如何使用 SourceProvider 根据条件启用和禁用菜单项 (eclipse rcp Indigo 3.7)

我有一个 eclipse rcp （版本 Indigo 3.7）应用程序（eclipse 插件项目）。我阅读了 Lars Vogel 的教程“Eclipse Commands Advanced”（修订版 0.2-2.1，2009 年 4 月 11 日-2011 年 9 月 24 日）。

首先，我使用带有菜单和一些命令的 menuContribution 创建了菜单扩展。

其次，我使用一些命令创建了命令扩展。

第三，我定义了处理程序扩展（具有启用时表达式的处理程序）。

第四，我用变量编写了服务扩展。

我的plugin.xml 看起来像：

<?xml version="1.0" encoding="UTF-8"?>
<?eclipse version="3.4"?>
<plugin>
    <extension id="application" point="org.eclipse.core.runtime.applications">
        ...
    </extension>
    <extension point="org.eclipse.ui.perspectives">
        ...
    </extension>
    <extension id="product" point="org.eclipse.core.runtime.products">
        ...
    </extension>
    <extension point="org.eclipse.ui.views">
        ...
    </extension>
    <extension point="org.eclipse.ui.menus">
        <menuContribution allPopups="false" locationURI="menu:org.eclipse.ui.main.menu">
            <menu id="fileMenuItem" label="File" mnemonic="F">
                <command commandId="de.falk.rcp37.drawfigures.commands.new" id="newFileMenuItem" label="New" mnemonic="N" style="push">
                </command>
                <command commandId="de.falk.rcp37.drawfigures.commands.open" id="openFileMenuItem" label="Open..." mnemonic="O" style="push">
                </command>
                <separator name="de.falk.rcp37.drawfigures.menu.file.separator1" visible="true">
                </separator>
                <command commandId="de.falk.rcp37.drawfigures.commands.close" id="closeFileMenuItem" label="Close" mnemonic="C" style="push">
                </command>
                <separator name="de.falk.rcp37.drawfigures.menu.file.separator2" visible="true">
                </separator>
                <command commandId="de.falk.rcp37.drawfigures.commands.save" id="saveFileMenuItem" label="Save" mnemonic="S" style="push">
                </command>
                <command commandId="de.falk.rcp37.drawfigures.commands.saveas" id="saveAsFileMenuItem" label="Save as..." mnemonic="a" style="push">
                </command>
                <separator name="de.falk.rcp37.drawfigures.menu.file.separator3" visible="true">
                </separator>
                <command commandId="de.falk.rcp37.drawfigures.commands.exit" id="exitFileMenuItem" label="Exit" mnemonic="x" style="push">
                </command>
                <command commandId="de.falk.rcp37.drawfigures.commands.change" id="changeFileMenuItem" label="Change" mnemonic="h" style="push">
                </command>
            </menu>
        </menuContribution>
    </extension>
    <extension point="org.eclipse.ui.commands">
        <command id="de.falk.rcp37.drawfigures.commands.new" name="newFileCommand"></command>
        <command id="de.falk.rcp37.drawfigures.commands.open" name="openFileCommand"></command>
        <command id="de.falk.rcp37.drawfigures.commands.close" name="closeFileCommand"></command>
        <command id="de.falk.rcp37.drawfigures.commands.save" name="saveFileCommand"></command>
        <command id="de.falk.rcp37.drawfigures.commands.saveas" name="saveAsFileCommand"></command>
        <command id="de.falk.rcp37.drawfigures.commands.exit" name="exitFileCommand"></command>
        <command id="de.falk.rcp37.drawfigures.commands.change" name="changeFileCommand"></command>
    </extension>
    <extension point="org.eclipse.ui.handlers">
        <handler class="de.falk.rcp37.drawfigures.handler.NewHandler" commandId="de.falk.rcp37.drawfigures.commands.new"></handler>
        <handler class="de.falk.rcp37.drawfigures.handler.OpenHandler" commandId="de.falk.rcp37.drawfigures.commands.open"></handler>
        <handler class="de.falk.rcp37.drawfigures.handler.CloseHandler" commandId="de.falk.rcp37.drawfigures.commands.close">
            <enabledWhen>
                <with variable="de.falk.rcp37.drawfigures.miscellaneous.menuitemsstatesourceprovider.closestate">
                    <equals value="true"></equals>
                </with>
            </enabledWhen>
        </handler>
        <handler class="de.falk.rcp37.drawfigures.handler.SaveHandler" commandId="de.falk.rcp37.drawfigures.commands.save">
            <enabledWhen>
                <with variable="de.falk.rcp37.drawfigures.miscellaneous.menuitemsstatesourceprovider.savestate">
                    <equals value="true"></equals>
                </with>
            </enabledWhen>
        </handler>
        <handler class="de.falk.rcp37.drawfigures.handler.SaveAsHandler" commandId="de.falk.rcp37.drawfigures.commands.saveas">
            <enabledWhen>
                <with variable="de.falk.rcp37.drawfigures.miscellaneous.menuitemsstatesourceprovider.saveasstate">
                    <equals value="true"></equals>
                </with>
            </enabledWhen>
        </handler>
        <handler class="de.falk.rcp37.drawfigures.handler.ExitHandler" commandId="de.falk.rcp37.drawfigures.commands.exit"></handler>
        <handler class="de.falk.rcp37.drawfigures.handler.ChangeHandler" commandId="de.falk.rcp37.drawfigures.commands.change"></handler>
    </extension>
    <extension point="org.eclipse.ui.services">
        <sourceProvider provider="de.falk.rcp37.drawfigures.miscellaneous.MenuItemsStateSourceProvider">
            <variable name="de.falk.rcp37.drawfigures.miscellaneous.menuitemsstatesourceprovider.closestate" priorityLevel="workbench"></variable>
            <variable name="de.falk.rcp37.drawfigures.miscellaneous.menuitemsstatesourceprovider.savestate" priorityLevel="workbench"></variable>
            <variable name="de.falk.rcp37.drawfigures.miscellaneous.menuitemsstatesourceprovider.saveasstate" priorityLevel="workbench"></variable>
        </sourceProvider>
    </extension>
</plugin>

