如何在多边形上显示浮动工具提示文本 [英] How to display floating tool tip text on a polygon
问题描述
我已经编写了Java代码在图像上绘制多边形.当我将光标放在多边形内时,它会显示"Inside"(内),否则会显示"Outside"(外).因此,检测多边形内部的点工作正常.
I have written a Java code to draw a polygon on an image. When I put my cursor inside the polygon it prints "Inside" otherwise "Outside". So the detection of the points inside the polygon is working fine.
但是我想在多边形内部实现setToolTipText
的效果,即,当鼠标悬停在多边形内部时,它将显示浮动文本内部".
But I want to implement the effect of setToolTipText
inside the polygon i.e. at the time of mouse hover inside the polygon, it will show the floating text "Inside".
类似于此图片中的效果:
Similar to the effect in this image:
http://www.java2s.com/Code/Java/Swing-JFC/WorkingwithTooltipText.htm
为了达到预期的效果,以下代码中需要进行哪些最小的更改?
What are the minimal changes to be made in the following code to get the desired effect?
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.border.*;
import java.awt.image.*;
import java.awt.Graphics.*;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Point;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionAdapter;
class page1 extends JFrame implements MouseListener,MouseMotionListener ,ActionListener
{
JFrame f;
JLabel l;
JPanel p1;
ImageIcon ii;
Image img;
int height;
int width;
Container c;
int pixels[];
PixelGrabber pg;
JPanel panel;
Graphics2D gg;
Polygon pp1=new Polygon();
boolean startHovercurrent,startHoverprev=false;
page1()
{
f=new JFrame("Sample Page");
ii=new ImageIcon("sample.jpg");
img=ii.getImage();
height=ii.getIconHeight();
width=ii.getIconWidth();
pixels=new int[ii.getIconWidth()*ii.getIconHeight()];
pg=new PixelGrabber(img,0,0,ii.getIconWidth(),ii.getIconHeight(),pixels,0,ii.getIconWidth());
try
{
pg.grabPixels();
}
catch(InterruptedException k)
{
}
//add points of polygon
pp1.addPoint(300,300);
pp1.addPoint(380,300);
pp1.addPoint(380,220);
pp1.addPoint(300,220);
l=new JLabel(ii,JLabel.CENTER);
c=f.getContentPane();
JDesktopPane desk = new JDesktopPane();
JInternalFrame p = new JInternalFrame("Image Frame",false, false, true, false);
JScrollPane scroll = new JScrollPane(l);
p.setContentPane(scroll);
p.setBounds(0, 0, 740, 600);
desk.add(p);
p.setVisible(true);
l.addMouseListener(this);
l.addMouseMotionListener(this);
c.add(desk, BorderLayout.CENTER);
f.setSize(1024,738);
f.setVisible(true);
}
public static void main(String args[])
{
new page1();
}
public void mouseClicked(MouseEvent me)
{
}
public void mouseEntered(MouseEvent me)
{
}
public void mouseExited(MouseEvent me)
{
}
public void mousePressed(MouseEvent me)
{
}
public void mouseReleased(MouseEvent me)
{
}
public void mouseMoved(MouseEvent me)
{
boolean contain1;
int mx,my;
gg=(Graphics2D)l.getGraphics();
gg.setColor(new Color(255,0,0) );
gg.fillPolygon(pp1);
mx = me.getX();
my = me.getY();
//check if mouse cursor is inside polygon or not
// do not print anything if next cursor position is in same state
contain1=pp1.contains(mx,my);
if (contain1) {
startHovercurrent = true;
if(startHovercurrent!=startHoverprev)
System.out.println("Inside");
startHoverprev=startHovercurrent;
}
else {
startHovercurrent = false;
if(startHovercurrent!=startHoverprev)
System.out.println("Outside");
startHoverprev=startHovercurrent;
}
}
public void mouseDragged(MouseEvent me)
{
}
public void actionPerformed(ActionEvent ae)
{
}
}
推荐答案
对于此用法, JComponent
.此 answer 概述了JMapViewer
和ChartPanel
的方法.在下面的示例中,getToolTipText()
仅返回contains()
触发鼠标事件的任何Shape
的名称.为了进行比较,窗口底部的JLabel
通过setToolTipText()
获得了常规的提示.
For this usage, How to Use Tool Tips suggests overriding the getToolTipText()
method of the enclosing JComponent
. This answer outlines the approach for JMapViewer
and ChartPanel
. In the example below, getToolTipText()
simply returns the name of any Shape
that contains()
the triggering mouse event. For comparison, the JLabel
at window's bottom gets a conventional too tip via setToolTipText()
.
import java.awt.BasicStroke;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Polygon;
import java.awt.Shape;
import java.awt.event.MouseEvent;
import java.awt.geom.Ellipse2D;
import java.util.ArrayList;
import java.util.List;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.ToolTipManager;
/**
* @see https://stackoverflow.com/a/53609066/230513
* @see https://stackoverflow.com/a/25944439/230513
*/
public class ShapeToolTip {
private static class ShapePanel extends JPanel {
private final List<Shape> list = new ArrayList<>();
public ShapePanel() {
Polygon p = new Polygon();
p.addPoint(500, 100);
p.addPoint(500, 400);
p.addPoint(200, 400);
list.add(p);
list.add(new Ellipse2D.Double(100, 100, 200, 200));
ToolTipManager.sharedInstance().registerComponent(this);
}
@Override
public String getToolTipText(MouseEvent e) {
for (Shape shape : list) {
if (shape.contains(e.getX(), e.getY())) {
return shape.getClass().getName();
}
}
return "Outside";
}
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.setColor(Color.blue);
Graphics2D g2d = (Graphics2D) g;
g2d.setStroke(new BasicStroke(2));
for (Shape shape : list) {
g2d.draw(shape);
}
}
@Override
public Dimension getPreferredSize() {
return new Dimension(640, 480);
}
}
private void display() {
JFrame f = new JFrame("ShapeToolTip");
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.add(new ShapePanel());
JLabel title = new JLabel("Shape Tool Tip", JLabel.CENTER);
title.setToolTipText("Title");
title.setFont(title.getFont().deriveFont(Font.BOLD, 24));
f.add(title, BorderLayout.SOUTH);
f.pack();
f.setLocationRelativeTo(null);
f.setVisible(true);
}
public static void main(String[] args) {
EventQueue.invokeLater(new ShapeToolTip()::display);
}
}
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