Context Menu

OSSIM provides a global context menu system for right-click interactions anywhere in the OS, including the desktop surface and within applications.

Showing a Context Menu

From C++

UContextMenuSubsystem* CM = GameInstance->GetSubsystem<UContextMenuSubsystem>();

TArray<FContextMenuItem> Items;

FContextMenuItem OpenItem;
OpenItem.Label = FText::FromString("Open");
OpenItem.OnSelected.BindLambda([]() { /* handle open */ });
Items.Add(OpenItem);

Items.Add(FContextMenuItem::Separator());

FContextMenuItem DeleteItem;
DeleteItem.Label = FText::FromString("Delete");
DeleteItem.OnSelected.BindLambda([]() { /* handle delete */ });
Items.Add(DeleteItem);

CM->ShowContextMenu(MousePosition, Items);

Context Menu Item (`FContextMenuItem`)

Field	Type	Description
`Label`	`FText`	Display text for the menu item
`Icon`	`UTexture2D*`	Optional icon
`OnSelected`	`FOnContextMenuItemSelected`	Delegate fired when clicked
`bIsEnabled`	`bool`	Whether the item is clickable (default: `true`)
`bIsSeparator`	`bool`	Render as a separator line (default: `false`)

Static helper: FContextMenuItem::Separator() creates a separator item.

Subsystem API

`UContextMenuSubsystem`

Method	Description
`ShowContextMenu(FVector2D, TArray<FContextMenuItem>)`	Display menu at viewport position (Z-order: 9999)
`HideContextMenu()`	Dismiss the active menu
`IsMenuOpen()`	Query whether a menu is currently visible
`Set/GetContextMenuClass()`	Configure the widget class used for menus

Delegate: OnRequestCloseAllMenus() (dynamic/BP) — Broadcast to dismiss all open menus.

Widget Implementation

`UContextMenuWidget`

PopulateMenu(Items[]) — Builds menu item rows.
SetPosition(Pos) — Positions the menu at screen coordinates.
Auto-dismisses on focus loss or mouse leave.

`UContextMenuItemWidget`

Setup(FContextMenuItem) — Configures display and click handler.
OnButtonClicked → invokes OnSelected delegate.

Desktop Integration

The UDesktopSurfaceWidget provides a built-in desktop right-click menu with:

"Change Wallpaper" — Opens wallpaper selection.
"Open Desktop in Explorer" — Launches File Explorer at the user's desktop path.