Capturing mouse input
Mouse clicks create mouse events that can be used to trigger interactive functionality. You can add an event listener to the Stage to listen for mouse events that occur anywhere within the SWF file. You can also add event listeners to objects on the Stage that inherit from InteractiveObject (for example, Sprite or MovieClip); these listeners are triggered when the object is clicked.
As with keyboard events, mouse events bubble. In the following example, because
square
is a child of the Stage, the event dispatches both from the sprite
square
as well as from the Stage object when the square is clicked:
var square:Sprite = new Sprite();
square.graphics.beginFill(0xFF0000);
square.graphics.drawRect(0,0,100,100);
square.graphics.endFill();
square.addEventListener(MouseEvent.CLICK, reportClick);
square.x =
square.y = 50;
addChild(square);
stage.addEventListener(MouseEvent.CLICK, reportClick);
function reportClick(event:MouseEvent):void
{
trace(event.currentTarget.toString() + " dispatches MouseEvent. Local coords [" + event.localX + "," + event.localY + "] Stage coords [" + event.stageX + "," + event.stageY + "]");
}
In the previous example, notice that the mouse event contains positional
information about the click. The localX
and localY
properties contain the
location of the click on the lowest child in the display chain. For example,
clicking at the top-left corner of square
reports local coordinates of [0,0]
because that is the registration point of square
. Alternatively, the stageX
and stageY
properties refer to the global coordinates of the click on the
Stage. The same click reports [50,50] for these coordinates, because square
was moved to these coordinates. Both of these coordinate pairs can be useful
depending on how you want to respond to user interaction.
Note: In full-screen mode, you can configure the application to use mouse locking. Mouse locking disables the cursor and enables unbounded mouse movement. For more information, see Working with full-screen mode.
The MouseEvent object also contains altKey
, ctrlKey
, and shiftKey
Boolean
properties. You can use these properties to check if the Alt, Ctrl, or Shift key
is also being pressed at the time of the mouse click.
Dragging Sprites around the stage
You can allow users to drag a Sprite object around the stage using the
startDrag()
method of the Sprite class. The following code shows an example of
this:
import flash.display.Sprite;
import flash.events.MouseEvent;
var circle:Sprite = new Sprite();
circle.graphics.beginFill(0xFFCC00);
circle.graphics.drawCircle(0, 0, 40);
var target1:Sprite = new Sprite();
target1.graphics.beginFill(0xCCFF00);
target1.graphics.drawRect(0, 0, 100, 100);
target1.name = "target1";
var target2:Sprite = new Sprite();
target2.graphics.beginFill(0xCCFF00);
target2.graphics.drawRect(0, 200, 100, 100);
target2.name = "target2";
addChild(target1);
addChild(target2);
addChild(circle);
circle.addEventListener(MouseEvent.MOUSE_DOWN, mouseDown)
function mouseDown(event:MouseEvent):void
{
circle.startDrag();
}
circle.addEventListener(MouseEvent.MOUSE_UP, mouseReleased);
function mouseReleased(event:MouseEvent):void
{
circle.stopDrag();
trace(circle.dropTarget.name);
}
For more details, see the section on creating mouse drag interaction in Changing position.
Drag-and-drop in AIR
In Adobe AIR, you can enable drag-and-drop support to allow users to drag data into and out of your application. For more details, see Drag and drop in AIR.
Customizing the mouse cursor
The mouse cursor (mouse pointer) can be hidden or swapped for any display object
on the Stage. To hide the mouse cursor, call the Mouse.hide()
method.
Customize the cursor by calling Mouse.hide()
, listening to the Stage for the
MouseEvent.MOUSE_MOVE
event, and setting the coordinates of a display object
(your custom cursor) to the stageX
and stageY
properties of the event. The
following example illustrates a basic execution of this task:
var cursor:Sprite = new Sprite();
cursor.graphics.beginFill(0x000000);
cursor.graphics.drawCircle(0,0,20);
cursor.graphics.endFill();
addChild(cursor);
stage.addEventListener(MouseEvent.MOUSE_MOVE,redrawCursor);
Mouse.hide();
function redrawCursor(event:MouseEvent):void
{
cursor.x = event.stageX;
cursor.y = event.stageY;
}