Glossary

This page defines common terms and acronyms used throughout the Launcher3 and Lawnchair codebase. Use these terms when naming variables, classes, or documenting code.

Terminology mapping

Some terminology shown in the UI is shown differently in Launcher3's code. This is summarized in the table below:

UI terminology	Code terminology
Home screen	Workspace
Dock	Hotseat
App drawer	All apps
At a Glance	Smartspace
Recents screen	Overview
Search bar	Quick Search Bar (QSB)
App icon with label	BubbleTextView

Core concepts

• Launcher

  • An Android app that provides the Home screen experience for a device.

• Launcher3

  • The default AOSP launcher codebase that Lawnchair builds on and customizes.

• Quickstep

  • The launcher integration layer for Recents, gesture navigation, and task transitions.

• Home screen

  • The main user surface containing pages of apps, widgets, and folders.

• All Apps

  • The app drawer surface that lists installed apps.

• Widget

  • A resizable app-provided view that can be placed on the Home screen.

• Shortcut

  • A launchable item representing an app entry point or deep link.

• Deep shortcut

  • A shortcut exposed by an app for a specific in-app action.

Launcher UI surfaces

• Workspace

  • The paged container that holds the home screen content.

• Hotseat

  • The fixed dock area used for frequently accessed apps.

• CellLayout

  • The grid layout for a single Workspace page.

• PagedView

  • The base horizontally paged view used by Workspace and related surfaces.

• AllAppsContainerView

  • The root container responsible for presenting the All Apps UI.

• BubbleTextView

  • The icon-and-label view used for app and shortcut items.

• Folder

  • A container item that groups multiple app or shortcut items.

• FolderIcon

  • The Home screen representation of a Folder.

• Folder open state

  • The transient UI state where folder contents are shown in an overlay.

• DragLayer

  • The top-level overlay layer used during drag and floating UI operations.

• AbstractFloatingView

  • Base class for floating surfaces like open folders and popups.

Data model

• ItemInfo

  • Base model type for items shown by the launcher.

• WorkspaceItemInfo

  • Model for app and shortcut items placed on the Workspace or Hotseat.

• AppInfo

  • Model representing an installed application entry in All Apps.

• FolderInfo

  • Model for folder metadata and its contained items.

• LauncherAppWidgetInfo

  • Model for widgets placed on the Workspace.

• BgDataModel

  • In-memory store for Workspace, Hotseat, and folder data.

• AllAppsList

  • In-memory list of app entries used to build All Apps.

• LauncherModel

  • Coordinator that loads launcher data and binds it to UI callbacks.

• LoaderTask

  • Background task that reads and builds launcher model data.

• ModelCallbacks

  • Callback contract used to bind model updates to UI surfaces.

• PendingAddItemInfo

  • Temporary model used while adding a new item before final placement.

Launcher UI state

• LauncherState

  • A named UI mode such as NORMAL, ALL_APPS, or OVERVIEW.

• StateManager

  • Component that transitions between LauncherState values and animations.

• NORMAL state

  • Default launcher state showing the Home screen.

• ALL_APPS state

  • State where the app drawer is the primary visible surface.

• OVERVIEW state

  • State where recent tasks are shown for switching.

• SPRING_LOADED state

  • Temporary drag-focused state used during Workspace edits and rearrangement.

• StateHandler

  • Interface for components that apply per-state visual and behavioral changes.

Drag and placement state

• DragController

  • Controller that owns drag lifecycle events from start to drop.

• DragSource

  • Interface for a component that initiates a drag operation.

• DropTarget

  • Interface for a component that can accept dropped items.

• DragObject

  • Runtime object carrying drag data, drag view, and coordinates.

• DragView

  • Floating visual copy of the dragged item shown during drag.

• Pre-drag

  • Early long-press phase before a full drag session begins.

• GridOccupancy

  • Internal grid map used to track filled and free cells.

• Reorder

  • Item movement logic that shifts neighbors to satisfy a drop placement.

Device layout profile

• Device Profile

  • Runtime profile containing size, orientation, and layout measurements.

• IDP (Invariant Device Profile)

  • Base profile used without activity context to define core grid metrics.

• Grid size

  • The row and column configuration used for Workspace item placement.

• Window bounds

  • The available screen region used for layout calculations.

• Responsive layout

  • Layout behavior that adapts dimensions and spacing by device class.

Lawnchair-specific features

• Preferences screen

  • User-facing settings UI used to configure launcher behavior.

• Default launcher

  • The launcher app currently selected by Android to handle Home intent.

• PreferenceManager2

  • Lawnchair's modern settings layer used for most feature preferences.

• ReloadHelper

  • Utility that triggers launcher reloads after preference or profile changes.

• Icon Pack

  • Third-party icon provider used to replace default app icons.

• Icon Shape

  • User-selectable icon mask style such as circle or squircle.

• Themed Icons

  • Icons tinted to match system or wallpaper-derived dynamic colors.

• Color tokens

  • Theme abstraction values used to keep colors consistent across UI states.

• Hidden apps

  • User-selected apps excluded from normal app drawer visibility.

• Overlay mode

  • Visual transition style used when opening or closing apps.

Feed

• Feed integration

  • Optional left-page content integration such as a Discover-style feed.

• Google Feed

  • Also known as Google Discover. A content feed that shows news and other personalized content.

• MINUS_ONE_PAGE

  • The home screen page used by feed integrations, such as Google Feed.

  • One can add a new feed by creating a service in a different app then adding it to Lawnchair's whitelist.

Search

• QSB (Quick Search Bar)

  • Search entry surface shown in Workspace, Hotseat, and All Apps contexts.

• Search Provider

  • Source implementation that returns search results such as apps or web suggestions.

• Local search

  • On-device search mode that prioritizes launcher data and indexed content.

• Web search

  • Online search mode delegated to a web-capable provider.

Smartspace

• Smartspace

  • The At a Glance style surface for contextual information like weather and events.

• Smartspace provider

  • Data source implementation that supplies Smartspace cards.

• Predictions

  • Suggested apps or targets ranked by usage context.

Launcher gestures

• Gesture handler

  • Component that maps gesture input to launcher actions.

• DT2S (Double Tap to Sleep)

  • Gesture action that turns the screen off from launcher surfaces.

• Long-press

  • Press-and-hold interaction used to open menus or start drag operations.

• Swipe-up

  • Primary gesture used to open All Apps or enter task navigation flows.

Quickstep and Recents

• Gesture navigation

  • Navigation mode that uses edge and swipe gestures instead of buttons.

• Recents

  • The task-switching surface that shows recent running tasks.

• Overview

  • Alternate name for the Recents task-switching surface.

• RecentsView

  • Core view responsible for rendering and managing task cards in Recents.

• TaskView

  • UI card representing a single task inside RecentsView.

• GestureState

  • State machine tracking the current swipe and transition lifecycle.

• GestureEndTarget

  • The resolved destination of a gesture, such as HOME or RECENTS.

• AbsSwipeUpHandler

  • Core handler that drives swipe-up transition behavior.

• RecentsAnimation

  • Animation pipeline that synchronizes app surfaces during task transitions.

• RemoteAnimationTarget

  • System object representing an app surface under remote animation.

• Taskbar

  • Persistent app bar surface used in supported modes and form factors.

• Taskbar stash and unstash

  • Taskbar collapse and restore behavior tied to app and launcher state.