Update tutorial.md

ftxui/include/ftxui/component/checkbox.hpp

@@ -20,6 +20,9 @@ class CheckBox : public Component {
   std::wstring checked = L"☑ ";
   std::wstring unchecked = L"☐ ";
 
+  Decorator focused_style = inverted;
+  Decorator unfocused_style = nothing;
+
   // State update callback.
   std::function<void()> on_change = [](){};
 

ftxui/include/ftxui/component/screen_interactive.hpp

@@ -12,6 +12,7 @@ class ScreenInteractive : public Screen {
   public:
     static ScreenInteractive FixedSize(size_t dimx, size_t dimy);
     static ScreenInteractive Fullscreen();
+    static ScreenInteractive FitComponent();
     static ScreenInteractive TerminalOutput();
 
     ~ScreenInteractive();
@@ -23,9 +24,10 @@ class ScreenInteractive : public Screen {
    bool quit_ = false;
 
    enum class Dimension {
+     FitComponent,
      Fixed,
-     TerminalOutput,
      Fullscreen,
+     TerminalOutput,
    };
    Dimension dimension_ = Dimension::Fixed;
    ScreenInteractive(size_t dimx, size_t dimy, Dimension dimension);

ftxui/include/ftxui/screen/screen.hpp

@@ -50,6 +50,8 @@ class Screen {
   // Fill with space.
   void Clear();
 
+  void ApplyShader();
+
  protected:
   size_t dimx_;
   size_t dimy_;

ftxui/src/ftxui/component/checkbox.cpp

@@ -4,8 +4,8 @@
 namespace ftxui {
 
 Element CheckBox::Render() {
-  auto style = Focused() ? bold : nothing;
-  return text((state ? checked : unchecked) + label) | style;
+  auto style = Focused() ? focused_style : unfocused_style;
+  return hbox(text(state ? checked : unchecked), text(label) | style);
 }
 
 bool CheckBox::OnEvent(Event event) {

ftxui/src/ftxui/component/screen_interactive.cpp

@@ -65,6 +65,11 @@ ScreenInteractive ScreenInteractive::TerminalOutput() {
   return ScreenInteractive(0, 0, Dimension::TerminalOutput);
 }
 
+// static
+ScreenInteractive ScreenInteractive::FitComponent() {
+  return ScreenInteractive(0, 0, Dimension::FitComponent);
+}
+
 void ScreenInteractive::Loop(Component* component) {
   //std::cout << "\033[?9h";    [> Send Mouse Row & Column on Button Press <]
   //std::cout << "\033[?1000h"; [> Send Mouse X & Y on button press and release <]
@@ -114,10 +119,14 @@ void ScreenInteractive::Draw(Component* component) {
       dimy = document->requirement().min.y;
       break;
     case Dimension::Fullscreen:
-      document->ComputeRequirement();
       dimx = Terminal::Size().dimx;
       dimy = Terminal::Size().dimy;
       break;
+    case Dimension::FitComponent:
+      document->ComputeRequirement();
+      dimx = document->requirement().min.x;
+      dimy = document->requirement().min.y;
+      break;
   }
 
   if (dimx != dimx_ || dimy != dimy_) {

ftxui/src/ftxui/dom/frame.cpp

@@ -61,20 +61,6 @@ class Frame : public Node {
       screen.at(box_.right,y) = charset[5];
     }
 
-    // Try to merge with separator.
-    for(float x = box_.left + 1; x<box_.right; ++x) {
-      if (screen.at(x, box_.top + 1) == charset[5])
-        screen.at(x, box_.top) = charset[6];
-      if (screen.at(x, box_.bottom - 1) == charset[5])
-        screen.at(x, box_.bottom) = charset[7];
-    }
-    for(float y = box_.top + 1; y<box_.bottom; ++y) {
-      if (screen.at(box_.left+1, y) == charset[4])
-        screen.at(box_.left, y) = charset[9];
-      if (screen.at(box_.right-1, y) == charset[4])
-        screen.at(box_.right,y) = charset[8];
-    }
-
     // Draw title.
     if (children.size() == 2)
       children[1]->Render(screen);

ftxui/src/ftxui/dom/node.cpp

@@ -38,6 +38,9 @@ void Render(Screen& screen, Node* node) {
 
   // Step 3: Draw the element.
   node->Render(screen);
+
+  // Step 4: Apply shaders
+  screen.ApplyShader();
 }
 
 };  // namespace ftxui

ftxui/src/ftxui/screen/screen.cpp

@@ -22,6 +22,10 @@ static const wchar_t* BLINK_RESET = L"\e[25m";
 static const wchar_t* INVERTED_SET = L"\e[7m";
 static const wchar_t* INVERTED_RESET = L"\e[27m";
 
+static const char* MOVE_LEFT = "\r";
+static const char* MOVE_UP = "\e[1A";
+static const char* CLEAR_LINE = "\e[2K";
+
 Screen::Screen(size_t dimx, size_t dimy)
     : dimx_(dimx), dimy_(dimy), pixels_(dimy, std::vector<Pixel>(dimx)) {}
 
@@ -94,9 +98,9 @@ Screen Screen::TerminalOutput(std::unique_ptr<Node>& element) {
 
 std::string Screen::ResetPosition() {
   std::stringstream ss;
-  ss << '\r';
+  ss << MOVE_LEFT << CLEAR_LINE;
   for (size_t y = 1; y < dimy_; ++y) {
-    ss << "\e[2K\r\e[1A";
+    ss << MOVE_UP << CLEAR_LINE;
   }
   return ss.str();
 }
@@ -106,4 +110,37 @@ void Screen::Clear() {
                                             std::vector<Pixel>(dimx_, Pixel()));
 }
 
+void Screen::ApplyShader() {
+
+  // Merge box characters togethers.
+  for(size_t y = 1; y<dimy_; ++y) {
+    for(size_t x = 1; x<dimx_; ++x) {
+      wchar_t& left = at(x - 1, y);
+      wchar_t& top = at(x, y - 1);
+      wchar_t& cur = at(x, y);
+
+      // Left vs current
+      if (cur== U'│' && left == U'─')
+        cur= U'┤';
+      if (cur== U'─' && left == U'│')
+        left = U'├';
+      if (cur== U'├' && left == U'─')
+        cur= U'┼';
+      if (cur== U'─' && left == U'┤')
+        left = U'┼';
+
+      // Top vs current
+      if (cur== U'─' && top == U'│')
+        cur= U'┴';
+      if (cur== U'│' && top == U'─')
+        top = U'┬';
+      if (cur== U'┬' && top == U'│')
+        cur= U'┼';
+      if (cur== U'│' && top == U'┴')
+        top = U'┼';
+    }
+  }
+}
+
+
 };  // namespace ftxui