另外，我实现了 MenuItemsStateSourceProvider：

package de.falk.rcp37.drawfigures.miscellaneous;
import java.util.HashMap;
import java.util.Map;

import org.eclipse.ui.AbstractSourceProvider;

public class MenuItemsStateSourceProvider extends AbstractSourceProvider {
    public static final String ID = "de.falk.rcp37.drawfigures.miscellaneous.menuitemsstatesourceprovider";
    public static final String DRAWING_CLOSE_STATE = "de.falk.rcp37.drawfigures.miscellaneous.menuitemsstatesourceprovider.closestate";
    public static final String DRAWING_SAVE_STATE = "de.falk.rcp37.drawfigures.miscellaneous.menuitemsstatesourceprovider.savestate";
    public static final String DRAWING_SAVEAS_STATE = "de.falk.rcp37.drawfigures.miscellaneous.menuitemsstatesourceprovider.saveasstate";

    @Override
    public void dispose() {

    }

    @SuppressWarnings("rawtypes")
    @Override
    public Map getCurrentState() {
        HashMap<String, String> hashMap = new HashMap<String, String>();
        hashMap.put(ID, ID);
        hashMap.put(DRAWING_CLOSE_STATE, "false");
        hashMap.put(DRAWING_SAVE_STATE, "false");
        hashMap.put(DRAWING_SAVEAS_STATE, "false");
        return hashMap;
}

