构建eclipse plugin 的Preferences

现在正在做一个rcp软件，刚刚做好了Preferences,总结一下。此方法也适用eclipse plugin。在作ipass的时候，没有发现有这么简便的方法。

以一个配置密码策略的页面为例：

public class PreferencePassPolicyPage extends FieldEditorPreferencePage

implements IWorkbenchPreferencePage {

public static final String PASSWORD_CHARS = "passgate.password.chars";

public static final String ALPHABETIC = "alphabetic";

public static final String ALPHANUMERIC = "alphanumeric";

public static final String NUMERIC = "numeric";

public static final String PASSWORD_CASE = "passgate.password.case";

public static final String UPPER = "uppercase";

public static final String LOWER = "lowercase";

public static final String MIXED = "mixed";

public static final String PASSWORD_LENGTH = "passgate.password.length";

public PreferencePassPolicyPage() {

super(GRID);

setTitle("Password Policy");

setImageDescriptor(ImageShop.getDescriptor("category_obj"));

setPreferenceStore(PwdgatePlugin.getDefault().getPreferenceStore());

}

public void init(IWorkbench workbench) {

}

protected void createFieldEditors() {

// characters

String[][] choose = new String[][] {

new String[] { "Use alphabetic only", ALPHABETIC },

new String[] { "Use numberic only", NUMERIC },

new String[] { "Use alphanumeric only", ALPHANUMERIC } };

FieldEditor charcterEditor = new RadioGroupFieldEditor(PASSWORD_CHARS,

"Characters", 1, choose, getFieldEditorParent(), true);

addField(charcterEditor);

// case

choose = new String[][] { new String[] { "Lower case", LOWER },

new String[] { "Upper case", UPPER },

new String[] { "Mixed", MIXED } };

FieldEditor caseEditor = new RadioGroupFieldEditor(PASSWORD_CASE,

"Case", 1, choose, getFieldEditorParent(), true);

addField(caseEditor);

FieldEditor lengthEditor = new IntegerFieldEditor(PASSWORD_LENGTH,

"Password length", getFieldEditorParent());

addField(lengthEditor);

}

}

页面继承了FieldEditorPreferencePage，只需要实现createFieldEditors()即可构建自己的Preference结构；实现了IWorkbenchPreferencePage接口，这样eclipse才能够通过plugin.xml中定义的extension point="org.eclipse.ui.preferencePages"加载本页。程序开始的静态常量是本页要用到的key，用来保存相应的属性值。在createFieldEditors()方法中，RadioGroupFieldEditor是一组Radio Button，省去了自己一个一个的常见控件。相应的还有IntegerFieldEditor，BooleanFieldEditor，StringFieldEditor等等可以使用，使用方法十分简单，参考api即可。实现的效果如下：

在plugin.xml文件中加入如下内容：

<extension

point="org.eclipse.ui.preferencePages">

<page

class="com.mi.pwdgate.dialog.PreferenceEditorPage"

id="com.mi.pwdgate.dialog.PreferenceEditorPage"

name="PassGate"/>

<page

category="com.mi.pwdgate.dialog.PreferenceEditorPage"

class="com.mi.pwdgate.dialog.PreferencePassPolicyPage"

id="com.mi.pwdgate.dialog.PreferencePassPolicyPage"

name="Password Policy"/>

</extension>

class为自己编写的preference页面的类，id可以任意取，但必须要使唯一的，一般都用类名，name是用来显示在界面上的名字，category是当前的Preference属于哪个Preference，就填写哪个Preference的id。本例中Password Policy的父节点是PassGate。

设定Preference的默认值

编写PreferenceInitializer.java，在这里设定preference的默认值，必须要继承AbstractPreferenceInitializer类。

public class PreferenceInitializer extends AbstractPreferenceInitializer {

public void initializeDefaultPreferences() {

IPreferenceStore store = PwdgatePlugin.getDefault()

.getPreferenceStore();

// for PassPolicy Preference

store.setDefault(PreferencePassPolicyPage.PASSWORD_CHARS,

PreferencePassPolicyPage.ALPHANUMERIC);

store.setDefault(PreferencePassPolicyPage.PASSWORD_CASE,

PreferencePassPolicyPage.LOWER);

store.setDefault(PreferencePassPolicyPage.PASSWORD_LENGTH, 8);

// for interaction preference

store.setDefault(PreferenceInteractionPage.DELETE_COMFIRM, true);

store.setDefault(PreferenceInteractionPage.DELETE_TO_BIN, true);

}

}

在plugin.xml文件中加入如下内容：

<extension

point="org.eclipse.core.runtime.preferences">

<initializerclass="com.mi.pwdgate.dialog.PreferenceInitializer"/>

</extension>

再给一张截图