Java 在乐谱软件中向JPanel添加图形的正确方法
我一直在开发一个记谱软件,我想用它来训练我的音乐学生的视觉阅读能力 我想知道我是否采取了正确的方法,或者是否有更好的方法 我已经使用Unicode和支持音乐符号的字体制作了谱号、音符和staff对象,代码如下:Java 在乐谱软件中向JPanel添加图形的正确方法,java,swing,repaint,Java,Swing,Repaint,我一直在开发一个记谱软件,我想用它来训练我的音乐学生的视觉阅读能力 我想知道我是否采取了正确的方法,或者是否有更好的方法 我已经使用Unicode和支持音乐符号的字体制作了谱号、音符和staff对象,代码如下: public static void spaceStaff(Graphics g){ Graphics2D g2 = (Graphics2D) g; g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, Renderin
public static void spaceStaff(Graphics g){
Graphics2D g2 = (Graphics2D) g;
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
Font font = new Font("Bravura", Font.PLAIN, 32);
g2.setFont(font);
g2.drawString("\uD834\uDD1A", note.spacing-2, staffDistance);
note.spacing = note.spacing + 16;
}
然后我有一个名为Surface的类,它将注释绘制到JPanel上:
public class Surface extends JPanel {
@Override
public void paintComponent(Graphics g){
super.paintComponent(g);
staff.spaceStaff(g);
clef.drawGclef(g);//not given in example code above
note.drawCrotchet(g, note.B1);//not given in example code above
}
}
我正在使用此代码启动应用程序并显示音符:
public class SightreadHelper extends JFrame {
public SightreadHelper(){
initUI();
}
private void initUI() {
JButton button = new JButton("add notes"); //explanation for this button below
button.setSize(150, 75);
button.setVisible(true);
add( button );
button.addActionListener( new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
repaint();//this doesn't work as I expect: explanation below
}
});
Surface srf = new Surface();
add(new Surface());
setSize(700, 1000);
setLocationRelativeTo(null);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
SightreadHelper srh = new SightreadHelper();
srh.setVisible(true);
}
});
}
}
该按钮应该在现有注释的末尾添加注释,但它没有
我是否使用正确的程序来做我想做的事情?非常感谢你的帮助。
我看到了这个问题,但它对我没有帮助:一般来说,您的方法可能有效,但如果您倾向于将其应用到应用程序中,这是一种简单结构化的方法来正确工作。这里缺少数据模型。软件直接绘制注释,而不使用表示内部状态的模型 您应该看看抽象模式。首先开发一个数据模型,它与呈现注释无关 然后,开始为单个元素(例如注释)进行可视化。您将根据数据模型告诉您的内容在面板中组合组件并进行渲染。这就是在doPaintComponent方法中应该执行的操作 单击“添加注释”按钮时,应执行以下步骤:
我知道答案在短期内可能对您没有帮助,但我相信在试图让代码以某种方式运行之前,最好先了解UI开发的概念 可视化乐谱的类,它应该嵌入到应用程序中,而不是在其上启动帧。这只是为了演示MVC编码模式。 可视化严格地描述了模型(NoteSequence)所说的内容
package com.musicsheet;
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
public class MusicSheetComponent extends JPanel implements PropertyChangeListener {
private NoteSequence noteSequence;
public MusicSheetComponent(NoteSequence noteSequence) {
this.noteSequence = noteSequence;
this.noteSequence.addNoteSequenceChangedListener(this);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> {
JFrame f = new JFrame();
NoteSequence noteSequence = new NoteSequence(); // the model
f.setLayout(new BorderLayout()); // how should the screen be layouted
f.add(new MusicSheetComponent(noteSequence), BorderLayout.CENTER); // the sheet component is the view, it renders whatever the model
// tells
f.add(new JButton(new AbstractAction("Add note") {
@Override
public void actionPerformed(ActionEvent e) {
noteSequence.addNote(new NoteSequence.Note((int)(Math.random()*5))); // add a note on a random line
}
}), BorderLayout.SOUTH);
f.setSize(320, 240);
f.setVisible(true);
});
}
@Override
protected void paintComponent(Graphics g2d) {
super.paintComponent(g2d);
Graphics2D g = (Graphics2D) g2d; // graphics2d has more functions
int w = getWidth();
int h = getHeight();
int lines = 5;
int spacing = h / lines;
paintSheetBackground(g, w, h, spacing);
drawNotes(g, spacing);
}
private void paintSheetBackground(Graphics2D g, int w, int h, int spacing) {
g.setColor(Color.white);
g.fillRect(0, 0, w, h);
g.setColor(Color.black);
for (int i = 0; i < 5; i++) {
final int y2 = i * spacing;
g.drawLine(0, y2, w, y2);
}
}
private void drawNotes(Graphics2D g, int heigtSpacing) {
int xSpacing = 30;
int x = 0;
for (NoteSequence.Note note : noteSequence.getNotes()) {
int y = (int) (note.getLine()*heigtSpacing);
g.fillOval(x, y-3, 7, 6); // -3 because note should sit on line
x+= xSpacing;
}
}
@Override
public void propertyChange(PropertyChangeEvent evt) {
if (NoteSequence.PROP_NOTE_ADDED.equals(evt.getPropertyName()) || NoteSequence.PROP_NOTE_REMOVED.equals(evt.getPropertyName())) {