    @Override
    public String[] getProvidedSourceNames() {
        return new String[] { ID, DRAWING_CLOSE_STATE, DRAWING_SAVE_STATE, DRAWING_SAVEAS_STATE };
    }

public void setDrawingNewed(boolean drawingNewed) {
    if (ModelDefinitions.currentDrawing.getNewed() != drawingNewed) {
            ModelDefinitions.currentDrawing.setNewed(drawingNewed);
            fireSourceChanged(ISources.WORKBENCH, DRAWING_SAVEAS_STATE, ModelDefinitions.currentDrawing.getSaveAsStateString());
    }
}
public void setDrawingOpend(boolean drawingOpend) {
        if (ModelDefinitions.currentDrawing.getOpend() != drawingOpend) {
            ModelDefinitions.currentDrawing.setOpend(drawingOpend);
    fireSourceChanged(ISources.WORKBENCH, DRAWING_CLOSE_STATE, ModelDefinitions.currentDrawing.getCloseStateString());
            fireSourceChanged(ISources.WORKBENCH, DRAWING_SAVE_STATE, ModelDefinitions.currentDrawing.getSaveStateString());
            fireSourceChanged(ISources.WORKBENCH, DRAWING_SAVEAS_STATE, ModelDefinitions.currentDrawing.getSaveAsStateString());
        }
}
public void setDrawingChanged(boolean drawingChanged) {
        if (ModelDefinitions.currentDrawing.getChanged() != drawingChanged) {
            ModelDefinitions.currentDrawing.setChanged(drawingChanged);
            fireSourceChanged(ISources.WORKBENCH, DRAWING_SAVE_STATE, ModelDefinitions.currentDrawing.getSaveStateString());
        }
}
}

以及不同的处理程序：

public class ChangeHandler extends AbstractHandler {
@Override
public Object execute(ExecutionEvent event) throws ExecutionException {

        // doing some CHANGE operations...

    // Get the source provider service
    ISourceProviderService sourceProviderService = (ISourceProviderService) HandlerUtil.getActiveWorkbenchWindow(event).getService(ISourceProviderService.class);
    // Now get my service
    MenuItemsStateSourceProvider menuItemsStateSourceProvider = (MenuItemsStateSourceProvider)sourceProviderService.getSourceProvider(MenuItemsStateSourceProvider.ID);
    menuItemsStateSourceProvider.setDrawingChanged(true);

    return null;
    }
}

or:

public class NewHandler extends AbstractHandler {
@Override
public Object execute(ExecutionEvent event) throws ExecutionException {

        // doing some NEW operations...

    // Get the source provider service
    ISourceProviderService sourceProviderService = (ISourceProviderService) HandlerUtil.getActiveWorkbenchWindow(event).getService(ISourceProviderService.class);
    // Now get my service
    MenuItemsStateSourceProvider menuItemsStateSourceProvider = (MenuItemsStateSourceProvider)sourceProviderService.getSourceProvider(MenuItemsStateSourceProvider.ID);
    menuItemsStateSourceProvider.setDrawingNewed(true);
    menuItemsStateSourceProvider.setDrawingOpend(false);
    menuItemsStateSourceProvider.setDrawingChanged(false);

    return null;
}
}

等等（对于所有处理程序）...

最后在绘图课上：

public String getCloseStateString() {
    return (opend) ? "true" : "false";
}
public String getSaveStateString() {
    return (opend && changed) ? "true" : "false";
}
public String getSaveAsStateString() {
    return (opend || newed) ? "true" : "false";
}

public void setNewed(boolean newed) {
    this.newed = newed;
}
public void setOpend(boolean opend) {
    this.opend = opend;
}
public void setChanged(boolean changed) {
    this.changed = changed;
}

但没有任何作用！有人可以帮忙吗？

谢谢鲁莫

ISourceProvider.getCurrentState期望一个Map<String, Object>作为返回值（参见 Javadoc）。检查启用的处理程序使用Boolean值，而不是String.

如果你改变你的getCurrentState中的方法MenuItemsStateSourceProvider to

@SuppressWarnings("rawtypes")
@Override
public Map getCurrentState() {
  HashMap<String, Object> hashMap = new HashMap<String, Object>();
  hashMap.put(ID, ID);
  hashMap.put(DRAWING_CLOSE_STATE, Boolean.TRUE);
  hashMap.put(DRAWING_SAVE_STATE, Boolean.FALSE);
  hashMap.put(DRAWING_SAVEAS_STATE, Boolean.FALSE);
  return hashMap;
}

the Close菜单条目将被启用，其他条目将被禁用。 所有状态值必须是Boolean.