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	/*
	* Copyright (c) 2005, 2011, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation. Oracle designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Oracle in the LICENSE file that accompanied this code.
	*
	* This code 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 General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/
	package sun.swing;

	import java.awt.Container;
	import java.awt.Insets;
	import javax.swing.*;
	import javax.swing.LayoutStyle.ComponentPlacement;
	import javax.swing.border.Border;
	import javax.swing.plaf.UIResource;

	/**
	* An implementation of <code>LayoutStyle</code> that returns 6 for related
	* components, otherwise 12. This class also provides helper methods for
	* subclasses.
	*
	*/
	public class DefaultLayoutStyle extends LayoutStyle {
	private static final DefaultLayoutStyle INSTANCE =
	new DefaultLayoutStyle();

	public static LayoutStyle getInstance() {
	return INSTANCE;
	}

	@Override
	public int getPreferredGap(JComponent component1, JComponent component2,
	ComponentPlacement type, int position, Container parent) {
	if (component1 == null \|\| component2 == null \|\| type == null) {
	throw new NullPointerException();
	}

	checkPosition(position);

	if (type == ComponentPlacement.INDENT &&
	(position == SwingConstants.EAST \|\|
	position == SwingConstants.WEST)) {
	int indent = getIndent(component1, position);
	if (indent > 0) {
	return indent;
	}
	}
	return (type == ComponentPlacement.UNRELATED) ? 12 : 6;
	}

	@Override
	public int getContainerGap(JComponent component, int position,
	Container parent) {
	if (component == null) {
	throw new NullPointerException();
	}
	checkPosition(position);
	return 6;
	}

	/**
	* Returns true if the classes identify a JLabel and a non-JLabel
	* along the horizontal axis.
	*/
	protected boolean isLabelAndNonlabel(JComponent c1, JComponent c2,
	int position) {
	if (position == SwingConstants.EAST \|\|
	position == SwingConstants.WEST) {
	boolean c1Label = (c1 instanceof JLabel);
	boolean c2Label = (c2 instanceof JLabel);
	return ((c1Label \|\| c2Label) && (c1Label != c2Label));
	}
	return false;
	}

	/**
	* For some look and feels check boxs and radio buttons typically
	* don't paint the border, yet they have padding for a border. Look
	* and feel guidelines generally don't include this space. Use
	* this method to subtract this space from the specified
	* components.
	*
	* @param source First component
	* @param target Second component
	* @param position Position doing layout along.
	* @param offset Ideal offset, not including border/margin
	* @return offset - border/margin around the component.
	*/
	protected int getButtonGap(JComponent source, JComponent target,
	int position, int offset) {
	offset -= getButtonGap(source, position);
	if (offset > 0) {
	offset -= getButtonGap(target, flipDirection(position));
	}
	if (offset < 0) {
	return 0;
	}
	return offset;
	}

	/**
	* For some look and feels check boxs and radio buttons typically
	* don't paint the border, yet they have padding for a border. Look
	* and feel guidelines generally don't include this space. Use
	* this method to subtract this space from the specified
	* components.
	*
	* @param source Component
	* @param position Position doing layout along.
	* @param offset Ideal offset, not including border/margin
	* @return offset - border/margin around the component.
	*/
	protected int getButtonGap(JComponent source, int position, int offset) {
	offset -= getButtonGap(source, position);
	return Math.max(offset, 0);
	}

	/**
	* If <code>c</code> is a check box or radio button, and the border is
	* not painted this returns the inset along the specified axis.
	*/
	public int getButtonGap(JComponent c, int position) {
	String classID = c.getUIClassID();
	if ((classID == "CheckBoxUI" \|\| classID == "RadioButtonUI") &&
	!((AbstractButton)c).isBorderPainted()) {
	Border border = c.getBorder();
	if (border instanceof UIResource) {
	return getInset(c, position);
	}
	}
	return 0;
	}

	private void checkPosition(int position) {
	if (position != SwingConstants.NORTH &&
	position != SwingConstants.SOUTH &&
	position != SwingConstants.WEST &&
	position != SwingConstants.EAST) {
	throw new IllegalArgumentException();
	}
	}

	protected int flipDirection(int position) {
	switch(position) {
	case SwingConstants.NORTH:
	return SwingConstants.SOUTH;
	case SwingConstants.SOUTH:
	return SwingConstants.NORTH;
	case SwingConstants.EAST:
	return SwingConstants.WEST;
	case SwingConstants.WEST:
	return SwingConstants.EAST;
	}
	assert false;
	return 0;
	}

	/**
	* Returns the amount to indent the specified component if it's
	* a JCheckBox or JRadioButton. If the component is not a JCheckBox or
	* JRadioButton, 0 will be returned.
	*/
	protected int getIndent(JComponent c, int position) {
	String classID = c.getUIClassID();
	if (classID == "CheckBoxUI" \|\| classID == "RadioButtonUI") {
	AbstractButton button = (AbstractButton)c;
	Insets insets = c.getInsets();
	Icon icon = getIcon(button);
	int gap = button.getIconTextGap();
	if (isLeftAligned(button, position)) {
	return insets.left + icon.getIconWidth() + gap;
	} else if (isRightAligned(button, position)) {
	return insets.right + icon.getIconWidth() + gap;
	}
	}
	return 0;
	}

	private Icon getIcon(AbstractButton button) {
	Icon icon = button.getIcon();
	if (icon != null) {
	return icon;
	}
	String key = null;
	if (button instanceof JCheckBox) {
	key = "CheckBox.icon";
	} else if (button instanceof JRadioButton) {
	key = "RadioButton.icon";
	}
	if (key != null) {
	Object oIcon = UIManager.get(key);
	if (oIcon instanceof Icon) {
	return (Icon)oIcon;
	}
	}
	return null;
	}

	private boolean isLeftAligned(AbstractButton button, int position) {
	if (position == SwingConstants.WEST) {
	boolean ltr = button.getComponentOrientation().isLeftToRight();
	int hAlign = button.getHorizontalAlignment();
	return ((ltr && (hAlign == SwingConstants.LEFT \|\|
	hAlign == SwingConstants.LEADING)) \|\|
	(!ltr && (hAlign == SwingConstants.TRAILING)));
	}
	return false;
	}

	private boolean isRightAligned(AbstractButton button, int position) {
	if (position == SwingConstants.EAST) {
	boolean ltr = button.getComponentOrientation().isLeftToRight();
	int hAlign = button.getHorizontalAlignment();
	return ((ltr && (hAlign == SwingConstants.RIGHT \|\|
	hAlign == SwingConstants.TRAILING)) \|\|
	(!ltr && (hAlign == SwingConstants.LEADING)));
	}
	return false;
	}

	private int getInset(JComponent c, int position) {
	return getInset(c.getInsets(), position);
	}

	private int getInset(Insets insets, int position) {
	if (insets == null) {
	return 0;
	}
	switch(position) {
	case SwingConstants.NORTH:
	return insets.top;
	case SwingConstants.SOUTH:
	return insets.bottom;
	case SwingConstants.EAST:
	return insets.right;
	case SwingConstants.WEST:
	return insets.left;
	}
	assert false;
	return 0;
	}
	}

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