java - Piccolo可缩放界面，缩放时如何更改文字

Question

我正在试验一些 Piccolo 来创建一个可缩放的界面。

我正在 Canvas 上创建一个矩形，上面有一些 PText。现在缩放时，我想将文本更改为不同的内容。

我已经在我的初始化中做到了这一点:

//
        //specify the current Piccolo PCanvas
        //
        m_canvas = getCanvas();
        m_canvas.removeInputEventListener(m_canvas.getPanEventHandler());
        //m_canvas.addInputEventListener(new ClickAndDragHandler(m_canvas));

        //
        //add nodes to the collection -> adding to the collection = adding to the canvas
        //
        m_nodecollection = new NodeCollection(m_canvas);

        RectangleNode node_links = new RectangleNode();
        node_links.setBounds(10, 10, 500, 500);
        m_nodecollection.addNode(node_links);

        RectangleNode node_rechts = new RectangleNode();
        node_rechts.setBounds(600,10,500,500);
        m_nodecollection.addNode(node_rechts);

        PImage node_arrowLeft = new PImage("left.gif");
        node_arrowLeft.setBounds(600, 550, node_arrowLeft.getWidth(), node_arrowLeft.getHeight());
        m_nodecollection.addNode(node_arrowLeft);

        PImage node_arrowRight = new PImage("right.gif");
        node_arrowRight.setBounds(680, 550, node_arrowRight.getWidth(), node_arrowRight.getHeight());
        m_nodecollection.addNode(node_arrowRight);

        m_nodecollection.connectNodesWithLine(node_rechts, node_arrowRight, true);
        m_nodecollection.connectNodesWithLine(node_rechts, node_arrowLeft, true);


        PText node_text = new PText("Zoomlevel Not Supported");
        node_text.setBounds(180,150, node_text.getWidth(), node_text.getHeight());
        m_nodecollection.connectNodesWithLine(node_links, node_text, true);
        m_nodecollection.addNode(node_text);
        node_links.addChild(node_text);
        node_links.setCollection(m_nodecollection);

使用整个节点集合和 PText 作为成员创建了我自己的矩形类。

public class RectangleNode extends PNode{

    private Rectangle2D m_rectangle;
    private NodeCollection collection;
private PText text;

    public RectangleNode()
    {
        m_rectangle = new Rectangle2D.Double();
    }

    public Rectangle2D getRectangle()
    {
        if(m_rectangle == null)
            m_rectangle = new Rectangle2D.Double();
        return m_rectangle;
    }

    public boolean setBounds(double x, double y, double w, double h)
    {
        if(super.setBounds(x, y, w, h))
        {
            m_rectangle.setFrame(x, y, w, h);
            return true;
        }
        return false;
    }

    public void setCollection(NodeCollection collection)
    {
        this.collection = collection;
    }
        public void setText(PText text)
{
    this.text = text;
}
    public void paint(PPaintContext paintcontext)
    {
        Graphics2D g2 = paintcontext.getGraphics();

        //niet ingezoomd
        if(paintcontext.getScale() <= 0.2)
            g2.setPaint(Color.BLACK);

        //half ingezoomd
        if(paintcontext.getScale() > 0.2 && paintcontext.getScale() < 0.7)
        {

            g2.setPaint(Color.BLACK);

        }

        //volledig ingezoomd
        if(paintcontext.getScale() > 0.7)
        {
            g2.setPaint(Color.RED);
            g2.fill(getRectangle());
            g2.setPaint(Color.BLACK);
            g2.draw(getRectangle());
        }
    }
}

现在，我想我可以像这样更改文本: text.setText("Tester");但它不起作用，例如，当 settext 然后将节点添加到集合时，它会在当前文本上显示一个巨大的错误......

有人可以帮我吗？

亲切的问候，

Answer 1

考虑将整个示例发布为 SSCCE , 看起来代码的某些部分丢失了。不清楚您实际如何执行 setText .

组合现有节点并监听从相机触发的事件可能更容易。考虑以下示例，该示例绘制一个矩形，其中包含一些根据缩放级别更新的文本:

import java.awt.Color;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;

import edu.umd.cs.piccolo.PCamera;
import edu.umd.cs.piccolo.nodes.PPath;
import edu.umd.cs.piccolo.nodes.PText;
import edu.umd.cs.piccolo.util.PPaintContext;
import edu.umd.cs.piccolox.PFrame;

public class TestRectZoom extends PFrame {
    public TestRectZoom() {
        super("TestRectZoom", false, null);
    }

    public void initialize() {
        getCanvas().setInteractingRenderQuality(
                PPaintContext.HIGH_QUALITY_RENDERING);
        getCanvas().setDefaultRenderQuality(
                PPaintContext.HIGH_QUALITY_RENDERING);
        getCanvas().setAnimatingRenderQuality(
                PPaintContext.HIGH_QUALITY_RENDERING);

        final PPath rect = PPath.createRectangle(100, 100, 200, 200);
        rect.setPaint(Color.GREEN);
        getCanvas().getLayer().addChild(rect);

        final PText text = new PText(getZoomLevelString());
        rect.addChild(text);

        text.centerFullBoundsOnPoint(rect.getBounds().getCenterX(), rect
                .getBounds().getCenterY());

        getCanvas().getCamera().addPropertyChangeListener(
                PCamera.PROPERTY_VIEW_TRANSFORM, new PropertyChangeListener() {
                    public void propertyChange(final PropertyChangeEvent evt) {
                        text.setText(getZoomLevelString());

                        if (getCanvas().getCamera().getViewScale() > 0.9) {
                            rect.setPaint(Color.GREEN);
                        } else {
                            rect.setPaint(Color.RED);
                        }
                    }
                });
    }

    private String getZoomLevelString() {
        return "Zoom level:"
                + String.format("%.2f", getCanvas().getCamera().getViewScale());
    }

    public static void main(final String[] args) {
        new TestRectZoom();
    }
}

结果如下所示: