mytextbox.java

基于j2me的高等代数计算工具

package edu.neu.aatk.textbox;

import javax.microedition.lcdui.Font;
import javax.microedition.lcdui.Graphics;

public class MyTextBox {
	public static final int maxLength = 2;
	public static final int WIDTH = 24;
	public static final int HEIGHT = 18;
	private int length = 0;
	public int pos = 0;
	
	private StringBuffer numString = new StringBuffer("");
	private int num;
	
	private int xPos;
	private int yPos;
	
	public MyTextBox(int xPos, int yPos) {
		this.xPos = xPos;
		this.yPos = yPos;
	}
	
	public void drawTextBox(Graphics g) {
		g.setColor(0, 0, 0);
		g.drawRect(xPos, yPos, WIDTH, HEIGHT);
	}
	
	public void insert(Graphics g, int keyCode) throws Exception {
		Font font = Font.getFont(Font.FACE_PROPORTIONAL, Font.STYLE_PLAIN, 
				Font.SIZE_LARGE);
		g.setFont(font);

		if(++ length <= 2) {
			numString.append(keyCode - 48);
			g.drawString(numString.toString(), 
					xPos + 4, yPos - 1, 
					Graphics.TOP | Graphics.LEFT);
			pos ++;
		} 
		else {
			g.drawString(numString.toString(), 
					xPos + 4, yPos - 1, 
					Graphics.TOP | Graphics.LEFT);
			throw new Exception("位数不得大于2");
		}
	}
	
	public void delete() {
		numString.delete(0, numString.length());
		length = 0;
		pos  = 0;
	}
	
	public int getNumber() {
		num = Integer.parseInt(numString.toString());
		return num;
	}
	
	public void focused(Graphics g) {
		g.setColor(255, 0, 0);
		g.drawRect(xPos, yPos, 24, 18);
		g.setColor(0, 0, 0);
		g.drawString(numString.toString(), 
				xPos + 4, yPos - 1, 
				Graphics.TOP | Graphics.LEFT);
	}
	
	public void drawString(Graphics g) {
		g.drawString(numString.toString(), 
				xPos + 4, yPos - 1, 
				Graphics.TOP | Graphics.LEFT);
	}
}