OpenOffice 电子表格监听器

Question

我想使用 Java 跟踪用户对 LibreOffice / OpenOffice 电子表格的输入。目前，我从the first LibreOffice examples 开始，并想附上类似的东西

• com.sun.star.chart.XChartDataChangeEventListener（见here），也许是一个
• com.sun.star.container.XContainerListener 到电子表格。

我在尝试将 XSpreadsheetDocument 转换为 XContainer 时收到 NullPointerException。 我发现 API 文档非常难以浏览，并且非常感谢您提供以下提示：

• 找出 XSpreadsheetDocument 的类型层次结构，
• 将哪个侦听器附加到哪个接口，以及
• 该接口的工厂链

Answer 1

通过猜测，我发现从private:factory/scalc加载的XComponent属于可以转换为接口com.sun.star.util.XModifyBroadcaster的服务，从而可以安装com.sun.star.util.XModifyListener。

这是一个工作示例：

import com.sun.star.beans.PropertyValue;
import com.sun.star.comp.helper.Bootstrap;
import com.sun.star.comp.helper.BootstrapException;
import com.sun.star.frame.XComponentLoader;
import com.sun.star.lang.EventObject;
import com.sun.star.lang.XComponent;
import com.sun.star.lang.XMultiComponentFactory;
import com.sun.star.sheet.XSpreadsheetDocument;
import com.sun.star.uno.Exception;
import com.sun.star.uno.UnoRuntime;
import com.sun.star.uno.XComponentContext;
import com.sun.star.util.XModifyBroadcaster;

public class CalcListener {
    public static void main( String[] args) {
        try {
            // Lots of verbose code to get a Document instance
            final XComponentContext xRemoteContext = Bootstrap.bootstrap();
            if( xRemoteContext == null ) {
                System.err.println("ERROR: Could not bootstrap default Office.");
                return;
            }
            final XMultiComponentFactory xRemoteServiceManager = xRemoteContext.getServiceManager();
            final Object desktop = xRemoteServiceManager.createInstanceWithContext( "com.sun.star.frame.Desktop", xRemoteContext );
            final XComponentLoader xComponentLoader = (XComponentLoader) UnoRuntime.queryInterface(XComponentLoader.class, desktop);

            final PropertyValue[] loadProps = new PropertyValue[0];
            final XComponent xSpreadsheetComponent = xComponentLoader.loadComponentFromURL("private:factory/scalc", "_blank", 0, loadProps);

            // Cast to interface Document, to do anything useful later
            final XSpreadsheetDocument xSpreadsheetDocument = (XSpreadsheetDocument) UnoRuntime.queryInterface(XSpreadsheetDocument.class, xSpreadsheetComponent);

            // Cast to interface XModifyBroadcaster to attach listener
            final XModifyBroadcaster messageHost = (XModifyBroadcaster) UnoRuntime.queryInterface(XModifyBroadcaster.class, xSpreadsheetDocument );
            messageHost.addModifyListener( new XModifyListener()
            {
                public void modified(EventObject eo) {
                    System.out.println("modified:"+eo.Source);
                }

                public void disposing(EventObject eo) {
                    System.out.println("disposing:"+eo);
                }
            });

            // Do possibly useful stuff
            // ...

        } catch (BootstrapException | Exception ex) {
            System.err.println("bad things happened:"+ex);
        }
    }
}