JTree--树(节点渲染和资源管理器加载)(一)

<meta http-equiv="Content-Type" content="text/html; charset=utf-8"> <meta name="ProgId" content="Word.Document"> <meta name="Generator" content="Microsoft Word 12"> <meta name="Originator" content="Microsoft Word 12"> <link rel="File-List" href="file:///C:%5CDOCUME%7E1%5Cphoenix%5CLOCALS%7E1%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_filelist.xml"> <link rel="Edit-Time-Data" href="file:///C:%5CDOCUME%7E1%5Cphoenix%5CLOCALS%7E1%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_editdata.mso"> <!--[if !mso]> <style> v":* {behavior:url(#default#VML);} o":* {behavior:url(#default#VML);} w":* {behavior:url(#default#VML);} .shape {behavior:url(#default#VML);} </style> <![endif]--><link rel="themeData" href="file:///C:%5CDOCUME%7E1%5Cphoenix%5CLOCALS%7E1%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_themedata.thmx"> <link rel="colorSchemeMapping" href="file:///C:%5CDOCUME%7E1%5Cphoenix%5CLOCALS%7E1%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_colorschememapping.xml"> <!--[if gte mso 9]><xml> Normal 0 false 7.8 磅 0 2 false false false EN-US ZH-CN X-NONE </xml><![endif]--><!--[if gte mso 9]><![endif]--><style> <!-- /* Font Definitions */ @font-face {font-family:宋体; panose-1:2 1 6 0 3 1 1 1 1 1;} @font-face {font-family:"Cambria Math"; panose-1:2 4 5 3 5 4 6 3 2 4;} @font-face {font-family:Calibri; panose-1:0 0 0 0 0 0 0 0 0 0; mso-font-alt:"Times New Roman";} @font-face {font-family:""@宋体"; panose-1:2 1 6 0 3 1 1 1 1 1;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal { mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; text-align:justify; text-justify:inter-ideograph; font-size:10.5pt; font-family:"Calibri","serif"; mso-bidi-font-family:"Times New Roman";} .MsoChpDefault { mso-bidi-font-family:"Times New Roman";} /* Page Definitions */ @page {} @page Section1 {size:595.3pt 841.9pt; margin:72.0pt 90.0pt 72.0pt 90.0pt; layout-grid:15.6pt;} div.Section1 {page:Section1;} --> </style> <!--[if gte mso 10]> <style> /* Style Definitions */ table.MsoNormalTable { mso-style-parent:""; font-size:10.5pt; font-family:"Calibri","serif";} </style> <![endif]-->

前面已经把树的基本使用、树的事件和树的数据取得写完了,并看了一个Sun提供的最简单的树的例子,这一专题我们讲两个方面,一个是使用树的Renderer和Editor构造一棵我们自己的树;一个树使用SwingWorker完成一棵资源管理器树的加载.

先看渲染的例子:

<!--[if gte vml 1]> <![endif]-->

<!--[if gte vml 1]> <![endif]-->

我们为我们的树增加了可用与否、可见与否和节点图片的属性,当然你也可以自己添加想要的属性,比如顺序等.

整个实现的过程很清晰,也不复杂,我们首先实现我们自己的TreeNode,它继承于DefaultMutableTreeNode,我们在里面添加自己的属性;然后是实现树的节点的Renderer和Editor,在Renderer里我们设置可用也否,选择状态,节点图片等;在Editor里我们设置树的容器布局.最后构造树时使用setRenderer和setEditor就可以了,需要注意的是如果仅仅是呈现,设置Renderer就可以了,如果除了呈现还有操作的话,必须都要设置.

先看我们自己的TreeNode类, 继承于DefaultMutableTreeNode,

/**

 * the tree node that I rewrite it.

*/

publicclass MyTreeNode extends DefaultMutableTreeNode {

我们添加了属性：

    /** is select or not. */

    privatebooleanisSelected = false;

节点的选择状态

    /** is enable. */

    privatebooleanenabled = false;

节点使用与否

    /** is visible or not. */

    privatebooleanisVisible = false;

节点可见与否

    /** it's icon. */

    private Icon icon = null;

    /** icon name. */

    private String iconName = null;

节点图片和图片名字

然后是构造函数,我们初始化属性,或使用默认的:

public MyTreeNode() {

    this(null, true, false, true, true, null);

}

public MyTreeNode(Object userObject, boolean allowsChildren,

    boolean isSelected, boolean enabled, boolean isVisible, Icon icon) {

    super(userObject, allowsChildren);

    this.isSelected = isSelected;

    this.enabled = enabled;

    this.isVisible = isVisible;

    this.icon = icon;

       setSelectionMode(TreeSelectionModel.DISCONTIGUOUS_TREE_SELECTI

 ON);

}

然后就是一些设置和取得属性的方法,这个类就相当于一个Bean.

然后就是Rnederer了,我们这里继承于DefaultTreeCellRenderer

publicclass MyTreeRenderer extends DefaultTreeCellRenderer {

然后复写它的getTreeCellRendererComponent方法:

@Override

public Component getTreeCellRendererComponent(JTree tree, Object value, boolean sel, boolean expanded, boolean leaf, int row,

     boolean hasFocus) {

然后设置节点的属性:

首先是显示文本:

String stringValue = tree.convertValueToText(value, sel, expanded, leaf, row, hasFocus);

setText(stringValue);

然后是可用与否:

       boolean nodeIsEnabled = ((MyTreeNode) value).isEnabled();

       boolean isEnabled = (treeIsEnabled && nodeIsEnabled);

       setEnabled(isEnabled);

然后是是图片

    Icon icon = ((MyTreeNode) value).getIcon();

setIcon(icon);

还有一些基本的属性,比如背景色等:

    setForeground(getTextSelectionColor());

再来需要看的类就是Editor了,它继承于DefaultTreeCellEditor:

publicclass MyCellEditor extends DefaultTreeCellEditor {

因为我们使用的是JLabel作为显示控件,所以我们的主要实现是布局处理,对于事件可以不需要考虑.我们复习了DefaultTreeCellEditor的默认布局：

    /**

     * Container responsible for placing the editingComponent.

     */

    privateclass MyEditorContainer extends

           DefaultTreeCellEditor.EditorContainer {

复写它的doLayout方法：

    @Override

publicvoid doLayout() {

取得节点的边缘和大小:

r = tree.getBounds(r);

eSize.width = r.width - (offset * n);

editingComponent.setLocation(offset, 0);

设置节点的位置和大小:

     setSize(new Dimension(eSize.width + offset, cSize.height));

最后就是使用了,很简单和以前一样,直接使用JTree的设置方法就可以了:

      MyTreeRenderer renderer = new MyTreeRenderer();

      tree.setCellRenderer(renderer);

      tree.setEditable(true);

      tree.setCellEditor(new MyCellEditor(tree,

           (DefaultTreeCellRenderer) tree.getCellRenderer()));