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/*
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* Copyright 1995-2006 Sun Microsystems, Inc. All Rights Reserved.
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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*
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* This code is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 only, as
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* published by the Free Software Foundation. Sun designates this
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* particular file as subject to the "Classpath" exception as provided
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* by Sun in the LICENSE file that accompanied this code.
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*
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* This code is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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* version 2 for more details (a copy is included in the LICENSE file that
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* accompanied this code).
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*
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* You should have received a copy of the GNU General Public License version
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* 2 along with this work; if not, write to the Free Software Foundation,
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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*
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* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
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* CA 95054 USA or visit www.sun.com if you need additional information or
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* have any questions.
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*/
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package java.awt;
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import java.util.Hashtable;
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/**
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* A border layout lays out a container, arranging and resizing
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* its components to fit in five regions:
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* north, south, east, west, and center.
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* Each region may contain no more than one component, and
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* is identified by a corresponding constant:
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* <code>NORTH</code>, <code>SOUTH</code>, <code>EAST</code>,
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* <code>WEST</code>, and <code>CENTER</code>. When adding a
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* component to a container with a border layout, use one of these
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* five constants, for example:
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* <pre>
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* Panel p = new Panel();
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* p.setLayout(new BorderLayout());
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* p.add(new Button("Okay"), BorderLayout.SOUTH);
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* </pre>
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* As a convenience, <code>BorderLayout</code> interprets the
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* absence of a string specification the same as the constant
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* <code>CENTER</code>:
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* <pre>
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* Panel p2 = new Panel();
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* p2.setLayout(new BorderLayout());
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* p2.add(new TextArea()); // Same as p.add(new TextArea(), BorderLayout.CENTER);
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* </pre>
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* <p>
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* In addition, <code>BorderLayout</code> supports the relative
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* positioning constants, <code>PAGE_START</code>, <code>PAGE_END</code>,
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* <code>LINE_START</code>, and <code>LINE_END</code>.
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* In a container whose <code>ComponentOrientation</code> is set to
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* <code>ComponentOrientation.LEFT_TO_RIGHT</code>, these constants map to
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* <code>NORTH</code>, <code>SOUTH</code>, <code>WEST</code>, and
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* <code>EAST</code>, respectively.
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* <p>
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* For compatibility with previous releases, <code>BorderLayout</code>
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* also includes the relative positioning constants <code>BEFORE_FIRST_LINE</code>,
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* <code>AFTER_LAST_LINE</code>, <code>BEFORE_LINE_BEGINS</code> and
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* <code>AFTER_LINE_ENDS</code>. These are equivalent to
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* <code>PAGE_START</code>, <code>PAGE_END</code>, <code>LINE_START</code>
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* and <code>LINE_END</code> respectively. For
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* consistency with the relative positioning constants used by other
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* components, the latter constants are preferred.
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* <p>
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* Mixing both absolute and relative positioning constants can lead to
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* unpredicable results. If
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* you use both types, the relative constants will take precedence.
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* For example, if you add components using both the <code>NORTH</code>
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* and <code>PAGE_START</code> constants in a container whose
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* orientation is <code>LEFT_TO_RIGHT</code>, only the
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* <code>PAGE_START</code> will be layed out.
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* <p>
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* NOTE: Currently (in the Java 2 platform v1.2),
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* <code>BorderLayout</code> does not support vertical
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* orientations. The <code>isVertical</code> setting on the container's
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* <code>ComponentOrientation</code> is not respected.
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* <p>
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* The components are laid out according to their
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* preferred sizes and the constraints of the container's size.
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* The <code>NORTH</code> and <code>SOUTH</code> components may
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* be stretched horizontally; the <code>EAST</code> and
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* <code>WEST</code> components may be stretched vertically;
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* the <code>CENTER</code> component may stretch both horizontally
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* and vertically to fill any space left over.
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* <p>
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* Here is an example of five buttons in an applet laid out using
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* the <code>BorderLayout</code> layout manager:
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* <p>
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* <img src="doc-files/BorderLayout-1.gif"
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* alt="Diagram of an applet demonstrating BorderLayout.
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* Each section of the BorderLayout contains a Button corresponding to its position in the layout, one of:
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* North, West, Center, East, or South."
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* ALIGN=center HSPACE=10 VSPACE=7>
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* <p>
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* The code for this applet is as follows:
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* <p>
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* <hr><blockquote><pre>
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* import java.awt.*;
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* import java.applet.Applet;
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*
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* public class buttonDir extends Applet {
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* public void init() {
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* setLayout(new BorderLayout());
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* add(new Button("North"), BorderLayout.NORTH);
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* add(new Button("South"), BorderLayout.SOUTH);
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* add(new Button("East"), BorderLayout.EAST);
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* add(new Button("West"), BorderLayout.WEST);
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* add(new Button("Center"), BorderLayout.CENTER);
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* }
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* }
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* </pre></blockquote><hr>
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* <p>
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* @author Arthur van Hoff
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* @see java.awt.Container#add(String, Component)
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* @see java.awt.ComponentOrientation
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* @since JDK1.0
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*/
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public class BorderLayout implements LayoutManager2,
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java.io.Serializable {
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/**
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* Constructs a border layout with the horizontal gaps
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* between components.
