使用Swing组件在Java Swing中创建简单的GUI编辑器 [英] Make a simple GUI editor in Java Swing using Swing components

问题描述

我目前正在一个项目中，我需要一个非常简单的GUI类对象编辑器。该编辑器将是一个画布，可以在上面放置众所周知的GUI小部件。例如，可以在其中放置一个按钮和一个文本字段，在其中移动它们并调整其大小。

I'm currently working on a project in which I need a very simple editor for GUI-like objects. This editor would be a canvas on which well known GUI widgets can be placed. For example one can place a button and a textfield on there, move them around and resize them. No interaction with the widgets themselves is needed.

我一直在尝试通过改编一个非常简单的绘画教程来实现这一点，我认为这样做很容易方式，但是我在画布上绘制自定义形状和文本并拖放这些形状时遇到了很多问题。

I've been trying to accomplish this by adapting a very simple paint tutorial, I thought it would be easy to implement it this way, yet I bump into many problems with drawing custom shapes and text on a canvas and dragging and dropping those shapes.

我想知道是否可以在上面重用真正的Swing小部件JPanel，让用户放置，移动并调整大小。如果是这样，我应该考虑什么？

I was wondering if I could reuse real Swing widgets on a JPanel and let the user place, move around and resize them. If so, what are the things I should look into?

我知道这似乎很少信息，但是老实说我一直在寻找解决方案。

I know this might seem very little information but I'm honestly stuck in searching for a solution.

推荐答案

我想我应该记得Swing的美好时光，并且有一些乐趣可以为您编写一个概念证明。它支持在主面板上添加一个按钮，然后移动并调整一些基本大小。

I thought I should remember the good old Swing days and have a little bit of fun writing you a proof of concept for this. It supports adding a button to the main panel and then move and some basic resize.

这只是概念上的证明，但它已经回答了许多您已经提出的问题有。我在那里添加了一些待办事项，例如，您将知道下一步该怎么做。

It is just a proof of concept, but it answers a lot of the questions you already have. I added a few TODOs there, such as you will know what to do next.

享受...

import java.awt.BorderLayout;
import java.awt.Cursor;
import java.awt.Rectangle;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionAdapter;

import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JToolBar;

public class UIBuilder {
  private static final int NONE = -1;

  private static final int BORDER = 3;

  private JFrame frame = new JFrame("Builder");

  private JToolBar toolbar = new JToolBar();

  private JPanel main = new JPanel();

  private int startX = NONE;

  private int startY = NONE;

  private int prevX = NONE;

  private int prevY = NONE;

  private boolean resize = false;

  public UIBuilder() {
    frame.setBounds(100, 100, 600, 450);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.getContentPane().setLayout(new BorderLayout());
    frame.getContentPane().add(toolbar, BorderLayout.PAGE_START);
    frame.getContentPane().add(main, BorderLayout.CENTER);
    frame.setVisible(true);
    buildToolbox();
    buildMainPanel();
  }

  private void buildToolbox() {
    JButton button = new JButton("Button");
    button.addActionListener(new ActionListener() {
      public void actionPerformed(ActionEvent e) {
        JButton btn = new JButton("Button");
        addComponent(btn);
      }
    });
    toolbar.add(button);
  }

  private void buildMainPanel() {
    main.setLayout(null);
  }

  private void addComponent(JComponent comp) {
    comp.setBounds(10, 10, 80, 24);

    comp.addMouseListener(new MouseAdapter() {
      public void mouseReleased(MouseEvent e) {
        startX = NONE;
        startY = NONE;
        ((JComponent) e.getSource()).setCursor(Cursor.getDefaultCursor());
      }

      public void mousePressed(MouseEvent e) {
        startX = e.getX();
        startY = e.getY();
      }
    });

    comp.addMouseMotionListener(new MouseMotionAdapter() {
      public void mouseMoved(MouseEvent e) {
        JComponent source = (JComponent) e.getSource();
        int x = e.getX();
        int y = e.getY();
        Rectangle bounds = source.getBounds();
        resize = x < BORDER || y < BORDER || Math.abs(bounds.width - x) < BORDER || Math.abs(bounds.height - y) < BORDER;
        if (resize) {
          // TODO: there are a lot of resize cursors here, this is just of proof of concept
          source.setCursor(Cursor.getPredefinedCursor(Cursor.E_RESIZE_CURSOR));
        } else {
          source.setCursor(Cursor.getPredefinedCursor(Cursor.MOVE_CURSOR));
        }
      }

      public void mouseDragged(MouseEvent e) {
        int x = e.getX();
        int y = e.getY();
        if (startX != NONE && startY != NONE) {
          JComponent source = (JComponent) e.getSource();
          Rectangle bounds = source.getBounds();
          int deltaX = x - startX;
          int deltaY = y - startY;
          if (resize) {
            // TODO: handle all resize cases, left, right,...
            source.setSize(Math.max(10, bounds.width + x - prevX), Math.max(10, bounds.height + y - prevY));
          } else {
            source.setLocation(bounds.x + deltaX, bounds.y + deltaY);
          }
          // TODO: make sure you don't resize it as much as it disappears
          // TODO: make sure you don't move it outside the main panel
        } else {
          startX = x;
          startY = y;
        }
        prevX = x;
        prevY = y;
      }
    });
    main.add(comp);
    main.validate();
    main.repaint();
  }

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

}

这篇关于使用Swing组件在Java Swing中创建简单的GUI编辑器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！