Internals: Routing recoverable user errors via IMGUI_USER_ERROR() macro. (#1651)

imgui.cpp

@@ -5820,17 +5820,16 @@ void ImGui::End()
     ImGuiWindow* window = g.CurrentWindow;
 
     // Error checking: verify that user hasn't called End() too many times!
-    // FIXME-ERRORHANDLING
     if (g.CurrentWindowStack.Size <= 1 && g.WithinFrameScopeWithImplicitWindow)
     {
-        IM_ASSERT(g.CurrentWindowStack.Size > 1 && "Calling End() too many times!");
+        IMGUI_USER_ERROR(g.CurrentWindowStack.Size > 1, "Calling End() too many times!");
         return;
     }
     IM_ASSERT(g.CurrentWindowStack.Size > 0);
 
     // Error checking: verify that user doesn't directly call End() on a child window.
     if (window->Flags & ImGuiWindowFlags_ChildWindow)
-        IM_ASSERT(g.WithinEndChild && "Must call EndChild() and not End()!");
+        IMGUI_USER_ERROR(g.WithinEndChild, "Must call EndChild() and not End()!");
 
     // Close anything that is open
     if (window->DC.CurrentColumns)
@@ -7004,13 +7003,13 @@ static void ImGui::ErrorCheckEndFrame()
     {
         if (g.CurrentWindowStack.Size > 1)
         {
-            IM_ASSERT(g.CurrentWindowStack.Size == 1 && "Mismatched Begin/BeginChild vs End/EndChild calls: did you forget to call End/EndChild?");
+            IMGUI_USER_ERROR(g.CurrentWindowStack.Size == 1, "Mismatched Begin/BeginChild vs End/EndChild calls: did you forget to call End/EndChild?");
-            while (g.CurrentWindowStack.Size > 1) // FIXME-ERRORHANDLING
+            while (g.CurrentWindowStack.Size > 1)
                 End();
         }
         else
         {
-            IM_ASSERT(g.CurrentWindowStack.Size == 1 && "Mismatched Begin/BeginChild vs End/EndChild calls: did you call End/EndChild too much?");
+            IMGUI_USER_ERROR(g.CurrentWindowStack.Size == 1, "Mismatched Begin/BeginChild vs End/EndChild calls: did you call End/EndChild too much?");
         }
     }
 

imgui_internal.h

@@ -161,6 +161,11 @@ extern IMGUI_API ImGuiContext* GImGui;  // Current implicit context pointer
 #define IM_FLOOR(_VAL)                  ((float)(int)(_VAL))                                    // ImFloor() is not inlined in MSVC debug builds
 #define IM_ROUND(_VAL)                  ((float)(int)((_VAL) + 0.5f))                           //
 
+// Error handling
+#ifndef IMGUI_USER_ERROR
+#define IMGUI_USER_ERROR(_EXPR, _MSG)   IM_ASSERT((_EXPR) && (_MSG))    // Recoverable User Error
+#endif
+
 // Debug Logging
 #ifndef IMGUI_DEBUG_LOG
 #define IMGUI_DEBUG_LOG(_FMT,...)       printf("[%05d] " _FMT, GImGui->FrameCount, __VA_ARGS__)

imgui_widgets.cpp

@@ -6472,8 +6472,8 @@ void    ImGui::EndTabBar()
     ImGuiTabBar* tab_bar = g.CurrentTabBar;
     if (tab_bar == NULL)
     {
-        IM_ASSERT(tab_bar != NULL && "Mismatched BeginTabBar()/EndTabBar()!");
+        IMGUI_USER_ERROR(tab_bar != NULL, "Mismatched BeginTabBar()/EndTabBar()!");
-        return; // FIXME-ERRORHANDLING
+        return;
     }
     if (tab_bar->WantLayout)
         TabBarLayout(tab_bar);
@@ -6869,8 +6869,8 @@ bool    ImGui::BeginTabItem(const char* label, bool* p_open, ImGuiTabItemFlags f
     ImGuiTabBar* tab_bar = g.CurrentTabBar;
     if (tab_bar == NULL)
     {
-        IM_ASSERT(tab_bar && "Needs to be called between BeginTabBar() and EndTabBar()!");
+        IMGUI_USER_ERROR(tab_bar, "BeginTabItem() Needs to be called between BeginTabBar() and EndTabBar()!");
-        return false; // FIXME-ERRORHANDLING
+        return false;
     }
     bool ret = TabItemEx(tab_bar, label, p_open, flags);
     if (ret && !(flags & ImGuiTabItemFlags_NoPushId))