bankcardfield.java

j2me下的1套UI框架.包含j2me开发中会应用的各种低级组件

package com.jmobilecore.ui;

import com.jmobilecore.ui.core.TextField;
import com.jmobilecore.ui.core.TextComponent;

/**
 * This abstract class displays formatted textfield for entering bank card
 * information (like VISA/MasterCard/AMEX).
 * Blocks of digits are separated by space.
 *
 * @author Igor Shevlyakov - initial implementation
 * @author Greg Gridin - redesign
 */
abstract public class BankCardField extends TextField {

    /**
     * Constructs a new <code>BankCardField</code> field.
     */
    public BankCardField() {
        super(-1, TextComponent.C_NUMERIC);
        composer = initComposer();
        composer.setCaretPosition(0);
    };

    /**
     * Abstract method for initiating bank card field composer.
     * This methods should be defined in inherited classes
     */
    abstract protected CustomFieldComposer initComposer();

    /**
     * Constructs a new <code>BankCardField</code> object of type
     * <code>style</code>
     * with the specified value.
     *
     * @param cardNumber the card number, unformatted, no spaces or dashes
     */
    public BankCardField(String cardNumber) {
        this();
        setText(cardNumber);
    }

    /**
     * Get formatted representation of <code>BankCardField</code> value
     * or <code>null</code> if <code>BankCardField</code> object value is set to null or incomplete
     *
     * @return the <code>String</code> representing bank card number
     */
    public String getFormattedText() {
        if (isValid()) {
            return String.valueOf(getFormattedText(false));
        }
        return null;
    }

    /**
     * Sets the <code>BankCardField</code> field to specified value
     *
     * @param cardNumber the card number, unformatted, no spaces or dashes
     */
    public void setText(String cardNumber) {
        if (validate(cardNumber)) {
            composer.setText(cardNumber);
        }
    }

    /**
     * Tests bank card field value for correctness
     *
     * @return <code>true</code> if the bank card field is valid
     *         <code>false</code> otherwise
     */
    public boolean isValid() {
        return ((CustomFieldComposer) composer).isComplete();
    }

    /**
     * Tests if the specified card valid
     *
     * @param cardNumber bank card number without formatting (spaces, dashes etc.)
     * @return <code>true</code> if the bank card field is valid
     *         <code>false</code> otherwise
     */
    public boolean validate(String cardNumber) {

        if (cardNumber != null) {
            final int FIELD_LEN = ((CustomFieldComposer) composer).getMaxSize();
            if (cardNumber.length() == FIELD_LEN) {
                char curChar;
                for (int i = 0; i < FIELD_LEN; i++) {
                    curChar = cardNumber.charAt(i);
                    if (!(Character.isDigit(curChar))) return false;
                }
                return true;
            }
        }
        return false;
    }
}