【插件开发】—— 10 JFace开发详解

时间:2022-04-22
本文章向大家介绍【插件开发】—— 10 JFace开发详解，主要内容包括ListViewer、tableViewer、TreeViewer、TextViewer、基本概念、基础应用、原理机制和需要注意的事项等，并结合实例形式分析了其使用技巧，希望通过本文能帮助到大家理解应用这部分内容。

前几篇讲过SWT的使用，但是SWT是基本的小控件，只能针对使用简单的数据类型，比如字符串，数字等等。但是遇到了复杂的类，该怎么办呢？

　　不要担心！这里就可以使用JFace了，它是对SWT的封装，可以应用于复杂的数据类型。

　　下面的介绍中有时候说控件，有时候说视图，原因就是这个JFace通常用于某个视图中，但是它其实就是一个复杂的组合控件而已，只不过需要我们额外的去设定内容与复杂类的内容匹配。因此如果想使用复杂的数据类型，必然要与JFace提供的控件进行兼容，就涉及到两个主要的函数：setContentProvider() 以及 setLabelProvider()。这两个函数下面会进行详细的介绍：

setContentProvider() 内容提供者

　　这个函数为JFace的控件提供内容，总的来说一共有一下几种：

　ListViewer列表视图 TabelViewer表格视图 TreeViewer树形视图 TextViewer文本视图

　　除了最后一种比较特殊，不需压指定内容提供者，其他的三个JFace视图都需要设置内容提供者，以便设定关联的内容。

setLabelProvider()标签提供者

　　这个函数设置了标签提供者，用于JFace的控件视图现实内容，一般来说都有两个函数：

getColumnImage()和getColumnText()，一个用于设定标签上现实的图片，一个用于设定现实的内容

　　那么下面就看一下不同的JFace视图，这两个函数使用的差异。

　　ListViewer

　　这个列表视图，属于最简单的视图了，这里我们创建一个复杂点的元素

 1 class Person{
 2     private int id;
 3     private String name;
 4     private int age;
 5     private String address;
 6     public int getId() {
 7         return id;
 8     }
 9     public void setId(int id) {
10         this.id = id;
11     }
12     public String getName() {
13         return name;
14     }
15     public void setName(String name) {
16         this.name = name;
17     }
18     public int getAge() {
19         return age;
20     }
21     public void setAge(int age) {
22         this.age = age;
23     }
24     public String getAddress() {
25         return address;
26     }
27     public void setAddress(String address) {
28         this.address = address;
29     }
30     public String toString() {
31         return name;
32     }
33 }

　　当我们从扩展点创建一个视图，并打开它的实现类时，插件为我们自动添加好了接口，里面有三个直接生成的函数

public class ListViewerTest extends ViewPart {

    public ListViewerTest() {
        
    }

    public void createPartControl(Composite parent) {

    }

    public void setFocus() {

    }
}

　　此时，我们需要扩展createPartControl，在这里面创建一个view，并在其中添加 内容提供者函数，以及标签提供者函数。

viewer = new ListViewer(parent, SWT.SINGLE);
viewer.setContentProvider(new ViewContentProvider());
viewer.setLabelProvider(new ViewLabelProvider());
viewer.setSorter(new MySorter());
viewer.setInput(getSite());

　　通常来说，都会有上面的五句话

第一行：创建了一个ListViewer的视图

　　第二行：设置它的内容提供者

　　第三行：设置它的标签提供者

　　第四行：设置排序规则

　　第五行：设置输入，这里面我们的输入由内容提供者提供，因此这里就直接设置参数为getSite()（可以理解为一个字符串，这个地方随便写都行，但是一定要有这个函数，空串都可以）就可以了。

　　下面看一下这几个函数的实现：

　　 class ViewContentProvider implements IStructuredContentProvider{
        public Object[] getElements(Object inputElement) {
            