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* The horizontal gap is specified by <code>hgap</code>.
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*
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* @see #getHgap()
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* @see #setHgap(int)
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*
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* @serial
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*/
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int hgap;
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/**
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* Constructs a border layout with the vertical gaps
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* between components.
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* The vertical gap is specified by <code>vgap</code>.
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*
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* @see #getVgap()
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* @see #setVgap(int)
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* @serial
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*/
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int vgap;
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/**
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* Constant to specify components location to be the
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* north portion of the border layout.
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* @serial
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* @see #getChild(String, boolean)
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* @see #addLayoutComponent
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* @see #getLayoutAlignmentX
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* @see #getLayoutAlignmentY
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* @see #removeLayoutComponent
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*/
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Component north;
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/**
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* Constant to specify components location to be the
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* west portion of the border layout.
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* @serial
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* @see #getChild(String, boolean)
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* @see #addLayoutComponent
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* @see #getLayoutAlignmentX
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* @see #getLayoutAlignmentY
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* @see #removeLayoutComponent
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*/
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Component west;
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/**
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* Constant to specify components location to be the
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* east portion of the border layout.
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* @serial
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* @see #getChild(String, boolean)
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* @see #addLayoutComponent
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* @see #getLayoutAlignmentX
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* @see #getLayoutAlignmentY
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* @see #removeLayoutComponent
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*/
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Component east;
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/**
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* Constant to specify components location to be the
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* south portion of the border layout.
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* @serial
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* @see #getChild(String, boolean)
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* @see #addLayoutComponent
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* @see #getLayoutAlignmentX
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* @see #getLayoutAlignmentY
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* @see #removeLayoutComponent
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*/
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Component south;
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/**
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* Constant to specify components location to be the
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* center portion of the border layout.
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* @serial
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* @see #getChild(String, boolean)
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* @see #addLayoutComponent
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* @see #getLayoutAlignmentX
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* @see #getLayoutAlignmentY
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* @see #removeLayoutComponent
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*/
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Component center;
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/**
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*
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* A relative positioning constant, that can be used instead of
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* north, south, east, west or center.
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* mixing the two types of constants can lead to unpredicable results. If
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* you use both types, the relative constants will take precedence.
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* For example, if you add components using both the <code>NORTH</code>
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* and <code>BEFORE_FIRST_LINE</code> constants in a container whose
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* orientation is <code>LEFT_TO_RIGHT</code>, only the
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* <code>BEFORE_FIRST_LINE</code> will be layed out.
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* This will be the same for lastLine, firstItem, lastItem.
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* @serial
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*/
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Component firstLine;
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/**
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* A relative positioning constant, that can be used instead of
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* north, south, east, west or center.
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* Please read Description for firstLine.
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* @serial
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*/
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Component lastLine;
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/**
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* A relative positioning constant, that can be used instead of
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* north, south, east, west or center.
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* Please read Description for firstLine.
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* @serial
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*/
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Component firstItem;
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/**
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* A relative positioning constant, that can be used instead of
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* north, south, east, west or center.
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* Please read Description for firstLine.
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* @serial
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*/
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Component lastItem;
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/**
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* The north layout constraint (top of container).
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*/
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public static final String NORTH = "North";
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/**
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* The south layout constraint (bottom of container).
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*/
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public static final String SOUTH = "South";
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/**
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* The east layout constraint (right side of container).
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*/
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public static final String EAST = "East";
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/**
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* The west layout constraint (left side of container).
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*/
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public static final String WEST = "West";
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/**
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* The center layout constraint (middle of container).
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*/
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public static final String CENTER = "Center";
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/**
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* Synonym for PAGE_START. Exists for compatibility with previous
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* versions. PAGE_START is preferred.
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*
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* @see #PAGE_START
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* @since 1.2
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*/
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public static final String BEFORE_FIRST_LINE = "First";
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/**
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* Synonym for PAGE_END. Exists for compatibility with previous
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* versions. PAGE_END is preferred.
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*
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* @see #PAGE_END
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* @since 1.2
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*/
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public static final String AFTER_LAST_LINE = "Last";
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/**
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* Synonym for LINE_START. Exists for compatibility with previous
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* versions. LINE_START is preferred.
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*
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* @see #LINE_START
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* @since 1.2
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*/
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public static final String BEFORE_LINE_BEGINS = "Before";
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/**
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* Synonym for LINE_END. Exists for compatibility with previous
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* versions. LINE_END is preferred.
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*
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* @see #LINE_END
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* @since 1.2
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*/
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public static final String AFTER_LINE_ENDS = "After";
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/**
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* The component comes before the first line of the layout's content.
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* For Western, left-to-right and top-to-bottom orientations, this is
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* equivalent to NORTH.
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*
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* @see java.awt.Component#getComponentOrientation
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* @since 1.4
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*/
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public static final String PAGE_START = BEFORE_FIRST_LINE;
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/**
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* The component comes after the last line of the layout's content.
