Start the gauge widget.

ftxui/CMakeLists.txt

@@ -6,8 +6,11 @@ add_library(ftxui
   src/ftxui/core/dom/flex.cpp
   src/ftxui/core/dom/hbox.cpp
   src/ftxui/core/dom/node.cpp
+  src/ftxui/core/dom/separator.cpp
   src/ftxui/core/dom/text.cpp
+  src/ftxui/core/dom/centered.cpp
   src/ftxui/core/dom/vbox.cpp
+  src/ftxui/core/dom/gauge.cpp
   src/ftxui/core/screen.cpp
   src/ftxui/core/terminal.cpp
   src/ftxui/util/string.cpp

ftxui/include/ftxui/core/dom/elements.hpp

@@ -7,17 +7,29 @@
 namespace ftxui {
 namespace dom {
 
-using Child = std::unique_ptr<Node>;
+using Element = std::unique_ptr<Node>;
 using Children = std::vector<std::unique_ptr<Node>>;
 
+
+// --- Layout ----
 std::unique_ptr<Node> vbox(Children);
 std::unique_ptr<Node> hbox(Children);
-std::unique_ptr<Node> text(std::wstring text);
 std::unique_ptr<Node> flex();
+std::unique_ptr<Node> flex(Element);
+
+// --- Widget --
+std::unique_ptr<Node> text(std::wstring text);
+std::unique_ptr<Node> separator();
+std::unique_ptr<Node> gauge(float ratio);
+
+// --- Decorator ---
+std::unique_ptr<Node> hcenter(Element);
+std::unique_ptr<Node> vcenter(Element);
+std::unique_ptr<Node> center(Element);
 
 template <class... Args>
-std::vector<Child> unpack(Args... args) {
-  std::vector<Child> vec;
+std::vector<Element> unpack(Args... args) {
+  std::vector<Element> vec;
   (vec.push_back(std::forward<Args>(args)), ...);
   return vec;
 }

ftxui/include/ftxui/core/screen.hpp

@@ -3,8 +3,12 @@
 
 #include <string>
 #include <vector>
+#include <memory>
 
 namespace ftxui {
+namespace dom {
+  class Node;
+}
 
 class Screen {
  public:
@@ -16,6 +20,7 @@ class Screen {
   size_t dimy() { return dimy_;}
 
   static Screen WholeTerminal();
+  static Screen TerminalOutput(std::unique_ptr<dom::Node>& element);
 
  private:
   size_t dimx_;

ftxui/src/ftxui/core/dom/centered.cpp

@@ -0,0 +1,20 @@
+#include "ftxui/core/dom/node.hpp"
+#include "ftxui/core/dom/elements.hpp"
+
+namespace ftxui {
+namespace dom {
+
+std::unique_ptr<Node> hcenter(Element child) {
+  return hbox(flex(), std::move(child), flex());
+}
+
+std::unique_ptr<Node> vcenter(Element child) {
+  return vbox(flex(), std::move(child), flex());
+}
+
+std::unique_ptr<Node> center(Element child) {
+  return hcenter(vcenter(std::move(child)));
+}
+
+} // namespace dom
+} // namespace ftxui

ftxui/src/ftxui/core/dom/flex.cpp

@@ -1,4 +1,5 @@
 #include "ftxui/core/dom/node.hpp"
+#include "ftxui/core/dom/elements.hpp"
 
 namespace ftxui {
 namespace dom {
@@ -6,18 +7,33 @@ namespace dom {
 class Flex : public Node {
  public:
   Flex() {}
+  Flex(Element child) : Node(unpack(std::move(child))) {}
   ~Flex() override {}
   void ComputeRequirement() {
     requirement_.min.x = 0;
     requirement_.min.y = 0;
+    if (!children.empty()) {
+      children[0]->ComputeRequirement();
+      requirement_ = children[0]->requirement();
+    }
     requirement_.flex.x = 1;
     requirement_.flex.y = 1;
   }
+
+  void SetBox(Box box) override {
+    if (children.empty())
+      return;
+    children[0]->SetBox(box);
+  }
 };
 
 std::unique_ptr<Node> flex() {
   return std::make_unique<Flex>();
 }
 
+std::unique_ptr<Node> flex(Element child) {
+  return std::make_unique<Flex>(std::move(child));
+}
+
 };  // namespace dom
 };  // namespace ftxui

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

@@ -0,0 +1,32 @@
+#include "ftxui/core/dom/node.hpp"
+#include "ftxui/core/dom/elements.hpp"
+
+namespace ftxui {
+namespace dom {
+
+class Gauge : public Node {
+ public:
+  Gauge(float progress) : progress_(progress) {}
+  ~Gauge() {}
+
+  void ComputeRequirement() override {
+    requirement_.flex.x = 1;
+    requirement_.min.y = 1;
+  }
+
+  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';
+  }
+ private:
+  float progress_;
+};
+
+std::unique_ptr<Node> gauge(float progress) {
+  return std::make_unique<Gauge>(progress);
+}
+
+};  // namespace dom
+};  // namespace ftxui

ftxui/src/ftxui/core/dom/separator.cpp

@@ -0,0 +1,38 @@
+#include "ftxui/core/dom/node.hpp"
+
+namespace ftxui {
+namespace dom {
+
+class Separator : public Node {
+ public:
+  Separator() {}
+  ~Separator() override {}
+  void ComputeRequirement() override {
+    requirement_.min.x = 1;
+    requirement_.min.y = 1;
+  }
+
+  void Render(Screen& screen) override {
+    bool is_column = (box_.right == box_.left);
+    bool is_line = (box_.top == box_.bottom);
+
+    wchar_t c = U'+';
+    if (is_line && !is_column)
+      c = U'─';
+    else if (!is_line && is_column)
+      c = U'│';
+
+    for (int y = box_.top; y <= box_.bottom; ++y) {
+      for (int x = box_.left; x <= box_.right; ++x) {
+        screen.at(x, y) = c;
+      }
+    }
+  }
+};
+
+std::unique_ptr<Node> separator() {
+  return std::make_unique<Separator>();
+}
+
+};  // namespace dom
+};  // namespace ftxui

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

@@ -35,7 +35,7 @@ class VBox : public Node {
     int remaining_flex = flex_sum;
     int remaining_extra_space = extra_space;
 
-    int y = box.left;
+    int y = box.top;
     for (auto& child : children) {
       if (y > box.right)
         break;

ftxui/src/ftxui/core/screen.cpp

@@ -1,6 +1,7 @@
 #include "ftxui/core/screen.hpp"
 #include "ftxui/core/terminal.hpp"
 #include "ftxui/util/string.hpp"
+#include "ftxui/core/dom/node.hpp"
 
 #include <sstream>
 
@@ -28,4 +29,10 @@ Screen Screen::WholeTerminal() {
   return Screen(size.dimx, size.dimy);
 }
 
+Screen Screen::TerminalOutput(std::unique_ptr<dom::Node>& element) {
+  element->ComputeRequirement();
+  Terminal::Dimensions size = Terminal::Size();
+  return Screen(size.dimx, element->requirement().min.y);
+}
+
 };  // namespace ftxui