            Person[] persons = new Person[3];
            persons[0] = new Person();
            persons[0].setId(001);
            persons[0].setName("xingoo");
            persons[0].setAge(25);
            persons[0].setAddress("ChangChun");
            
            persons[1] = new Person();
            persons[1].setId(002);
            persons[1].setName("halo");
            persons[1].setAge(27);
            persons[1].setAddress("ShenYang");
            
            persons[2] = new Person();
            persons[2].setId(003);
            persons[2].setName("haha");
            persons[2].setAge(25);
            persons[2].setAddress("DaLian");
            
            return persons;
        }
        public void dispose() {
        }
        public void inputChanged(Viewer viewer, Object oldInput, Object newInput) {
        }
    }
    class ViewLabelProvider extends LabelProvider{
        public Image getColumnImage(Object element) {
            return null;
        }
        public String getColumnText(Object element) {
            return getText(element);
        }
    }
    class MySorter extends ViewerSorter{
        public int compare(Viewer viewer,Object ob1,Object ob2){
            return ((Person)ob1).getId() - ((Person)ob2).getId();
        }
    }

　　对于内容提供者来说，最重要的一个方法就是getElements，因为视图上现实的数据，都要从这个方法获得。

　　下面看一下对应的全部代码

  1 package testpreference.views;
  2 
  3 import org.eclipse.jface.viewers.DoubleClickEvent;
  4 import org.eclipse.jface.viewers.IDoubleClickListener;
  5 import org.eclipse.jface.viewers.ISelectionChangedListener;
  6 import org.eclipse.jface.viewers.IStructuredContentProvider;
  7 import org.eclipse.jface.viewers.IStructuredSelection;
  8 import org.eclipse.jface.viewers.LabelProvider;
  9 import org.eclipse.jface.viewers.ListViewer;
 10 import org.eclipse.jface.viewers.SelectionChangedEvent;
 11 import org.eclipse.jface.viewers.Viewer;
 12 import org.eclipse.jface.viewers.ViewerSorter;
 13 import org.eclipse.swt.SWT;
 14 import org.eclipse.swt.graphics.Image;
 15 import org.eclipse.swt.widgets.Composite;
 16 import org.eclipse.ui.part.ViewPart;
 17 class Person{
 18     private int id;
 19     private String name;
 20     private int age;
 21     private String address;
 22     public int getId() {
 23         return id;
 24     }
 25     public void setId(int id) {
 26         this.id = id;
 27     }
 28     public String getName() {
 29         return name;
 30     }
 31     public void setName(String name) {
 32         this.name = name;
 33     }
 34     public int getAge() {
 35         return age;
 36     }
 37     public void setAge(int age) {
 38         this.age = age;
 39     }
 40     public String getAddress() {
 41         return address;
 42     }
 43     public void setAddress(String address) {
 44         this.address = address;
 45     }
 46     public String toString() {
 47         return name;
 48     }
 49 }
 50 
 51 
 52 public class ListViewerTest extends ViewPart {
 53     public static final String ID = "testpreference.views.ListViewerTest";
 54     private ListViewer viewer;
 55     
 56     public ListViewerTest() {
 57         
 58     }
 59 
 60     public void createPartControl(Composite parent) {
 61         viewer = new ListViewer(parent, SWT.SINGLE);
 62         viewer.setContentProvider(new ViewContentProvider());
 63         viewer.setLabelProvider(new ViewLabelProvider());
 64         viewer.setSorter(new MySorter());
 65         viewer.setInput(getSite());
 66 
 67         viewer.addSelectionChangedListener( new ISelectionChangedListener() {
 68             public void selectionChanged(SelectionChangedEvent event) {
 69                 IStructuredSelection selection = (IStructuredSelection)event.getSelection();
 70                 System.out.println("Now selecting "+selection.getFirstElement().toString());
 71             }
 72         });
 73         
 74         viewer.addDoubleClickListener( new IDoubleClickListener() {
 75             public void doubleClick(DoubleClickEvent event) {
 76                 IStructuredSelection selection = (IStructuredSelection)event.getSelection();
 77                 System.out.println("Double clicking "+selection.getFirstElement().toString());
 78             }
 79         });
 80     }
 81 
 82     public void setFocus() {
 83 
 84     }
 85     class ViewContentProvider implements IStructuredContentProvider{
 86         public Object[] getElements(Object inputElement) {
 87             
 88             Person[] persons = new Person[3];
 89             persons[0] = new Person();
 90             persons[0].setId(001);
 91             persons[0].setName("xingoo");
 92             persons[0].setAge(25);
 93             persons[0].setAddress("ChangChun");
 94             
 95             persons[1] = new Person();
 96             persons[1].setId(002);
 97             persons[1].setName("halo");
 98             persons[1].setAge(27);
 99             persons[1].setAddress("ShenYang");
100             
101             persons[2] = new Person();
102             persons[2].setId(003);
103             persons[2].setName("haha");
104             persons[2].setAge(25);
105             persons[2].setAddress("DaLian");
106             
107             return persons;
108         }
109         public void dispose() {
110         }
111         public void inputChanged(Viewer viewer, Object oldInput, Object newInput) {
112         }
113     }
114     class ViewLabelProvider extends LabelProvider{
115         public Image getColumnImage(Object element) {
116             return null;
117         }
118         public String getColumnText(Object element) {
119             return getText(element);
120         }
121     }
122     class MySorter extends ViewerSorter{
123         public int compare(Viewer viewer,Object ob1,Object ob2){
124             return ((Person)ob1).getId() - ((Person)ob2).getId();
125         }
126     }
127 }

