@ -35,8 +35,8 @@ class DBox : public Node {
       requirement_.min_y =
           std::max(requirement_.min_y, child->requirement().min_y);
 
-      if (requirement_.selection < child->requirement().selection) {
-        requirement_.selection = child->requirement().selection;
+      if (!requirement_.is_selected && child->requirement().is_selected) {
+        requirement_.is_selected = true;
         requirement_.selected_box = child->requirement().selected_box;
       }
     }

src/ftxui/dom/flexbox.cpp

@@ -104,7 +104,7 @@ class Flexbox : public Node {
     Layout(global, true);
 
     // Reset:
-    requirement_.selection = Requirement::Selection::NORMAL;
+    requirement_.is_selected = false;
     requirement_.selected_box = Box();
     requirement_.min_x = 0;
     requirement_.min_y = 0;
@@ -130,10 +130,11 @@ class Flexbox : public Node {
 
     // Find the selection:
     for (size_t i = 0; i < children_.size(); ++i) {
-      if (requirement_.selection >= children_[i]->requirement().selection) {
+      if (requirement_.is_selected ||
+          !children_[i]->requirement().is_selected) {
         continue;
       }
-      requirement_.selection = children_[i]->requirement().selection;
+      requirement_.is_selected = true;
       Box selected_box = children_[i]->requirement().selected_box;
 
       // Shift |selected_box| according to its position inside this component:

src/ftxui/dom/focus.cpp

@@ -36,7 +36,7 @@ Decorator focusPositionRelative(float x, float y) {
 
     void ComputeRequirement() override {
       NodeDecorator::ComputeRequirement();
-      requirement_.selection = Requirement::Selection::NORMAL;
+      requirement_.is_selected = false;
 
       Box& box = requirement_.selected_box;
       box.x_min = int(float(requirement_.min_x) * x_);
@@ -75,7 +75,7 @@ Decorator focusPosition(int x, int y) {
 
     void ComputeRequirement() override {
       NodeDecorator::ComputeRequirement();
-      requirement_.selection = Requirement::Selection::NORMAL;
+      requirement_.is_selected = false;
 
       Box& box = requirement_.selected_box;
       box.x_min = x_;

src/ftxui/dom/frame.cpp

@@ -27,7 +27,7 @@ class Select : public Node {
     selected_box.y_min = 0;
     selected_box.x_max = requirement_.min_x - 1;
     selected_box.y_max = requirement_.min_y - 1;
-    requirement_.selection = Requirement::SELECTED;
+    requirement_.is_selected = true;
   }
 
   void SetBox(Box box) override {
@@ -42,7 +42,6 @@ class Focus : public Select {
 
   void ComputeRequirement() override {
     Select::ComputeRequirement();
-    requirement_.selection = Requirement::FOCUSED;
   }
 
   void Render(Screen& screen) override {

src/ftxui/dom/gridbox.cpp

@@ -76,13 +76,14 @@ class GridBox : public Node {
     requirement_.min_y = Integrate(size_y);
 
     // Forward the selected/focused child state:
-    requirement_.selection = Requirement::NORMAL;
+    requirement_.is_selected = false;
     for (int x = 0; x < x_size; ++x) {
       for (int y = 0; y < y_size; ++y) {
-        if (requirement_.selection >= lines_[y][x]->requirement().selection) {
+        if (requirement_.is_selected ||
+            !lines_[y][x]->requirement().is_selected) {
           continue;
         }
-        requirement_.selection = lines_[y][x]->requirement().selection;
+        requirement_.is_selected = true;
         requirement_.selected_box = lines_[y][x]->requirement().selected_box;
         requirement_.selected_box.x_min += size_x[x];
         requirement_.selected_box.x_max += size_x[x];

src/ftxui/dom/hbox.cpp

@@ -19,7 +19,10 @@ namespace {
 class HBox : public Node {
  public:
   explicit HBox(Elements children) : Node(std::move(children)) {}
+  explicit HBox(Elements children, int index)
+      : Node(std::move(children)), index_(index) {}
 
+ private:
   void ComputeRequirement() override {
     requirement_.min_x = 0;
     requirement_.min_y = 0;
@@ -27,11 +30,11 @@ class HBox : public Node {
     requirement_.flex_grow_y = 0;
     requirement_.flex_shrink_x = 0;
     requirement_.flex_shrink_y = 0;
-    requirement_.selection = Requirement::NORMAL;
+    requirement_.is_selected = false;
     for (auto& child : children_) {
       child->ComputeRequirement();
-      if (requirement_.selection < child->requirement().selection) {
-        requirement_.selection = child->requirement().selection;
+      if (children_[index_] == child && child->requirement().is_selected) {
+        requirement_.is_selected = true;
         requirement_.selected_box = child->requirement().selected_box;
         requirement_.selected_box.x_min += requirement_.min_x;
         requirement_.selected_box.x_max += requirement_.min_x;
@@ -77,6 +80,7 @@ class HBox : public Node {
       child->Select(selection_saturated);
     }
   }
+  int index_ = 0;
 };
 
 }  // namespace
@@ -97,4 +101,8 @@ Element hbox(Elements children) {
   return std::make_shared<HBox>(std::move(children));
 }
 
+Element hbox(Elements children, int index) {
+  return std::make_shared<HBox>(std::move(children), index);
+}
+
 }  // namespace ftxui

src/ftxui/dom/vbox.cpp

@@ -19,7 +19,10 @@ namespace {
 class VBox : public Node {
  public:
   explicit VBox(Elements children) : Node(std::move(children)) {}
+  explicit VBox(Elements children, int index)
+      : Node(std::move(children)), index_(index) {}
 
+ private:
   void ComputeRequirement() override {
     requirement_.min_x = 0;
     requirement_.min_y = 0;
@@ -27,11 +30,11 @@ class VBox : public Node {
     requirement_.flex_grow_y = 0;
     requirement_.flex_shrink_x = 0;
     requirement_.flex_shrink_y = 0;
-    requirement_.selection = Requirement::NORMAL;
+    requirement_.is_selected = false;
     for (auto& child : children_) {
       child->ComputeRequirement();
-      if (requirement_.selection < child->requirement().selection) {
-        requirement_.selection = child->requirement().selection;
+      if (children_[index_] == child && child->requirement().is_selected) {
+        requirement_.is_selected = true;
         requirement_.selected_box = child->requirement().selected_box;
         requirement_.selected_box.y_min += requirement_.min_y;
         requirement_.selected_box.y_max += requirement_.min_y;
@@ -78,6 +81,8 @@ class VBox : public Node {
       child->Select(selection_saturated);
     }
   }
+
+  int index_ = 0;
 };
 }  // namespace
 
@@ -98,4 +103,8 @@ Element vbox(Elements children) {
   return std::make_shared<VBox>(std::move(children));
 }
 
+Element vbox(Elements children, int index) {
+  return std::make_shared<VBox>(std::move(children), index);
+}
+
 }  // namespace ftxui