add custom key repeat handler to allow for user-configurable, mode-dependent key repeats

src/gui/Window.cc

@@ -6,6 +6,8 @@
 #define INITIAL_HEIGHT  500
 #define FONT_SIZE 16
 
+bool Key_Statuses[SDL_NUM_SCANCODES];
+
 /**
  * Initialize SDL.
  *
@@ -21,7 +23,7 @@ static bool Initialize_SDL()
         return true;
     }
 
-    if (SDL_Init(SDL_INIT_VIDEO) != 0)
+    if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_TIMER) != 0)
     {
         return false;
     }
@@ -133,6 +135,26 @@ void Window::run_event_loop()
     }
 }
 
+Uint32 Key_Repeat(Uint32 interval, void * param)
+{
+    if (Key_Statuses[(uintptr_t)param])
+    {
+        SDL_Event event;
+
+        event.user.code = 0;
+        event.user.data1 = param;
+        event.type = SDL_USEREVENT;
+
+        SDL_PushEvent(&event);
+
+        return 25u;
+    }
+    else
+    {
+        return 0u;
+    }
+}
+
 /**
  * Handle a SDL event.
  */
@@ -145,28 +167,33 @@ void Window::handle_event(SDL_Event & event)
         break;
 
     case SDL_KEYDOWN:
-        switch (event.key.keysym.sym)
+        Key_Statuses[event.key.keysym.scancode] = true;
+        switch (event.key.keysym.scancode)
         {
-        case SDLK_ESCAPE:
+        case SDL_SCANCODE_ESCAPE:
             m_exit_requested = true;
             break;
-        case SDLK_j:
-            if (m_line < m_buffer->get_num_lines() - 1)
+        case SDL_SCANCODE_J:
+            if (event.key.repeat == 0u)
             {
-                m_line++;
-                redraw();
+                SDL_AddTimer(200, Key_Repeat, (void *)event.key.keysym.scancode);
+                scroll_down();
             }
             break;
-        case SDLK_k:
-            if (m_line > 0)
+        case SDL_SCANCODE_K:
+            if (event.key.repeat == 0u)
             {
-                m_line--;
-                redraw();
+                SDL_AddTimer(200, Key_Repeat, (void *)event.key.keysym.scancode);
+                scroll_up();
             }
             break;
         }
         break;
 
+    case SDL_KEYUP:
+        Key_Statuses[event.key.keysym.scancode] = false;
+        break;
+
     case SDL_WINDOWEVENT:
         switch (event.window.event)
         {
@@ -179,6 +206,36 @@ void Window::handle_event(SDL_Event & event)
             break;
         }
         break;
+
+    case SDL_USEREVENT:
+        switch ((uintptr_t)event.user.data1)
+        {
+        case SDL_SCANCODE_J:
+            scroll_down();
+            break;
+        case SDL_SCANCODE_K:
+            scroll_up();
+            break;
+        }
+        break;
+    }
+}
+
+void Window::scroll_down()
+{
+    if (m_line < m_buffer->get_num_lines() - 1)
+    {
+        m_line++;
+        redraw();
+    }
+}
+
+void Window::scroll_up()
+{
+    if (m_line > 0)
+    {
+        m_line--;
+        redraw();
     }
 }
 

src/gui/Window.h

@@ -16,6 +16,8 @@ protected:
     void resize();
     void redraw();
     void handle_event(SDL_Event & event);
+    void scroll_down();
+    void scroll_up();
 
     SDL_Window * m_window;
     bool m_exit_requested;