Handle all available input before redrawing

src/commands.cc

@@ -654,7 +654,7 @@ public:
         assert(m_pos < m_keys.size());
         return m_keys[m_pos++];
     }
-    bool has_key_left() const { return m_pos < m_keys.size(); }
+    bool is_key_available() override { return m_pos < m_keys.size(); }
 
     void print_status(const String& , CharCount) override {}
     void draw(const DisplayBuffer&, const String&) override {}
@@ -681,8 +681,7 @@ void exec_keys(const KeyList& keys, Context& context)
     scoped_edition edition(context.editor());
 
     Context new_context(batch_input_handler, context.editor(), batch_ui);
-    while (batch_ui.has_key_left())
-        batch_input_handler.handle_next_input(new_context);
+    batch_input_handler.handle_available_inputs(new_context);
     context.change_editor(new_context.editor());
 }
 

src/input_handler.cc

@@ -625,11 +625,14 @@ void InputHandler::on_next_key(KeyCallback callback)
     m_mode.reset(new InputModes::NextKey(*this, callback));
 }
 
-void InputHandler::handle_next_input(Context& context)
+void InputHandler::handle_available_inputs(Context& context)
 {
+    while (context.ui().is_key_available())
+    {
         Key key = context.ui().get_key();
         if (key != Key::Invalid)
             m_mode->on_key(key, context);
+    }
     context.draw_ifn();
 }
 

src/input_handler.hh

@@ -36,7 +36,7 @@ public:
 
     void on_next_key(KeyCallback callback);
 
-    void handle_next_input(Context& context);
+    void handle_available_inputs(Context& context);
 
 private:
     friend class InputMode;

src/main.cc

@@ -529,7 +529,7 @@ Client create_local_client(const String& file)
     EventManager::instance().watch(0, [=](int) {
         try
         {
-            input_handler->handle_next_input(*context);
+            input_handler->handle_available_inputs(*context);
         }
         catch (Kakoune::runtime_error& error)
         {
@@ -573,7 +573,7 @@ void setup_server()
         EventManager::instance().watch(sock, [=](int) {
             try
             {
-                input_handler->handle_next_input(*context);
+                input_handler->handle_available_inputs(*context);
             }
             catch (Kakoune::runtime_error& error)
             {

src/ncurses.cc

@@ -211,6 +211,16 @@ struct getch_iterator
     getch_iterator& operator++(int) { return *this; }
 };
 
+bool NCursesUI::is_key_available()
+{
+    timeout(0);
+    const int c = getch();
+    if (c != ERR)
+        ungetch(c);
+    timeout(-1);
+    return c != ERR;
+}
+
 Key NCursesUI::get_key()
 {
     const unsigned c = getch();

src/ncurses.hh

@@ -23,6 +23,7 @@ public:
               const String& status_line) override;
     void print_status(const String& status, CharCount cursor_pos) override;
 
+    bool   is_key_available() override;
     Key    get_key() override;
 
     void menu_show(const memoryview<String>& choices,

src/remote.cc

@@ -193,6 +193,20 @@ void RemoteUI::draw(const DisplayBuffer& display_buffer,
 
 static const Key::Modifiers resize_modifier = (Key::Modifiers)0x80;
 
+bool RemoteUI::is_key_available()
+{
+    timeval tv;
+    fd_set  rfds;
+
+    FD_ZERO(&rfds);
+    FD_SET(m_socket, &rfds);
+
+    tv.tv_sec = 0;
+    tv.tv_usec = 0;
+    int res = select(m_socket+1, &rfds, NULL, NULL, &tv);
+    return res == 1;
+}
+
 Key RemoteUI::get_key()
 {
     Key key = read<Key>(m_socket);

src/remote.hh

@@ -24,6 +24,8 @@ public:
     void menu_hide() override;
     void draw(const DisplayBuffer& display_buffer,
               const String& status_line) override;
+
+    bool is_key_available() override;
     Key  get_key() override;
     DisplayCoord dimensions() override;
 

src/user_interface.hh

@@ -31,6 +31,7 @@ public:
     virtual void draw(const DisplayBuffer& display_buffer,
                       const String& status_line) = 0;
     virtual DisplayCoord dimensions() = 0;
+    virtual bool is_key_available() = 0;
     virtual Key  get_key() = 0;
 };