TextBox.java

package javax.microedition.lcdui;

/**
 * 
 * @author Andre Nijholt
 */
public class TextBox extends Screen {	
	private final char[][] keyboard = {
			{'q', 'w', 'e', 'r', 't', 'y', 'u', 'i', 'o', 'p'},
			{'a', 's', 'd', 'f', 'g', 'h', 'j', 'k', 'l', 8},
			{5, 'z', 'x', 'c', 'v', 'b', 'n', 'm', ',', 13},
			{' ', ' ', ' ', ' ', ' ', ' ', '-', '!', '.', ' '},
			{'Q', 'W', 'E', 'R', 'T', 'Y', 'U', 'I', 'O', 'P'},
			{'A', 'S', 'D', 'F', 'G', 'H', 'J', 'K', 'L', 8},
			{5, 'Z', 'X', 'C', 'V', 'B', 'N', 'M', ';', 13},
			{' ', ' ', ' ', ' ', ' ', ' ', '-', '!', '.', ' '},
			{'(', ')', '"', '+', '*', '1', '2', '3', '@', '_'},
			{'<', '>', '\'', '-', '/', '4', '5', '6', '#', 8},
			{'[', ']', '^', '|', '=', '7', '8', '9', '~', 13},
			{' ', ' ', ' ', ' ', ' ', ' ', '0', '%', '&', '$'},
	};

	private final Image digits = new Image(8, 8, new byte[] {
		(byte) 0x02, (byte) 0x1f, (byte) 0x64, (byte) 0x52, 
		(byte) 0x4c, (byte) 0xa8, (byte) 0xa8, (byte) 0x50});
	private final Image chars = new Image(8, 8, new byte[] {
		(byte) 0x0e, (byte) 0x05, (byte) 0x0e, (byte) 0x7c, 
		(byte) 0x54, (byte) 0x68, (byte) 0x90, (byte) 0x90});

	private String text;
	private int maxSize;
	private int constraints;
	
	private char[] inputText = new char[16];
	private int inputIdx = 0;
	private int kSel;
	private int xSel;
	private int ySel;
	
	public TextBox(String title, String text, int maxSize, int constraints) {
		this.title = title;
		this.text = text;
		this.maxSize = maxSize;
		this.constraints = constraints;
	}
	
	public void setText(String text) {
		this.text = text;

		char[] caText = text.toCharArray();
		for (int i = 0; (i < caText.length) && (i < inputText.length); i++) {
			inputText[i] = caText[i];
		}
		inputIdx = caText.length;
	}
	
	public String getText() {
		return text;
	}
	
	public void setMaxSize(int maxSize) {
		this.maxSize = maxSize;
	}
	
	public void setConstraints(int constraints) {
		this.constraints = constraints;
	}

	protected void keyPressed(int keyCode) {
		if (keyCode == KEY_RIGHT) {
			xSel = (xSel + 1) % 10;
			repaint();
		} else if (keyCode == KEY_LEFT) {
			xSel = (xSel == 0) ? 9 : (xSel - 1);
			repaint();
		} else if (keyCode == KEY_BACK) {
			ySel = (ySel + 1) % 4;
			repaint();
		} else if (keyCode == KEY_ENTER) {
			if ((xSel == 0) && (ySel == 2) && ((kSel == 0) || (kSel == 4))) {
				kSel = (kSel == 4) ? 0 : 4;
			} else if ((xSel == 0) && (ySel == 3)) {
				kSel = (kSel == 8) ? 0 : 8;
			} else if ((xSel == 9) && (ySel == 1)) {
				// Backspace pressed
				if (inputIdx > 0) {
					inputText[--inputIdx] = '\0';
				}
			} else if ((xSel == 9) && (ySel == 2)) {
				// Enter pressed: store string and return
				text = new String(inputText, 0, inputIdx);
				
				// Reset input text
				for (int i = 0; i < inputText.length; i++) {
					inputText[i] = '\0';
				}
				inputIdx = 0;
				
				for (int i = 0; i < commands.size(); i++) {
					callCommandListener();
				}
			} else if (inputIdx < maxSize) {
				inputText[inputIdx++] = keyboard[kSel + ySel][xSel];
				if (!checkConstraints()) {
					// Text does not match constraints: remove new char
					inputText[--inputIdx] = '\0';
				}
			}
			repaint(); 				
		}
	}
	
	public void paint(Graphics g) {
		int line = Display.CHAR_HEIGHT;
		int ch = Display.CHAR_WIDTH;
		if (title != null) {
			g.drawString(title, 0, 1*line);
		}
		
		// Draw input string per character
		for (int i = 0; (i < inputIdx) && (inputText[i] > '\0'); i++) {
			g.drawChar(inputText[i], (i * ch), 2*line, false);
		}
		
		// Draw keyboard frame
		g.drawRect(0, 31, 99, 32);
		g.drawLine(0, 39, 100, 39);
		g.drawLine(0, 47, 100, 47);
		g.drawLine(0, 55, 100, 55);
		g.drawLine(9, 32, 10, 99);
		g.drawLine(20, 32, 20, 99);
		g.drawLine(30, 32, 30, 99);
		g.drawLine(40, 32, 40, 99);
		g.drawLine(50, 32, 50, 99);
		g.drawLine(60, 32, 60, 99);
		g.drawLine(70, 32, 70, 99);
		g.drawLine(80, 32, 80, 99);
		g.drawLine(90, 32, 90, 99);

		// Draw keyboard selection
		for (int x = 0; x < 10; x++) {
			for (int y = 0; y < 4; y++) {
				g.drawChar(keyboard[kSel + y][x], (x * 10) + 2, (y + 4)*line, ((x == xSel) && (y == ySel)));
			}
		}
		
		// Draw character / digit switch image
		g.drawImage((kSel == 8) ? chars : digits, 1, 56, (xSel == 0) && (ySel == 3));
	}
	
	private boolean checkConstraints() {
		// TODO: Check constraints of current input
		if (constraints == TextField.ANY) {
			return true;
		}
		
		return false;
	}
}