| /* Spring.java -- |
| Copyright (C) 2004 Free Software Foundation, Inc. |
| |
| This file is part of GNU Classpath. |
| |
| GNU Classpath is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2, or (at your option) |
| any later version. |
| |
| GNU Classpath is distributed in the hope that it will be useful, but |
| WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with GNU Classpath; see the file COPYING. If not, write to the |
| Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
| 02110-1301 USA. |
| |
| Linking this library statically or dynamically with other modules is |
| making a combined work based on this library. Thus, the terms and |
| conditions of the GNU General Public License cover the whole |
| combination. |
| |
| As a special exception, the copyright holders of this library give you |
| permission to link this library with independent modules to produce an |
| executable, regardless of the license terms of these independent |
| modules, and to copy and distribute the resulting executable under |
| terms of your choice, provided that you also meet, for each linked |
| independent module, the terms and conditions of the license of that |
| module. An independent module is a module which is not derived from |
| or based on this library. If you modify this library, you may extend |
| this exception to your version of the library, but you are not |
| obligated to do so. If you do not wish to do so, delete this |
| exception statement from your version. */ |
| |
| package javax.swing; |
| |
| import java.awt.Component; |
| import java.awt.Dimension; |
| |
| /** |
| * Calculates the space between component edges, that are layed out by |
| * {@link SpringLayout}. |
| * <p> |
| * A Spring defines a minimum, preferred and maximum distance for each edge |
| * (north, east, south, west) of a component. |
| * </p> |
| * However, springs are not static, their actual values are computed at |
| * runtime. That means, if a Spring C is defined as the sum of Spring A and |
| * Spring B, then the values (min, pref and max) are not calculated at |
| * creation of Spring C, but instead always when {@link #getValue} is |
| * called. So, when Spring A or Spring B changes, this is reflected in |
| * Spring C. |
| * |
| * @author Roman Kennke (roman@ontographics.com) |
| */ |
| public abstract class Spring |
| { |
| |
| /** Indicates a not-set value. **/ |
| public static final int UNSET = Integer.MIN_VALUE; |
| |
| /** |
| * Creates a new Spring object. This constructor is used by the static |
| * methods which create Springs. |
| */ |
| protected Spring() |
| { |
| // Nothing to do here. |
| } |
| |
| /** |
| * Creates a Spring which min, pref and max values are all the same. |
| * These kind of Springs are 'struts'. |
| * |
| * @param val the constant for min, pref and max values. |
| * @return a Spring object with constant values for min, pref and max. |
| */ |
| public static Spring constant(int val) |
| { |
| return new SimpleSpring(val, val, val); |
| } |
| |
| /** Creates a Spring which min, pref and max values are constants. |
| * @param min the constant for the minimum value. |
| * @param pref the constant for the preferred value. |
| * @param max the constant for the maximum value. |
| * @return a Spring object with constant values for min, pref and max. |
| */ |
| public static Spring constant(int min, int pref, int max) |
| { |
| return new SimpleSpring(min, pref, max); |
| } |
| |
| /** |
| * Returns the maximum value of the Spring. |
| * |
| * @return the maximum value. |
| */ |
| public abstract int getMaximumValue(); |
| |
| /** |
| * Returns the minimum value of this Spring. |
| * |
| * @return the minimum value. |
| */ |
| public abstract int getMinimumValue(); |
| |
| /** |
| * Return the preferred value of this Spring. |
| * |
| * @return the preferred value. |
| */ |
| public abstract int getPreferredValue(); |
| |
| /** |
| * Return the actual value of this Spring. |
| * |
| * @return the actual value of this Spring. |
| */ |
| public abstract int getValue(); |
| |
| /** |
| * Creates and returns a Spring, which always has the maximum values |
| * min = max(min_s1, min_s2), pref = max(pref_s1, pref_s2), max = |
| * max(max_s1, max_s2). |
| * |
| * @param s1 the first summand of the max Spring. |
| * @param s2 the second summand of the max Spring. |
| * @return a Spring which is max(s1, s2). |
| */ |
| public static Spring max(Spring s1, Spring s2) |