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* For Western, left-to-right and top-to-bottom orientations, this is
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* equivalent to SOUTH.
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*
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* @see java.awt.Component#getComponentOrientation
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* @since 1.4
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*/
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public static final String PAGE_END = AFTER_LAST_LINE;
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/**
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* The component goes at the beginning of the line direction for the
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* layout. For Western, left-to-right and top-to-bottom orientations,
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* this is equivalent to WEST.
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*
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* @see java.awt.Component#getComponentOrientation
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* @since 1.4
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*/
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public static final String LINE_START = BEFORE_LINE_BEGINS;
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/**
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* The component goes at the end of the line direction for the
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* layout. For Western, left-to-right and top-to-bottom orientations,
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* this is equivalent to EAST.
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*
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* @see java.awt.Component#getComponentOrientation
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* @since 1.4
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*/
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public static final String LINE_END = AFTER_LINE_ENDS;
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/*
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* JDK 1.1 serialVersionUID
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*/
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private static final long serialVersionUID = -8658291919501921765L;
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/**
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* Constructs a new border layout with
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* no gaps between components.
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*/
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public BorderLayout() {
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this(0, 0);
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}
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/**
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* Constructs a border layout with the specified gaps
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* between components.
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* The horizontal gap is specified by <code>hgap</code>
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359 |
* and the vertical gap is specified by <code>vgap</code>.
|
|
|
360 |
* @param hgap the horizontal gap.
|
|
|
361 |
* @param vgap the vertical gap.
|
|
|
362 |
*/
|
|
|
363 |
public BorderLayout(int hgap, int vgap) {
|
|
|
364 |
this.hgap = hgap;
|
|
|
365 |
this.vgap = vgap;
|
|
|
366 |
}
|
|
|
367 |
|
|
|
368 |
/**
|
|
|
369 |
* Returns the horizontal gap between components.
|
|
|
370 |
* @since JDK1.1
|
|
|
371 |
*/
|
|
|
372 |
public int getHgap() {
|
|
|
373 |
return hgap;
|
|
|
374 |
}
|
|
|
375 |
|
|
|
376 |
/**
|
|
|
377 |
* Sets the horizontal gap between components.
|
|
|
378 |
* @param hgap the horizontal gap between components
|
|
|
379 |
* @since JDK1.1
|
|
|
380 |
*/
|
|
|
381 |
public void setHgap(int hgap) {
|
|
|
382 |
this.hgap = hgap;
|
|
|
383 |
}
|
|
|
384 |
|
|
|
385 |
/**
|
|
|
386 |
* Returns the vertical gap between components.
|
|
|
387 |
* @since JDK1.1
|
|
|
388 |
*/
|
|
|
389 |
public int getVgap() {
|
|
|
390 |
return vgap;
|
|
|
391 |
}
|
|
|
392 |
|
|
|
393 |
/**
|
|
|
394 |
* Sets the vertical gap between components.
|
|
|
395 |
* @param vgap the vertical gap between components
|
|
|
396 |
* @since JDK1.1
|
|
|
397 |
*/
|
|
|
398 |
public void setVgap(int vgap) {
|
|
|
399 |
this.vgap = vgap;
|
|
|
400 |
}
|
|
|
401 |
|
|
|
402 |
/**
|
|
|
403 |
* Adds the specified component to the layout, using the specified
|
|
|
404 |
* constraint object. For border layouts, the constraint must be
|
|
|
405 |
* one of the following constants: <code>NORTH</code>,
|
|
|
406 |
* <code>SOUTH</code>, <code>EAST</code>,
|
|
|
407 |
* <code>WEST</code>, or <code>CENTER</code>.
|
|
|
408 |
* <p>
|
|
|
409 |
* Most applications do not call this method directly. This method
|
|
|
410 |
* is called when a component is added to a container using the
|
|
|
411 |
* <code>Container.add</code> method with the same argument types.
|
|
|
412 |
* @param comp the component to be added.
|
|
|
413 |
* @param constraints an object that specifies how and where
|
|
|
414 |
* the component is added to the layout.
|
|
|
415 |
* @see java.awt.Container#add(java.awt.Component, java.lang.Object)
|
|
|
416 |
* @exception IllegalArgumentException if the constraint object is not
|
|
|
417 |
* a string, or if it not one of the five specified
|
|
|
418 |
* constants.
|
|
|
419 |
* @since JDK1.1
|
|
|
420 |
*/
|
|
|
421 |
public void addLayoutComponent(Component comp, Object constraints) {
|
|
|
422 |
synchronized (comp.getTreeLock()) {
|
|
|
423 |
if ((constraints == null) || (constraints instanceof String)) {
|
|
|
424 |
addLayoutComponent((String)constraints, comp);
|
|
|
425 |
} else {
|
|
|
426 |
throw new IllegalArgumentException("cannot add to layout: constraint must be a string (or null)");
|
|
|
427 |
}
|
|
|
428 |
}
|
|
|
429 |
}
|
|
|
430 |
|
|
|
431 |
/**
|
|
|
432 |
* @deprecated replaced by <code>addLayoutComponent(Component, Object)</code>.
