Make sure widget don't handle key pressed while a modal is opened

Refs: #77

src/alerts.cc

@@ -178,19 +178,13 @@ void AlertViewer::display_next_alert_maybe() {
   }
 }
 
-bool AlertViewer::handle_key_press(int key) {
-  return (key == IV_KEY_PREV) or (key == IV_KEY_NEXT);
-}
-
 bool AlertViewer::handle_key_release(int key) {
   if (key == IV_KEY_PREV) {
     this->display_previous_alert_maybe();
-    return true;
   } else if (key == IV_KEY_NEXT) {
     this->display_next_alert_maybe();
-    return true;
   }
-  return false;
+  return true;
 }
 
 int AlertViewer::handle_pointer_event(int event_type, int pointer_pos_x,

src/alerts.h

@@ -43,8 +43,6 @@ class AlertViewer : public ModalWidget {
 
   void do_paint() override;
 
-  bool handle_key_press(int key) override;
-
   bool handle_key_release(int key) override;
 
   int handle_pointer_event(int event_type, int pointer_pos_x,

src/ui.cc

@@ -73,6 +73,7 @@ Ui::Ui(std::shared_ptr<Config> config, std::shared_ptr<Model> model)
   this->children.push_back(this->forecast_stack);
   this->children.push_back(status_bar);
 
+  this->register_key_event_consumer(this->alert_viewer);
   this->register_key_event_consumer(menu_button);
   this->register_key_event_consumer(this->forecast_stack);
 }
@@ -113,6 +114,14 @@ int Ui::handle_pointer_event(int event_type, int pointer_pos_x,
   return 0;
 }
 
+bool Ui::is_key_event_consumer_active(
+    std::shared_ptr<KeyEventConsumer> consumer) {
+  if (this->visible_modal) {
+    return consumer == this->visible_modal;
+  }
+  return KeyEventDispatcher::is_key_event_consumer_active(consumer);
+}
+
 void Ui::switch_forecast_widget() { this->forecast_stack->switch_forecast(); }
 
 void Ui::open_location_list(const std::vector<Location> &locations) {

src/ui.h

@@ -35,6 +35,9 @@ class Ui : public KeyEventDispatcher {
   int handle_pointer_event(int event_type, int pointer_pos_x,
                            int pointer_pos_y);
 
+  bool is_key_event_consumer_active(
+      std::shared_ptr<KeyEventConsumer> consumer) override;
+
   void display_alert() { this->alert_viewer->open(); }
 
   void switch_forecast_widget();

src/widget.h

@@ -39,10 +39,11 @@ struct Widget : public KeyEventConsumer {
 
   virtual bool is_modal() const { return false; }
   // a modal widget takes control of the screen, and receives all
-  // keys and pointer events
+  // keys and pointer events when visible
 
   virtual bool is_visible() const { return true; }
-  // invisible widgets are painted white
+  // invisible widgets are painted white, note that nothing ensures
+  // that the returned value change when a modal is opened!
 
   virtual bool is_enabled() const { return true; }
   // disabled widgets don't receive keys and pointer events
@@ -83,6 +84,8 @@ struct Widget : public KeyEventConsumer {
     return this->is_visible() and this->is_enabled();
   }
 
+  bool handle_key_press(int key) override { return this->is_modal(); }
+
 protected:
   irect bounding_box;