| { |
| return new MaxSpring(s1, s2); |
| } |
| |
| /** |
| * Creates and returns a Spring, which is always the negation of s. |
| * min = -min_s, pref = -pref_s, max = -max_pref. |
| * |
| * @param s the Spring to be negated. |
| * @return the negative of <code>s</code>. |
| */ |
| public static Spring minus(Spring s) |
| { |
| return new MinusSpring(s); |
| } |
| |
| /** |
| * Sets the actual value. If <code>value</code> is out of the (min, max) |
| * bounds, then the value is adjusted, so that is inside these bounds. |
| * |
| * @param value the value to be set. |
| */ |
| public abstract void setValue(int value); |
| |
| private int getShrinkRange() |
| { |
| return (getPreferredValue() - getMinimumValue()); |
| } |
| |
| private int getExpandRange() |
| { |
| return (getMaximumValue() - getPreferredValue()); |
| } |
| |
| double getStrain() |
| { |
| int v = getValue(); |
| int p = getPreferredValue(); |
| int r = (v < p) ? getShrinkRange() : getExpandRange(); |
| if (r == 0) |
| r = 1; |
| return (double)(v - p) / r; |
| } |
| |
| void setStrain(double strain) |
| { |
| int r = (strain < 0) ? getShrinkRange() : getExpandRange(); |
| int v = (getPreferredValue() + (int)(strain * r)); |
| setValue(v); |
| } |
| |
| /** |
| * Creates and returns a Spring, which is always the sum of s1 and s2. |
| * min_sum = min_s1 + min_s2, pref_sum = pref_s1 + pref_s2, max_sum = |
| * max_s1 + max_s2. |
| * |
| * @param s1 the 1st summand of the sum Spring. |
| * @param s2 the 2nd summand of the sum Spring. |
| * @return a sum which is <code>s1 + s2</code>. |
| */ |
| public static Spring sum(Spring s1, Spring s2) |
| { |
| return new AddSpring(s1, s2); |
| } |
| |
| /** |
| * Return a new Spring which computes its values by scaling |
| * the values of another spring by a constant factor. If the |
| * factor is negative, the minimum and maximum values of |
| * the argument spring will be interchanged. |
| * @param spring the spring to track |
| * @param factor the factor by which to scale |
| * @return a new multiplicative Spring |
| * @since 1.5 |
| */ |
| public static Spring scale(final Spring spring, final float factor) |
| { |
| if (spring == null) |
| throw new NullPointerException("spring argument is null"); |
| return new Spring() |
| { |
| public int getMaximumValue() |
| { |
| return (int) ((factor < 0 ? spring.getMinimumValue() |
| : spring.getMaximumValue()) |
| * factor); |
| } |
| |
| public int getMinimumValue() |
| { |
| return (int) ((factor < 0 ? spring.getMaximumValue() |
| : spring.getMinimumValue()) |
| * factor); |
| } |
| |
| public int getPreferredValue() |
| { |
| return (int) (spring.getPreferredValue() * factor); |
| } |
| |
| public int getValue() |
| { |
| return (int) (spring.getValue() * factor); |
| } |
| |
| public void setValue(int value) |
| { |
| spring.setValue((int) (value / factor)); |
| } |
| }; |
| } |
| |
| /** |
| * Return a new Spring which takes its values from the specified |
| * Component. In particular, the maximum value is taken from |
| * the maximumSize, the minimum value is taken from the minimumSize, |
| * the preferred value is taken from the preferredSize, and the |
| * value is taken from the component's current size. These values |
| * change as the component changes size. |
| * @param component the component |
| * @return a new Spring which tracks the component's width |
| * @since 1.5 |
| */ |
| public static Spring width(final Component component) |
| { |
| return new Spring() |
| { |
| public int getMaximumValue() |
| { |
| return component.getMaximumSize().width; |
| } |
| |
| public int getMinimumValue() |
| { |
| return component.getMinimumSize().width; |
| } |
| |
| public int getPreferredValue() |
| { |
| return component.getPreferredSize().width; |
| } |
| |
| public int getValue() |
| { |
| return component.getSize().width; |
| } |
| |
| public void setValue(int value) |
| { |
| Dimension d = component.getSize(); |
| component.setSize(value, d.height); |
| } |
| }; |
| } |
| |
| /** |
| * Return a new Spring which takes its values from the specified |
| * Component. In particular, the maximum value is taken from |
| * the maximumSize, the minimum value is taken from the minimumSize, |
| * the preferred value is taken from the preferredSize, and the |
| * value is taken from the component's current size. These values |
| * change as the component changes size. |
| * @param component the component |
