CollapsingHeader(bool*) variant: fixed for IsItemHovered() to work pr…

…operly 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

@@ -7346,8 +7346,11 @@ 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;

imgui_demo.cpp

@@ -460,11 +460,13 @@ void ImGui::ShowTestWindow(bool* p_open)
             ImGui::Checkbox("Enable extra group", &closable_group);
             if (ImGui::CollapsingHeader("Header"))
             {
+                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);
             }

imgui_internal.h

@@ -848,6 +848,17 @@ struct IMGUI_API ImGuiWindow
     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.