From 29836412e1f78dfda5802115b387a73460cb8563 Mon Sep 17 00:00:00 2001
From: ocornut <omarcornut@gmail.com>
Date: Tue, 22 Sep 2020 15:49:47 +0200
Subject: [PATCH] Internals, CollapsingHeader, TabItem: Standardized using a
 #CLOSE id prefix for TabItem and ColllapsingHeader (same as window)

---
 imgui.cpp         | 14 ++++++++++++++
 imgui_internal.h  |  1 +
 imgui_widgets.cpp |  5 +++--
 3 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/imgui.cpp b/imgui.cpp
index 4c867579..ec107aed 100644
--- a/imgui.cpp
+++ b/imgui.cpp
@@ -6742,6 +6742,20 @@ void ImGui::PushOverrideID(ImGuiID id)
     window->IDStack.push_back(id);
 }
 
+// Helper to avoid a common series of PushOverrideID -> GetID() -> PopID() call
+// (note that when using this pattern, TestEngine's "Stack Tool" will tend to not display the intermediate stack level.
+//  for that to work we would need to do PushOverrideID() -> ItemAdd() -> PopID() which would alter widget code a little more)
+ImGuiID ImGui::GetIDWithSeed(const char* str, const char* str_end, ImGuiID seed)
+{
+    ImGuiID id = ImHashStr(str, str_end ? (str_end - str) : 0, seed);
+    ImGui::KeepAliveID(id);
+#ifdef IMGUI_ENABLE_TEST_ENGINE
+    ImGuiContext& g = *GImGui;
+    IMGUI_TEST_ENGINE_ID_INFO2(id, ImGuiDataType_String, str, str_end);
+#endif
+    return id;
+}
+
 void ImGui::PopID()
 {
     ImGuiWindow* window = GImGui->CurrentWindow;
diff --git a/imgui_internal.h b/imgui_internal.h
index ec37b38b..c5b3028b 100644
--- a/imgui_internal.h
+++ b/imgui_internal.h
@@ -1847,6 +1847,7 @@ namespace ImGui
     IMGUI_API void          KeepAliveID(ImGuiID id);
     IMGUI_API void          MarkItemEdited(ImGuiID id);     // Mark data associated to given item as "edited", used by IsItemDeactivatedAfterEdit() function.
     IMGUI_API void          PushOverrideID(ImGuiID id);     // Push given value as-is at the top of the ID stack (whereas PushID combines old and new hashes)
+    IMGUI_API ImGuiID       GetIDWithSeed(const char* str_id_begin, const char* str_id_end, ImGuiID seed);
 
     // Basic Helpers for widget code
     IMGUI_API void          ItemSize(const ImVec2& size, float text_baseline_y = -1.0f);
diff --git a/imgui_widgets.cpp b/imgui_widgets.cpp
index 4a7f18c6..abc3f16c 100644
--- a/imgui_widgets.cpp
+++ b/imgui_widgets.cpp
@@ -5898,7 +5898,8 @@ bool ImGui::CollapsingHeader(const char* label, bool* p_open, ImGuiTreeNodeFlags
         float button_size = g.FontSize;
         float button_x = ImMax(window->DC.LastItemRect.Min.x, window->DC.LastItemRect.Max.x - g.Style.FramePadding.x * 2.0f - button_size);
         float button_y = window->DC.LastItemRect.Min.y;
-        if (CloseButton(window->GetID((void*)((intptr_t)id + 1)), ImVec2(button_x, button_y)))
+        ImGuiID close_button_id = GetIDWithSeed("#CLOSE", NULL, id);
+        if (CloseButton(close_button_id, ImVec2(button_x, button_y)))
             *p_open = false;
         last_item_backup.Restore();
     }
@@ -7539,7 +7540,7 @@ bool    ImGui::TabItemEx(ImGuiTabBar* tab_bar, const char* label, bool* p_open,
         flags |= ImGuiTabItemFlags_NoCloseWithMiddleMouseButton;
 
     // Render tab label, process close button
-    const ImGuiID close_button_id = p_open ? window->GetID((void*)((intptr_t)id + 1)) : 0;
+    const ImGuiID close_button_id = p_open ? GetIDWithSeed("#CLOSE", NULL, id) : 0;
     bool just_closed = TabItemLabelAndCloseButton(display_draw_list, bb, flags, tab_bar->FramePadding, label, id, close_button_id, tab_contents_visible);
     if (just_closed && p_open != NULL)
     {