// ============================================================================
// Copyright 2006-2012 Daniel W. Dyer
//
// 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 org.uncommons.swing;
import java.awt.Component;
import java.awt.Container;
import javax.swing.Spring;
import javax.swing.SpringLayout;
/**
* Utility methods for creating form-style or grid-style layouts with SpringLayout.
* Modified version of the class presented in the Sun Swing tutorial
* (http://java.sun.com/docs/books/tutorial/uiswing/layout/examples/SpringUtilities.java).
*/
public final class SpringUtilities
{
private SpringUtilities()
{
// Private constructor prevents instantiation of utility class.
}
/**
* Aligns the first {@code rows} * {@code cols} components of {@code parent}
* in a grid. Each component is as big as the maximum preferred width and
* height of the components. The parent is made just big enough to fit them
* all.
* @param parent The container to layout.
* @param rows Number of rows
* @param cols Number of columns
* @param initialX x location to start the grid at
* @param initialY y location to start the grid at
* @param xPad x padding between cells
* @param yPad y padding between cells
*/
public static void makeGrid(Container parent,
int rows,
int cols,
int initialX,
int initialY,
int xPad, int yPad)
{
if (!(parent.getLayout() instanceof SpringLayout))
{
throw new IllegalArgumentException("The first argument to makeGrid must use SpringLayout.");
}
SpringLayout layout = (SpringLayout) parent.getLayout();
Spring xPadSpring = Spring.constant(xPad);
Spring yPadSpring = Spring.constant(yPad);
Spring initialXSpring = Spring.constant(initialX);
Spring initialYSpring = Spring.constant(initialY);
int max = rows * cols;
// Calculate Springs that are the max of the width/height so that all
// cells have the same size.
Spring maxWidthSpring = layout.getConstraints(parent.getComponent(0)).getWidth();
Spring maxHeightSpring = layout.getConstraints(parent.getComponent(0)).getWidth();
for (int i = 1; i < max; i++)
{
SpringLayout.Constraints cons = layout.getConstraints(parent.getComponent(i));
maxWidthSpring = Spring.max(maxWidthSpring, cons.getWidth());
maxHeightSpring = Spring.max(maxHeightSpring, cons.getHeight());
}
// Apply the new width/height Spring. This forces all the
// components to have the same size.
for (int i = 0; i < max; i++)
{
SpringLayout.Constraints cons = layout.getConstraints(parent.getComponent(i));
cons.setWidth(maxWidthSpring);
cons.setHeight(maxHeightSpring);
}
// Then adjust the x/y constraints of all the cells so that they
// are aligned in a grid.
SpringLayout.Constraints lastConstraints = null;
SpringLayout.Constraints lastRowConstraints = null;
for (int i = 0; i < max; i++)
{
SpringLayout.Constraints constraints = layout.getConstraints(parent.getComponent(i));
if (i % cols == 0) // Start of new row.
{
lastRowConstraints = lastConstraints;
constraints.setX(initialXSpring);
}
else // X position depends on previous component.
{
constraints.setX(Spring.sum(lastConstraints.getConstraint(SpringLayout.EAST),
xPadSpring));
}
if (i / cols == 0) // First row.
{
constraints.setY(initialYSpring);
}
else // Y position depends on previous row.
{
constraints.setY(Spring.sum(lastRowConstraints.getConstraint(SpringLayout.SOUTH),
yPadSpring));
}
lastConstraints = constraints;
}
// Set the parent's size.
SpringLayout.Constraints pCons = layout.getConstraints(parent);
pCons.setConstraint(SpringLayout.SOUTH,
Spring.sum(Spring.constant(yPad),
lastConstraints.getConstraint(SpringLayout.SOUTH)));
pCons.setConstraint(SpringLayout.EAST,
Spring.sum(Spring.constant(xPad),
lastConstraints.getConstraint(SpringLayout.EAST)));
}
/**
* Aligns the first {@code rows} * {@code cols} components of {@code parent}
* in a grid. Each component in a column is as wide as the maximum preferred
* width of the components in that column; height is similarly determined for
* each row. The parent is made just big enough to fit them all.
* @param parent The container to layout.
* @param rows number of rows
* @param columns number of columns
* @param initialX x location to start the grid at
* @param initialY y location to start the grid at
* @param xPad x padding between cells
* @param yPad y padding between cells
*/
public static void makeCompactGrid(Container parent,
int rows,
int columns,
int initialX,
int initialY,
int xPad,
int yPad)
{
if (!(parent.getLayout() instanceof SpringLayout))
{
throw new IllegalArgumentException("The first argument to makeCompactGrid must use SpringLayout.");
}
SpringLayout layout = (SpringLayout) parent.getLayout();
// Align all cells in each column and make them the same width.
Spring x = Spring.constant(initialX);
for (int c = 0; c < columns; c++)
{
Spring width = Spring.constant(0);
for (int r = 0; r < rows; r++)
{
width = Spring.max(width,
getConstraintsForCell(r, c, parent, columns).getWidth());
}
for (int r = 0; r < rows; r++)
{
SpringLayout.Constraints constraints = getConstraintsForCell(r, c, parent, columns);
constraints.setX(x);
constraints.setWidth(width);
}
x = Spring.sum(x, Spring.sum(width, Spring.constant(xPad)));
}
// Align all cells in each row and make them the same height.
Spring y = Spring.constant(initialY);
for (int r = 0; r < rows; r++)
{
Spring height = Spring.constant(0);
for (int c = 0; c < columns; c++)
{
height = Spring.max(height,
getConstraintsForCell(r, c, parent, columns).getHeight());
}
for (int c = 0; c < columns; c++)
{
SpringLayout.Constraints constraints = getConstraintsForCell(r, c, parent, columns);
constraints.setY(y);
constraints.setHeight(height);
}
y = Spring.sum(y, Spring.sum(height, Spring.constant(yPad)));
}
// Set the parent's size.
SpringLayout.Constraints parentConstraints = layout.getConstraints(parent);
parentConstraints.setConstraint(SpringLayout.SOUTH, y);
parentConstraints.setConstraint(SpringLayout.EAST, x);
}
/**
* Helper method for {@link #makeCompactGrid(Container, int, int, int, int, int, int)}.
*/
private static SpringLayout.Constraints getConstraintsForCell(int row,
int col,
Container parent,
int cols)
{
SpringLayout layout = (SpringLayout) parent.getLayout();
Component c = parent.getComponent(row * cols + col);
return layout.getConstraints(c);
}
}