MACROMEDIA FLASH 8-ACTIONSCRIPT 2.0 LANGUAGE, Reference

Page: 923 / 1378

MovieClip 923
scrollRect (MovieClip.scrollRect property)
public scrollRect : Object
The
scrollRect
property allows you to quickly scroll movie clip content and have a window
viewing larger content. Text fields and complex content scroll much faster, because pixel level
copying is used to scroll data instead of regenerating the entire movie clip from vector data. To
see the performance gain, use
scrollRect
in conjunction with a movie clip that has
cacheAsBitmap
set to
true
.
The movie clip is cropped and scrolled with a specific width, height, and scrolling offsets. The
scrollRect
properties are stored in the movie clip's coordinate space and are scaled just like
the overall movie clip. The corner bounds of the cropped window on the scrolling movie clip
are the origin of the movie clip (0, 0) and the (
scrollWidth
,
scrollHeight
) point. These
points are not centered around the origin but use the origin at the upper-left corner. A scrolled
movie clip always scrolls in whole pixel increments. If the movie clip is rotated 90 degrees and
you scroll it left and right (by setting the
scrollRect.x
property), it scrolls up and down.
If set to a flash.geom.Rectangle object, the movie clip is cropped to a certain size and scrolled.
Availability: ActionScript 1.0; Flash Player 8
Example
The following example sets up a MovieClip hiearchy (by calling the
setUpContainer()
function) and then sets a new Rectangle as the
scrollRect
property.
import flash.geom.Rectangle;
var container:MovieClip = setUpContainer();
var window:Rectangle = new Rectangle(0, 0, 100, 40);
container.scrollRect = window;
function setUpContainer():MovieClip {
var mc:MovieClip = this.createEmptyMovieClip("container",
this.getNextHighestDepth());
mc._x = 50;
mc._y = 50;
mc.opaqueBackground = 0xCCCCCC;
var content:MovieClip = mc.createEmptyMovieClip("content",
mc.getNextHighestDepth());
var colors:Array = [0xFF0000, 0x0000FF];
var alphas:Array = [100, 100];
var ratios:Array = [0, 0xFF];
var matrix:Object = {a:150, b:0, c:0, d:0, e:150, f:0, g:150, h:150,
i:1};
content.beginGradientFill("linear", colors, alphas, ratios, matrix);
content.lineTo(300, 0);
content.lineTo(300, 300);