[PGI-Bis]

Questo è un pezzo di un esperimento di un pezzo di un editor XML. Tradotto, è niente di niente .

package it.tukano.xml;

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.util.*;

public class XMLEditor extends JComponent implements KeyListener {
	private int caretPosition;
	private ArticleNode root = new ArticleNode();
	private NodeView rootView = new ArticleView();
	private RenderInfo editorInfo = new RenderInfo();

	public XMLEditor() {
		setFocusable(true);
		addKeyListener(this);
		PCData data = new PCData();
		TitleNode node = new TitleNode();
		node.children().add(data);
		data.setParent(node);
		root.insert(node, 0);
	}
	
	public void save() {
		System.out.println(root);
	}
	
	public PCData getTextElement(IntRef offsetHolder) {
		ArrayList<XMLNode> buffer = new ArrayList<XMLNode>();
		buffer.addAll(root.children());
		PCData target = null;
		int textLen = 0;
		for(int i = 0; i < buffer.size(); i++) {
			XMLNode n = buffer.get(i);
			if(n.getName() == Tags.PCDATA) {
				if(caretPosition == 0) return (PCData)n;
				int len = n.toString().length();
				if(caretPosition >= textLen && caretPosition <= textLen + len) {
					target = (PCData)n;
					offsetHolder.value = caretPosition - textLen;
					break;
				}
				textLen += len;
			} else {
				buffer.addAll(n.children());
			}
		}
		return target;
	}
	
	public void insert(XMLNode newNode) {
		IntRef off = new IntRef();
		PCData target = getTextElement(off);
		target.insert(newNode, off.value);
		caretPosition++;
		repaint();
	}
	
	public void keyTyped(KeyEvent e) {
		processCharTyped(e.getKeyChar());
	}
	
	public void keyPressed(KeyEvent e) {
		processKeyPressed(e.getKeyCode());
	}
	
	public void keyReleased(KeyEvent e) {}
	
	private void processCharTyped(char c) {
		if(CharUtil.isValidChar(c)) {
			if(c == '\t') { System.out.println("tabb"); }
			IntRef offset = new IntRef();
			PCData node = getTextElement(offset);
			node.buffer().insert(offset.value, c);
			caretPosition++;
			repaint();
		} else if(c == '\t') {
			System.out.println("tab");
		}
	}
	
	private void processKeyPressed(int code) {
		switch(code) {
			case KeyEvent.VK_TAB:
				System.out.println("tab");
				break;
			case KeyEvent.VK_LEFT:
				if(caretPosition > 0) caretPosition--;
				repaint();
				break;
			case KeyEvent.VK_RIGHT:
				if(caretPosition < editorInfo.textLength) caretPosition++;
				repaint();
				break;
			case KeyEvent.VK_ENTER:
				generateNewNode();
				break;
			case KeyEvent.VK_BACK_SPACE:
				removeCharBefore();
				break;
			case KeyEvent.VK_DELETE:
				removeCharAfter();
				break;
		}
	}
	
	public void paintComponent(Graphics g) {
		g.setColor(Color.WHITE);
		g.fillRect(0, 0, getWidth(), getHeight());
		
		RenderInfo info = new RenderInfo();
		info.graphics = g;
		info.x = 0;
		info.y = 0;
		info.lineWidth = getWidth() - 20;
		info.caretPosition = caretPosition;
		
		g.translate(10, 0);
		rootView.paint(root, info);
		g.translate(-10, 0);
		
		editorInfo = info;
		int h = getPreferredSize().height;
		if(h != editorInfo.y + 20) {
			System.out.println("Reset size");
			setPreferredSize(new Dimension(getWidth(), editorInfo.y + 20));
			Component parent = this;
			while((parent = parent.getParent()) instanceof JViewport == false
				&& parent != null) ;
			if(parent != null) {
				((JViewport)parent).setView(this);
				requestFocusInWindow();
			}
		}
	}
	
	private void generateNewNode() {
		IntRef offset = new IntRef();
		PCData current = getTextElement(offset);
		if(current == null) {
			throw new RuntimeException("Element is not a text one");
		}
		TextNode txt = new TextNode();
		PCData text = new PCData(" ");
		text.setParent(txt);
		txt.children().add(text);
		
		current.insert(txt, offset.value);
		caretPosition++;
		repaint();
	}
	
	private void removeCharAfter() {

	}
	
	private void removeCharBefore() {
		IntRef offset = new IntRef();
		PCData current = getTextElement(offset);
		if(current == null) throw new RuntimeException("Remove: not PCData");
		StringBuilder buffer = current.buffer();
		if(buffer.length() == 0 ||
			(buffer.length() == 1 && buffer.charAt(0) == ' '))
		{
			System.out.println("vuoto");
			current.getParent().removeFromParent();
			caretPosition--;
			repaint();
		} else {
			buffer.deleteCharAt(offset.value - 1);
			caretPosition--;
			repaint();
		}
	}
}

Nel costruttore c'è un "addKeyListener" che riconduce all'argomento di questo thread. Il KeyListener nel codice è "this".

keyTyped intercetta gli eventi di digitazione e passa la palla a processCharTyped il cui scopo è iniettare il carattere nel nodo PCData corrente;

keyPressed intercetta gli eventi di pressione e li passa a processKeyPressed che si occupa di gestire i pulsanti di "controllo";

keyRelesed non fa niente

Il tutto funziona insieme ad altre 23 classi che non incollo per pietà .

Ciao.

Pierluigi.