|
|
|
433 |
*/
|
|
|
434 |
@Deprecated
|
|
|
435 |
public void addLayoutComponent(String name, Component comp) {
|
|
|
436 |
synchronized (comp.getTreeLock()) {
|
|
|
437 |
/* Special case: treat null the same as "Center". */
|
|
|
438 |
if (name == null) {
|
|
|
439 |
name = "Center";
|
|
|
440 |
}
|
|
|
441 |
|
|
|
442 |
/* Assign the component to one of the known regions of the layout.
|
|
|
443 |
*/
|
|
|
444 |
if ("Center".equals(name)) {
|
|
|
445 |
center = comp;
|
|
|
446 |
} else if ("North".equals(name)) {
|
|
|
447 |
north = comp;
|
|
|
448 |
} else if ("South".equals(name)) {
|
|
|
449 |
south = comp;
|
|
|
450 |
} else if ("East".equals(name)) {
|
|
|
451 |
east = comp;
|
|
|
452 |
} else if ("West".equals(name)) {
|
|
|
453 |
west = comp;
|
|
|
454 |
} else if (BEFORE_FIRST_LINE.equals(name)) {
|
|
|
455 |
firstLine = comp;
|
|
|
456 |
} else if (AFTER_LAST_LINE.equals(name)) {
|
|
|
457 |
lastLine = comp;
|
|
|
458 |
} else if (BEFORE_LINE_BEGINS.equals(name)) {
|
|
|
459 |
firstItem = comp;
|
|
|
460 |
} else if (AFTER_LINE_ENDS.equals(name)) {
|
|
|
461 |
lastItem = comp;
|
|
|
462 |
} else {
|
|
|
463 |
throw new IllegalArgumentException("cannot add to layout: unknown constraint: " + name);
|
|
|
464 |
}
|
|
|
465 |
}
|
|
|
466 |
}
|
|
|
467 |
|
|
|
468 |
/**
|
|
|
469 |
* Removes the specified component from this border layout. This
|
|
|
470 |
* method is called when a container calls its <code>remove</code> or
|
|
|
471 |
* <code>removeAll</code> methods. Most applications do not call this
|
|
|
472 |
* method directly.
|
|
|
473 |
* @param comp the component to be removed.
|
|
|
474 |
* @see java.awt.Container#remove(java.awt.Component)
|
|
|
475 |
* @see java.awt.Container#removeAll()
|
|
|
476 |
*/
|
|
|
477 |
public void removeLayoutComponent(Component comp) {
|
|
|
478 |
synchronized (comp.getTreeLock()) {
|
|
|
479 |
if (comp == center) {
|
|
|
480 |
center = null;
|
|
|
481 |
} else if (comp == north) {
|
|
|
482 |
north = null;
|
|
|
483 |
} else if (comp == south) {
|
|
|
484 |
south = null;
|
|
|
485 |
} else if (comp == east) {
|
|
|
486 |
east = null;
|
|
|
487 |
} else if (comp == west) {
|
|
|
488 |
west = null;
|
|
|
489 |
}
|
|
|
490 |
if (comp == firstLine) {
|
|
|
491 |
firstLine = null;
|
|
|
492 |
} else if (comp == lastLine) {
|
|
|
493 |
lastLine = null;
|
|
|
494 |
} else if (comp == firstItem) {
|
|
|
495 |
firstItem = null;
|
|
|
496 |
} else if (comp == lastItem) {
|
|
|
497 |
lastItem = null;
|
|
|
498 |
}
|
|
|
499 |
}
|
|
|
500 |
}
|
|
|
501 |
|
|
|
502 |
/**
|
|
|
503 |
* Gets the component that was added using the given constraint
|
|
|
504 |
*
|
|
|
505 |
* @param constraints the desired constraint, one of <code>CENTER</code>,
|
|
|
506 |
* <code>NORTH</code>, <code>SOUTH</code>,
|
|
|
507 |
* <code>WEST</code>, <code>EAST</code>,
|
|
|
508 |
* <code>PAGE_START</code>, <code>PAGE_END</code>,
|
|
|
509 |
* <code>LINE_START</code>, <code>LINE_END</code>
|
|
|
510 |
* @return the component at the given location, or <code>null</code> if
|
|
|
511 |
* the location is empty
|
|
|
512 |
* @exception IllegalArgumentException if the constraint object is
|
|
|
513 |
* not one of the nine specified constants
|
|
|
514 |
* @see #addLayoutComponent(java.awt.Component, java.lang.Object)
|
|
|
515 |
* @since 1.5
|
|
|
516 |
*/
|
|
|
517 |
public Component getLayoutComponent(Object constraints) {
|
|
|
518 |
if (CENTER.equals(constraints)) {
|
|
|
519 |
return center;
|
|
|
520 |
} else if (NORTH.equals(constraints)) {
|
|
|
521 |
return north;
|
|
|
522 |
} else if (SOUTH.equals(constraints)) {
|
|
|
523 |
return south;
|
|
|
524 |
} else if (WEST.equals(constraints)) {
|
|
|
525 |
return west;
|
|
|
526 |
} else if (EAST.equals(constraints)) {
|
|
|
527 |
return east;
|
|
|
528 |
} else if (PAGE_START.equals(constraints)) {
|
|
|
529 |
return firstLine;
|
|
|
530 |
} else if (PAGE_END.equals(constraints)) {
|
|
|
531 |
return lastLine;
|
|
|
532 |
} else if (LINE_START.equals(constraints)) {
|
|
|
533 |
return firstItem;
|
|
|
534 |
} else if (LINE_END.equals(constraints)) {
|
|
|
535 |
return lastItem;
|
|
|
536 |
} else {
|
|
|
537 |
throw new IllegalArgumentException("cannot get component: unknown constraint: " + constraints);
|
|
|
538 |
}
|
|
|
539 |
}
|
|
|
540 |
|
|
|
541 |
|
|
|
542 |
/**
|
|
|
543 |
* Returns the component that corresponds to the given constraint location
|
|
|
544 |
* based on the target <code>Container</code>'s component orientation.
