public abstract class Spring extends Object
Spring class holds three properties that
  characterize its behavior: the minimum, preferred, and
  maximum values. Each of these properties may be involved in
  defining its fourth, value, property based on a series of rules.
  
  An instance of the Spring class can be visualized as a
  mechanical spring that provides a corrective force as the spring is compressed
  or stretched away from its preferred value. This force is modelled
  as linear function of the distance from the preferred value, but with
  two different constants -- one for the compressional force and one for the
  tensional one. Those constants are specified by the minimum and maximum
  values of the spring such that a spring at its minimum value produces an
  equal and opposite force to that which is created when it is at its
  maximum value. The difference between the preferred and
  minimum values, therefore, represents the ease with which the
  spring can be compressed and the difference between its maximum
  and preferred values, indicates the ease with which the
  Spring can be extended.
  See the sum(javax.swing.Spring, javax.swing.Spring) method for details.
  
  By defining simple arithmetic operations on Springs,
  the behavior of a collection of Springs
  can be reduced to that of an ordinary (non-compound) Spring. We define
  the "+", "-", max, and min operators on
  Springs so that, in each case, the result is a Spring
  whose characteristics bear a useful mathematical relationship to its constituent
  springs.
  
  A Spring can be treated as a pair of intervals
  with a single common point: the preferred value.
  The following rules define some of the
  arithmetic operators that can be applied to intervals
  ([a, b] refers to the interval
  from a
  to b,
  where a <= b).
  
          [a1, b1] + [a2, b2] = [a1 + a2, b1 + b2]
                      -[a, b] = [-b, -a]
      max([a1, b1], [a2, b2]) = [max(a1, a2), max(b1, b2)]
  
  
  If we denote Springs as [a, b, c],
  where a <= b <= c, we can define the same
  arithmetic operators on Springs:
  
          [a1, b1, c1] + [a2, b2, c2] = [a1 + a2, b1 + b2, c1 + c2]
                           -[a, b, c] = [-c, -b, -a]
      max([a1, b1, c1], [a2, b2, c2]) = [max(a1, a2), max(b1, b2), max(c1, c2)]
  
  
  With both intervals and Springs we can define "-" and min
  in terms of negation:
  
      X - Y = X + (-Y)
      min(X, Y) = -max(-X, -Y)
  
  
  For the static methods in this class that embody the arithmetic
  operators, we do not actually perform the operation in question as
  that would snapshot the values of the properties of the method's arguments
  at the time the static method is called. Instead, the static methods
  create a new Spring instance containing references to
  the method's arguments so that the characteristics of the new spring track the
  potentially changing characteristics of the springs from which it
  was made. This is a little like the idea of a lazy value
  in a functional language.
 
 If you are implementing a SpringLayout you
 can find further information and examples in
 How to Use SpringLayout,
 a section in The Java Tutorial.
 