　　tableViewer

　　这个对于上面的Listviewer来说，标签提供者方面复杂了一些

　　首先，创建视图时，需要定义Table的样式

 1 viewer = new TableViewer(parent,SWT.SINGLE|SWT.FULL_SELECTION);
 2         Table table = viewer.getTable();
 3         table.setHeaderVisible(true);
 4         table.setLinesVisible(true);
 5         
 6         String[] columnNames = new String[]{"id","name","age","address"};
 7         int[] columnWidths = new int[]{100,100,100,100};
 8         int[] columnAlignments = new int[]{SWT.LEFT,SWT.LEFT,SWT.LEFT,SWT.LEFT};
 9         for(int i=0;i<columnNames.length;i++){
10             TableColumn tableColumn  = new TableColumn(table,columnAlignments[i]);
11             tableColumn.setText(columnNames[i]);
12             tableColumn.setWidth(columnWidths[i]);
13         }
14         
15         viewer.setContentProvider(new ViewContentProvider());
16         viewer.setLabelProvider(new ViewLabelProvider());
17         viewer.setSorter(new MySorter());
18         viewer.setInput(getSite());

　　对于标签提供者函数来说，稍微麻烦一点，需要根据index指定每一列显示的内容

class ViewLabelProvider extends LabelProvider implements ITableLabelProvider{
        public Image getColumnImage(Object element,int index) {
            return null;
        }
        public String getColumnText(Object element,int index) {
            Person person = (Person)element;
            switch(index){
            case 0:
                return person.getId()+"";
            case 1:
                return person.getName();
            case 2:
                return person.getAge()+"";
            case 3:
                return person.getAddress();
            default:
                return "unknown"+index;
            }
        }
    }

