Layout (Codename One API)

java.lang.Object
- com.codename1.ui.layouts.Layout

Direct Known Subclasses:

BorderLayout, BoxLayout, CoordinateLayout, FlowLayout, GridBagLayout, GridLayout, GroupLayout, LayeredLayout, MigLayout, TableLayout, TextModeLayout
```
public abstract class Layout
extends Object
```
Abstract class that can be used to arrange components in a container using a predefined algorithm. This class may be implemented externally and is similar in spirit to the AWT/Swing layout managers.

Constructor Summary

Constructors
Constructor and Description

Layout()

Constructors
Constructor and Description
`Layout()`

Method Summary

All Methods Instance Methods Abstract Methods Concrete Methods
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.
`Object`	`cloneConstraint(Object constraint)`
`boolean`	`equals(Object o)` Indicates whether some other object is "equal to" this one.
`protected Component[]`	`getChildrenInTraversalOrder(Container parent)` Gets the children of the parent container in the order that they should be traversed when tabbing through a form.
`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.
`boolean`	`overridesTabIndices(Container parent)` If a layout specifies a different traversal order of its components than the component index, then it should override this method to return true, and it should also override `getChildrenInTraversalOrder(com.codename1.ui.Container)` to set the tab indices of a container's children.
`void`	`removeLayoutComponent(Component comp)` Removes the component from the layout this operation is only useful if the layout maintains references to components within it
`int`	`updateTabIndices(Container parent, int offset)` Updates the tab traversal order

Methods inherited from class java.lang.Object
clone, getClass, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - Layout
```
public Layout()
```
- Method Detail
  - layoutContainer
```
public abstract void layoutContainer(Container parent)
```
    Layout the given parent container children
    
    Parameters:
    
    parent - the given parent container
  - getPreferredSize
```
public abstract Dimension getPreferredSize(Container parent)
```
    Returns the container preferred size
    
    Parameters:
    
    parent - the parent container
    
    Returns:
    
    the container preferred size
  - addLayoutComponent
```
public 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.
    
    Parameters:
    
    value - optional meta data information, like alignment orientation
    
    comp - the added component to the layout
    
    c - the parent container
  - removeLayoutComponent
```
public void removeLayoutComponent(Component comp)
```
    Removes the component from the layout this operation is only useful if the layout maintains references to components within it
    
    Parameters:
    
    comp - the removed component from layout
  - getComponentConstraint
```
public Object getComponentConstraint(Component comp)
```
    Returns the optional component constraint
    
    Parameters:
    
    comp - the component whose constraint should be returned
    
    Returns:
    
    the optional component constraint
  - cloneConstraint
```
public Object cloneConstraint(Object constraint)
```
  - isOverlapSupported
```
public boolean isOverlapSupported()
```
    This method returns true if the Layout allows Components to Overlap.
    
    Returns:
    
    true if Components may intersect in this layout
  - equals
```
public boolean equals(Object o)
```
    Indicates whether some other object is "equal to" this one. The equals method implements an equivalence relation: It is reflexive: for any reference value x, x.equals(x) should return true. It is symmetric: for any reference values x and y, x.equals(y) should return true if and only if y.equals(x) returns true. It is transitive: for any reference values x, y, and z, if x.equals(y) returns true and y.equals(z) returns true, then x.equals(z) should return true. It is consistent: for any reference values 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 object is modified. For any non-null reference value 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 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).
    
    Overrides:
    
    equals in class Object
  - hashCode
```
public int hashCode()
```
    Returns a hash code value for the object. This method is supported for the benefit of hashtables such as those provided by java.util.Hashtable. The general contract of hashCode is: Whenever it is invoked on the same object more than once during an execution of a Java application, the 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. If two objects are equal according to the equals(Object) method, then calling the hashCode method on each of the two objects must produce the same integer result. It is not required that if two objects are unequal according to the 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 hashtables. 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 JavaTM programming language.)
    
    Overrides:
    
    hashCode in class Object
  - isConstraintTracking
```
public boolean isConstraintTracking()
```
    If this method returns true, the addLayoutComponent method will be called when replacing a layout for every component within the container
    
    Returns:
    
    false by default
  - obscuresPotential
```
public 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. This method doesn't take padding/margin etc. into account since that is checked by the caller
    
    Parameters:
    
    parent - parent container
    
    Returns:
    
    true if there is a chance that this layout manager can fully obscure the background, when in doubt return false...
  - overridesTabIndices
```
public boolean overridesTabIndices(Container parent)
```
    If a layout specifies a different traversal order of its components than the component index, then it should override this method to return true, and it should also override getChildrenInTraversalOrder(com.codename1.ui.Container) to set the tab indices of a container's children.
    
    Parameters:
    
    parent - The parent component.
    
    Returns:
    
    True if this layout overrides tab traversal order.
  - updateTabIndices
```
public final int updateTabIndices(Container parent,
                                  int offset)
```
    Updates the tab traversal order
    
    Parameters:
    
    parent -
    
    offset -
    
    Returns:
  - getChildrenInTraversalOrder
```
protected Component[] getChildrenInTraversalOrder(Container parent)
```
    Gets the children of the parent container in the order that they should be traversed when tabbing through a form.
    This should only be overridden if the Layout defines a different traversal order than the standard index order.
    
    Layouts that implement this method, should override the overridesTabIndices(com.codename1.ui.Container) method to return true.
    
    Parameters:
    
    parent -
    
    Returns:
    
    Array of Components in the order

Class Layout

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

Layout

Method Detail

layoutContainer

getPreferredSize

addLayoutComponent

removeLayoutComponent

getComponentConstraint

cloneConstraint

isOverlapSupported

equals

hashCode

isConstraintTracking

obscuresPotential

overridesTabIndices

updateTabIndices

getChildrenInTraversalOrder