|
|
|
545 |
* Components added with the relative constraints <code>PAGE_START</code>,
|
|
|
546 |
* <code>PAGE_END</code>, <code>LINE_START</code>, and <code>LINE_END</code>
|
|
|
547 |
* take precedence over components added with the explicit constraints
|
|
|
548 |
* <code>NORTH</code>, <code>SOUTH</code>, <code>WEST</code>, and <code>EAST</code>.
|
|
|
549 |
* The <code>Container</code>'s component orientation is used to determine the location of components
|
|
|
550 |
* added with <code>LINE_START</code> and <code>LINE_END</code>.
|
|
|
551 |
*
|
|
|
552 |
* @param constraints the desired absolute position, one of <code>CENTER</code>,
|
|
|
553 |
* <code>NORTH</code>, <code>SOUTH</code>,
|
|
|
554 |
* <code>EAST</code>, <code>WEST</code>
|
|
|
555 |
* @param target the {@code Container} used to obtain
|
|
|
556 |
* the constraint location based on the target
|
|
|
557 |
* {@code Container}'s component orientation.
|
|
|
558 |
* @return the component at the given location, or <code>null</code> if
|
|
|
559 |
* the location is empty
|
|
|
560 |
* @exception IllegalArgumentException if the constraint object is
|
|
|
561 |
* not one of the five specified constants
|
|
|
562 |
* @exception NullPointerException if the target parameter is null
|
|
|
563 |
* @see #addLayoutComponent(java.awt.Component, java.lang.Object)
|
|
|
564 |
* @since 1.5
|
|
|
565 |
*/
|
|
|
566 |
public Component getLayoutComponent(Container target, Object constraints) {
|
|
|
567 |
boolean ltr = target.getComponentOrientation().isLeftToRight();
|
|
|
568 |
Component result = null;
|
|
|
569 |
|
|
|
570 |
if (NORTH.equals(constraints)) {
|
|
|
571 |
result = (firstLine != null) ? firstLine : north;
|
|
|
572 |
} else if (SOUTH.equals(constraints)) {
|
|
|
573 |
result = (lastLine != null) ? lastLine : south;
|
|
|
574 |
} else if (WEST.equals(constraints)) {
|
|
|
575 |
result = ltr ? firstItem : lastItem;
|
|
|
576 |
if (result == null) {
|
|
|
577 |
result = west;
|
|
|
578 |
}
|
|
|
579 |
} else if (EAST.equals(constraints)) {
|
|
|
580 |
result = ltr ? lastItem : firstItem;
|
|
|
581 |
if (result == null) {
|
|
|
582 |
result = east;
|
|
|
583 |
}
|
|
|
584 |
} else if (CENTER.equals(constraints)) {
|
|
|
585 |
result = center;
|
|
|
586 |
} else {
|
|
|
587 |
throw new IllegalArgumentException("cannot get component: invalid constraint: " + constraints);
|
|
|
588 |
}
|
|
|
589 |
|
|
|
590 |
return result;
|
|
|
591 |
}
|
|
|
592 |
|
|
|
593 |
|
|
|
594 |
/**
|
|
|
595 |
* Gets the constraints for the specified component
|
|
|
596 |
*
|
|
|
597 |
* @param comp the component to be queried
|
|
|
598 |
* @return the constraint for the specified component,
|
|
|
599 |
* or null if component is null or is not present
|
|
|
600 |
* in this layout
|
|
|
601 |
* @see #addLayoutComponent(java.awt.Component, java.lang.Object)
|
|
|
602 |
* @since 1.5
|
|
|
603 |
*/
|
|
|
604 |
public Object getConstraints(Component comp) {
|
|
|
605 |
//fix for 6242148 : API method java.awt.BorderLayout.getConstraints(null) should return null
|
|
|
606 |
if (comp == null){
|
|
|
607 |
return null;
|
|
|
608 |
}
|
|
|
609 |
if (comp == center) {
|
|
|
610 |
return CENTER;
|
|
|
611 |
} else if (comp == north) {
|
|
|
612 |
return NORTH;
|
|
|
613 |
} else if (comp == south) {
|
|
|
614 |
return SOUTH;
|
|
|
615 |
} else if (comp == west) {
|
|
|
616 |
return WEST;
|
|
|
617 |
} else if (comp == east) {
|
|
|
618 |
return EAST;
|
|
|
619 |
} else if (comp == firstLine) {
|
|
|
620 |
return PAGE_START;
|
|
|
621 |
} else if (comp == lastLine) {
|
|
|
622 |
return PAGE_END;
|
|
|
623 |
} else if (comp == firstItem) {
|
|
|
624 |
return LINE_START;
|
|
|
625 |
} else if (comp == lastItem) {
|
|
|
626 |
return LINE_END;
|
|
|
627 |
}
|
|
|
628 |
return null;
|
|
|
629 |
}
|
|
|
630 |
|
|
|
631 |
/**
|
|
|
632 |
* Determines the minimum size of the <code>target</code> container
|
|
|
633 |
* using this layout manager.
