Make event selection 'soft' blocking instead of hard blocking

* Normally SetEventID is synchronous and blocking, and will stall the UI while
  it is processing. However we can at least pop up a progress dialog and allow
  the UI to function (if not be interactive due to the blocking progress dialog)
  when some other long-running task is delaying the processing on the replay
  thread.

qrenderdoc/Code/CaptureContext.cpp

@@ -1478,15 +1478,36 @@ void CaptureContext::SetEventID(const rdcarray<ICaptureViewer *> &exclude, uint3
   uint32_t prevEventID = m_EventID;
   m_EventID = eventId;
 
-  m_Replay.BlockInvoke([this, eventId, force](IReplayController *r) {
+  bool done = false;
+
+  QString tag = lit("replaySetEvent");
+
+  // we can't return until the event is selected, but a blocking invoke on the UI thread can cause
+  // the UI to stall. We ideally want to have at least an interactive UI and a progress bar.
+  m_Replay.AsyncInvoke(tag, [this, eventId, force, &done](IReplayController *r) {
     r->SetFrameEvent(eventId, force);
     m_CurD3D11PipelineState = r->GetD3D11PipelineState();
     m_CurD3D12PipelineState = r->GetD3D12PipelineState();
     m_CurGLPipelineState = r->GetGLPipelineState();
     m_CurVulkanPipelineState = r->GetVulkanPipelineState();
     m_CurPipelineState = &r->GetPipelineState();
+
+    done = true;
   });
 
+  // wait a short while before displaying the progress dialog (which won't show if we're already
+  // done by the time we reach it).
+  // Keep waiting if the current tag is a set event, we don't want to be popping up progress bars
+  // when the user is browsing the frame if it's going slow. If that's the case we'll just block the
+  // UI thread. Instead only pop up the progress bar if some other large task is blocking.
+  for(int i = 0; !done && (i < 100 || m_Replay.GetCurrentProcessingTag().isEmpty() ||
+                           m_Replay.GetCurrentProcessingTag() == tag);
+      i++)
+    QThread::msleep(5);
+
+  ShowProgressDialog(m_MainWindow->Widget(), tr("Please wait, working..."),
+                     [&done]() { return done; });
+
   bool updateSelectedEvent = force || prevSelectedEventID != selectedEventID;
   bool updateEvent = force || prevEventID != eventId;
 

qrenderdoc/Code/ReplayManager.cpp

@@ -240,6 +240,12 @@ float ReplayManager::GetCurrentProcessingTime()
   return m_CommandTimer.isValid() ? double(m_CommandTimer.elapsed()) / 1000.0 : 0.0;
 }
 
+QString ReplayManager::GetCurrentProcessingTag()
+{
+  QMutexLocker lock(&m_TimerLock);
+  return m_CommandTag;
+}
+
 void ReplayManager::AsyncInvoke(const rdcstr &tag, ReplayManager::InvokeCallback m)
 {
   QString qtag(tag);
@@ -486,6 +492,7 @@ void ReplayManager::run(int proxyRenderer, const QString &capturefile, const Rep
       {
         QMutexLocker lock(&m_TimerLock);
         m_CommandTimer.start();
+        m_CommandTag = cmd->tag;
       }
 
       cmd->method(m_Renderer);
@@ -493,6 +500,7 @@ void ReplayManager::run(int proxyRenderer, const QString &capturefile, const Rep
       {
         QMutexLocker lock(&m_TimerLock);
         m_CommandTimer.invalidate();
+        m_CommandTag = QString();
       }
     }
 

qrenderdoc/Code/ReplayManager.h

@@ -55,6 +55,7 @@ public:
   bool IsRunning();
   ReplayStatus GetCreateStatus() { return m_CreateStatus; }
   float GetCurrentProcessingTime();
+  QString GetCurrentProcessingTag();
   // this tagged version is for cases when we might send a request - e.g. to pick a vertex or pixel
   // - and want to pre-empt it with a new request before the first has returned. Either because some
   // other work is taking a while or because we're sending requests faster than they can be
@@ -119,6 +120,7 @@ private:
 
   QMutex m_TimerLock;
   QElapsedTimer m_CommandTimer;
+  QString m_CommandTag;
 
   QMutex m_RenderLock;
   QQueue<InvokeHandle *> m_RenderQueue;