// ============================================================================ // 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); } }