public abstract class Layout extends Object
Constructor and Description |
---|
Layout() |
Modifier and Type | Method and Description |
---|---|
void |
addLayoutComponent(Object value,
Component comp,
Container c)
Some layouts can optionally track the addition of elements with meta-data
that allows the user to "hint" on object positioning.
|
boolean |
equals(Object o)
Indicates whether some other object is "equal to" this one.
|
Object |
getComponentConstraint(Component comp)
Returns the optional component constraint
|
abstract Dimension |
getPreferredSize(Container parent)
Returns the container preferred size
|
int |
hashCode()
Returns a hash code value for the object.
|
boolean |
isConstraintTracking()
If this method returns true, the addLayoutComponent method will be called when replacing a
layout for every component within the container
|
boolean |
isOverlapSupported()
This method returns true if the Layout allows Components to
Overlap.
|
abstract void |
layoutContainer(Container parent)
Layout the given parent container children
|
boolean |
obscuresPotential(Container parent)
Some layout managers can obscure their child components in some cases this
returns true if the basic underpinnings are in place for that.
|
void |
removeLayoutComponent(Component comp)
Removes the component from the layout this operation is only useful if the
layout maintains references to components within it
|
public abstract void layoutContainer(Container parent)
parent
- the given parent containerpublic abstract Dimension getPreferredSize(Container parent)
parent
- the parent containerpublic void addLayoutComponent(Object value, Component comp, Container c)
value
- optional meta data information, like alignment orientationcomp
- the added component to the layoutc
- the parent containerpublic void removeLayoutComponent(Component comp)
comp
- the removed component from layoutpublic Object getComponentConstraint(Component comp)
comp
- the component whose constraint should be returnedpublic boolean isOverlapSupported()
public boolean equals(Object o)
Object
The equals
method implements an equivalence relation
on non-null object references:
x
, x.equals(x)
should return
true
.
x
and y
, x.equals(y)
should return true
if and only if
y.equals(x)
returns true
.
x
, y
, and z
, if
x.equals(y)
returns true
and
y.equals(z)
returns true
, then
x.equals(z)
should return true
.
x
and y
, multiple invocations of
x.equals(y)
consistently return true
or consistently return false
, provided no
information used in equals
comparisons on the
objects is modified.
x
,
x.equals(null)
should return false
.
The equals
method for class Object
implements
the most discriminating possible equivalence relation on objects;
that is, for any non-null reference values x
and
y
, this method returns true
if and only
if x
and y
refer to the same object
(x == y
has the value true
).
Note that it is generally necessary to override the hashCode
method whenever this method is overridden, so as to maintain the
general contract for the hashCode
method, which states
that equal objects must have equal hash codes.
equals
in class Object
o
- the reference object with which to compare.true
if this object is the same as the obj
argument; false
otherwise.Object.hashCode()
,
HashMap
public int hashCode()
Object
HashMap
.
The general contract of hashCode
is:
hashCode
method
must consistently return the same integer, provided no information
used in equals
comparisons on the object is modified.
This integer need not remain consistent from one execution of an
application to another execution of the same application.
equals(Object)
method, then calling the hashCode
method on each of
the two objects must produce the same integer result.
Object.equals(java.lang.Object)
method, then calling the hashCode
method on each of the
two objects must produce distinct integer results. However, the
programmer should be aware that producing distinct integer results
for unequal objects may improve the performance of hash tables.
As much as is reasonably practical, the hashCode method defined by
class Object
does return distinct integers for distinct
objects. (This is typically implemented by converting the internal
address of the object into an integer, but this implementation
technique is not required by the
Java™ programming language.)
hashCode
in class Object
Object.equals(java.lang.Object)
,
System.identityHashCode(java.lang.Object)
public boolean isConstraintTracking()
public boolean obscuresPotential(Container parent)
parent
- parent container