Android APIs
public static class

ViewGroup.LayoutParams

extends Object
java.lang.Object
   ↳ android.view.ViewGroup.LayoutParams
Known Direct Subclasses
Known Indirect Subclasses

Class Overview

LayoutParams are used by views to tell their parents how they want to be laid out. See ViewGroup Layout Attributes for a list of all child view attributes that this class supports.

The base LayoutParams class just describes how big the view wants to be for both width and height. For each dimension, it can specify one of:

  • FILL_PARENT (renamed MATCH_PARENT in API Level 8 and higher), which means that the view wants to be as big as its parent (minus padding)
  • WRAP_CONTENT, which means that the view wants to be just big enough to enclose its content (plus padding)
  • an exact number
There are subclasses of LayoutParams for different subclasses of ViewGroup. For example, AbsoluteLayout has its own subclass of LayoutParams which adds an X and Y value.

Developer Guides

For more information about creating user interface layouts, read the XML Layouts developer guide.

Summary

XML Attributes
Attribute Name Related Method Description
android:layout_height Specifies the basic height of the view. 
android:layout_width Specifies the basic width of the view. 
Constants
int FILL_PARENT Special value for the height or width requested by a View.
int MATCH_PARENT Special value for the height or width requested by a View.
int WRAP_CONTENT Special value for the height or width requested by a View.
Fields
public int height Information about how tall the view wants to be.
public LayoutAnimationController.AnimationParameters layoutAnimationParameters Used to animate layouts.
public int width Information about how wide the view wants to be.
Public Constructors
ViewGroup.LayoutParams(Context c, AttributeSet attrs)
Creates a new set of layout parameters.
ViewGroup.LayoutParams(int width, int height)
Creates a new set of layout parameters with the specified width and height.
ViewGroup.LayoutParams(ViewGroup.LayoutParams source)
Copy constructor.
Public Methods
void resolveLayoutDirection(int layoutDirection)
Resolve layout parameters depending on the layout direction.
Protected Methods
void setBaseAttributes(TypedArray a, int widthAttr, int heightAttr)
Extracts the layout parameters from the supplied attributes.
[Expand]
Inherited Methods
From class java.lang.Object

XML Attributes

android:layout_height

Specifies the basic height of the view. This is a required attribute for any view inside of a containing layout manager. Its value may be a dimension (such as "12dip") for a constant height or one of the special constants.

May be a dimension value, which is a floating point number appended with a unit such as "14.5sp". Available units are: px (pixels), dp (density-independent pixels), sp (scaled pixels based on preferred font size), in (inches), mm (millimeters).

This may also be a reference to a resource (in the form "@[package:]type:name") or theme attribute (in the form "?[package:][type:]name") containing a value of this type.

May be one of the following constant values.

ConstantValueDescription
fill_parent-1 The view should be as big as its parent (minus padding). This constant is deprecated starting from API Level 8 and is replaced by match_parent.
match_parent-1 The view should be as big as its parent (minus padding). Introduced in API Level 8.
wrap_content-2 The view should be only big enough to enclose its content (plus padding).

This corresponds to the global attribute resource symbol layout_height.

Related Methods

android:layout_width

Specifies the basic width of the view. This is a required attribute for any view inside of a containing layout manager. Its value may be a dimension (such as "12dip") for a constant width or one of the special constants.

May be a dimension value, which is a floating point number appended with a unit such as "14.5sp". Available units are: px (pixels), dp (density-independent pixels), sp (scaled pixels based on preferred font size), in (inches), mm (millimeters).

This may also be a reference to a resource (in the form "@[package:]type:name") or theme attribute (in the form "?[package:][type:]name") containing a value of this type.

May be one of the following constant values.

ConstantValueDescription
fill_parent-1 The view should be as big as its parent (minus padding). This constant is deprecated starting from API Level 8 and is replaced by match_parent.
match_parent-1 The view should be as big as its parent (minus padding). Introduced in API Level 8.
wrap_content-2 The view should be only big enough to enclose its content (plus padding).

This corresponds to the global attribute resource symbol layout_width.

Related Methods

Constants

public static final int FILL_PARENT

Added in API level 1

Special value for the height or width requested by a View. FILL_PARENT means that the view wants to be as big as its parent, minus the parent's padding, if any. This value is deprecated starting in API Level 8 and replaced by MATCH_PARENT.

Constant Value: -1 (0xffffffff)

public static final int MATCH_PARENT

Added in API level 8

Special value for the height or width requested by a View. MATCH_PARENT means that the view wants to be as big as its parent, minus the parent's padding, if any. Introduced in API Level 8.

Constant Value: -1 (0xffffffff)

public static final int WRAP_CONTENT

Added in API level 1

Special value for the height or width requested by a View. WRAP_CONTENT means that the view wants to be just large enough to fit its own internal content, taking its own padding into account.

Constant Value: -2 (0xfffffffe)

Fields

public int height

Added in API level 1

Information about how tall the view wants to be. Can be one of the constants FILL_PARENT (replaced by MATCH_PARENT in API Level 8) or WRAP_CONTENT, or an exact size.

public LayoutAnimationController.AnimationParameters layoutAnimationParameters

Added in API level 1

Used to animate layouts.

public int width

Added in API level 1

Information about how wide the view wants to be. Can be one of the constants FILL_PARENT (replaced by MATCH_PARENT in API Level 8) or WRAP_CONTENT, or an exact size.

Public Constructors

public ViewGroup.LayoutParams (Context c, AttributeSet attrs)

Added in API level 1

Creates a new set of layout parameters. The values are extracted from the supplied attributes set and context. The XML attributes mapped to this set of layout parameters are:

Parameters
c Context: the application environment
attrs AttributeSet: the set of attributes from which to extract the layout parameters' values

public ViewGroup.LayoutParams (int width, int height)

Added in API level 1

Creates a new set of layout parameters with the specified width and height.

Parameters
width int: the width, either WRAP_CONTENT, FILL_PARENT (replaced by MATCH_PARENT in API Level 8), or a fixed size in pixels
height int: the height, either WRAP_CONTENT, FILL_PARENT (replaced by MATCH_PARENT in API Level 8), or a fixed size in pixels

public ViewGroup.LayoutParams (ViewGroup.LayoutParams source)

Added in API level 1

Copy constructor. Clones the width and height values of the source.

Parameters
source ViewGroup.LayoutParams: The layout params to copy from.

Public Methods

public void resolveLayoutDirection (int layoutDirection)

Added in API level 17

Resolve layout parameters depending on the layout direction. Subclasses that care about layoutDirection changes should override this method. The default implementation does nothing.

Parameters
layoutDirection int: the direction of the layout LAYOUT_DIRECTION_LTR LAYOUT_DIRECTION_RTL

Protected Methods

protected void setBaseAttributes (TypedArray a, int widthAttr, int heightAttr)

Added in API level 1

Extracts the layout parameters from the supplied attributes.

Parameters
a TypedArray: the style attributes to extract the parameters from
widthAttr int: the identifier of the width attribute
heightAttr int: the identifier of the height attribute