　　全部代码及运行结果

  1 package testpreference.views;
  2 
  3 import org.eclipse.jface.viewers.IStructuredContentProvider;
  4 import org.eclipse.jface.viewers.ITableLabelProvider;
  5 import org.eclipse.jface.viewers.LabelProvider;
  6 import org.eclipse.jface.viewers.TableViewer;
  7 import org.eclipse.jface.viewers.Viewer;
  8 import org.eclipse.jface.viewers.ViewerSorter;
  9 import org.eclipse.swt.SWT;
 10 import org.eclipse.swt.graphics.Image;
 11 import org.eclipse.swt.widgets.Composite;
 12 import org.eclipse.swt.widgets.Table;
 13 import org.eclipse.swt.widgets.TableColumn;
 14 import org.eclipse.ui.part.ViewPart;
 15 
 16 public class TableViewerTest extends ViewPart {
 17     public static final String ID = "testpreference.views.TableViewerTest";
 18     private TableViewer viewer;
 19     public TableViewerTest() {
 20         // TODO Auto-generated constructor stub
 21     }
 22 
 23     public void createPartControl(Composite parent) {
 24         viewer = new TableViewer(parent,SWT.SINGLE|SWT.FULL_SELECTION);
 25         Table table = viewer.getTable();
 26         table.setHeaderVisible(true);
 27         table.setLinesVisible(true);
 28         
 29         String[] columnNames = new String[]{"id","name","age","address"};
 30         int[] columnWidths = new int[]{100,100,100,100};
 31         int[] columnAlignments = new int[]{SWT.LEFT,SWT.LEFT,SWT.LEFT,SWT.LEFT};
 32         for(int i=0;i<columnNames.length;i++){
 33             TableColumn tableColumn  = new TableColumn(table,columnAlignments[i]);
 34             tableColumn.setText(columnNames[i]);
 35             tableColumn.setWidth(columnWidths[i]);
 36         }
 37         
 38         viewer.setContentProvider(new ViewContentProvider());
 39         viewer.setLabelProvider(new ViewLabelProvider());
 40         viewer.setSorter(new MySorter());
 41         viewer.setInput(getSite());
 42     }
 43 
 44     public void setFocus() {
 45         // TODO Auto-generated method stub
 46 
 47     }
 48     class ViewContentProvider implements IStructuredContentProvider {
 49         public Object[] getElements(Object inputElement) {
 50             
 51             Person[] persons = new Person[3];
 52             persons[0] = new Person();
 53             persons[0].setId(001);
 54             persons[0].setName("xingoo");
 55             persons[0].setAge(25);
 56             persons[0].setAddress("ChangChun");
 57             
 58             persons[1] = new Person();
 59             persons[1].setId(002);
 60             persons[1].setName("halo");
 61             persons[1].setAge(27);
 62             persons[1].setAddress("ShenYang");
 63             
 64             persons[2] = new Person();
 65             persons[2].setId(003);
 66             persons[2].setName("haha");
 67             persons[2].setAge(25);
 68             persons[2].setAddress("DaLian");
 69             
 70             return persons;
 71         }
 72         public void dispose() {
 73         }
 74         public void inputChanged(Viewer viewer, Object oldInput, Object newInput) {
 75         }
 76     }
 77     class ViewLabelProvider extends LabelProvider implements ITableLabelProvider{
 78         public Image getColumnImage(Object element,int index) {
 79             return null;
 80         }
 81         public String getColumnText(Object element,int index) {
 82             Person person = (Person)element;
 83             switch(index){
 84             case 0:
 85                 return person.getId()+"";
 86             case 1:
 87                 return person.getName();
 88             case 2:
 89                 return person.getAge()+"";
 90             case 3:
 91                 return person.getAddress();
 92             default:
 93                 return "unknown"+index;
 94             }
 95         }
 96     }
 97     class MySorter extends ViewerSorter{
 98         public int compare(Viewer viewer,Object ob1,Object ob2){
 99             return ((Person)ob1).getId() - ((Person)ob2).getId();
100         }
101     }
102 
103 }

　　TreeViewer

　　这个视图相比前面的这个复杂在它的内容提供者函数，我们需要让他的ContentProvider函数继承ITreeContentProvider接口，需要实现下面几个方法：

