TabView: Fix for terminal handling scrollviewer load issue (#1339)

microsoft · Sep 17, 2019 · 96b64c0 · 96b64c0
1 parent 44a2d6f
commit 96b64c0
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Showing 3 changed files with 21 additions and 5 deletions.
diff --git a/dev/TabView/TabView.cpp b/dev/TabView/TabView.cpp
@@ -237,14 +237,20 @@ void TabView::OnListViewLoaded(const winrt::IInspectable&, const winrt::RoutedEv
         SelectedIndex(listView.SelectedIndex());
         SelectedItem(listView.SelectedItem());
 
-        m_scrollViewer.set([this, listView]() {
-            auto scrollViewer = SharedHelpers::FindInVisualTreeByName(listView, L"ScrollViewer").as<winrt::FxScrollViewer>();
-            if (scrollViewer)
+        auto scrollViewer = SharedHelpers::FindInVisualTreeByName(listView, L"ScrollViewer").as<winrt::FxScrollViewer>();
+        m_scrollViewer.set(scrollViewer);
+        if (scrollViewer)
+        {
+            if (SharedHelpers::IsIsLoadedAvailable() && scrollViewer.IsLoaded())
+            {
+                // This scenario occurs reliably for Terminal in XAML islands
+                OnScrollViewerLoaded(nullptr, nullptr);
+            }
+            else
             {
                 m_scrollViewerLoadedRevoker = scrollViewer.Loaded(winrt::auto_revoke, { this, &TabView::OnScrollViewerLoaded });
             }
-            return scrollViewer;
-        }());
+        }
     }
 }
 

diff --git a/dev/dll/SharedHelpers.cpp b/dev/dll/SharedHelpers.cpp
@@ -198,6 +198,14 @@ bool SharedHelpers::IsThemeShadowAvailable()
     return s_isThemeShadowAvailable;
 }
 
+bool SharedHelpers::IsIsLoadedAvailable()
+{
+    static bool s_isAvailable =
+        IsRS5OrHigher() ||
+        winrt::ApiInformation::IsPropertyPresent(L"Windows.UI.Xaml.FrameworkElement", L"IsLoaded");
+    return s_isAvailable;
+}
+
 template <uint16_t APIVersion> bool SharedHelpers::IsAPIContractVxAvailable()
 {
     static bool isAPIContractVxAvailableInitialized = false;

diff --git a/dev/inc/SharedHelpers.h b/dev/inc/SharedHelpers.h
@@ -55,6 +55,8 @@ class SharedHelpers
 
     static bool IsThemeShadowAvailable();
 
+    static bool IsIsLoadedAvailable();
+
     // Actual OS version checks
     static bool IsAPIContractV9Available(); // 19H2
     static bool IsAPIContractV8Available(); // 19H1