 Warning:
 Serialized objects of this class will not be compatible with
 future Swing releases. The current serialization support is
 appropriate for short term storage or RMI between applications running
 the same version of Swing.  As of 1.4, support for long term storage
 of all JavaBeans™
 has been added to the java.beans package.
 Please see XMLEncoder.
SpringLayout, 
SpringLayout.Constraints| Modifier and Type | Field and Description | 
|---|---|
| static int | UNSETAn integer value signifying that a property value has not yet been calculated. | 
| Modifier | Constructor and Description | 
|---|---|
| protected  | Spring()Used by factory methods to create a  Spring. | 
| Modifier and Type | Method and Description | 
|---|---|
| static Spring | constant(int pref)Returns a strut -- a spring whose minimum, preferred, and
 maximum values each have the value  pref. | 
| static Spring | constant(int min,
        int pref,
        int max)Returns a spring whose minimum, preferred, and
 maximum values have the values:  min,pref,
 andmaxrespectively. | 
| abstract int | getMaximumValue()Returns the maximum value of this  Spring. | 
| abstract int | getMinimumValue()Returns the minimum value of this  Spring. | 
| abstract int | getPreferredValue()Returns the preferred value of this  Spring. | 
| abstract int | getValue()Returns the current value of this  Spring. | 
| static Spring | height(Component c)Returns a spring whose minimum, preferred, maximum
 and value properties are defined by the heights of the minimumSize,
 preferredSize, maximumSize and size properties
 of the supplied component. | 
| static Spring | max(Spring s1,
   Spring s2)Returns  max(s1, s2): a spring whose value is always greater than (or equal to)
         the values of boths1ands2. | 
| static Spring | minus(Spring s)Returns  -s: a spring running in the opposite direction tos. | 
| static Spring | scale(Spring s,
     float factor)Returns a spring whose minimum, preferred, maximum
 and value properties are each multiples of the properties of the
 argument spring,  s. | 
| abstract void | setValue(int value)Sets the current value of this  Springtovalue. | 
| static Spring | sum(Spring s1,
   Spring s2)Returns  s1+s2: a spring representings1ands2in series. | 
| static Spring | width(Component c)Returns a spring whose minimum, preferred, maximum
 and value properties are defined by the widths of the minimumSize,
 preferredSize, maximumSize and size properties
 of the supplied component. | 
public static final int UNSET
public abstract int getMinimumValue()
Spring.minimumValue property of this Springpublic abstract int getPreferredValue()
Spring.preferredValue of this Springpublic abstract int getMaximumValue()
Spring.maximumValue property of this Springpublic abstract int getValue()
Spring.value property of this SpringsetValue(int)public abstract void setValue(int value)
Spring to value.value - the new setting of the value propertygetValue()public static Spring constant(int pref)
pref.pref - the minimum, preferred, and
         maximum values of the new springprefSpringpublic static Spring constant(int min, int pref, int max)
min, pref,
 and max respectively.min - the minimum value of the new springpref - the preferred value of the new springmax - the maximum value of the new springmin, pref,
         and max respectivelySpringpublic static Spring minus(Spring s)
-s: a spring running in the opposite direction to s.-s: a spring running in the opposite direction to sSpringpublic static Spring sum(Spring s1, Spring s2)
s1+s2: a spring representing s1 and s2
 in series. In a sum, s3, of two springs, s1 and s2,
 the strains of s1, s2, and s3 are maintained
 at the same level (to within the precision implied by their integer values).
 The strain of a spring in compression is:
 
         value - pref
         ------------
          pref - min
 
 and the strain of a spring in tension is:
 
         value - pref
         ------------
          max - pref
 
 When setValue is called on the sum spring, s3, the strain
 in s3 is calculated using one of the formulas above. Once the strain of
 the sum is known, the values of s1 and s2 are
 then set so that they are have a strain equal to that of the sum. The formulas are
 evaluated so as to take rounding errors into account and ensure that the sum of
 the values of s1 and s2 is exactly equal to
 the value of s3.s1+s2: a spring representing s1 and s2 in seriesSpringpublic static Spring max(Spring s1, Spring s2)
max(s1, s2): a spring whose value is always greater than (or equal to)
         the values of both s1 and s2.max(s1, s2): a spring whose value is always greater than (or equal to)
         the values of both s1 and s2Springpublic static Spring scale(Spring s, float factor)
s. Minimum and maximum properties are
 swapped when factor is negative (in accordance with the
 rules of interval arithmetic).
 When factor is, for example, 0.5f the result represents 'the mid-point' of its input - an operation that is useful for centering components in a container.
s - the spring to scalefactor - amount to scale by.s
 multiplied by factorNullPointerException - if s is nullpublic static Spring width(Component c)
c - Component used for calculating sizeNullPointerException - if c is nullpublic static Spring height(Component c)
c - Component used for calculating sizeNullPointerException - if c is null Submit a bug or feature 
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