/*
* IzPack - Copyright 2001-2008 Julien Ponge, All Rights Reserved.
*
* http://izpack.org/
* http://izpack.codehaus.org/
*
* Copyright 2002 Elmar Grom
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.izforge.izpack.gui;
import java.awt.*;
/*---------------------------------------------------------------------------*/
/**
* A flow layout arranges components in a left-to-right flow, much like lines of text in a
* paragraph. Flow layouts are typically used to arrange buttons in a panel. It will arrange buttons
* left to right until no more buttons fit on the same line. Each line is centered.
* <p/>
* For example, the following picture shows an applet using the flow layout manager (its default
* layout manager) to position three buttons:
* <p/>
* <img src="doc-files/FlowLayout-1.gif" ALT="Graphic of Layout for Three Buttons" ALIGN=center
* HSPACE=10 VSPACE=7>
* <p/>
* Here is the code for this applet:
* <p/>
* <hr>
* <blockquote>
* <p/>
* <pre>
* import java.awt.*;
* import java.applet.Applet;
* <p/>
* public class myButtons extends Applet
* {
* <p/>
* Button button1, button2, button3;
* <p/>
* public void init()
* {
* button1 = new Button("Ok");
* button2 = new Button("Open");
* button3 = new Button("Close");
* add(button1);
* add(button2);
* add(button3);
* }
* }
* <p/>
* </pre>
* <p/>
* </blockquote>
* <hr>
* <p/>
* A flow layout lets each component assume its natural (preferred) size.
* <p/>
* This class is a bit different from java.awt.FlowLayout. <blockquote> java.awt.FlowLayout has a
* minor problem that was bugging me when I wrote the UserInputPanel. FlowLayout puts some amount of
* space in between each component that it lays out. In addition it adds that same amount of space
* to the left and to the right of the entire group. Therefore items such as the RuleInputfield that
* are laid out with a FlowLayout would never line up properly with the other components (it would
* appear to be slightly indented). Because there is no way to circumvent this behavior in
* FlowLayout (it's hard coded) I copied the source and modified it so that it does not add the
* space to the left and to the right. Now my stuff lines up properly. (Elmar Grom)</blockquote>
*
* @author Arthur van Hoff
* @author Sami Shaio
* @author Elmar Grom
* @version 1.39, 11/29/02
*/
/*---------------------------------------------------------------------------*/
public class FlowLayout implements LayoutManager
{
/**
* This value indicates that each row of components should be left-justified.
*/
public static final int LEFT = 0;
/**
* This value indicates that each row of components should be centered.
*/
public static final int CENTER = 1;
/**
* This value indicates that each row of components should be right-justified.
*/
public static final int RIGHT = 2;
/**
* This value indicates that each row of components should be justified to the leading edge of
* the container's orientation, for example, to the left in left-to-right orientations.
*
* @see java.awt.Component#getComponentOrientation
* @see java.awt.ComponentOrientation
* @since 1.2 Package-private pending API change approval
*/
public static final int LEADING = 3;
/**
* This value indicates that each row of components should be justified to the leading edge of
* the container's orientation, for example, to the right in left-to-right orientations.
*
* @see java.awt.Component#getComponentOrientation
* @see java.awt.ComponentOrientation
* @since 1.2 Package-private pending API change approval
*/
public static final int TRAILING = 4;
/**
* <code>align</code> is the proprty that determines how each row distributes empty space. It
* can be one of the following three values : <code>LEFT</code>
* <code>RIGHT</code>
* <code>CENTER</code>
*
* @serial
* @see #getAlignment
* @see #setAlignment
*/
int align; // This is for 1.1 serialization compatibilitys
/**
* <code>newAlign</code> is the property that determines how each row distributes empty space
* for the Java 2 platform, v1.2 and greater. It can be one of the following three values :
* <code>LEFT</code>
* <code>RIGHT</code>
* <code>CENTER</code>
*
* @serial
* @see #getAlignment
* @see #setAlignment
* @since 1.2
*/
int newAlign; // This is the one we actually use
/**
* The flow layout manager allows a seperation of components with gaps. The horizontal gap will
* specify the space between components.
*
* @serial
* @see #getHgap
* @see #setHgap
*/
int hgap;
/**
* The flow layout manager allows a seperation of components with gaps. The vertical gap will
* specify the space between rows.
*
* @serial
* @see #getVgap
* @see #setVgap
*/
int vgap;
/*--------------------------------------------------------------------------*/
/**
* Constructs a new Flow Layout with a centered alignment and a default 5-unit horizontal and
* vertical gap.