　　getChildren();获取节点的孩子节点。

　　getParent();获取节点的父节点

　　hasChildren();判断是否有孩子节点

　　getElements();获取全部的节点

　　下面看一下示例的代码

 1 class ViewContentProvider extends ArrayContentProvider implements ITreeContentProvider{
 2 
 3         public Object[] getChildren(Object parentElement) {
 4             TreePerson person = (TreePerson)parentElement;
 5             return person.getChildren().toArray();
 6         }
 7 
 8         public Object getParent(Object element) {
 9             TreePerson person = (TreePerson)element;
10             return person.getParent();
11         }
12 
13         public boolean hasChildren(Object element) {
14             TreePerson person = (TreePerson)element;
15             return person.getChildren().size()>0?true:false;
16         }
17         
18         public Object[] getElements(Object inputElement) {
19             TreePerson[] persons = new TreePerson[3];
20             persons[0] = new TreePerson();
21             persons[0].setId(001);
22             persons[0].setName("xingoo");
23             persons[0].setAge(25);
24             persons[0].setAddress("ChangChun");
25             
26             persons[1] = new TreePerson();
27             persons[1].setId(002);
28             persons[1].setName("halo");
29             persons[1].setAge(27);
30             persons[1].setAddress("ShenYang");
31             
32             persons[2] = new TreePerson();
33             persons[2].setId(003);
34             persons[2].setName("haha");
35             persons[2].setAge(25);
36             persons[2].setAddress("DaLian");
37             
38             persons[0].getChildren().add(persons[1]);
39             persons[0].getChildren().add(persons[2]);
40             persons[1].setParent(persons[0]);
41             persons[2].setParent(persons[0]);
42             
43             return persons;
44         }
45         
46     }

　　而他的标签提供者跟ListViewer的差不多，仅仅需要提供一个简单的名称就可以了。

class ViewLabelProvider extends LabelProvider{
        public Image getColumnImage(Object element) {
            return null;
        }
        public String getColumnText(Object element) {
            return ((TreePerson)element).toString();
        }
    }

　　全部代码以及运行结果

  1 package testpreference.views;
  2 
  3 import java.util.ArrayList;
  4 import java.util.List;
  5 
  6 import org.eclipse.jface.viewers.ArrayContentProvider;
  7 import org.eclipse.jface.viewers.ITreeContentProvider;
  8 import org.eclipse.jface.viewers.LabelProvider;
  9 import org.eclipse.jface.viewers.TreeViewer;
 10 import org.eclipse.jface.viewers.Viewer;
 11 import org.eclipse.jface.viewers.ViewerSorter;
 12 import org.eclipse.swt.SWT;
 13 import org.eclipse.swt.graphics.Image;
 14 import org.eclipse.swt.widgets.Composite;
 15 import org.eclipse.ui.part.ViewPart;
 16 class TreePerson{
 17     private int id;
 18     private String name;
 19     private int age;
 20     private String address;
 21     private List<TreePerson> children;
 22     private TreePerson parent = null; 
 23     
 24     public TreePerson() {
 25         children = new ArrayList();
 26     }
 27     public List<TreePerson> getChildren() {
 28         return children;
 29     }
 30     public void setChildren(List<TreePerson> children) {
 31         this.children = children;
 32     }
 33     public TreePerson getParent() {
 34         return parent;
 35     }
 36     public void setParent(TreePerson parent) {
 37         this.parent = parent;
 38     }
 39     public int getId() {
 40         return id;
 41     }
 42     public void setId(int id) {
 43         this.id = id;
 44     }
 45     public String getName() {
 46         return name;
 47     }
 48     public void setName(String name) {
 49         this.name = name;
 50     }
 51     public int getAge() {
 52         return age;
 53     }
 54     public void setAge(int age) {
 55         this.age = age;
 56     }
 57     public String getAddress() {
 58         return address;
 59     }
 60     public void setAddress(String address) {
 61         this.address = address;
 62     }
 63     public String toString() {
 64         return name;
 65     }
 66 }
 67 public class TreeViewerTest extends ViewPart {
 68     public static final String ID = "testpreference.views.TreeViewerTest";
 69     private TreeViewer viewer;
 70     public TreeViewerTest() {
 71         // TODO Auto-generated constructor stub
 72     }
 73 
 74     public void createPartControl(Composite parent) {
 75         viewer = new TreeViewer(parent,SWT.SINGLE);
 76         viewer.setLabelProvider(new ViewLabelProvider());
 77         viewer.setContentProvider(new ViewContentProvider());
 78         viewer.setSorter(new MySorter());
 79         viewer.setInput(getSite());
 80     }
 81 
 82     public void setFocus() {
 83         // TODO Auto-generated method stub
 84 
 85     }
 86     class ViewContentProvider extends ArrayContentProvider implements ITreeContentProvider{
 87 
 88         public Object[] getChildren(Object parentElement) {
 89             TreePerson person = (TreePerson)parentElement;
 90             return person.getChildren().toArray();
 91         }
 92 
 93         public Object getParent(Object element) {
 94             TreePerson person = (TreePerson)element;
 95             return person.getParent();
 96         }
 97 
 98         public boolean hasChildren(Object element) {
 99             TreePerson person = (TreePerson)element;
100             return person.getChildren().size()>0?true:false;
101         }
102         
103         public Object[] getElements(Object inputElement) {
104             TreePerson[] persons = new TreePerson[3];
105             persons[0] = new TreePerson();
106             persons[0].setId(001);
107             persons[0].setName("xingoo");
108             persons[0].setAge(25);
109             persons[0].setAddress("ChangChun");
110             
111             persons[1] = new TreePerson();
112             persons[1].setId(002);
113             persons[1].setName("halo");
114             persons[1].setAge(27);
115             persons[1].setAddress("ShenYang");
116             
117             persons[2] = new TreePerson();
118             persons[2].setId(003);
119             persons[2].setName("haha");
120             persons[2].setAge(25);
121             persons[2].setAddress("DaLian");
122             
123             persons[0].getChildren().add(persons[1]);
124             persons[0].getChildren().add(persons[2]);
125             persons[1].setParent(persons[0]);
126             persons[2].setParent(persons[0]);
127             
128             return persons;
129         }
130         
131     }
132     class ViewLabelProvider extends LabelProvider{
133         public Image getColumnImage(Object element) {
134             return null;
135         }
136         public String getColumnText(Object element) {
137             return ((TreePerson)element).toString();
138         }
139     }
140     class MySorter extends ViewerSorter{
141         public int compare(Viewer viewer,Object ob1,Object ob2){
142             return ((TreePerson)ob1).getId() - ((TreePerson)ob2).getId();
143         }
144     }
145 }

