Dropdown

The dropdown component is made up of a trigger, raised surface, and a list of choices for the user to select from. The dropdown variations: menu dropdown, selection dropdown, and text field dropdown. Note: Only the menu variant can be used as multi-select. 

The extensions of the dropdown component (and each variant) can optionally include search or slot. The list items for the dropdown component can include text, Icon and text or account options. 

Menu Dropdown

The menu dropdown variant is triggered by tapping or clicking on either a static trigger or dynamic trigger (more on triggers at the bottom of this menu dropdown section). The trigger can be one of four options: quick action button or label and caret  — each trigger option has unique features and behaviors.

Quick Action Button

The quick action button trigger allows the dropdown to be triggered by interacting with the quick action button. Any icon can be used within the quick action button. What’s unique about this trigger option is a badge can be utilized to show how many selections have been made.

1. Quick action component — Embedded QAB (any variant)
2. Badge (optional)

Badges represent how many list items have been selected by the user. Usability when selecting multiple list items starts to take a hit when more than just a handful of selections are made. If a user may want to select more than 5 selection, consider using a different solution. A bottom sheet or side sheet could be a great place to list out a large group of chips that a user could add/remove one by one instead of tediously selecting from a dropdown (that could easily be cancelled inadvertently. 

Label and Caret

This combo trigger is unique because the caret will spin around to provide affordance for the user both when the dropdown is open or closed.

1. Trigger label — Body 1
2. Trigger icon

Static triggers

The static trigger maintains a consistent label and/or icon before and after a selection is made. Both the icon only trigger and quick action trigger are considered to be static since the icon will not change as a result of the user's selection. Both the label and icon combo trigger and the label and caret trigger can be static if the label does not change as a result of the user's selection.

1. Label and caret trigger (before selection)
2. Label and caret trigger (after selection)

1. Quick action button trigger (before selection)
2. Quick action button trigger (after selection)

Note: Although the quick action button cannot change as a result of a user's selection, a badge can be shown as a way to let the user know how many list items have been selected. A badge cannot be used with any other trigger types.

Dynamic triggers

The dynamic trigger updates the trigger label based on the user uselection, and requires a default selection. Only the label and icon combo trigger and the label and caret trigger can utilize the dynamic updating of the text label (since these are the only triggers with a text label that can be updated).

1. Label and caret trigger (before selection)
2. Label and caret trigger (after selection)

Selection Dropdown

The selection dropdown variant for choosing a value from a list item options. It is triggered by clicking the caret or anywhere on the text field area. Note: Only the values shown in the dropdown can be selected. A custom value cannot be entered.

1. Select trigger (Focus state)
2. Selected Item Label - Subtitle 1 (see also cloaked checkbox or cloaked radio button)
3. List Item Icon (optional) - 24px
4. Raised Surface
5. Selected item indicator (see also cloaked checkbox or cloaked radio button)
6. Selected item background (see states matrix)
7. List Item Label - Body 1
8. Divider (Optional)

Text Field Dropdown

The dropdown uses an input text field as the trigger. In the focus state, it will show a dropdown of suggested values but the user has the option to type out a new value. 

Note: A value does not have to be selected from the dropdown list and cannot use the account component.

1. Input field trigger (Focus state & before typing)
2. Suggestions

1. Input field trigger (Focused state & after typing)
2. Input field typed (New value)

Account

The account within a selection dropdown will house the account caption variant component. The dropdown will show the list of accounts. Note: The single line caption variant is used in the input field trigger while only the caption single line or two line variant can be used in the dropdown. 

1. Selection trigger (Static)
2. Account component - Caption variant

1. Selection trigger (Focus state)
2. Account item - Caption variant
   

Search

The search provides a way for the user to type out their value in the search field within the dropdown. The list items in the dropdown will filter out depending on what the user types. Note: A value has to be selected from the dropdown list. If the user were to search for a value that is not in the list, a “No results found.” text will be displayed.

1. Selection trigger (focus state)
2. Search Icon - 24px
3. Search Placeholder - Body 1
4. Divider

Filtering

1. Select trigger (Focused state)
2. Search filtering

Empty state 

1. Select trigger (focus state)
2. Empty state of dropdown list - Caption

Selected state

1. Input field trigger (focused state & while typing)
2. Selected value
3. Selected list item

Account

The search extension can be added to the account dropdown. The user has the option to choose from a list of accounts or search the accounts to filter the list.

1. Selection trigger (Focus state & while typing)
2. Search (Optional)
3. Account component - Caption variant

International Phone Number Dropdown

The search extension can be added to the international phone number dropdown variant. 

1. International phone dropdown trigger
2. Search (Optional)

Menu Dropdown

1. Quick Action Button Trigger
2. Search (Optional)

1. Label and Caret
2. Search (Optional)

Slot

Slot is an optional section at the bottom of a dropdown where design will determine the content inside when there is a need for a call to action. 

Menu Dropdown

1. Quick Action Trigger
2. Slot (Optional)

1. Label and Caret
2. Slot (Optional)

Selection Dropdown

1. Select trigger (Focus state)
2. Slot (Optional)

Text Field Dropdown

1. Input field trigger (Focus state & before typing)
2. Slot (Optional)

Account

1. Selection trigger (Focus state)
2. Slot (Optional)
   

The default placement of dropdowns should be immediately below the trigger (referred to as the flow down placement) and aligned along the left edge; but due to information density or scroll position, the dropdown can also appear above the trigger (referred to as the flow up placement), aligned along the right edge, or centered vertically or horizontally with the trigger.

1. Flow down placement aligned along the left edge
2. Flow down placement aligned along the right edge
3. Flow up placement aligned along the right edge (but could also be left aligned)
4. Flow up placement center aligned (could also follow the flow down placement)

Flow down placement

The flow down placement is the default way to position the dropdown component, and is used when the dropdown height is smaller than the distance from the trigger to the bottom of the viewport minus one list item.

1. The distance from the trigger to the bottom of the viewport
2. The height of a list item within the dropdown
3. The height of a list item distance from the bottom of the viewport

Flow up placement

The flow up placement should only be used when there’s not enough space to utilize the flow down placement.

1. The height of the dropdown component
2. The distance of the trigger to the bottom fo the viewport is not tall enough to display the entire dropdown, so the flow up placement is used

Scrollable

In most cases, the height of the dropdown is based on the amount of content contained within the dropdown. The exception to this rule is when the height of a dropdown would otherwise be taller than the visible space within the viewport. In this case, a scrollable dropdown should be utilized.

Scrollable dropdowns can follow both the flow down or the flow up placement, and should always maintain at least one list item height distance away from the viewport edge and honor “safe areas” on mobile devices with notches in the display.

Truncation

List items that contain account information can become truncated if there’s not enough horizontal space to display the full account nickname. See the account component for more details about truncation and priorities. Standard list items should never truncate, but wrap to another line.