|
|
|
634 |
* <p>
|
|
|
635 |
* This method is called when a container calls its
|
|
|
636 |
* <code>getMinimumSize</code> method. Most applications do not call
|
|
|
637 |
* this method directly.
|
|
|
638 |
* @param target the container in which to do the layout.
|
|
|
639 |
* @return the minimum dimensions needed to lay out the subcomponents
|
|
|
640 |
* of the specified container.
|
|
|
641 |
* @see java.awt.Container
|
|
|
642 |
* @see java.awt.BorderLayout#preferredLayoutSize
|
|
|
643 |
* @see java.awt.Container#getMinimumSize()
|
|
|
644 |
*/
|
|
|
645 |
public Dimension minimumLayoutSize(Container target) {
|
|
|
646 |
synchronized (target.getTreeLock()) {
|
|
|
647 |
Dimension dim = new Dimension(0, 0);
|
|
|
648 |
|
|
|
649 |
boolean ltr = target.getComponentOrientation().isLeftToRight();
|
|
|
650 |
Component c = null;
|
|
|
651 |
|
|
|
652 |
if ((c=getChild(EAST,ltr)) != null) {
|
|
|
653 |
Dimension d = c.getMinimumSize();
|
|
|
654 |
dim.width += d.width + hgap;
|
|
|
655 |
dim.height = Math.max(d.height, dim.height);
|
|
|
656 |
}
|
|
|
657 |
if ((c=getChild(WEST,ltr)) != null) {
|
|
|
658 |
Dimension d = c.getMinimumSize();
|
|
|
659 |
dim.width += d.width + hgap;
|
|
|
660 |
dim.height = Math.max(d.height, dim.height);
|
|
|
661 |
}
|
|
|
662 |
if ((c=getChild(CENTER,ltr)) != null) {
|
|
|
663 |
Dimension d = c.getMinimumSize();
|
|
|
664 |
dim.width += d.width;
|
|
|
665 |
dim.height = Math.max(d.height, dim.height);
|
|
|
666 |
}
|
|
|
667 |
if ((c=getChild(NORTH,ltr)) != null) {
|
|
|
668 |
Dimension d = c.getMinimumSize();
|
|
|
669 |
dim.width = Math.max(d.width, dim.width);
|
|
|
670 |
dim.height += d.height + vgap;
|
|
|
671 |
}
|
|
|
672 |
if ((c=getChild(SOUTH,ltr)) != null) {
|
|
|
673 |
Dimension d = c.getMinimumSize();
|
|
|
674 |
dim.width = Math.max(d.width, dim.width);
|
|
|
675 |
dim.height += d.height + vgap;
|
|
|
676 |
}
|
|
|
677 |
|
|
|
678 |
Insets insets = target.getInsets();
|
|
|
679 |
dim.width += insets.left + insets.right;
|
|
|
680 |
dim.height += insets.top + insets.bottom;
|
|
|
681 |
|
|
|
682 |
return dim;
|
|
|
683 |
}
|
|
|
684 |
}
|
|
|
685 |
|
|
|
686 |
/**
|
|
|
687 |
* Determines the preferred size of the <code>target</code>
|
|
|
688 |
* container using this layout manager, based on the components
|
|
|
689 |
* in the container.
|
|
|
690 |
* <p>
|
|
|
691 |
* Most applications do not call this method directly. This method
|
|
|
692 |
* is called when a container calls its <code>getPreferredSize</code>
|
|
|
693 |
* method.
|
|
|
694 |
* @param target the container in which to do the layout.
|
|
|
695 |
* @return the preferred dimensions to lay out the subcomponents
|
|
|
696 |
* of the specified container.
