Marked the weird IMGUI_ONCE_UPON_A_FRAME helper macro as obsolete. prefer using the more explicit ImGuiOnceUponAFrame. Removed the broken __LINE__ from IMGUI_ONCE_UPON_A_FRAME

imgui.cpp

@@ -204,6 +204,7 @@
  Here is a change-log of API breaking changes, if you are using one of the functions listed, expect to have to fix some code.
  Also read releases logs https://github.com/ocornut/imgui/releases for more details.
 
+ - 2017/08/15 (1.51) - marked the weird IMGUI_ONCE_UPON_A_FRAME helper macro as obsolete. prefer using the more explicit ImGuiOnceUponAFrame.
  - 2017/08/15 (1.51) - changed parameter order for BeginPopupContextWindow(), note that most uses relied on default parameters completely.
  - 2017/08/13 (1.51) - renamed ImGuiCol_Columns_*** to ImGuiCol_Separator_***
  - 2017/08/11 (1.51) - renamed ImGuiSetCond_*** types and flags to ImGuiCond_***. Kept redirection enums (will obsolete).

imgui.h

@@ -924,15 +924,11 @@ public:
     inline iterator             insert(const_iterator it, const value_type& v)  { IM_ASSERT(it >= Data && it <= Data+Size); const ptrdiff_t off = it - Data; if (Size == Capacity) reserve(Capacity ? Capacity * 2 : 4); if (off < (int)Size) memmove(Data + off + 1, Data + off, ((size_t)Size - (size_t)off) * sizeof(value_type)); Data[off] = v; Size++; return Data + off; }
 };
 
-// Helper: execute a block of code at maximum once a frame
-// Convenient if you want to quickly create an UI within deep-nested code that runs multiple times every frame.
+// Helper: execute a block of code at maximum once a frame. Convenient if you want to quickly create an UI within deep-nested code that runs multiple times every frame.
 // Usage:
-//   IMGUI_ONCE_UPON_A_FRAME
-//   {
-//      // code block will be executed one per frame
-//   }
-// Attention! the macro expands into 2 statement so make sure you don't use it within e.g. an if() statement without curly braces.
-#define IMGUI_ONCE_UPON_A_FRAME    static ImGuiOnceUponAFrame imgui_oaf##__LINE__; if (imgui_oaf##__LINE__)
+//   static ImGuiOnceUponAFrame oaf;
+//   if (oaf)
+//       ImGui::Text("This will be called only once per frame");
 struct ImGuiOnceUponAFrame
 {
     ImGuiOnceUponAFrame() { RefFrame = -1; }
@@ -940,6 +936,11 @@ struct ImGuiOnceUponAFrame
     operator bool() const { int current_frame = ImGui::GetFrameCount(); if (RefFrame == current_frame) return false; RefFrame = current_frame; return true; }
 };
 
+// Helper macro for ImGuiOnceUponAFrame. Attention: The macro expands into 2 statement so make sure you don't use it within e.g. an if() statement without curly braces.
+#ifndef IMGUI_DISABLE_OBSOLETE_FUNCTIONS    // Will obsolete
+#define IMGUI_ONCE_UPON_A_FRAME     static ImGuiOnceUponAFrame imgui_oaf; if (imgui_oaf)
+#endif
+
 // Helper: Parse and apply text filters. In format "aaaaa[,bbbb][,ccccc]"
 struct ImGuiTextFilter
 {

imgui_demo.cpp

@@ -308,14 +308,11 @@ void ImGui::ShowTestWindow(bool* p_open)
                 ImGui::EndTooltip();
             }
 
-            // Testing IMGUI_ONCE_UPON_A_FRAME macro
+            // Testing ImGuiOnceUponAFrame helper.
+            //static ImGuiOnceUponAFrame once;
             //for (int i = 0; i < 5; i++)
-            //{
-            //  IMGUI_ONCE_UPON_A_FRAME
-            //  {
-            //      ImGui::Text("This will be displayed only once.");
-            //  }
-            //}
+            //    if (once)
+            //        ImGui::Text("This will be displayed only once.");
 
             ImGui::Separator();