放大和缩小jPanel [英] Zoom in and out of jPanel

问题描述

我想知道使用面板的paintComponent进行缩放后，检索鼠标clic位置的最佳方法是什么? (相对于此缩放的位置).

I am wondering what is the best way to retrieve the location of a mouse clic after a zoom was made using paintComponent of a panel? (The location relative to this zoom).

这是缩放代码:

public void paintComponent(Graphics g) {
    super.paintComponent(g);
    Graphics2D g2 = (Graphics2D) g;
    if(zoomer==true){    
        at.scale(zoom,zoom);//at = AffineTransform...
        zoomer=false;
    }
    g2.transform(at);

在我的主类中，我使用鼠标侦听器私有类并重写mouseRelase方法:

In my main class, I use a mouse listener private class and override the mouseRelase method :

 @Override
    public void mouseReleased(MouseEvent e) 
     e.getX();//Location of the mouse on the X axis

我正在绘制不同的形状，例如点.每个点都存储有其像素"位置，因此，如果在X:20和Y:30进行创建，则此点永远不会改变.当我调用paintComponent时，它会缩放得更大或更小.我的问题是，我可以把握这些点在面板上的位置，它可以在一些textFields中为我提供一些有关单击的点的信息.如果面板已放大/缩小，则clic的位置仍然相同，因此，假设我放大了，形状将不会位于x:20和y:30，而是基于比例尺的随机位置.我该如何调整我的老巢位置?

I am drawing different shapes such as dots. Every dot has it's Pixels locations stored so if a create it at X:20 and Y:30 this never changes. When I call paintComponent, it is scaled either bigger or smaller. My problem is, I can clic on the location of these dots on the panel and it gives me some information in some textFields about the dots I clicked on. If the panel has been zoomed in/out, the location of the clic is still the same so let's say I zoom in, the shapes won't be at x:20 and y:30 but at a random location based on the scale. How can I ajust my clic location to this scale?

不确定我是否清楚自己的意思，如果您需要更多信息，请不要犹豫.

Not sure if I am making myselft clear so do not hesitate if you need more information.

谢谢

推荐答案

好吧，我整夜都在工作，终于找到了解决方法.

Alright, I have been working all night long and finally figured out how to do this.

首先，这是当我滚动鼠标滚轮时发生的事情:

First of all here's what happens when I roll the mouse wheel :

 @Override
    public void mouseWheelMoved(MouseWheelEvent e) {

        //Zoom in
        if(e.getWheelRotation()<0){
            mydrawer.setZoomFactor(1.1*mydrawer.getZoomFactor());
            mydrawer.repaint();
        }
        //Zoom out
        if(e.getWheelRotation()>0){
            mydrawer.setZoomFactor(mydrawer.getZoomFactor()/1.1);
            mydrawer.repaint();
        }
    }

setZoomFactor方法执行此操作:

The setZoomFactor method does this :

public void setZoomFactor(double factor){        
    if(factor<this.zoomFactor){
        this.zoomFactor=this.zoomFactor/1.1;
    }
    else{
        this.zoomFactor=factor;
    }
    this.zoomer=true;
}

之后，当我调用repaint()时，我将Graphics2D对象转换为如下所示的缩放比例:

After, when I call repaint() I transform my Graphics2D object to zoom like this :

 @Override
public void paintComponent(Graphics g) {
    super.paintComponent(g);
    Graphics2D g2 = (Graphics2D) g;
    if(zoomer==true){    
        at = new AffineTransform();
        at.scale(zoomFactor,zoomFactor);
        zoomer=false;
        g2.transform(at);
    }
 }

在这一点上，没有什么新的...我的问题是，当我在缩放后单击绘制的对象时，我需要调整相对于缩放系数的clic位置.就我而言，我需要将Y轴的0设置为默认情况下的左下角而不是左上角，这就是为什么我必须根据面板高度反转该值的原因:

At this point, nothing really new... My problem was when I clicked on a drawn objet after zoom, I needed to ajust the clic location relative to the zoom factor. In my case, I needed the 0 of the Y axis to be at the bottom left corner instead of top left by default which is why I had to reverse the value based on the panel height :

 @Override
    public void mouseReleased(MouseEvent e) {
        int myXLocationWithoutZoom = e.getX()*(1/myDrawer.getZoomFactor());
        int myYLocationWithoutZoom = myPanel.getSize().height-((e.getY())*(1/myDrawer.getZoomFactor()));

如果您想出另一种方法来做这件事，或者认为我没有做这件事的好方法，请告诉我.

If you figure out another way to do this or think I did not do it the good way, let me know.

谢谢

这篇关于放大和缩小jPanel的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！