　　TextViewer

　　这个前一篇的源码编辑器上有讲解过，是一种可以编辑的Text文本，它可以设定特定复杂的样式，这里就看一个简单的例子

 1 viewer = new TextViewer(parent,SWT.MULTI | SWT.V_SCROLL);
 2         String str = "this is test n this is test";
 3         Document document = new Document(str);
 4         viewer.setDocument(document);
 5         
 6         TextPresentation style = new TextPresentation();
 7         style.addStyleRange(new StyleRange(0,12,null,null,SWT.BOLD));
 8         viewer.changeTextPresentation(style, true);
 9         
10         viewer.setInput(getSite());

　　全部代码以及运行结果

 1 package testpreference.views;
 2 
 3 import org.eclipse.jface.text.Document;
 4 import org.eclipse.jface.text.TextPresentation;
 5 import org.eclipse.jface.text.TextViewer;
 6 import org.eclipse.jface.viewers.TreeViewer;
 7 import org.eclipse.swt.SWT;
 8 import org.eclipse.swt.custom.StyleRange;
 9 import org.eclipse.swt.graphics.Color;
10 import org.eclipse.swt.widgets.Composite;
11 import org.eclipse.ui.part.ViewPart;
12 
13 import testpreference.views.TreeViewerTest.MySorter;
14 import testpreference.views.TreeViewerTest.ViewContentProvider;
15 import testpreference.views.TreeViewerTest.ViewLabelProvider;
16 
17 public class TextViewerTest extends ViewPart {
18     public static final String ID = "testpreference.views.TreeViewerTest";
19     private TextViewer viewer;
20     
21     public TextViewerTest() {
22         // TODO Auto-generated constructor stub
23     }
24 
25     public void createPartControl(Composite parent) {
26         viewer = new TextViewer(parent,SWT.MULTI | SWT.V_SCROLL);
27         String str = "this is test n this is test";
28         Document document = new Document(str);
29         viewer.setDocument(document);
30         
31         TextPresentation style = new TextPresentation();
32         style.addStyleRange(new StyleRange(0,12,null,null,SWT.BOLD));
33         viewer.changeTextPresentation(style, true);
34         
35         viewer.setInput(getSite());
36     }
37 
38     public void setFocus() {
39         // TODO Auto-generated method stub
40 
41     }
42 
43 }

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