|
|
|
697 |
* @see java.awt.Container
|
|
|
698 |
* @see java.awt.BorderLayout#minimumLayoutSize
|
|
|
699 |
* @see java.awt.Container#getPreferredSize()
|
|
|
700 |
*/
|
|
|
701 |
public Dimension preferredLayoutSize(Container target) {
|
|
|
702 |
synchronized (target.getTreeLock()) {
|
|
|
703 |
Dimension dim = new Dimension(0, 0);
|
|
|
704 |
|
|
|
705 |
boolean ltr = target.getComponentOrientation().isLeftToRight();
|
|
|
706 |
Component c = null;
|
|
|
707 |
|
|
|
708 |
if ((c=getChild(EAST,ltr)) != null) {
|
|
|
709 |
Dimension d = c.getPreferredSize();
|
|
|
710 |
dim.width += d.width + hgap;
|
|
|
711 |
dim.height = Math.max(d.height, dim.height);
|
|
|
712 |
}
|
|
|
713 |
if ((c=getChild(WEST,ltr)) != null) {
|
|
|
714 |
Dimension d = c.getPreferredSize();
|
|
|
715 |
dim.width += d.width + hgap;
|
|
|
716 |
dim.height = Math.max(d.height, dim.height);
|
|
|
717 |
}
|
|
|
718 |
if ((c=getChild(CENTER,ltr)) != null) {
|
|
|
719 |
Dimension d = c.getPreferredSize();
|
|
|
720 |
dim.width += d.width;
|
|
|
721 |
dim.height = Math.max(d.height, dim.height);
|
|
|
722 |
}
|
|
|
723 |
if ((c=getChild(NORTH,ltr)) != null) {
|
|
|
724 |
Dimension d = c.getPreferredSize();
|
|
|
725 |
dim.width = Math.max(d.width, dim.width);
|
|
|
726 |
dim.height += d.height + vgap;
|
|
|
727 |
}
|
|
|
728 |
if ((c=getChild(SOUTH,ltr)) != null) {
|
|
|
729 |
Dimension d = c.getPreferredSize();
|
|
|
730 |
dim.width = Math.max(d.width, dim.width);
|
|
|
731 |
dim.height += d.height + vgap;
|
|
|
732 |
}
|
|
|
733 |
|
|
|
734 |
Insets insets = target.getInsets();
|
|
|
735 |
dim.width += insets.left + insets.right;
|
|
|
736 |
dim.height += insets.top + insets.bottom;
|
|
|
737 |
|
|
|
738 |
return dim;
|
|
|
739 |
}
|
|
|
740 |
}
|
|
|
741 |
|
|
|
742 |
/**
|
|
|
743 |
* Returns the maximum dimensions for this layout given the components
|
|
|
744 |
* in the specified target container.
|
|
|
745 |
* @param target the component which needs to be laid out
|
|
|
746 |
* @see Container
|
|
|
747 |
* @see #minimumLayoutSize
|
|
|
748 |
* @see #preferredLayoutSize
|
|
|
749 |
*/
|
|
|
750 |
public Dimension maximumLayoutSize(Container target) {
|
|
|
751 |
return new Dimension(Integer.MAX_VALUE, Integer.MAX_VALUE);
|
|
|
752 |
}
|
|
|
753 |
|
|
|
754 |
/**
|
|
|
755 |
* Returns the alignment along the x axis. This specifies how
|
|
|
756 |
* the component would like to be aligned relative to other
|
|
|
757 |
* components. The value should be a number between 0 and 1
|
|
|
758 |
* where 0 represents alignment along the origin, 1 is aligned
|
|
|
759 |
* the furthest away from the origin, 0.5 is centered, etc.
|
|
|
760 |
*/
|
|
|
761 |
public float getLayoutAlignmentX(Container parent) {
|
|
|
762 |
return 0.5f;
|
|
|
763 |
}
|
|
|
764 |
|
|
|
765 |
/**
|
|
|
766 |
* Returns the alignment along the y axis. This specifies how
|
|
|
767 |
* the component would like to be aligned relative to other
|
|
|
768 |
* components. The value should be a number between 0 and 1
|
|
|
769 |
* where 0 represents alignment along the origin, 1 is aligned
|
|
|
770 |
* the furthest away from the origin, 0.5 is centered, etc.
|
|
|
771 |
*/
|
|
|
772 |
public float getLayoutAlignmentY(Container parent) {
|
|
|
773 |
return 0.5f;
|
|
|
774 |
}
|
|
|
775 |
|
|
|
776 |
/**
|
|
|
777 |
* Invalidates the layout, indicating that if the layout manager
|
|
|
778 |
* has cached information it should be discarded.
|
|
|
779 |
*/
|
|
|
780 |
public void invalidateLayout(Container target) {
|
|
|
781 |
}
|
|
|
782 |
|
|
|
783 |
/**
|
|
|
784 |
* Lays out the container argument using this border layout.
|
|
|
785 |
* <p>
|
|
|
786 |
* This method actually reshapes the components in the specified
|
|
|
787 |
* container in order to satisfy the constraints of this
|
|
|
788 |
* <code>BorderLayout</code> object. The <code>NORTH</code>
|
|
|
789 |
* and <code>SOUTH</code> components, if any, are placed at
|
|
|
790 |
* the top and bottom of the container, respectively. The
|
|
|
791 |
* <code>WEST</code> and <code>EAST</code> components are
|
|
|
792 |
* then placed on the left and right, respectively. Finally,
|
|
|
793 |
* the <code>CENTER</code> object is placed in any remaining
|
|
|
794 |
* space in the middle.
