jtextfield.java

纯java操作系统jnode,安装简单和操作简单的个人使用的Java操作系统

/* class JTextField
 *
 * Copyright (C) 2001  R M Pitman
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

package charvax.swing;

import java.util.Enumeration;
import java.util.Vector;

import charva.awt.Dimension;
import charva.awt.Font;
import charva.awt.Insets;
import charva.awt.Point;
import charva.awt.Toolkit;
import charva.awt.event.AWTEvent;
import charva.awt.event.ActionEvent;
import charva.awt.event.ActionListener;
import charva.awt.event.KeyEvent;
import charva.awt.event.MouseEvent;
import charvax.swing.text.JTextComponent;

/**
 * JTextField is a component that allows the display and editing of a 
 * single line of text.
 * The JTextField class, being a subclass of JComponent, has a setBorder()
 * method which allows an optional Border to be set.
 */
public class JTextField
    extends JTextComponent
{
    /** Construct a text field. The initial string is empty and the
     * number of columns is 10.
     */
    public JTextField()
    {
	this("", 10);
    }

    /** Use this constructor when you want to initialize the value.
     */
    public JTextField(String text_) {
	this(text_, text_.length());
    }

    /** 
     * Use this constructor when you want to leave the text field empty
     * but set its length.
     */
    public JTextField(int length_) {
	this("", length_);
    }

    /**
     * Use this constructor when you want to set both the initial value and the
     * length.
     */
    public JTextField(String text_, int length_) {
	super.setText(text_);
	setColumns(length_);
	super._caretPosition = super._document.length();
	if (super._document.length() > _columns)
	    _offset = super._document.length() - _columns;
	else
	    _offset = 0;
    }

    /** Sets the number of columns in this Textfield, and then invalidates 
     * the layout.
     */
    public void setColumns(int columns_) {
	_columns = columns_;

	StringBuffer padbuf = new StringBuffer();
	for (int i=0; i<_columns; i++)
	    padbuf.append(' ');
	_padding = new String(padbuf);
	super.invalidate();
    }

    /** Return the number of columns in the text field.
     */
    public int getColumns() { return _columns; }

    public void setFont(Font font_)
    {
	_bold = ((font_.getStyle() & Font.BOLD) != 0);
    }


    /** Set the action command
     */
    public void setActionCommand(String cmd_) { _actionCommand = cmd_; }

    /** Get the action command
     */
    public String getActionCommand() { return _actionCommand; }

    /**
     * Return the size of the text field. Overrides the method in the
     * Component superclass.
     */
    public Dimension getSize() {
	Insets insets = super.getInsets();
	return new Dimension(_columns + insets.left + insets.right, 
		1 + insets.top + insets.bottom);
    }

    public int getWidth() { 
	Insets insets = super.getInsets();
	return _columns + insets.left + insets.right; 
    }

    public int getHeight() { 
	Insets insets = super.getInsets();
	return 1 + insets.top + insets.bottom; 
    }

    /** Called by the LayoutManager.
     */
    public Dimension minimumSize() {
	return getSize();
    }

    /** Sets whether this textfield can be edited.
     */
    public void setEditable(boolean editable_)
    {
	super.setEnabled(editable_);
    }

    public boolean isEditable() { return isEnabled(); }

    /**
     * Called by this JTextField's parent container.
     */
    public void draw() {

	/* Draw the border inherited from JComponent, if it exists.
	 */
	super.draw();

	/* If the field is enabled, it is drawn with the UNDERLINE
	 * attribute.  If it is disabled, it is drawn without the
	 * UNDERLINE attribute.
	 */
	int attrib = 0;
	if (super._enabled)
	    attrib |= Toolkit.A_UNDERLINE;

	if (_bold)
	    attrib |= Toolkit.A_BOLD;

	/* Get the absolute origin of this component.
	 */
	Point origin = getLocationOnScreen();
	Insets insets = super.getInsets();
	origin.translate(insets.left, insets.top);

	Toolkit term = Toolkit.getDefaultToolkit();

	int colorpair = getCursesColor();

	term.setCursor(origin);
	term.addString(_padding, attrib, colorpair);
	term.setCursor(origin);

	// Get the displayable portion of the string
	int end;
	if (super.getText().length() > (_offset + _columns))
	    end = _offset + _columns;
	else
	    end = super.getText().length();

	term.addString(
		super.getText().substring(_offset, end).toString(), 
		attrib, colorpair);
	term.setCursor(origin.addOffset(super._caretPosition - _offset, 0));
    }

    /**
     * Process KeyEvents that have been generated by this JTextField.
     */
    public void processKeyEvent(KeyEvent ke_) {

	/* First call all KeyListener objects that may have been registered
	 * for this component. 
	 */
	super.processKeyEvent(ke_);

	/* Check if any of the KeyListeners consumed the KeyEvent.
	 */
	if (ke_.isConsumed())
	    return;

	int key = ke_.getKeyCode();
	if (key == '\t') {
	    getParent().nextFocus();
	    return;
	}
	else if (key == KeyEvent.VK_BACK_TAB) {
	    getParent().previousFocus();
	    return;
	}

	/*
	 */
	if (ke_.isActionKey() == false) {

	    /* If it is a control character, ignore it.
	     * @todo Do something more useful with control chars.
	     */
	    if (key >= ' ') {
		super._document.insert(super._caretPosition, (char ) key);
		super._caretPosition++;
		if (super._caretPosition - _offset > _columns)
		    _offset++;
	    }
	}
	else {

