Add gauge and frame.

ftxui/src/ftxui/core/dom/frame.cpp

@@ -0,0 +1,57 @@
+#include "ftxui/core/dom/node.hpp"
+#include "ftxui/core/dom/elements.hpp"
+
+namespace ftxui {
+namespace dom {
+
+static wchar_t charset[] = L"┌┐└┘─│";
+
+class Frame : public Node {
+ public:
+  Frame(Child child) : Node(unpack(std::move(child))) {}
+  ~Frame() override {}
+
+  void ComputeRequirement() override {
+    children[0]->ComputeRequirement();
+    requirement_ = children[0]->requirement();
+    requirement_.min.x += 2;
+    requirement_.min.y += 2;
+  }
+
+  void SetBox(Box box) override {
+    Node::SetBox(box);
+    box.left++;
+    box.right--;
+    box.top++;
+    box.bottom--;
+    children[0]->SetBox(box);
+  }
+
+  void Render(Screen& screen) override {
+    if (box_.left >= box_.right || box_.top >= box_.bottom)
+      return;
+
+    screen.at(box_.left, box_.top) = charset[0];
+    screen.at(box_.right, box_.top) = charset[1];
+    screen.at(box_.left, box_.bottom) = charset[2];
+    screen.at(box_.right, box_.bottom) = charset[3];
+    for(float x = box_.left + 1; x<box_.right; ++x) {
+      screen.at(x, box_.top) = charset[4];
+      screen.at(x, box_.bottom) = charset[4];
+    }
+    for(float y = box_.top + 1; y<box_.bottom; ++y) {
+      screen.at(box_.left, y) = charset[5];
+      screen.at(box_.right,y) = charset[5];
+    }
+    children[0]->Render(screen);
+  }
+ private:
+  float progress_;
+};
+
+std::unique_ptr<Node> frame(Child child) {
+  return std::make_unique<Frame>(std::move(child));
+}
+
+};  // namespace dom
+};  // namespace ftxui

ftxui/src/ftxui/core/dom/gauge.cpp

@@ -4,10 +4,12 @@
 namespace ftxui {
 namespace dom {
 
+static wchar_t charset[] = L"  ▏▎▍▌▋▊▉█";
+
 class Gauge : public Node {
  public:
   Gauge(float progress) : progress_(progress) {}
-  ~Gauge() {}
+  ~Gauge() override {}
 
   void ComputeRequirement() override {
     requirement_.flex.x = 1;
@@ -16,9 +18,14 @@ class Gauge : public Node {
 
   void Render(Screen& screen) override {
     float y = box_.top;
-    int limit = box_.left + progress_ * (box_.right - box_.left);
-    for(int i = box_.left; i<=limit; ++i)
-      screen.at(i, y) = 'X';
+    float limit = box_.left + progress_ * (box_.right - box_.left + 1);
+    int limit_int = limit;
+    int x = box_.left;
+    while (x < limit_int)
+      screen.at(x++, y) = charset[9];
+    screen.at(x++, y) = charset[int(9*(limit-limit_int))];
+    while (x <= box_.right)
+      screen.at(x++, y) = charset[0];
   }
  private:
   float progress_;

ftxui/src/ftxui/core/dom/vbox.cpp

@@ -37,7 +37,7 @@ class VBox : public Node {
 
     int y = box.top;
     for (auto& child : children) {
-      if (y > box.right)
+      if (y > box.bottom)
         break;
 
       Box child_box = box;