repaint();
}
}
}
package com.musicsheet;
导入javax.swing.*;
导入java.awt.*;
导入java.awt.event.ActionEvent;
导入java.beans.PropertyChangeEvent;
导入java.beans.PropertyChangeListener;
公共类MusicSheetComponent扩展JPanel实现PropertyChangeListener{
私有记事本顺序记事本顺序;
公共音乐表组件(NoteSequence NoteSequence){
this.noteSequence=noteSequence;
this.noteSequence.addNoteSequenceChangedListener(this);
}
公共静态void main(字符串[]args){
SwingUtilities.invokeLater(()->{
JFrame f=新的JFrame();
NoteSequence NoteSequence=新的NoteSequence();//模型
f、 setLayout(newborderlayout());//屏幕应该如何布局
f、 添加(新的MusicSheetComponent(noteSequence),BorderLayout.CENTER);//图纸组件是视图,它呈现模型中的任何内容
//告诉
f、 添加(新JButton)(新抽象操作(“添加注释”){
@凌驾
已执行的公共无效操作(操作事件e){
noteSequence.addNote(新的noteSequence.Note((int)(Math.random()*5));//在随机行上添加注释
}
}),边界布局(南部);
f、 设置大小(320240);
f、 setVisible(真);
});
}
@凌驾
受保护的组件(图形g2d){
超级油漆组件(g2d);
Graphics2D g=(Graphics2D)g2d;//Graphics2D具有更多功能
int w=getWidth();
inth=getHeight();
整数行=5;
int间距=h/行;
油漆板背景(g、w、h、间距);
纸币(g,间距);
}
私有void paintSheetBackground(图形2D g、int w、int h、int间距){
g、 setColor(Color.white);
g、 fillRect(0,0,w,h);
g、 设置颜色(颜色为黑色);
对于(int i=0;i<5;i++){
最终int y2=i*间距;
g、 抽绳(0,y2,w,y2);
}
}
专用空心图纸(图形2D g,内部高度间距){
int xSpacing=30;
int x=0;
for(NoteSequence.Note:NoteSequence.getNotes()){
int y=(int)(注意.getLine()*高度间隔);
g、 填充椭圆(x,y-3,7,6);//-3,因为音符应该在直线上
x+=xSpacing;
}
}
@凌驾
公共作废属性更改(属性更改事件evt){
if(NoteSequence.PROP_NOTE_ADDED.equals(evt.getPropertyName())| | NoteSequence.PROP_NOTE_REMOVED.equals(evt.getPropertyName()){
重新油漆();
}
}
}
下一步,为乐谱或音符序列建模的类
package com.musicsheet;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import java.beans.PropertyChangeSupport;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
/**
* The model class, that holds all notes.
*/
public class NoteSequence {
public static final String PROP_NOTE_ADDED = "noteAdded";
public static final String PROP_NOTE_REMOVED = "noteRemoved";
private PropertyChangeSupport propertyChangeSupport = new PropertyChangeSupport(this);
private final List<Note> notes = new ArrayList<>();
public List<Note> getNotes() {
return Collections.unmodifiableList(notes);
}
/**
* is called by the UI or a button listener when a note should be added to this music sheet / notesequence
* @param note
*/
public void addNote(Note note) {
this.notes.add(note);
propertyChangeSupport.firePropertyChange(new PropertyChangeEvent(this, PROP_NOTE_ADDED, null, note));
}
public void removeNote(Note note) {
this.notes.remove(note);
propertyChangeSupport.firePropertyChange(new PropertyChangeEvent(this, PROP_NOTE_REMOVED, note, null));
}
void addNoteSequenceChangedListener(PropertyChangeListener listener) {
propertyChangeSupport.addPropertyChangeListener(listener);
}
// not really needed atm
void removeNoteSequenceChangedListener(PropertyChangeListener listener) {
propertyChangeSupport.removePropertyChangeListener(listener);
}
/**
* a single note.
*/
public static class Note {
private float line; // where does the note sit
private float timestampSinceBeginning; // not used, but you have to know WHEN a note is played
// ... more properties, e.g. name, or modifiers or whatever
public Note(float line) { // this is certainly to easy, since notes can sit in between lines,
// i did not try to think deeply into it, to define a better model
this.line = line;
}
public float getLine() {
return line;
}
public float getTimestampSinceBeginning() {
return timestampSinceBeginning;
}
}
}
package com.musicsheet;
导入java.beans.PropertyChangeEvent;
导入java.beans.PropertyChangeListener;
导入java.beans.PropertyChangeSupport;
导入java.util.ArrayList;
导入java.util.Collections;
导入java.util.List;
/**
*模型类,它保存所有注释。
*/
公共类注释序列{
public static final String PROP_NOTE_ADDED=“notepadded”;
公共静态最终字符串属性\u NOTE\u REMOVED=“noteRemoved”;
私有属性更改支持属性更改支持=新属性更改支持(此);
私有最终列表注释=新建ArrayList();
公共列表getNotes(){
返回集合。不可修改列表(备注);
}
/**
*当应将音符添加到此乐谱/音符序列时,由UI或按钮侦听器调用
*@param注释
*/
公共无效添加注释(注释){
本.注释.添加(注释);
firePropertyChange(新的PropertyChangeEvent(此