# Context Menu

The context menu is displayed after right clicking on the viewer. It displays commands that may depends on the contexts and can be customized.

# Get the context menu

The context menu can be accessed on the $viewer object:


# Interface

Property Description
registerContextCommand(command: ContextMenuCommand): number Add command for the openning context menu. Returns the command id.
registerCommand(command: ContextMenuCommand): number Add command on context menu, displayed if the predicate exists and returns true. Returns the command id.
unregisterCommand(commandId: number): boolean Remove the command corresponding to the given id. Returns true if a command was removed, false otherwise.
preventDefault(): void; Prevent registered commands to show. Usefull when only context commands are needed.
groupPositions: Object An object with select, visibility and color properties that represent the group positions of corresponding default commands.

# Command Interface

Property Description
label: string The text displayed on the menu.
picto: string Usually a letter to show the associated shortcut.
execute() The function to execute when the command is clicked.
predicate()? An optional predicate function that is run when the context menu opens. The command is displayed if the function returns true. If the predicate is an async function, the command is displayed when the Promise returned by the function resolves.
group?: number The group the command belongs to. Default to 0.
position?: number The position where to display the command in its group. Default to 0.

# Examples

This examples are plugins or plugin components.

# Command with predicate

Description: The following plugin register a command using the startupScript method. The command is displayed on the context menu only if at least one element is selected. Once clicked, the selected objects are logged.

const MyPlugin = {
  name: "selection-log",
  startupScript($viewer) {

    const myCommand = {
      label: "Log selection",
      execute: () => console.log($viewer.state.selectedObjects),
      predicate: () => $viewer.state.selectedObjects.length > 0,


# Context command

Description: Right clicking on the button element clear default commands and add a custom command to the context menu. The command is called "Hello" and log "Hello World !" on the console.

  methods: {
    onContextMenu() {
        label: "Hello",
        execute: () => console.log("Hello World !"),
  template: `
      <button type="button" @click="onClick" @contextmenu="onContextMenu">Click me!</button>