[simulator] Refresh screen on web python

The refresh was done in the scan, but commit 9bfa204 "[ion] Simulator and
device keyboard works similarly by queuing keyboard" changed the times
where we could call scan, so the refresh was no longer done at the right
moments. As a result, Python drawings on a web emulator would not be
displayed in real time.

Author: LeaNumworks

ion/src/device/shared/drivers/keyboard.cpp

@@ -45,6 +45,11 @@
 #include <shared/drivers/keyboard.h>
 
 namespace Ion {
+
+namespace Keyboard {
+ void willPopState() {}
+}
+
 namespace Device {
 namespace Keyboard {
 

ion/src/shared/keyboard.cpp

@@ -7,6 +7,7 @@ namespace Ion {
 namespace Keyboard {
 
 State popState() {
+  willPopState();
   if (Queue::sharedQueue()->isEmpty()) {
     return State(-1);
   }

ion/src/shared/keyboard.h

@@ -6,6 +6,7 @@
 namespace Ion {
 namespace Keyboard {
 
+void willPopState(); // Callback only implemented on simulator, to refresh the window
 void resetMemoizedState();
 void keyboardWasScanned(State state);
 

ion/src/simulator/shared/keyboard.cpp

@@ -47,6 +47,11 @@ constexpr int sNumberOfKeyPairs = sizeof(sKeyPairs)/sizeof(KeySDLKeyPair);
 namespace Ion {
 namespace Keyboard {
 
+void willPopState() {
+  // Grab this opportunity to refresh the display if needed
+  Simulator::Window::refresh();
+}
+
 State scan() {
   State state(0);
 
@@ -60,9 +65,6 @@ State scan() {
   // Notify callbacks in case we need to do something
   Simulator::Keyboard::didScan();
 
-  // Grab this opportunity to refresh the display if needed
-  Simulator::Window::refresh();
-
 #if !EPSILON_SDL_SCREEN_ONLY
   // Register a key for the mouse, if any
   Key k = Simulator::Layout::getHighlightedKey();