Avoid unnecessary re-layouts when populating thumbnails

qrenderdoc/Widgets/ResourcePreview.h

@@ -58,10 +58,8 @@ public:
   void setActive(bool b)
   {
     m_Active = b;
-    if(b)
-      show();
-    else
-      hide();
+    // we unconditionally hide the preview, the thumbnail strip will show it
+    hide();
   }
   bool isActive() { return m_Active; }
   void setSize(QSize s);

qrenderdoc/Widgets/ThumbnailStrip.cpp

@@ -77,6 +77,9 @@ void ThumbnailStrip::showEvent(QShowEvent *event)
 
 void ThumbnailStrip::refreshLayout()
 {
+  if(updatesEnabled())
+    setUpdatesEnabled(false);
+
   QRect avail = geometry();
   avail.adjust(6, 6, -6, -6);
 
@@ -97,9 +100,7 @@ void ThumbnailStrip::refreshLayout()
     ui->scrollArea->setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
 
     delete layout;
-    layout = new QHBoxLayout(ui->scrollAreaWidgetContents);
-    for(ResourcePreview *w : m_Thumbnails)
-      layout->addWidget(w);
+    layout = new QHBoxLayout();
     layout->setSpacing(6);
     layout->setContentsMargins(6, 6, 6, 6);
     layout->setAlignment(Qt::AlignTop);
@@ -139,9 +140,7 @@ void ThumbnailStrip::refreshLayout()
     ui->scrollArea->setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
 
     delete layout;
-    layout = new QVBoxLayout(ui->scrollAreaWidgetContents);
-    for(ResourcePreview *w : m_Thumbnails)
-      layout->addWidget(w);
+    layout = new QVBoxLayout();
     layout->setSpacing(6);
     layout->setContentsMargins(6, 6, 6, 6);
     layout->setAlignment(Qt::AlignTop);
@@ -172,4 +171,15 @@ void ThumbnailStrip::refreshLayout()
         c->setSize(QSize(avail.width(), aspectHeight));
     }
   }
+
+  for(ResourcePreview *w : m_Thumbnails)
+    layout->addWidget(w);
+
+  for(ResourcePreview *w : m_Thumbnails)
+    if(w->isActive())
+      w->show();
+
+  ui->scrollAreaWidgetContents->setLayout(layout);
+
+  setUpdatesEnabled(true);
 }

qrenderdoc/Windows/TextureViewer.cpp

@@ -3013,6 +3013,9 @@ void TextureViewer::OnEventChanged(uint32_t eventId)
   int outIndex = 0;
   int inIndex = 0;
 
+  ui->outputThumbs->setUpdatesEnabled(false);
+  ui->inputThumbs->setUpdatesEnabled(false);
+
   bool copy = false, clear = false, compute = false;
   Following::GetDrawContext(m_Ctx, copy, clear, compute);