	    /* It is an action key.
	     */
	    if (key == KeyEvent.VK_LEFT && super._caretPosition > 0) {
		super._caretPosition--;
		if (super._caretPosition < _offset)
		    _offset--;
	    }

	    else if (key == KeyEvent.VK_RIGHT && super._caretPosition < super._document.length()) {
		super._caretPosition++;
		if (super._caretPosition - _offset > _columns)
		    _offset++;
	    }

	    else if (key == KeyEvent.VK_BACK_SPACE && super._caretPosition > 0) {
		super._caretPosition--;
		super._document.deleteCharAt(super._caretPosition);
		if (super._caretPosition < _offset)
		    _offset--;
	    }

	    else if (key == KeyEvent.VK_DELETE && 
		    super._caretPosition >= 0 && super._caretPosition < super._document.length()) {
		super._document.deleteCharAt(super._caretPosition);
	    }

	    else if (key == KeyEvent.VK_HOME) {
		super._caretPosition = 0;
		_offset = 0;
	    }

	    else if (key == KeyEvent.VK_END) {
		super._caretPosition = super._document.length();
		if (super._document.length() > _columns)
		    _offset = super._document.length() - _columns;
		else
		    _offset = 0;
	    }

	    /* Post an action event if ENTER was pressed.
	     */
	    else if (key == KeyEvent.VK_ENTER) {
		ActionEvent ae = new ActionEvent(this, _actionCommand);
		Toolkit.getDefaultToolkit().getSystemEventQueue().postEvent(ae);
	    }
	}
	draw();
	super.requestSync();
    }

    /** Process a MouseEvent that was generated by clicking the mouse
     * somewhere inside this JTextField.
     * Clicking the mouse inside the JTextField moves the caret position
     * to where the mouse was clicked.
     */
    public void processMouseEvent(MouseEvent e_) {
	super.processMouseEvent(e_);

	if (e_.getButton() == MouseEvent.BUTTON1 &&
		e_.getModifiers() == MouseEvent.MOUSE_CLICKED &&
		this.isFocusTraversable()) {

	    int x = e_.getX();

	    /* Get the absolute origin of this component.
	     */
	    Point origin = getLocationOnScreen();
	    Insets insets = super.getInsets();
	    origin.translate(insets.left, insets.top);

	    int new_caret = _offset + (x - origin.x);
	    super._caretPosition = 
		    (new_caret < super._document.length()) ?
		    new_caret : super._document.length();
	    repaint();
	}
    }

    /**
     * Set the text that is presented by this JTextField.
     * This method is thread-safe, although most Charva methods are not.
     */
    public synchronized void setText(String text_) {
	super.setText(text_);

	super._caretPosition = super._document.length();
	if (super._document.length() > _columns)
	    _offset = super._document.length() - _columns;
	else
	    _offset = 0;

	/* If this component is already displayed, generate a PaintEvent
	 * and post it onto the queue.
	 */
	super.repaint();
    }

    /**
     * Process events.
     */
    protected void processEvent(AWTEvent evt_) {

	super.processEvent(evt_);

	if (evt_ instanceof ActionEvent)
	    postActionEvent((ActionEvent) evt_);
    }

    /** Invoke all the ActionListener callbacks that may have been registered
     * for this component. 
     */
    public void postActionEvent(ActionEvent ae_) {
	if (_actionListeners != null) {
	    for (Enumeration e = _actionListeners.elements(); 
		    e.hasMoreElements(); ) {

		ActionListener al = (ActionListener) e.nextElement();
		al.actionPerformed(ae_);
	    }
	}
    }

    /**
     * Register an ActionListener object for this component.
     */
    public void addActionListener(ActionListener al_) {
	if (_actionListeners == null)
	    _actionListeners = new Vector();
	_actionListeners.add(al_);
    }

    public void requestFocus() {
	/* Generate the FOCUS_GAINED event.
	 */
	super.requestFocus();

	/* Get the absolute origin of this component.
	 */
	Point origin = getLocationOnScreen();
	Insets insets = super.getInsets();
	origin.translate(insets.left, insets.top);
	Toolkit.getDefaultToolkit().setCursor(
		origin.addOffset(super._caretPosition - _offset, 0));
    }

    /** Returns a String representation of this component.
     */
    public String toString() {
	return "JTextField location=" + getLocation() + 
	    " text=\"" + super._document + "\"" +
	    " actionCommand=\"" + _actionCommand + "\"";
    }

    public void debug(int level_) {
	for (int i=0; i<level_; i++)
	    System.err.print("    ");
	System.err.println("JTextField origin=" + _origin + 
	    " size=" + getSize() + " text=" + super._document);
    }

    //====================================================================
    // INSTANCE VARIABLES

    protected boolean _bold = false;

    protected int _columns;

    /**
     * Index (from the start of the string) of the character displayed
     * in the left corner of the field. This is always 0 if the string 
     * is shorter than the field.
     */
    protected int _offset = 0;

    /** A blank-filled string the same length as the JTextField.
     */
    protected String _padding;

    /** The string that is sent inside an ActionEvent when ENTER is pressed.
     */
    private String _actionCommand = new String("");

    /**
     * A list of ActionListeners registered for this component.
     */
    protected Vector _actionListeners = null;
}