| * @return a new Spring which tracks the component's height |
| * @since 1.5 |
| */ |
| public static Spring height(final Component component) |
| { |
| return new Spring() |
| { |
| public int getMaximumValue() |
| { |
| return component.getMaximumSize().height; |
| } |
| |
| public int getMinimumValue() |
| { |
| return component.getMinimumSize().height; |
| } |
| |
| public int getPreferredValue() |
| { |
| return component.getPreferredSize().height; |
| } |
| |
| public int getValue() |
| { |
| return component.getSize().height; |
| } |
| |
| public void setValue(int value) |
| { |
| Dimension d = component.getSize(); |
| component.setSize(d.width, value); |
| } |
| }; |
| } |
| |
| /** |
| * A simple Spring, that holds constant values for min, pref and max. |
| * |
| * @author Roman Kennke (roman@ontographics.com) |
| */ |
| private static final class SimpleSpring extends Spring |
| { |
| |
| /** The constant value for min. */ |
| private final int min; |
| |
| /** The constant value for pref. */ |
| private final int pref; |
| |
| /** The constant value for max. */ |
| private final int max; |
| |
| /** The actual value of the spring. */ |
| private int value; |
| |
| public String toString() |
| { |
| return "SimpleSpring of " + value; |
| } |
| |
| /** |
| * Creates a new SimpleSpring object. |
| * |
| * @param newMin the constant minimum value. |
| * @param newPref the constant preferred value. |
| * @param newMax the constant maximum value. |
| */ |
| public SimpleSpring(int newMin, int newPref, int newMax) |
| { |
| min = newMin; |
| pref = newPref; |
| max = newMax; |
| value = newPref; |
| } |
| |
| /** |
| * Returns the maximum value of this Spring. |
| * |
| * @return the maximum value. |
| */ |
| public int getMaximumValue() |
| { |
| return max; |
| } |
| |
| /** |
| * Returns the minimum value of this Spring. |
| * |
| * @return the minimum value. |
| */ |
| public int getMinimumValue() |
| { |
| return min; |
| } |
| |
| /** |
| * Returns the preferred value of this Spring. |
| * |
| * @return the preferred value. |
| */ |
| public int getPreferredValue() |
| { |
| return pref; |
| } |
| |
| /** |
| * Return the actual current value of this Spring. |
| * |
| * @return the current value. |
| */ |
| public int getValue() |
| { |
| if (value == Spring.UNSET) |
| return pref; |
| return value; |
| } |
| |
| /** |
| * Sets the current value. |
| * |
| * @param val the value to be set. |
| */ |
| public void setValue(int val) |
| { |
| value = val; |
| } |
| } |
| |
| |
| /** |
| * A Spring, that is the sum of two other Springs. |
| * |
| * @author Roman Kennke (roman@ontographics.com) |
| */ |
| private static final class AddSpring extends Spring |
| { |
| |
| /** The springs, that are the 'operands' of this Spring. */ |
| private final Spring s1; |
| private final Spring s2; |
| |
| /** The current value for this Spring. */ |
| private int value; |
| |
| public String toString() |
| { |
| return "AddSpring of " + s1 + " and " + s2; |
| } |
| |
| /** |
| * Creates a new AddSpring object. |
| * |
| * @param s1 the first operand. |
| * @param s2 the second operand. |
| */ |
| protected AddSpring(Spring s1, Spring s2) |
| { |
| super(); |
| this.s1 = s1; |
| this.s2 = s2; |
| value = Spring.UNSET; |
| } |
| |
| /** |
| * Returns the maximum value of this Spring. |
| * |
| * @return the maximum value. |
| */ |
| public int getMaximumValue() |
| { |
| int max1 = s1.getMaximumValue(); |
| int max2 = s2.getMaximumValue(); |
| return max1 + max2; |
| } |
| |
| /** |
| * Return the minimum value of this Spring. |
| * |
| * @return the minimum value. |
| */ |
| public int getMinimumValue() |
| { |
| int min1 = s1.getMinimumValue(); |
| int min2 = s2.getMinimumValue(); |
| return min1 + min2; |
| } |
| |
| /** |
| * Returns the preferred value of this Spring. |
| * |
| * @return the preferred value. |
| */ |
| public int getPreferredValue() |
| { |
| int pref1 = s1.getPreferredValue(); |
| int pref2 = s2.getPreferredValue(); |
| return pref1 + pref2; |
| } |
| |
| /** |
| * Returns the actual current value of this Spring. |
| * |
| * @return the current value of this Spring. |
| */ |
| public int getValue() |
| { |
| if (value == Spring.UNSET) |
| { |
| int val1 = s1.getValue(); |
| int val2 = s2.getValue(); |
| value = val1 + val2; |
| } |
| return value; |
| } |
| |
| /** |
| * Sets the current value. |
| * |
| * @param val the value to be set. |
| */ |
