Bug fixes. (#367)

- Do not draw more frames than what is needed.
- Fix MenuEntry transform state.
- Fix Canvas animated example.

examples/component/canvas_animated.cpp

@@ -167,7 +167,7 @@ int main(int argc, const char* argv[]) {
       for (int x = 0; x < size; x++) {
         float dx = x - mx;
         float dy = y - my;
-        ys[y][x] = (int)(-1.5 + 3.0 * std::exp(-0.2f * (dx * dx + dy * dy)));
+        ys[y][x] = -1.5 + 3.0 * std::exp(-0.2f * (dx * dx + dy * dy));
       }
     }
     for (int y = 0; y < size; y++) {

include/ftxui/component/screen_interactive.hpp

@@ -79,7 +79,7 @@ class ScreenInteractive : public Screen {
   std::atomic<bool> quit_ = false;
   std::thread event_listener_;
   std::thread animation_listener_;
-  bool animation_requested_ = true;
+  bool animation_requested_ = false;
   animation::TimePoint previous_animation_time;
 
   int cursor_x_ = 1;

src/ftxui/component/menu.cpp

@@ -512,9 +512,9 @@ Component MenuEntry(ConstStringRef label, Ref<MenuEntryOption> option) {
 
       EntryState state = {
           *label_,
+          false,
           hovered_,
           focused,
-          false,
       };
 
       Element element =

src/ftxui/component/screen_interactive.cpp

@@ -485,21 +485,19 @@ void ScreenInteractive::Main(Component component) {
     Clear();
   };
 
-  draw();
+  bool attempt_draw = true;
-
   while (!quit_) {
-    if (!task_receiver_->HasPending())
+    if (attempt_draw && !task_receiver_->HasPending()) {
       draw();
+      attempt_draw = false;
+    }
 
-    bool continue_event_loop = true;
-    while (continue_event_loop) {
-      continue_event_loop = false;
     Task task;
     if (!task_receiver_->Receive(&task))
       break;
 
-      std::visit(
+    // clang-format off
-          [&](auto&& arg) {
+    std::visit([&](auto&& arg) {
       using T = std::decay_t<decltype(arg)>;
 
       // Handle Event.
@@ -517,6 +515,8 @@ void ScreenInteractive::Main(Component component) {
 
         arg.screen_ = this;
         component->OnEvent(arg);
+        attempt_draw = true;
+        return;
       }
 
       // Handle callback
@@ -527,10 +527,9 @@ void ScreenInteractive::Main(Component component) {
 
       // Handle Animation
       if constexpr (std::is_same_v<T, AnimationTask>) {
-              if (!animation_requested_) {
+        if (!animation_requested_)
-                continue_event_loop = true;
           return;
-              }
+
         animation_requested_ = false;
         animation::TimePoint now = animation::Clock::now();
         animation::Duration delta = now - previous_animation_time;
@@ -538,10 +537,12 @@ void ScreenInteractive::Main(Component component) {
 
         animation::Params params(delta);
         component->OnAnimation(params);
+        attempt_draw = true;
+        return;
       }
     },
     task);
-    }
+    // clang-format on
   }
 }