# Class: display_options

## LocusZoom_Widgets~display_options()

Dropdown menu allowing the user to choose between different display options for a single specific data layer within a panel.

This allows controlling how points on a datalayer can be displayed- any display options supported via the layout for the target datalayer. This includes point size/shape, coloring, etc.

This button intentionally limits display options it can control to those available on common plot types. Although the list of options it sets can be overridden (to control very special custom plot types), this capability should be used sparingly if at all.

## Constructor

#### new display_options()

##### Parameters:

Name | Type | Attributes | Default | Description
--- | --- | --- | --- | ---
`layout.layer_name` | string |  |  | Specify the datalayer that this button should affect
`layout.button_html` | String | <optional> | "Display options..." | Text to display on the toolbar button
`layout.button_title` | String | <optional> | "Control how plot items are displayed" | Hover text for the toolbar button
`layout.default_config_display_name` | string | <optional> |  | Store the default configuration for this datalayer configuration, and show a button to revert to the "default" (listing the human-readable display name provided)
`layout.fields_whitelist` | Array | <optional> | 'see code' | The list of presentation fields that this button can control. This can be overridden if this button needs to be used on a custom layer type with special options. The whitelist is chosen to be things that are known to be easily modified with few side effects. When the button is first created, all fields in the whitelist will have their default values saved, so the user can revert to the default view easily.
`layout.options` | Array.<module:LocusZoom_Widgets~DisplayOptionsButtonConfigField> |  |  | Specify a label and set of layout directives associated with this `display` option. Display field should include all changes that will be merged to datalayer layout options.
`layout.custom_event_name` | string | <optional> | 'widget_display_options_choice' | The name of the event that will be emitted when an option is selected

Source:
  - components/toolbar/widgets.js, line 1387
See:
  - module:LocusZoom_Widgets~BaseWidget for additional options