customfieldcomposer.java

开发j2me 手机程序必须的用到的。文件较小

package com.jmobilecore.ui;

import com.jmobilecore.ui.core.AbstractComposer;

import javax.microedition.lcdui.Font;

abstract public class CustomFieldComposer implements AbstractComposer {

    protected TextBlockComposer[] textBlocks;
    protected int curBlock = 0;

    public CustomFieldComposer(TextBlockComposer[] textBlocks) {
        this.textBlocks = textBlocks;
    }

    public void clear() {
        for (int i = 0; i < textBlocks.length; i++) {
            textBlocks[i].clear();
        }
    }

    /**
     * Get maximum lenght of the text which can be entered in TextFieldComposer
     *
     * @return maxSize max length of the text
     */
    public int getMaxSize() {

        int size = 0;
        for (int i = 0; i < textBlocks.length; i++) {
            size += textBlocks[i].getMaxSize();
        }
        return size;
    }

    /**
     * Moves the caret one position left
     *
     * @return <code>true</code> if the moving is possible/done, <code>false</code> otherwise
     */
    public boolean caretLeft() {
        if (textBlocks[curBlock].caretLeft()) {
            if (textBlocks[curBlock].getCaretPosition() >= 0) {
                return true;
            }
        }
        boolean isComplete = textBlocks[curBlock].isComplete();
        if (!isComplete) return true;
        if (curBlock == 0) return true;
        curBlock--;
        return textBlocks[curBlock].setCaretPosition(textBlocks[curBlock].getText().length() - 1);
    }

    /**
     * Moves the caret one position right
     *
     * @return <code>true</code> if the moving is possible/done, <code>false</code> otherwise
     */
    public boolean caretRight() {
//        if (curBlock<0 && curBlock>=textBlocks.length) return false;
        if (textBlocks[curBlock].caretRight()) {
            if (textBlocks[curBlock].getCaretPosition() < textBlocks[curBlock].getMaxSize()) {
                return true;
            }
        }
        boolean isComplete = textBlocks[curBlock].isComplete();
        if (!isComplete) return true;
        if (curBlock == textBlocks.length - 1) return true;
        curBlock++;
        return textBlocks[curBlock].setCaretPosition(0);
    }

    /**
     * Deletes previous symbol, moves cursor one position left
     *
     * @return <code>true</code> if the delete and moving is possible/done, <code>false</code> otherwise
     */
    public boolean backspace() {

        if (!caretLeft()) return false;
        return deleteChar();
    }

    /**
     * Deletes current symbol
     *
     * @return <code>true</code> if the delete possible/done, <code>false</code> otherwise
     */
    public boolean deleteChar() {

        return textBlocks[curBlock].deleteChar();
    }

    /**
     * Adds new symbol or replaces the current one
     *
     * @param ch         new symbol
     * @param insertMode if <code>true</code> then new symbol will be added, otherwise the current symbol
     *                   will be replaced
     * @return <code>true</code> if the add/replace is possible, <code>false</code> otherwise
     */
    public boolean addChar(char ch, boolean insertMode) {

        return textBlocks[curBlock].addChar(ch, insertMode);
    }

    /**
     * Returns the text that is presented by this text component.
     */
    public char[] getChars() {

        return getText().toCharArray();
    }

    /**
     * Returns the text that is presented by this text component.
     */
    public String getText() {

        StringBuffer rslt = new StringBuffer();
        for (int i = 0; i < textBlocks.length; i++) {
            rslt.append(textBlocks[i].getChars());
        }
        return new String(rslt);
    }

    /**
     * Returns the cursor offset (in pixels) for the composed string
     *
     * @param font     the current font.
     * @param echoChar the echo character, not used if equal to <code>0</code>
     */
    public int getCursorOffset(Font font, char echoChar) {

        char[] text = getChars();
        int caretPosition = getCaretPosition();
        int offset;
        if (echoChar == 0) {
            offset = font.charsWidth(text, 0, caretPosition);
        } else {
            offset = font.charWidth(echoChar) * caretPosition;
        }
        return (offset < 0) ? 0 : offset;
    }

    public int getCurrentLength() {

        int len = 0;
        for (int i = 0; i < textBlocks.length; i++) {
            len += textBlocks[i].getCurrentLength();
        }
        return len;
    }

    public int getCaretPosition() {
        int caretPosition = textBlocks[curBlock].getCaretPosition();
        for (int i = 0; i < curBlock; i++) {
            caretPosition += textBlocks[i].getCurrentLength();
        }
        return caretPosition;
    }

    public int getCurrentBlock() {
        return curBlock;
    }

    public boolean setCaretPosition(int caretPosition) {

        if (caretPosition < 0) {
            return false;
        }
        int cp = caretPosition;
        int cl;
        for (int i = 0; i < textBlocks.length; i++) {
            cl = textBlocks[i].getCurrentLength();
            if (cp < cl) {
                textBlocks[i].setCaretPosition(cp);
                curBlock = i;
                return true;
            }
            cp -= cl;
        }
        return false;
    }

    public boolean isComplete() {

        for (int i = 0; i < textBlocks.length; i++) {
            if (!textBlocks[i].isComplete()) {
                return false;
            }
        }
        return true;
    }

    /**
     * Default destructor. Helps VM to perform garbage collection
     */
    public void destructor() {
        for (int i = 0; i < textBlocks.length; i++) {
            textBlocks[i] = null;
        }
        textBlocks = null;
    }
}