| public void setValue(int val) |
| { |
| if (val == Spring.UNSET) |
| { |
| if (value != Spring.UNSET) |
| { |
| s1.setValue(Spring.UNSET); |
| s2.setValue(Spring.UNSET); |
| } |
| value = Spring.UNSET; |
| return; |
| } |
| |
| value = val; |
| |
| //Spead the value over the two components |
| double fStrain = getStrain(); |
| s1.setStrain(fStrain); |
| int remainder = val - s1.getValue(); |
| s2.setValue(remainder); |
| } |
| |
| } |
| |
| |
| /** |
| * A Spring that is calculated as the negation of another Spring. |
| * |
| * @author Roman Kennke (roman@ontographics.com) |
| */ |
| private static final class MinusSpring extends Spring |
| { |
| |
| /** The Spring from which to calculate the negation. */ |
| private final Spring s; |
| |
| public String toString() |
| { |
| return "MinusSpring of " + s; |
| } |
| |
| /** |
| * Creates a new MinusSpring object. |
| * @param s the Spring from which to calculate the negation. |
| */ |
| protected MinusSpring(Spring s) |
| { |
| super(); |
| this.s = s; |
| } |
| |
| /** Returns the maximum value of this Spring. |
| * |
| * @return the maximum value. |
| */ |
| public int getMaximumValue() |
| { |
| return -s.getMinimumValue(); |
| } |
| |
| /** |
| * Returns the minimum value of this Spring. |
| * |
| * @return the minimum value. |
| */ |
| public int getMinimumValue() |
| { |
| return -s.getMaximumValue(); |
| } |
| |
| /** |
| * Returns the preferred value of this Spring. |
| * |
| * @return the preferred value. |
| */ |
| public int getPreferredValue() |
| { |
| return -s.getPreferredValue(); |
| } |
| |
| /** |
| * Returns the current value of this Spring. |
| * |
| * @return the current value. |
| */ |
| public int getValue() |
| { |
| return -s.getValue(); |
| } |
| |
| /** |
| * Sets the current value. |
| * |
| * @param val the value to be set. |
| */ |
| public void setValue(int val) |
| { |
| if (val == Spring.UNSET) |
| s.setValue(Spring.UNSET); |
| else |
| s.setValue(-val); |
| } |
| } |
| |
| |
| /** |
| * A Spring, that is calculated as the maximum of two Springs. |
| * |
| * @author Roman Kennke (roman@ontographics.com) |
| */ |
| private static final class MaxSpring extends Spring |
| { |
| |
| /** The two other Springs from which to calculate the maximum. */ |
| private final Spring s1; |
| private final Spring s2; |
| |
| public String toString() |
| { |
| return "MaxSpring of " + s1 + " and " + s2; |
| } |
| |
| /** The current value of this Spring. */ |
| private int value; |
| |
| /** |
| * Creates a new MaxSpring object. |
| * |
| * @param s1 the 1st operand. |
| * @param s2 the 2nd operand. |
| */ |
| protected MaxSpring(Spring s1, Spring s2) |
| { |
| super(); |
| this.s1 = s1; |
| this.s2 = s2; |
| value = Spring.UNSET; |
| } |
| |
| |
| /** |
| * Returns the maximum value of this Spring. |
| * |
| * @return the maximum value. |
| */ |
| public int getMaximumValue() |
| { |
| int max1 = s1.getMaximumValue(); |
| int max2 = s2.getMaximumValue(); |
| return Math.max(max1, max2); |
| } |
| |
| /** |
| * Returns the minimum value of this Spring. |
| * |
| * @return the minimum value. |
| */ |
| public int getMinimumValue() |
| { |
| int min1 = s1.getMinimumValue(); |
| int min2 = s2.getMinimumValue(); |
| return Math.max(min1, min2); |
| } |
| |
| /** |
| * Returns the preferred value of this Spring. |
| * |
| * @return the preferred value. |
| */ |
| public int getPreferredValue() |
| { |
| int pref1 = s1.getPreferredValue(); |
| int pref2 = s2.getPreferredValue(); |
| return Math.max(pref1, pref2); |
| } |
| |
| /** |
| * Returns the actual value of this Spring. |
| * |
| * @return the current value. |
| */ |
| public int getValue() |
| { |
| if (value == Spring.UNSET) |
| { |
| int val1 = s1.getValue(); |
| int val2 = s2.getValue(); |
| value = Math.max(val1, val2); |
| } |
| return value; |
| } |
| |
| /** |
| * Sets the current value. |
| * |
| * @param val the value to be set. |
| */ |
| public void setValue(int val) |
| { |
| if (val == Spring.UNSET) |
| { |
| if (value != Spring.UNSET) |
| { |
| s1.setValue(Spring.UNSET); |
| s2.setValue(Spring.UNSET); |
| } |
| value = Spring.UNSET; |
| return; |
| } |
| |
| value = val; |
| |
| int p1 = s1.getPreferredValue(); |
| int p2 = s2.getPreferredValue(); |
| |
| if (p1 < p2) |
| { |
| s1.setValue(Math.min(val, p1)); |
| s2.setValue(val); |
| } |
| else |
| { |
| s1.setValue(val); |
| s2.setValue(Math.min(val, p2)); |
| } |
| } |
| } |
| } |