Factorized some code (+ declared as static function without namespace, a pattern with the Nav branch has started to use)

imgui.cpp

@@ -659,6 +659,11 @@ static inline void      DataTypeFormatString(ImGuiDataType data_type, void* data
 static void             DataTypeApplyOp(ImGuiDataType data_type, int op, void* value1, const void* value2);
 static bool             DataTypeApplyOpFromText(const char* buf, const char* initial_value_buf, ImGuiDataType data_type, void* data_ptr, const char* scalar_format);
 
+namespace ImGui
+{
+static void             FocusPreviousWindow();
+}
+
 //-----------------------------------------------------------------------------
 // Platform dependent default implementations
 //-----------------------------------------------------------------------------
@@ -2434,12 +2439,7 @@ void ImGui::NewFrame()
 
     // Closing the focused window restore focus to the first active root window in descending z-order
     if (g.NavWindow && !g.NavWindow->WasActive)
-        for (int i = g.Windows.Size-1; i >= 0; i--)
-            if (g.Windows[i]->WasActive && !(g.Windows[i]->Flags & ImGuiWindowFlags_ChildWindow))
-            {
-                FocusWindow(g.Windows[i]);
-                break;
-            }
+        FocusPreviousWindow();
 
     // No window should be open at the beginning of the frame.
     // But in order to allow the user to call NewFrame() multiple times without calling Render(), we are doing an explicit clear.
@@ -4833,6 +4833,17 @@ void ImGui::FocusWindow(ImGuiWindow* window)
     g.Windows.push_back(window);
 }
 
+void ImGui::FocusPreviousWindow()
+{
+    ImGuiContext& g = *GImGui;
+    for (int i = g.Windows.Size - 1; i >= 0; i--)
+        if (g.Windows[i]->WasActive && !(g.Windows[i]->Flags & ImGuiWindowFlags_ChildWindow))
+        {
+            FocusWindow(g.Windows[i]);
+            return;
+        }
+}
+
 void ImGui::PushItemWidth(float item_width)
 {
     ImGuiWindow* window = GetCurrentWindow();