Mobile Scrolllist Mobilescrolllist

MobileScrollList

The MobileScrollList is a custom list component designed for mobile applications, extending MovieClip. It provides a scrollable list functionality, with support for touch input and rendering list items dynamically.

This component is built for use within a wider framework for building user interfaces in Adobe Flash ActionScript 3.0.

Class Definition

package Mobile.ScrollList {
    import Shared.AS3.BSScrollingList;
    import Shared.BGSExternalInterface;
    import flash.display.MovieClip;
    import flash.display.Sprite;
    import flash.events.Event;
    import flash.events.MouseEvent;
    import flash.geom.Point;
    import flash.geom.Rectangle;

    public class MobileScrollList extends MovieClip {
        ...
    }
}

Properties

Property	Type	Description
ITEM_SELECT	String	Event string for item selection.
ITEM_RELEASE	String	Event string for item release.
ITEM_RELEASE_OUTSIDE	String	Event string for release outside of an item.
HORIZONTAL	uint	Constant indicating horizontal scroll direction.
VERTICAL	uint	Constant indicating vertical scroll direction.
_availableRenderers	Vector.<MobileListItemRenderer>	A vector of available item renderers.
_data	Vector.<Object>	A vector containing data objects for the list.
_rendererRect	Rectangle	A rectangle defining the size of the renderer.
_bounds	Rectangle	A rectangle defining the scrollable bounds of the list.
_scrollDim	Number	The dimension of the scrollable area.
_deltaBetweenButtons	Number	The space between the list items.
_renderers	Vector.<MobileListItemRenderer>	A vector of item renderers currently in use.
_tempSelectedIndex	int	Temporary selected index during interactions.
_selectedIndex	int	The currently selected index.
_position	Number	The current scroll position.
_direction	uint	The direction of the scroll (horizontal or vertical).
_itemRendererLinkageId	String	The linkage ID for the item renderer MovieClip.
_background	Sprite	A sprite for the background of the list.
_scrollList	Sprite	The sprite container for the list items.
_scrollMask	Sprite	A sprite used as a mask to clip the visible area of the list.
_touchZone	Sprite	A sprite defining the touchable area for scrolling.
_prevIndicator	MovieClip	A movie clip acting as the previous page/scroll indicator.
_nextIndicator	MovieClip	A movie clip acting as the next page/scroll indicator.
_mouseDown	Boolean	Flag indicating if the mouse is currently down.
_velocity	Number	The current velocity of the scrolling list.
_mouseDownPos	Number	The position of the mouse when pressed down.
_mousePressPos	Number	The position of the mouse when an item is pressed.
_hasBackground	Boolean	Flag indicating whether the list has a background.
_backgroundColor	int	The color of the background.
_noScrollShortList	Boolean	Flag indicating if short lists should not be scrollable.
_clickable	Boolean	Flag indicating if list items are clickable.
_endListAlign	Boolean	Flag indicating if the list should align at the end.
_textOption	String	Text option for rendering the list items.
_elasticity	Boolean	Flag indicating if the list has elasticity/bounce effect.

Constants

Constant	Value	Description
EPSILON	0.01	A small number used to determine if the list should stop moving.
VELOCITY_MOVE_FACTOR	0.4	Factor used to calculate the velocity during a move.
VELOCITY_MOUSE_DOWN_FACTOR	0.5	Factor used when the mouse is down.
VELOCITY_MOUSE_UP_FACTOR	0.8	Factor used when the mouse is up.
RESISTANCE_OUT_BOUNDS	0.15	Resistance factor when scrolling out of bounds.
BOUNCE_FACTOR	0.6	Bounce factor used for the elasticity of the list.
DELTA_MOUSE_POS	15	The delta position of the mouse to determine a drag.

Methods

Public Methods

• MobileScrollList(scrollDimension: Number, deltaBetweenButtons: Number = 0, direction: uint = 1)
  • Constructor to initialize the scroll list.
• setData(data: Vector.<Object>): void
  • Sets the data for the list and initializes it.
• setScrollIndicators(prevIndicator: MovieClip, nextIndicator: MovieClip): void
  • Sets the indicators for scrolling.
• invalidateData(): void
  • Clears the data and resets the list to an empty state.
• destroy(): void
  • Cleans up the list and prepares it for garbage collection.

Protected Methods

• setPosition(): void
  • Updates the position of the scroll list.
• addRenderer(position: int, data: Object): MobileListItemRenderer
  • Adds a renderer to a specific position in the list.
• removeRenderer(position: int): void
  • Removes a renderer from a specific position in the list.
• createMask(): void
  • Creates a mask to clip the scrolling list’s visible area.
• createBackground(): void
  • Creates the background of the list based on the provided color.

Event Handlers

• enterFrameHandler(e: Event): void
  • Handles the physics of the list’s motion on every frame.
• mouseDownHandler(e: MouseEvent): void
  • Handles the user’s initial touch on the list.
• mouseMoveHandler(e: MouseEvent): void
  • Handles the user’s dragging motion on the list.
• mouseUpHandler(e: MouseEvent): void
  • Handles the end of the user’s touch interaction with the list.

Usage Example

// Creating an instance of MobileScrollList
var scrollList: MobileScrollList = new MobileScrollList(300, 5, MobileScrollList.VERTICAL);

// Setting up data for the list
var listData: Vector.<Object> = new Vector.<Object>();
for (var i: int = 0; i < 10; i++) {
    listData.push({label: "Item " + i});
}

// Assigning data to the list
scrollList.setData(listData);

// Adding the list to the display
addChild(scrollList);

Notes

• This component relies on external interfaces (Shared.BGSExternalInterface) and other shared resources (Shared.AS3.BSScrollingList), which suggests it is part of a larger framework or application.
• The list supports both vertical and horizontal scrolling, indicated by the direction constants.
• The list has features for handling click and drag events, making it suitable for touch interactions.
• The list implements an elasticity feature to provide a natural feel to the scroll behavior on mobile devices.