|
|
|
795 |
* <p>
|
|
|
796 |
* Most applications do not call this method directly. This method
|
|
|
797 |
* is called when a container calls its <code>doLayout</code> method.
|
|
|
798 |
* @param target the container in which to do the layout.
|
|
|
799 |
* @see java.awt.Container
|
|
|
800 |
* @see java.awt.Container#doLayout()
|
|
|
801 |
*/
|
|
|
802 |
public void layoutContainer(Container target) {
|
|
|
803 |
synchronized (target.getTreeLock()) {
|
|
|
804 |
Insets insets = target.getInsets();
|
|
|
805 |
int top = insets.top;
|
|
|
806 |
int bottom = target.height - insets.bottom;
|
|
|
807 |
int left = insets.left;
|
|
|
808 |
int right = target.width - insets.right;
|
|
|
809 |
|
|
|
810 |
boolean ltr = target.getComponentOrientation().isLeftToRight();
|
|
|
811 |
Component c = null;
|
|
|
812 |
|
|
|
813 |
if ((c=getChild(NORTH,ltr)) != null) {
|
|
|
814 |
c.setSize(right - left, c.height);
|
|
|
815 |
Dimension d = c.getPreferredSize();
|
|
|
816 |
c.setBounds(left, top, right - left, d.height);
|
|
|
817 |
top += d.height + vgap;
|
|
|
818 |
}
|
|
|
819 |
if ((c=getChild(SOUTH,ltr)) != null) {
|
|
|
820 |
c.setSize(right - left, c.height);
|
|
|
821 |
Dimension d = c.getPreferredSize();
|
|
|
822 |
c.setBounds(left, bottom - d.height, right - left, d.height);
|
|
|
823 |
bottom -= d.height + vgap;
|
|
|
824 |
}
|
|
|
825 |
if ((c=getChild(EAST,ltr)) != null) {
|
|
|
826 |
c.setSize(c.width, bottom - top);
|
|
|
827 |
Dimension d = c.getPreferredSize();
|
|
|
828 |
c.setBounds(right - d.width, top, d.width, bottom - top);
|
|
|
829 |
right -= d.width + hgap;
|
|
|
830 |
}
|
|
|
831 |
if ((c=getChild(WEST,ltr)) != null) {
|
|
|
832 |
c.setSize(c.width, bottom - top);
|
|
|
833 |
Dimension d = c.getPreferredSize();
|
|
|
834 |
c.setBounds(left, top, d.width, bottom - top);
|
|
|
835 |
left += d.width + hgap;
|
|
|
836 |
}
|
|
|
837 |
if ((c=getChild(CENTER,ltr)) != null) {
|
|
|
838 |
c.setBounds(left, top, right - left, bottom - top);
|
|
|
839 |
}
|
|
|
840 |
}
|
|
|
841 |
}
|
|
|
842 |
|
|
|
843 |
/**
|
|
|
844 |
* Get the component that corresponds to the given constraint location
|
|
|
845 |
*
|
|
|
846 |
* @param key The desired absolute position,
|
|
|
847 |
* either NORTH, SOUTH, EAST, or WEST.
|
|
|
848 |
* @param ltr Is the component line direction left-to-right?
|
|
|
849 |
*/
|
|
|
850 |
private Component getChild(String key, boolean ltr) {
|
|
|
851 |
Component result = null;
|
|
|
852 |
|
|
|
853 |
if (key == NORTH) {
|
|
|
854 |
result = (firstLine != null) ? firstLine : north;
|
|
|
855 |
}
|
|
|
856 |
else if (key == SOUTH) {
|
|
|
857 |
result = (lastLine != null) ? lastLine : south;
|
|
|
858 |
}
|
|
|
859 |
else if (key == WEST) {
|
|
|
860 |
result = ltr ? firstItem : lastItem;
|
|
|
861 |
if (result == null) {
|
|
|
862 |
result = west;
|
|
|
863 |
}
|
|
|
864 |
}
|
|
|
865 |
else if (key == EAST) {
|
|
|
866 |
result = ltr ? lastItem : firstItem;
|
|
|
867 |
if (result == null) {
|
|
|
868 |
result = east;
|
|
|
869 |
}
|
|
|
870 |
}
|
|
|
871 |
else if (key == CENTER) {
|
|
|
872 |
result = center;
|
|
|
873 |
}
|
|
|
874 |
if (result != null && !result.visible) {
|
|
|
875 |
result = null;
|
|
|
876 |
}
|
|
|
877 |
return result;
|
|
|
878 |
}
|
|
|
879 |
|
|
|
880 |
/**
|
|
|
881 |
* Returns a string representation of the state of this border layout.
|
|
|
882 |
* @return a string representation of this border layout.
|
|
|
883 |
*/
|
|
|
884 |
public String toString() {
|
|
|
885 |
return getClass().getName() + "[hgap=" + hgap + ",vgap=" + vgap + "]";
|
|
|
886 |
}
|
|
|
887 |
}
|