From db261d2356a017fc4af6255842166cb9b8596e59 Mon Sep 17 00:00:00 2001
From: gered <gered@blarg.ca>
Date: Sun, 22 May 2022 10:50:12 -0400
Subject: [PATCH] add 'Resume' state that game states go through when they wake
 up again

this is to provide an easy way for game states to react to the specific
scenario where they were previously paused and then are re-awakened and
may want to perform (re-)initialization like they may have done in a
previous 'Pending' state (which is only set when states are first
created)
---
 libretrogd/src/states/mod.rs | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/libretrogd/src/states/mod.rs b/libretrogd/src/states/mod.rs
index 702188c..025ae37 100644
--- a/libretrogd/src/states/mod.rs
+++ b/libretrogd/src/states/mod.rs
@@ -18,6 +18,7 @@ pub enum TransitionDirection {
 #[derive(Copy, Clone, Eq, PartialEq, Debug)]
 pub enum State {
     Pending,
+    Resume,
     Active,
     Paused,
     TransitionIn,
@@ -108,7 +109,7 @@ impl<ContextType> StateContainer<ContextType> {
 
     pub fn transition_in(&mut self, context: &mut ContextType) -> Result<(), StateError> {
         match self.current_state {
-            State::Pending | State::Paused => {
+            State::Pending | State::Paused | State::Resume => {
                 self.change_state(State::TransitionIn, context);
                 Ok(())
             },
@@ -312,6 +313,7 @@ impl<ContextType> States<ContextType> {
                             // otherwise, we're probably waking up a state that was paused and needs to
                             // be resumed since it's once again on top
                             let state = self.states.front_mut().unwrap();
+                            state.change_state(State::Resume, context);
                             state.transition_in(context)?;
                         }
                     },
@@ -754,7 +756,8 @@ mod tests {
             context.take_log(),
             vec![
                 StateChange(SECOND, Dead, TransitionOut(TransitionTo::Dead)),
-                StateChange(FIRST, TransitionIn, Paused),
+                StateChange(FIRST, Resume, Paused),
+                StateChange(FIRST, TransitionIn, Resume),
                 Transition(FIRST, TransitionIn),
                 Update(FIRST, TransitionIn),
                 Render(FIRST, TransitionIn)
@@ -945,7 +948,8 @@ mod tests {
             context.take_log(),
             vec![
                 StateChange(SECOND, Dead, TransitionOut(TransitionTo::Dead)),
-                StateChange(FIRST, TransitionIn, Paused),
+                StateChange(FIRST, Resume, Paused),
+                StateChange(FIRST, TransitionIn, Resume),
                 Transition(FIRST, TransitionIn),
                 Update(FIRST, TransitionIn),
                 Render(FIRST, TransitionIn)
@@ -1387,7 +1391,8 @@ mod tests {
             context.take_log(),
             vec![
                 StateChange(SECOND, Dead, TransitionOut(TransitionTo::Dead)),
-                StateChange(FIRST, TransitionIn, Paused),
+                StateChange(FIRST, Resume, Paused),
+                StateChange(FIRST, TransitionIn, Resume),
                 Transition(FIRST, TransitionIn),
                 Update(FIRST, TransitionIn),
                 Render(FIRST, TransitionIn)