Java SWT - 透明外壳上的文本？

Question

在 Java SWT 中，有没有办法在透明外壳上绘制文本，以便只有文本可见？我想做的是让文本出现在我的桌面上，没有任何背景窗口。使用 shell.setAlpha() 将使整个 shell 透明，包括出现在上面的任何元素（我试图避免）。

Answer 1

这是一个示例displaying an image without the shell。您可以相当轻松地调整它以显示文本。

更新：

好吧，我觉得无聊。这是一个在透明背景上绘制“Hello”的基本示例：

package swttest;

import org.eclipse.swt.SWT;
import org.eclipse.swt.events.PaintEvent;
import org.eclipse.swt.events.PaintListener;
import org.eclipse.swt.graphics.Font;
import org.eclipse.swt.graphics.FontData;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.graphics.Region;
import org.eclipse.swt.widgets.Canvas;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Shell;

public class Test {

    public static void main(String[] args) {
        Test test = new Test();

        test.show();
    }

    public void show() {
        Display display = new Display();
        // Create a shell with no trim
        final Shell shell = new Shell(display, SWT.NO_TRIM);
        shell.setForeground(display.getSystemColor(SWT.COLOR_WHITE));

        //set the transparent canvas on the shell
        Canvas canvas = new Canvas(shell, SWT.NO_BACKGROUND);

        //create an area to paint the text
        Rectangle size = new Rectangle(0, 0, 200, 200);
        canvas.setBounds(size);

        Region region = canvas.getRegion();

        //mucking about with fonts
        Font font = display.getSystemFont();

        FontData[] fd = font.getFontData();

        fd[0].setHeight(24);
        fd[0].setStyle(SWT.BOLD);

        Font bigFont = new Font(display, fd[0]);
        canvas.setFont(bigFont);

        // define the shape of the shell using setRegion
        shell.setRegion(region);
        shell.setSize(size.width, size.height);

        canvas.addPaintListener(new PaintListener() {
            public void paintControl(PaintEvent e) {
                e.gc.drawString("Hello", 10, 10, true);
            }
        });

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