Made it guaranteed by API that after calling Begin() the last Item re…

…present the title bar. (#823)

imgui.cpp

@@ -4589,6 +4589,11 @@ bool ImGui::Begin(const char* name, bool* p_open, ImGuiWindowFlags flags)
         window->InnerRect.Max.x = window->Pos.x + window->Size.x - window->ScrollbarSizes.x;
         window->InnerRect.Max.y = window->Pos.y + window->Size.y - window->ScrollbarSizes.y;
         //window->DrawList->AddRect(window->InnerRect.Min, window->InnerRect.Max, IM_COL32_WHITE);
+
+        // After Begin() we fill the last item / hovered data using the title bar data. Make that a standard behavior (to allow usage of context menus on title bar only, etc.).
+        window->DC.LastItemId = window->MoveId;
+        window->DC.LastItemRect = title_bar_rect;
+        window->DC.LastItemRectHoveredRect = IsMouseHoveringRect(title_bar_rect.Min, title_bar_rect.Max, false);
     }
 
     // Inner clipping rectangle

imgui_demo.cpp

@@ -2406,6 +2406,15 @@ struct ExampleAppConsole
             return;
         }
 
+        // As a specific feature guaranteed by the library, after calling Begin() the last Item represent the title bar. So e.g. IsItemHovered() will return true when hovering the title bar.
+        // Here we create a context menu only available from the title bar.
+        if (ImGui::BeginPopupContextItem())
+        {
+            if (ImGui::MenuItem("Close"))
+                *p_open = false;
+            ImGui::EndPopup();
+        }
+
         ImGui::TextWrapped("This example implements a console with basic coloring, completion and history. A more elaborate implementation may want to store entries along with extra data such as timestamp, emitter, etc.");
         ImGui::TextWrapped("Enter 'HELP' for help, press TAB to use text completion.");
 
@@ -2850,7 +2859,7 @@ static void ShowExampleAppLongText(bool* p_open)
     static ImGuiTextBuffer log;
     static int lines = 0;
     ImGui::Text("Printing unusually long amount of text.");
-    ImGui::Combo("Test type", &test_type, "Single call to TextUnformatted()\0Multiple calls to Text(), clipped manually\0Multiple calls to Text(), not clipped\0");
+    ImGui::Combo("Test type", &test_type, "Single call to TextUnformatted()\0Multiple calls to Text(), clipped manually\0Multiple calls to Text(), not clipped (slow)\0");
     ImGui::Text("Buffer contents: %d lines, %d bytes", lines, log.size());
     if (ImGui::Button("Clear")) { log.clear(); lines = 0; }
     ImGui::SameLine();