Windows: Fixed IsItemXXXX() functions not working on append-version of EndChild(). (ocornut#8350)

Also made some of the fields accessible after BeginChild() to match Begin() logic.

Author: ocornut

docs/CHANGELOG.txt

@@ -69,6 +69,8 @@ Other changes:
   but in the meanwhile it works better now. (#2701, #8138, #1018)
 - Windows, Style: Fixed small rendering issues with menu bar, resize grip and
   scrollbar when using thick border sizes. (#8267, #7887)
+- Windows: Fixed IsItemXXXX() functions not working on append-version of EndChild(). (#8350)
+  Also made some of the fields accessible after BeginChild() to match Begin() logic.
 - ColorEdit, ColorPicker: Fixed alpha preview broken in 1.91.7. (#8336, #8241). [@PathogenDavid]
 - Tabs, Style: reworked selected overline rendering to better accommodate
   for rounded tabs. Reduced default thickness (style.TabBarOverlineSize),

imgui.cpp

@@ -1256,6 +1256,7 @@ static void             RenderWindowTitleBarContents(ImGuiWindow* window, const
 static void             RenderDimmedBackgroundBehindWindow(ImGuiWindow* window, ImU32 col);
 static void             RenderDimmedBackgrounds();
 static void             SetLastItemDataForWindow(ImGuiWindow* window, const ImRect& rect);
+static void             SetLastItemDataForChildWindowItem(ImGuiWindow* window, const ImRect& rect);
 
 // Viewports
 const ImGuiID           IMGUI_VIEWPORT_DEFAULT_ID = 0x11111111; // Using an arbitrary constant instead of e.g. ImHashStr("ViewportDefault", 0); so it's easier to spot in the debugger. The exact value doesn't matter.
@@ -4704,6 +4705,18 @@ void ImGui::SetLastItemData(ImGuiID item_id, ImGuiItemFlags item_flags, ImGuiIte
     g.LastItemData.Rect = g.LastItemData.NavRect = item_rect;
 }
 
+static void ImGui::SetLastItemDataForWindow(ImGuiWindow* window, const ImRect& rect)
+{
+    ImGuiContext& g = *GImGui;
+    SetLastItemData(window->MoveId, g.CurrentItemFlags, window->DC.WindowItemStatusFlags, rect);
+}
+
+static void ImGui::SetLastItemDataForChildWindowItem(ImGuiWindow* window, const ImRect& rect)
+{
+    ImGuiContext& g = *GImGui;
+    SetLastItemData(window->ChildId, g.CurrentItemFlags, window->DC.WindowItemStatusFlags, rect);
+}
+
 float ImGui::CalcWrapWidthForPos(const ImVec2& pos, float wrap_pos_x)
 {
     if (wrap_pos_x < 0.0f)
@@ -6157,7 +6170,14 @@ void ImGui::EndChild()
         }
         if (g.HoveredWindow == child_window)
             g.LastItemData.StatusFlags |= ImGuiItemStatusFlags_HoveredWindow;
+        child_window->DC.WindowItemStatusFlags = g.LastItemData.StatusFlags;
+        //SetLastItemDataForChildWindowItem(child_window, child_window->Rect()); // Not needed, effectively done by ItemAdd()
     }
+    else
+    {
+        SetLastItemDataForChildWindowItem(child_window, child_window->Rect());
+    }
+
     g.WithinEndChildID = backup_within_end_child_id;
     g.LogLinePosY = -FLT_MAX; // To enforce a carriage return
 }
@@ -7612,6 +7632,8 @@ bool ImGui::Begin(const char* name, bool* p_open, ImGuiWindowFlags flags)
 
         // We fill last item data based on Title Bar/Tab, in order for IsItemHovered() and IsItemActive() to be usable after Begin().
         // This is useful to allow creating context menus on title bar only, etc.
+        window->DC.WindowItemStatusFlags = ImGuiItemStatusFlags_None;
+        window->DC.WindowItemStatusFlags |= IsMouseHoveringRect(title_bar_rect.Min, title_bar_rect.Max, false) ? ImGuiItemStatusFlags_HoveredRect : 0;
         SetLastItemDataForWindow(window, title_bar_rect);
 
         // [DEBUG]
@@ -7717,12 +7739,6 @@ bool ImGui::Begin(const char* name, bool* p_open, ImGuiWindowFlags flags)
     return !window->SkipItems;
 }
 
-static void ImGui::SetLastItemDataForWindow(ImGuiWindow* window, const ImRect& rect)
-{
-    ImGuiContext& g = *GImGui;
-    SetLastItemData(window->MoveId, g.CurrentItemFlags, IsMouseHoveringRect(rect.Min, rect.Max, false) ? ImGuiItemStatusFlags_HoveredRect : 0, rect);
-}
-
 void ImGui::End()
 {
     ImGuiContext& g = *GImGui;

imgui_internal.h

@@ -2456,6 +2456,7 @@ struct IMGUI_API ImGuiWindowTempData
     ImGuiLayoutType         LayoutType;
     ImGuiLayoutType         ParentLayoutType;       // Layout type of parent window at the time of Begin()
     ImU32                   ModalDimBgColor;
+    ImGuiItemStatusFlags    WindowItemStatusFlags;
 
     // Local parameters stacks
     // We store the current settings outside of the vectors to increase memory locality (reduce cache misses). The vectors are rarely modified. Also it allows us to not heap allocate for short-lived windows which are not using those settings.