*/
/*--------------------------------------------------------------------------*/
public FlowLayout()
{
this(CENTER, 5, 5);
}
/*--------------------------------------------------------------------------*/
/**
* Constructs a new Flow Layout with the specified alignment and a default 5-unit horizontal and
* vertical gap. The value of the alignment argument must be one of <code>FlowLayout.LEFT</code>,
* <code>FlowLayout.RIGHT</code>, or <code>FlowLayout.CENTER</code>.
*
* @param align the alignment value
*/
/*--------------------------------------------------------------------------*/
public FlowLayout(int align)
{
this(align, 5, 5);
}
/*--------------------------------------------------------------------------*/
/**
* Creates a new flow layout manager with the indicated alignment and the indicated horizontal
* and vertical gaps.
* <p/>
* The value of the alignment argument must be one of <code>FlowLayout.LEFT</code>,
* <code>FlowLayout.RIGHT</code>, or <code>FlowLayout.CENTER</code>.
*
* @param align the alignment value.
* @param hgap the horizontal gap between components.
* @param vgap the vertical gap between components.
*/
/*--------------------------------------------------------------------------*/
public FlowLayout(int align, int hgap, int vgap)
{
this.hgap = hgap;
this.vgap = vgap;
setAlignment(align);
}
/*--------------------------------------------------------------------------*/
/**
* Gets the alignment for this layout. Possible values are <code>FlowLayout.LEFT</code>,
* <code>FlowLayout.RIGHT</code>, or <code>FlowLayout.CENTER</code>.
*
* @return the alignment value for this layout.
* @see java.awt.FlowLayout#setAlignment
*/
/*--------------------------------------------------------------------------*/
public int getAlignment()
{
return (newAlign);
}
/*--------------------------------------------------------------------------*/
/**
* Sets the alignment for this layout. Possible values are <code>FlowLayout.LEFT</code>,
* <code>FlowLayout.RIGHT</code>, and <code>FlowLayout.CENTER</code>.
*
* @param align the alignment value.
* @see #getAlignment()
*/
/*--------------------------------------------------------------------------*/
public void setAlignment(int align)
{
this.newAlign = align;
// this.align is used only for serialization compatibility,
// so set it to a value compatible with the 1.1 version
// of the class
switch (align)
{
case LEADING:
this.align = LEFT;
break;
case TRAILING:
this.align = RIGHT;
break;
default:
this.align = align;
break;
}
}
/*--------------------------------------------------------------------------*/
/**
* Gets the horizontal gap between components.
*
* @return the horizontal gap between components.
* @see #setHgap(int)
*/
/*--------------------------------------------------------------------------*/
public int getHgap()
{
return (hgap);
}
/*--------------------------------------------------------------------------*/
/**
* Sets the horizontal gap between components.
*
* @param hgap the horizontal gap between components
* @see #getHgap()
*/
/*--------------------------------------------------------------------------*/
public void setHgap(int hgap)
{
this.hgap = hgap;
}
/*--------------------------------------------------------------------------*/
/**
* Gets the vertical gap between components.
*
* @return the vertical gap between components.\
* @see #setVgap(int)
*/
/*--------------------------------------------------------------------------*/
public int getVgap()
{
return (vgap);
}
/*--------------------------------------------------------------------------*/
/**
* Sets the vertical gap between components.
*
* @param vgap the vertical gap between components
* @see #getVgap()
*/
/*--------------------------------------------------------------------------*/
public void setVgap(int vgap)
{
this.vgap = vgap;
}
/*--------------------------------------------------------------------------*/
/**
* Adds the specified component to the layout. Not used by this class.
*
* @param name the name of the component
* @param comp the component to be added
*/
/*--------------------------------------------------------------------------*/
public void addLayoutComponent(String name, Component comp)
{
}
/*--------------------------------------------------------------------------*/
/**
* Removes the specified component from the layout. Not used by this class.
*
* @param comp the component to remove
*/
/*--------------------------------------------------------------------------*/
public void removeLayoutComponent(Component comp)
{
}
/*--------------------------------------------------------------------------*/
/**
* Returns the preferred dimensions for this layout given the components in the specified target
* container.
*
* @param target the component which needs to be laid out
* @return the preferred dimensions to lay out the subcomponents of the specified container.
* @see #minimumLayoutSize(Container)
*/
/*--------------------------------------------------------------------------*/
public Dimension preferredLayoutSize(Container target)
{
synchronized (target.getTreeLock())
{
Dimension dim = new Dimension(0, 0);
int nmembers = target.getComponentCount();
boolean firstVisibleComponent = true;
for (int i = 0; i < nmembers; i++)
{
Component m = target.getComponent(i);
if (m.isVisible())
{
Dimension d = m.getPreferredSize();
dim.height = Math.max(dim.height, d.height);
if (firstVisibleComponent)
{
firstVisibleComponent = false;
}
else
{
dim.width += hgap;
}
dim.width += d.width;
}
}
Insets insets = target.getInsets();
dim.width += insets.left + insets.right + hgap * 2;
dim.height += insets.top + insets.bottom + vgap * 2;
return (dim);
}
}
/*--------------------------------------------------------------------------*/
/**
* Returns the minimum dimensions needed to layout the components contained in the specified
* target container.
