Piccolo 可缩放界面，缩放时如何更改文本

Question

我正在尝试使用一些 Piccolo 来创建可缩放的界面。

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

我在初始化时已经这样做了：

//
        //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);

用整个节点集合和 PText 作为成员变量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 settext 然后将节点添加到集合然后它显示在当前文本上并出现巨大错误......

有人可以帮帮我吗？

亲切的问候，

Answer 1

考虑将整个示例发布为SSCCE，看起来缺少某些代码部分。目前尚不清楚您如何实际执行setText。

组合现有节点并侦听从相机触发的事件可能更容易。考虑以下示例，该示例使用一些文本绘制一个矩形，该文本会根据缩放级别进行更新：

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();
    }
}

结果是这样的：

Answer 2

您正在寻找 Piccolo Patterns 页面上可用的语义缩放。 模式 17：语义缩放

http://www.piccolo2d.org/learn/patterns.html

Answer 3

我解决了 Aqua 建议的问题。