Core::SetState() allow state to change without sending a callback.

Some state changes are meant to be near instantanoues, before switching to something else. By reporting ithe instant switch, the UI will flicker between states (pause/play button) and the debugger will unnecessarily update. Skipping the callback avoids these issues.

3 files changed, 9 insertions, 6 deletions

diff --git a/Source/Core/Core/Core.cpp b/Source/Core/Core/Core.cpp
index 5599573e62..536244869a 100644
--- a/Source/Core/Core/Core.cpp
+++ b/Source/Core/Core/Core.cpp
@@ -712,7 +712,7 @@ static void EmuThread(std::unique_ptr<BootParameters> boot, WindowSystemInfo wsi
 
 // Set or get the running state
 
-void SetState(State state)
+void SetState(State state, bool report_state_change)
 {
   // State cannot be controlled until the CPU Thread is operational
   if (!IsRunningAndStarted())
@@ -739,7 +739,10 @@ void SetState(State state)
     break;
   }
 
-  CallOnStateChangedCallbacks(GetState());
+  // Certain callers only change the state momentarily. Sending a callback for them causes
+  // unwanted updates, such as the Pause/Play button flickering between states on frame advance.
+  if (report_state_change)
+    CallOnStateChangedCallbacks(GetState());
 }
 
 State GetState()
@@ -1083,7 +1086,7 @@ void DoFrameStep()
     // if already paused, frame advance for 1 frame
     s_stop_frame_step = false;
     s_frame_step = true;
-    SetState(State::Running);
+    SetState(State::Running, false);
   }
   else if (!s_frame_step)
   {
diff --git a/Source/Core/Core/Core.h b/Source/Core/Core/Core.h
index 0ff8c32b5c..d8c5c9a0da 100644
--- a/Source/Core/Core/Core.h
+++ b/Source/Core/Core/Core.h
@@ -147,7 +147,7 @@ bool IsHostThread();
 bool WantsDeterminism();
 
 // [NOT THREADSAFE] For use by Host only
-void SetState(State state);
+void SetState(State state, bool report_state_change = true);
 State GetState();
 
 void SaveScreenShot();
diff --git a/Source/Core/DolphinQt/Debugger/CodeDiffDialog.cpp b/Source/Core/DolphinQt/Debugger/CodeDiffDialog.cpp
index 6698a8289e..f8610e3b85 100644
--- a/Source/Core/DolphinQt/Debugger/CodeDiffDialog.cpp
+++ b/Source/Core/DolphinQt/Debugger/CodeDiffDialog.cpp
@@ -160,7 +160,7 @@ void CodeDiffDialog::ClearBlockCache()
   Core::State old_state = Core::GetState();

 

   if (old_state == Core::State::Running)

-    Core::SetState(Core::State::Paused);

+    Core::SetState(Core::State::Paused, false);

 

   Core::System::GetInstance().GetJitInterface().ClearCache();

 

@@ -349,7 +349,7 @@ void CodeDiffDialog::Update(bool include)
   // Wrap everything in a pause

   Core::State old_state = Core::GetState();

   if (old_state == Core::State::Running)

-    Core::SetState(Core::State::Paused);

+    Core::SetState(Core::State::Paused, false);

 

   // Main process

   if (include)