*
* @param target the component which needs to be laid out
* @return the minimum dimensions to lay out the subcomponents of the specified container.
* @see #preferredLayoutSize(Container)
*/
/*--------------------------------------------------------------------------*/
public Dimension minimumLayoutSize(Container target)
{
synchronized (target.getTreeLock())
{
Dimension dim = new Dimension(0, 0);
int nmembers = target.getComponentCount();
for (int i = 0; i < nmembers; i++)
{
Component m = target.getComponent(i);
if (m.isVisible())
{
Dimension d = m.getMinimumSize();
dim.height = Math.max(dim.height, d.height);
if (i > 0)
{
dim.width += hgap;
}
dim.width += d.width;
}
}
Insets insets = target.getInsets();
dim.width += insets.left + insets.right + hgap * 2;
dim.height += insets.top + insets.bottom + vgap * 2;
return (dim);
}
}
/*--------------------------------------------------------------------------*/
/**
* Centers the elements in the specified row, if there is any slack.
*
* @param target the component which needs to be moved
* @param x the x coordinate
* @param y the y coordinate
* @param width the width dimensions
* @param height the height dimensions
* @param rowStart the beginning of the row
* @param rowEnd the the ending of the row
*/
/*--------------------------------------------------------------------------*/
private void moveComponents(Container target, int x, int y, int width, int height,
int rowStart, int rowEnd, boolean ltr)
{
synchronized (target.getTreeLock())
{
switch (newAlign)
{
case LEFT:
x += ltr ? 0 : width;
break;
case CENTER:
x += width / 2;
break;
case RIGHT:
x += ltr ? width : 0;
break;
case LEADING:
break;
case TRAILING:
x += width;
break;
}
for (int i = rowStart; i < rowEnd; i++)
{
Component m = target.getComponent(i);
if (m.isVisible())
{
if (ltr)
{
m.setLocation(x, y + (height - m.getSize().height) / 2);
}
else
{
m.setLocation(target.getSize().width - x - m.getSize().width, y
+ (height - m.getSize().height) / 2);
}
x += m.getSize().width + hgap;
}
}
}
}
/*--------------------------------------------------------------------------*/
/**
* Lays out the container. This method lets each component take its preferred size by reshaping
* the components in the target container in order to satisfy the constraints of this
* <code>FlowLayout</code> object.
*
* @param target the specified component being laid out.
*/
/*--------------------------------------------------------------------------*/
public void layoutContainer(Container target)
{
synchronized (target.getTreeLock())
{
Insets insets = target.getInsets();
int maxWidth = target.getSize().width - (insets.left + insets.right + hgap * 2);
int nMembers = target.getComponentCount();
int x = 0;
int y = insets.top + vgap;
int rowh = 0;
int start = 0;
boolean ltr = target.getComponentOrientation().isLeftToRight();
for (int i = 0; i < nMembers; i++)
{
Component m = target.getComponent(i);
if (m.isVisible())
{
Dimension d = m.getPreferredSize();
m.setSize(d.width, d.height);
if ((x == 0) || ((x + d.width) <= maxWidth))
{
if (x > 0)
{
x += hgap;
}
x += d.width;
rowh = Math.max(rowh, d.height);
}
else
{
moveComponents(target, insets.left, y, maxWidth - x, rowh, start, i, ltr);
x = d.width;
y += vgap + rowh;
rowh = d.height;
start = i;
}
}
}
moveComponents(target, insets.left, y, maxWidth - x, rowh, start, nMembers, ltr);
}
}
/*--------------------------------------------------------------------------*/
/**
* Returns a string representation of this <code>FlowLayout</code> object and its values.
*
* @return a string representation of this layout.
*/
/*--------------------------------------------------------------------------*/
public String toString()
{
String str = "";
switch (align)
{
case LEFT:
str = ",align=left";
break;
case CENTER:
str = ",align=center";
break;
case RIGHT:
str = ",align=right";
break;
case LEADING:
str = ",align=leading";
break;
case TRAILING:
str = ",align=trailing";
break;
}
return (getClass().getName() + "[hgap=" + hgap + ",vgap=" + vgap + str + "]");
}
}
/*---------------------------------------------------------------------------*/