TITLE:JListのアイテムを範囲指定で選択
#navi(../)
*JListのアイテムを範囲指定で選択 [#va695101]
>編集者:[[Terai Atsuhiro>terai]]~
作成日:2006-08-14~
更新日:&lastmod;

#contents

**概要 [#x17f8eee]
JListのアイテムをラバーバンドで範囲指定して選択します。

#screenshot

**サンプルコード [#t7aa984b]
 class MyList extends JList {
   private final Color pcolor;
   private final AlphaComposite alcomp =
     AlphaComposite.getInstance(AlphaComposite.SRC_OVER, 0.1f);
   private final Polygon polygon = new Polygon();
   private final Line2D line = new Line2D.Double();
   private Point srcPoint = null;
   public MyList(ListModel model) {
     super(model);
     pcolor = makeColor();
     setLayoutOrientation(JList.HORIZONTAL_WRAP);
     setVisibleRowCount(0);
     setFixedCellWidth(62);
     setFixedCellHeight(62);
     setBorder(BorderFactory.createEmptyBorder(5,5,5,5));
     setCellRenderer(new ListCellRenderer() {
       public Component getListCellRendererComponent(JList list,
             Object value, int index,
             boolean isSelected, boolean cellHasFocus) {
         MyIcon icon = (MyIcon)getModel().getElementAt(index);
         icon.setSelected(isSelected);
         icon.setFocused(cellHasFocus);
         return icon;
       }
     });
     addMouseMotionListener(new MouseMotionAdapter() {
       public void mouseDragged(MouseEvent e){
         if(srcPoint==null) srcPoint = e.getPoint();
         Point destPoint = e.getPoint();
         polygon.reset();
         polygon.addPoint(srcPoint.x,  srcPoint.y);
         polygon.addPoint(destPoint.x, srcPoint.y);
         polygon.addPoint(destPoint.x, destPoint.y);
         polygon.addPoint(srcPoint.x,  destPoint.y);
         if(srcPoint.getX()==destPoint.getX() ||
            srcPoint.getY()==destPoint.getY()) {
           line.setLine(srcPoint.getX(),srcPoint.getY(),
                        destPoint.getX(),destPoint.getY());
           setSelectedIndices(getIntersectsIcons(line));
         }else{
           setSelectedIndices(getIntersectsIcons(polygon));
         }
         repaint();
       }
     });
     addMouseListener(new MouseAdapter() {
       public void mouseReleased(MouseEvent e) {
         srcPoint = null;
         repaint();
       }
       public void mousePressed(MouseEvent e) {
         if(locationToIndex(e.getPoint())<0) {
           clearSelection();
           repaint();
         }else{
           int index = locationToIndex(e.getPoint());
           MyIcon icon = (MyIcon)getModel().getElementAt(index);
           Rectangle rect = getCellBounds(index,index);
           if(!rect.contains(e.getPoint())) {
             clearSelection();
             repaint();
           }
         }
       }
     });
   }
   public void paint(Graphics g) {
     super.paint(g);
     if(srcPoint==null) return;
     Graphics2D g2d = (Graphics2D) g;
     g2d.setColor(SystemColor.activeCaption);
     g2d.drawPolygon(polygon);
     g2d.setComposite(alcomp);
     g2d.setColor(pcolor);
     g2d.fillPolygon(polygon);
   }
   private int[] getIntersectsIcons(Shape p) {
     ListModel model = getModel();
     Vector list = new Vector(model.getSize());
     for(int i=0;i<model.getSize();i++) {
       Rectangle r = MyList.this.getCellBounds(i,i);
       if(p.intersects(r)) {
         list.add(new Integer(i));
       }
     }
     int[] il = new int[list.size()];
     for(int i=0;i<list.size();i++) {
       il[i] = ((Integer)list.get(i)).intValue();
     }
     return il;
   }
   private Color makeColor() {
     int r = SystemColor.activeCaption.getRed();
     int g = SystemColor.activeCaption.getGreen();
     int b = SystemColor.activeCaption.getBlue();
     if(r>g) {
       if(r>b) {
         return new Color(r,0,0);
       }else{
         return new Color(0,0,b);
       }
     }else{
       if(g>b) {
         return new Color(0,g,0);
       }else{
         return new Color(0,0,b);
       }
     }
   }
 }

-&jnlp;
-&jar;
-&zip;

**解説 [#e178a26c]
JListにマウスリスナーを設定して、ドラッグに応じて矩形を描画しています。このとき、その矩形の内部にアイテムアイコンが重なる場合は、それを選択状態に変更しています。選択範囲が矩形にならずに直線になっている場合は、別途その直線と交差するアイテムを選択するようにしています。

JList内のアイテムの配置は、JList#setLayoutOrientation(JList.HORIZONTAL_WRAP)メソッドを使っているため、水平方向に整列されます。

**参考リンク [#o8eb5cf2]
-[[Can someone optimise the following code ?>http://forum.java.sun.com/thread.jspa?threadID=757107]]
-[[XP Style Icons - Windows Application Icon, Software XP Icons>http://www.icongalore.com/]]

**コメント [#re81cc47]
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