import java.awt.Component;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.Insets;
import java.awt.LayoutManager;
import java.util.Hashtable;
import javax.swing.JButton;
import javax.swing.JFrame;
public class VerticalFlowLayoutTest {
/**
* @param args
*/
public static void main(String[] args) {
JFrame f = new JFrame();
f.setExtendedState(JFrame.MAXIMIZED_BOTH);
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setLayout(new VerticalLayout());
for (int i = 0; i < 10; i++) {
JButton b = new JButton("xxxxxxxxxxx");
f.add(b);
}
f.setVisible(true);
}
}
/**
* THIS PROGRAM IS PROVIDED "AS IS" WITHOUT ANY WARRANTIES (OR CONDITIONS),
* EXPRESS OR IMPLIED WITH RESPECT TO THE PROGRAM, INCLUDING THE IMPLIED
* WARRANTIES (OR CONDITIONS) OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE. THE ENTIRE RISK ARISING OUT OF USE OR PERFORMANCE OF THE PROGRAM AND
* DOCUMENTATION REMAINS WITH THE USER.
*/
/**
*
* A vertical layout manager similar to java.awt.FlowLayout. Like FlowLayout
* components do not expand to fill available space except when the horizontal
* alignment is <code>BOTH</code> in which case components are stretched
* horizontally. Unlike FlowLayout, components will not wrap to form another
* column if there isn't enough space vertically. VerticalLayout can optionally
* anchor components to the top or bottom of the display area or center them
* between the top and bottom.
*
* Revision date 12th July 2001
*
* @author Colin Mummery e-mail: [email]colin_mummery@yahoo.com[/email]
* Homepage:[url=http://www.kagi.com/equitysoft]CellSpark - Java software and consulting[/url] - Based on 'FlexLayout' in Java
* class libraries Vol 2 Chan/Lee Addison-Wesley 1998
*/
class VerticalLayout implements LayoutManager {
/**
* The horizontal alignment constant that designates centering. Also used to
* designate center anchoring.
*/
public final static int CENTER = 0;
/**
* The horizontal alignment constant that designates right justification.
*/
public final static int RIGHT = 1;
/**
* The horizontal alignment constant that designates left justification.
*/
public final static int LEFT = 2;
/**
* The horizontal alignment constant that designates stretching the
* component horizontally.
*/
public final static int BOTH = 3;
/**
* The anchoring constant that designates anchoring to the top of the
* display area
*/
public final static int TOP = 1;
/**
* The anchoring constant that designates anchoring to the bottom of the
* display area
*/
public final static int BOTTOM = 2;
private int vgap; // the vertical vgap between components...defaults to 5
private int alignment; // LEFT, RIGHT, CENTER or BOTH...how the components
// are justified
private int anchor; // TOP, BOTTOM or CENTER ...where are the components
// positioned in an overlarge space
private Hashtable comps;
// Constructors
/**
* Constructs an instance of VerticalLayout with a vertical vgap of 5
* pixels, horizontal centering and anchored to the top of the display area.
*/
public VerticalLayout() {
this(5, CENTER, TOP);
}
/**
* Constructs a VerticalLayout instance with horizontal centering, anchored
* to the top with the specified vgap
*
* @param vgap
* An int value indicating the vertical seperation of the
* components
*/
public VerticalLayout(int vgap) {
this(vgap, CENTER, TOP);
}
/**
* Constructs a VerticalLayout instance anchored to the top with the
* specified vgap and horizontal alignment
*
* @param vgap
* An int value indicating the vertical seperation of the
* components
* @param alignment
* An int value which is one of
* <code>RIGHT, LEFT, CENTER, BOTH</code> for the horizontal
* alignment.
*/
public VerticalLayout(int vgap, int alignment) {
this(vgap, alignment, TOP);
}
/**
* Constructs a VerticalLayout instance with the specified vgap, horizontal
* alignment and anchoring
*
* @param vgap
* An int value indicating the vertical seperation of the
* components
* @param alignment
* An int value which is one of
* <code>RIGHT, LEFT, CENTER, BOTH</code> for the horizontal
* alignment.
* @param anchor
* An int value which is one of <code>TOP, BOTTOM, CENTER</code>
* indicating where the components are to appear if the display
* area exceeds the minimum necessary.
*/
public VerticalLayout(int vgap, int alignment, int anchor) {
this.vgap = vgap;
this.alignment = alignment;
this.anchor = anchor;
}
// ----------------------------------------------------------------------------
private Dimension layoutSize(Container parent, boolean minimum) {
Dimension dim = new Dimension(0, 0);
Dimension d;
synchronized (parent.getTreeLock()) {
int n = parent.getComponentCount();
for (int i = 0; i < n; i++) {
Component c = parent.getComponent(i);
if (c.isVisible()) {
d = minimum ? c.getMinimumSize() : c.getPreferredSize();
dim.width = Math.max(dim.width, d.width);
dim.height += d.height;
if (i > 0)
dim.height += vgap;
}
}
}
Insets insets = parent.getInsets();
dim.width += insets.left + insets.right;
dim.height += insets.top + insets.bottom + vgap + vgap;
return dim;
}
// -----------------------------------------------------------------------------
/**
* Lays out the container.
*/
public void layoutContainer(Container parent) {
Insets insets = parent.getInsets();
synchronized (parent.getTreeLock()) {
int n = parent.getComponentCount();
Dimension pd = parent.getSize();
int y = 0;
// work out the total size
for (int i = 0; i < n; i++) {
Component c = parent.getComponent(i);
Dimension d = c.getPreferredSize();
y += d.height + vgap;
}
y -= vgap; // otherwise there's a vgap too many
// Work out the anchor paint
if (anchor == TOP)
y = insets.top;
else if (anchor == CENTER)
y = (pd.height - y) / 2;
else
y = pd.height - y - insets.bottom;
// do layout
for (int i = 0; i < n; i++) {
Component c = parent.getComponent(i);
Dimension d = c.getPreferredSize();
int x = insets.left;
int wid = d.width;
if (alignment == CENTER)
x = (pd.width - d.width) / 2;
else if (alignment == RIGHT)
x = pd.width - d.width - insets.right;
else if (alignment == BOTH)
wid = pd.width - insets.left - insets.right;
c.setBounds(x, y, wid, d.height);
y += d.height + vgap;
}
}
}
// -----------------------------------------------------------------------------
public Dimension minimumLayoutSize(Container parent) {
return layoutSize(parent, false);
}
// -----------------------------------------------------------------------------
public Dimension preferredLayoutSize(Container parent) {
return layoutSize(parent, false);
}
// ----------------------------------------------------------------------------
/**
* Not used by this class
*/
public void addLayoutComponent(String name, Component comp) {
}
// -----------------------------------------------------------------------------
/**
* Not used by this class
*/
public void removeLayoutComponent(Component comp) {
}
// -----------------------------------------------------------------------------
public String toString() {
return getClass().getName() + "[vgap=" + vgap + " align=" + alignment
+ " anchor=" + anchor + "]";
}
}
