文本框滚动缓冲效果

// JTL
// http://www.hartech.cn
// e-mail: jtl.zheng@gmail.com

//初始化函数
function Var() {
//滚动条与上下按钮的间隙
space = 31;
//上下按钮的滚动速度
updown_speed = 5;
//文本框的滚动范围
block_range = block._height-mark._height;
//文本框的初始位置
block_origin = block._y;
//滚动条的滚动范围
drag_range = b_down._y-b_up._y-2*space;
//滚动条的初始位置
drag_origin = b_up._y+space;
//初始化滚动条位置
drag._y = drag_origin;
//滚动缓冲系数
k = .1;
}

Var();

//block为文本框，始终跟随滚动条（drag）变化
block.onEnterFrame = function() {
//pos为文本框目标位置
pos = block_origin-(drag._y-drag_origin)*block_range/drag_range;
//缓冲效果
this._y += (pos-this._y)*k;
};

drag.onPress = function() {
this.startDrag(false, this._x, drag_origin, this._x, (drag_origin+drag_range));
};

drag.onRelease = function() {
this.stopDrag();
};

//up_down按钮
b_up.onPress = function() {
onEnterFrame = function () {
if (drag._y<=drag_origin) {
drag._y = drag_origin;
} else {
drag._y -= updown_speed;
}
};
};

b_up.onRelease = function() {
onEnterFrame = null;
};

b_down.onPress = function() {
onEnterFrame = function () {
if (drag._y>=drag_origin+drag_range) {
drag._y = drag_origin+drag_range;
} else {
drag._y += updown_speed;
}
};
};

b_down.onRelease = function() {
onEnterFrame = null;
};

//侦听mouse滚轮
mouseListener = new Object();
mouseListener.onMouseWheel = function(delta) {
if (delta>0) {
drag._y -= updown_speed*2;
}
if (delta<0) {
drag._y += updown_speed*2;
}
if (drag._y<=drag_origin) {
drag._y = drag_origin;
}
if (drag._y>=drag_origin+drag_range) {
drag._y = drag_origin+drag_range;
}
};

Mouse.addListener(mouseListener);


建立文本框代码

loadVariables("text/diary.txt", this);
myTextFormat = new TextFormat();
myTextFormat.font = "宋体";
myTextFormat.size = 12;
myTextFormat.leading = 3;
createTextField("test_txt", 10, 0, 0, 210, 10);
test_txt.multiline = true;
test_txt.wordWrap = true;
test_txt.autoSize = true;
test_txt.html = true;
test_txt.htmlText = text;
test_txt.setTextFormat(myTextFormat);
test_txt.type = "Static";
// 演示地址：
// http://www.hartech.cn/blog/blogview.asp?logID=45