如何在SWT对象上调用Objective-C方法?

时间:2012-12-28 11:22:50

标签: java objective-c swt

我想使用Java应用程序以本机方式在OS X上的系统托盘/任务栏中显示文本。我想通过在setTitle上调用NSStatusItem(例如在this example中)来执行此操作。我从未在SWT中访问过底层本机库,而且我遇到了麻烦。

this thread上的某人演示了如何调用Objective-C方法来更改SWT中窗口的属性(全屏按钮)。这是他/她的代码:

Field field = Control.class.getDeclaredField("view");
Object /*NSView*/ view = field.get(rShell);

if (view != null)
{
    Class<?> c = Class.forName("org.eclipse.swt.internal.cocoa.NSView");
    Object /*NSWindow*/ window = c.getDeclaredMethod("window").invoke(view);

    c = Class.forName("org.eclipse.swt.internal.cocoa.NSWindow");
    Method setCollectionBehavior = c.getDeclaredMethod(
        "setCollectionBehavior", JVM.is64bit() ? long.class : int.class);
    setCollectionBehavior.invoke(window, getFullScreenMask());
}

所以我想这会产生这个Objective-C代码:

[window setCollectionBehaviour:1<<7];

现在我想对SWT TrayItem做同样的事情。目标是获得这个Objective-C代码的等价物:

[statusItem setTitle:@"Status"];

但我得到以下例外:

Exception in thread "main" java.lang.IllegalArgumentException: Can not set org.eclipse.swt.internal.cocoa.NSView field org.eclipse.swt.widgets.Control.view to org.eclipse.swt.widgets.TrayItem
    at sun.reflect.UnsafeFieldAccessorImpl.throwSetIllegalArgumentException(UnsafeFieldAccessorImpl.java:146)
    at sun.reflect.UnsafeFieldAccessorImpl.throwSetIllegalArgumentException(UnsafeFieldAccessorImpl.java:150)
    at sun.reflect.UnsafeFieldAccessorImpl.ensureObj(UnsafeFieldAccessorImpl.java:37)
    at sun.reflect.UnsafeObjectFieldAccessorImpl.get(UnsafeObjectFieldAccessorImpl.java:18)
    at java.lang.reflect.Field.get(Field.java:358)
    at com.teez.status.MainStatus.main(MainStatus.java:35)

我不确定这意味着什么。我标记了引发异常的行。尝试这个时我还会遇到哪些其他问题?这是我的代码:

import java.lang.reflect.Field;
import java.lang.reflect.Method;

import org.eclipse.swt.SWT;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Listener;
import org.eclipse.swt.widgets.Menu;
import org.eclipse.swt.widgets.MenuItem;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.Tray;
import org.eclipse.swt.widgets.TrayItem;

public class MainStatus {

    public static void main(String[] args) throws Exception {
        Display display = new Display();
        Shell shell = new Shell(display);
        Tray tray = display.getSystemTray();


        if (tray != null) {
            TrayItem item = new TrayItem(tray, SWT.NONE);

            Field field = Control.class.getDeclaredField("view");
            Object /*NSView*/ view = field.get(item); //Exception thrown here

            if (view != null)
            {
                Class<?> c = Class.forName("org.eclipse.swt.internal.cocoa.NSView");
                Object /*NSWindow*/ window = c.getDeclaredMethod("window").invoke(view);

                c = Class.forName("org.eclipse.swt.internal.cocoa.NSStatusItem");


                Method setCollectionBehavior = c.getDeclaredMethod("setTitle", long.class);

                setCollectionBehavior.invoke(window, "Desired title");
            }

            while (!shell.isDisposed ()) {
                if (!display.readAndDispatch ()) display.sleep ();
            }
            display.dispose ();

        }

    }

}

编辑:感谢Eugene解决此问题,但文本仍然没有显示在状态栏上,所以我问了另一个问题here

1 个答案:

答案 0 :(得分:1)

托盘项目不是控件。您需要在该类层次结构中查找Cocoa句柄。

sources判断Cocoa句柄存储在“item”字段中,它是NSStatusItem的实例。

不幸的是,我无法测试它。