From a03093b2d44f978d432fb81a85fd61e8cd9eb18d Mon Sep 17 00:00:00 2001
From: omar <omarcornut@gmail.com>
Date: Wed, 18 Oct 2017 19:51:32 +0200
Subject: [PATCH] CollapsingHeader(bool*) variant: fixed for IsItemHovered() to
 work properly in the nav branch.Basically the close button now has to use
 ItemAdd() to be navable into, which overwrite the IsItemHovered data. (#600,
 #787)

---
 imgui.cpp        |  3 +++
 imgui_demo.cpp   |  4 +++-
 imgui_internal.h | 11 +++++++++++
 3 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/imgui.cpp b/imgui.cpp
index 51f7f3f5e..d92817187 100644
--- a/imgui.cpp
+++ b/imgui.cpp
@@ -6273,8 +6273,11 @@ bool ImGui::CollapsingHeader(const char* label, bool* p_open, ImGuiTreeNodeFlags
         // Create a small overlapping close button // FIXME: We can evolve this into user accessible helpers to add extra buttons on title bars, headers, etc.
         ImGuiContext& g = *GImGui;
         float button_sz = g.FontSize * 0.5f;
+        ImGuiItemHoveredDataBackup last_item_backup;
+        last_item_backup.Backup();
         if (CloseButton(window->GetID((void*)(intptr_t)(id+1)), ImVec2(ImMin(window->DC.LastItemRect.Max.x, window->ClipRect.Max.x) - g.Style.FramePadding.x - button_sz, window->DC.LastItemRect.Min.y + g.Style.FramePadding.y + button_sz), button_sz))
             *p_open = false;
+        last_item_backup.Restore();
     }
 
     return is_open;
diff --git a/imgui_demo.cpp b/imgui_demo.cpp
index c0f96d750..2a3ce928e 100644
--- a/imgui_demo.cpp
+++ b/imgui_demo.cpp
@@ -454,14 +454,16 @@ void ImGui::ShowTestWindow(bool* p_open)
         if (ImGui::TreeNode("Collapsing Headers"))
         {
             static bool closable_group = true;
+            ImGui::Checkbox("Enable extra group", &closable_group);
             if (ImGui::CollapsingHeader("Header"))
             {
-                ImGui::Checkbox("Enable extra group", &closable_group);
+                ImGui::Text("IsItemHovered: %d", IsItemHovered());
                 for (int i = 0; i < 5; i++)
                     ImGui::Text("Some content %d", i);
             }
             if (ImGui::CollapsingHeader("Header with a close button", &closable_group))
             {
+                ImGui::Text("IsItemHovered: %d", IsItemHovered());
                 for (int i = 0; i < 5; i++)
                     ImGui::Text("More content %d", i);
             }
diff --git a/imgui_internal.h b/imgui_internal.h
index 7edcd9028..58aceec18 100644
--- a/imgui_internal.h
+++ b/imgui_internal.h
@@ -747,6 +747,17 @@ public:
     ImRect      MenuBarRect() const                     { float y1 = Pos.y + TitleBarHeight(); return ImRect(Pos.x, y1, Pos.x + SizeFull.x, y1 + MenuBarHeight()); }
 };
 
+// Backup and restore just enough data to be able to use IsItemHovered() on item A after another B in the same window has overwritten the data.  
+struct ImGuiItemHoveredDataBackup
+{
+    ImGuiID     LastItemId;
+    ImRect      LastItemRect;
+    bool        LastItemRectHoveredRect;
+
+    void Backup()  { ImGuiWindow* window = GImGui->CurrentWindow; LastItemId = window->DC.LastItemId; LastItemRect = window->DC.LastItemRect; LastItemRectHoveredRect = window->DC.LastItemRectHoveredRect; }
+    void Restore() { ImGuiWindow* window = GImGui->CurrentWindow; window->DC.LastItemId = LastItemId; window->DC.LastItemRect = LastItemRect; window->DC.LastItemRectHoveredRect = LastItemRectHoveredRect; }
+};
+
 //-----------------------------------------------------------------------------
 // Internal API
 // No guarantee of forward compatibility here.