スライダー

あとで勉強
*　AS3 でヒストグラムを作る (2) - スライダー篇

d.hatena.ne.jp/nitoyon/20071010/as3_histogram2

by darman 29 Jul 2009

Embed

/**
 * Copyright darman ( http://wonderfl.net/user/darman )
 * MIT License ( http://www.opensource.org/licenses/mit-license.php )
 * Downloaded from: http://wonderfl.net/c/cevP
 */

/*
 *あとで勉強
 *　AS3 でヒストグラムを作る (2) - スライダー篇
 *//http://d.hatena.ne.jp/nitoyon/20071010/as3_histogram2
*/
package {
    import flash.display.Sprite;
    import flash.geom.*;

    [SWF(width="280", height="20")]
    public class Histogram2 extends Sprite {
        private var dragging:Sprite;
        private var h2pos:Number = 0.5;
        private var h1:Sprite;
        private var h2:Sprite;
        private var h3:Sprite;

        public function Histogram2() {
            addChild(createSlider()).x = 10;
        }

        // スライダーを作成する
        private function createSlider():Sprite {
            // スライド可能範囲描画
            var slider:Sprite = new Sprite();
            slider.graphics.beginFill(0xffffff);
            slider.graphics.drawRect(0, 0, 256, 10);
            slider.graphics.endFill();
            slider.graphics.lineStyle(1, 0);
            slider.graphics.lineTo(255, 0);
            slider.buttonMode = true;
            slider.useHandCursor = true;

            // つまみ作成
            h1 = Sprite(slider.addChild(createButton(0xffffff))); h1.x = 0;
            h2 = Sprite(slider.addChild(createButton(0x999999))); h2.x = 128;
            h3 = Sprite(slider.addChild(createButton(0x000000))); h3.x = 255;

            // mouseDown
            slider.addEventListener("mouseDown", function(e:*):void {
                var localX:Number = slider.globalToLocal(new Point(mouseX, mouseY)).x;

                // ドラッグするつまみを決定する
                var d1:Number = Math.abs(localX - h1.x);
                var d2:Number = Math.abs(localX - h2.x);
                var d3:Number = Math.abs(localX - h3.x);
                var max:Number = Math.min(d1, d2, d3);
                dragging = (max == d1 ? h1 : max == d2 ? h2 : h3);

                // 場所補正
                var bounds:Rectangle = getDraggableBounds(dragging);
                dragging.x = Math.max(Math.min(localX, bounds.right), bounds.x);
                updateH2(null);

                dragging.startDrag(false, bounds);
            });

            // mouseMove
            stage.addEventListener("mouseMove", updateH2);

            // mouseUp
            stage.addEventListener("mouseUp", function(e:*):void {
                if(dragging) {
                    dragging.stopDrag();
                    dragging = null;
                }
            });

            return slider;
        }

        // つまみを描画する
        private function createButton(color:int):Sprite {
            var s:Sprite = new Sprite();
            s.graphics.lineStyle(1, 0);
            s.graphics.beginFill(color);
            s.graphics.lineTo(5, 8.6);
            s.graphics.lineTo(-5, 8.6);
            s.graphics.endFill();
            return s;
        }

        // つまみの移動可能範囲を計算する
        private function getDraggableBounds(s:Sprite):Rectangle {
            if(s == h1) return new Rectangle(0, 0, h3.x - 4, 0);
            if(s == h2) return new Rectangle(h1.x + 2, 0, h3.x - h1.x - 4, 0);
            if(s == h3) return new Rectangle(h1.x + 4, 0, 255 - h1.x - 4, 0);
            return null;
        }

        // 真ん中のつまみの位置を計算する
        private function updateH2(e:*):void {
            if(dragging && dragging != h2) {
                h2.x = (h3.x - h1.x) * h2pos + h1.x;
                h2.x = Math.max(Math.min(h2.x, h3.x - 2), h1.x + 2);
            }
            else if(dragging == h2){
                h2pos = (h2.x - h1.x) / (h3.x - h1.x);
            }
        }
    }
}