[Bundle] add GetID_AssertUnique: warns if the ID was already used in common widgets

Applies to ButtonEx, ArrowButtonEx, Checkbox, RadioButton , DragScalar, SliderScalar, Drag, InputTextEx

Author: pthom

imgui.cpp

@@ -8857,6 +8857,28 @@ ImGuiID ImGuiWindow::GetID(int n)
     return id;
 }
 
+// Addition to ImGui Bundle: a version of GetID that warns if the ID was already used
+IMGUI_API ImGuiID ImGuiWindow::GetID_AssertUnique(const char* str_id)
+{
+    static ImVector<ImGuiID> sIdsThisFrame;
+    static int sLastFrame = -1;
+    int currentFrame = ImGui::GetFrameCount();
+
+    if (currentFrame != sLastFrame)
+        sIdsThisFrame.clear();
+
+    ImGuiID r = GetID(str_id);
+    if (sIdsThisFrame.contains(r))
+        IM_ASSERT(false && "Either your widgets names/ids must be distinct, or you shall call ImGui::PushID before reusing an id");
+
+    sIdsThisFrame.push_back(r);
+    sLastFrame = currentFrame;
+
+    return r;
+}
+
+
+
 // This is only used in rare/specific situations to manufacture an ID out of nowhere.
 ImGuiID ImGuiWindow::GetIDFromRectangle(const ImRect& r_abs)
 {

imgui_internal.h

@@ -2883,6 +2883,10 @@ struct IMGUI_API ImGuiWindow
     ImGuiID     GetID(const char* str, const char* str_end = NULL);
     ImGuiID     GetID(const void* ptr);
     ImGuiID     GetID(int n);
+
+    // Addition to ImGui Bundle: a version of GetID that warns if the ID was already used
+    IMGUI_API ImGuiID       GetID_AssertUnique(const char* str_id);  // (Specific to ImGui Bundle) Calculate unique ID (hash of whole ID stack + given parameter). Will warn if the ID was already used, and advise to call ImGui::PushID() before
+
     ImGuiID     GetIDFromRectangle(const ImRect& r_abs);
 
     // We don't use g.FontSize because the window may be != g.CurrentWindow.

imgui_widgets.cpp

@@ -701,7 +701,7 @@ bool ImGui::ButtonEx(const char* label, const ImVec2& size_arg, ImGuiButtonFlags
 
     ImGuiContext& g = *GImGui;
     const ImGuiStyle& style = g.Style;
-    const ImGuiID id = window->GetID(label);
+    const ImGuiID id = window->GetID_AssertUnique(label);
     const ImVec2 label_size = CalcTextSize(label, NULL, true);
 
     ImVec2 pos = window->DC.CursorPos;
@@ -783,7 +783,7 @@ bool ImGui::ArrowButtonEx(const char* str_id, ImGuiDir dir, ImVec2 size, ImGuiBu
     if (window->SkipItems)
         return false;
 
-    const ImGuiID id = window->GetID(str_id);
+    const ImGuiID id = window->GetID_AssertUnique(str_id);
     const ImRect bb(window->DC.CursorPos, window->DC.CursorPos + size);
     const float default_size = GetFrameHeight();
     ItemSize(size, (size.y >= default_size) ? g.Style.FramePadding.y : -1.0f);
@@ -1121,7 +1121,7 @@ bool ImGui::Checkbox(const char* label, bool* v)
 
     ImGuiContext& g = *GImGui;
     const ImGuiStyle& style = g.Style;
-    const ImGuiID id = window->GetID(label);
+    const ImGuiID id = window->GetID_AssertUnique(label);
     const ImVec2 label_size = CalcTextSize(label, NULL, true);
 
     const float square_sz = GetFrameHeight();
@@ -1225,7 +1225,7 @@ bool ImGui::RadioButton(const char* label, bool active)
 
     ImGuiContext& g = *GImGui;
     const ImGuiStyle& style = g.Style;
-    const ImGuiID id = window->GetID(label);
+    const ImGuiID id = window->GetID_AssertUnique(label);
     const ImVec2 label_size = CalcTextSize(label, NULL, true);
 
     const float square_sz = GetFrameHeight();
@@ -2453,7 +2453,7 @@ bool ImGui::DragScalar(const char* label, ImGuiDataType data_type, void* p_data,
 
     ImGuiContext& g = *GImGui;
     const ImGuiStyle& style = g.Style;
-    const ImGuiID id = window->GetID(label);
+    const ImGuiID id = window->GetID_AssertUnique(label);
     const float w = CalcItemWidth();
 
     const ImVec2 label_size = CalcTextSize(label, NULL, true);
@@ -3044,7 +3044,7 @@ bool ImGui::SliderScalar(const char* label, ImGuiDataType data_type, void* p_dat
 
     ImGuiContext& g = *GImGui;
     const ImGuiStyle& style = g.Style;
-    const ImGuiID id = window->GetID(label);
+    const ImGuiID id = window->GetID_AssertUnique(label);
     const float w = CalcItemWidth();
 
     const ImVec2 label_size = CalcTextSize(label, NULL, true);
@@ -4134,7 +4134,7 @@ bool ImGui::InputTextEx(const char* label, const char* hint, char* buf, int buf_
 
     if (is_multiline) // Open group before calling GetID() because groups tracks id created within their scope (including the scrollbar)
         BeginGroup();
-    const ImGuiID id = window->GetID(label);
+    const ImGuiID id = window->GetID_AssertUnique(label);
     const ImVec2 label_size = CalcTextSize(label, NULL, true);
     const ImVec2 frame_size = CalcItemSize(size_arg, CalcItemWidth(), (is_multiline ? g.FontSize * 8.0f : label_size.y) + style.FramePadding.y * 2.0f); // Arbitrary default of 8 lines high for multi-line
     const ImVec2 total_size = ImVec2(frame_size.x + (label_size.x > 0.0f ? style.ItemInnerSpacing.x + label_size.x : 0.0f), frame_size.y);