Java JTextComponent setMandatoryBorder(JTextComponent comp)

Description

Sets the text component's border to use a new border that shall indicate that the component's content is mandatory.

Note: The component foreground and border colors are managed by the look&feel implementation.

License

Open Source License

Parameter

Parameter	Description
comp	the component that gets a new border

Declaration

public static void setMandatoryBorder(JTextComponent comp)

Method Source Code


//package com.java2s;
import java.awt.Color;

import java.awt.Container;

import javax.swing.*;
import javax.swing.border.Border;
import javax.swing.border.CompoundBorder;
import javax.swing.border.LineBorder;

import javax.swing.plaf.basic.BasicBorders;
import javax.swing.text.JTextComponent;

public class Main {
    private static final Color MANDATORY_FOREGROUND = new Color(70, 70, 210);
    /**/*from w  ww.j a va  2  s  . c o  m*/
     * Holds a cached Border that is used to indicate mandatory text components.
     * It will be lazily created in method {@link #getMandatoryBorder()}.
     * 
     * @see #getMandatoryBorder()
     * @see #setMandatoryBorder(JTextComponent)
     */
    private static Border mandatoryBorder;

    /**
     * Sets the text component's border to use a new border that shall indicate
     * that the component's content is mandatory.<p>
     * 
     * <strong>Note:</strong> The component foreground and border colors are 
     * managed by the look&amp;feel implementation. Many l&amp;fs will honor a
     * custom foreground color and custom border configuration. However, some 
     * l&amp;fs may ignore these custom settings. It is recommended to check
     * the appearance in all l&amp;fs available in an application.
     * 
     * @param comp   the component that gets a new border
     * 
     * @see #setMandatoryBackground(JTextComponent)
     * @see #getMandatoryBorder()
     */
    public static void setMandatoryBorder(JTextComponent comp) {
        Container parent = comp.getParent();
        if (parent instanceof JViewport) {
            Container grandpa = parent.getParent();
            if (grandpa instanceof JScrollPane) {
                ((JScrollPane) grandpa).setBorder(getMandatoryBorder());
                return;
            }
        }
        comp.setBorder(getMandatoryBorder());
    }

    /**
     * Lazily creates and returns a {@link Border} instance that is used
     * to indicate that a component's content is mandatory.
     * 
     * @return a <code>Border</code> that is used to indicate that 
     *     a component's content is mandatory
     */
    public static Border getMandatoryBorder() {
        if (mandatoryBorder == null) {
            mandatoryBorder = new CompoundBorder(new LineBorder(getMandatoryForeground()),
                    new BasicBorders.MarginBorder());
        }
        return mandatoryBorder;
    }

    /**
     * Returns a default foreground color that can be used as the component 
     * foreground for components with mandatory content. Typically this
     * color will be used with instances of {@link JTextComponent}.<p>
     * 
     * <strong>Note:</strong> The component foreground and border colors are 
     * managed by the look&amp;feel implementation. Many l&amp;fs will honor a
     * custom foreground color and custom border configuration. However, some 
     * l&amp;fs may ignore these custom settings. It is recommended to check 
     * the appearance in all l&amp;fs available in an application.
     * 
     * @return a foreground color useful for components with mandatory content
     * 
     * @see #getMandatoryBackground()
     * @see #getMandatoryBorder()
     */
    public static Color getMandatoryForeground() {
        return MANDATORY_FOREGROUND;
    }
}