View.MeasureSpec

public static class View.MeasureSpec
extends Object

java.lang.Object
   ↳ android.view.View.MeasureSpec


A MeasureSpec encapsulates the layout requirements passed from parent to child. Each MeasureSpec represents a requirement for either the width or the height. A MeasureSpec is comprised of a size and a mode. There are three possible modes:

UNSPECIFIED
The parent has not imposed any constraint on the child. It can be whatever size it wants.
EXACTLY
The parent has determined an exact size for the child. The child is going to be given those bounds regardless of how big it wants to be.
AT_MOST
The child can be as large as it wants up to the specified size.
MeasureSpecs are implemented as ints to reduce object allocation. This class is provided to pack and unpack the <size, mode> tuple into the int.

Summary

Constants

int AT_MOST

Measure specification mode: The child can be as large as it wants up to the specified size.

int EXACTLY

Measure specification mode: The parent has determined an exact size for the child.

int UNSPECIFIED

Measure specification mode: The parent has not imposed any constraint on the child.

Public constructors

MeasureSpec()

Public methods

static int getMode(int measureSpec)

Extracts the mode from the supplied measure specification.

static int getSize(int measureSpec)

Extracts the size from the supplied measure specification.

static int makeMeasureSpec(int size, int mode)

Creates a measure specification based on the supplied size and mode.

static String toString(int measureSpec)

Returns a String representation of the specified measure specification.

Inherited methods

Constants

AT_MOST

Added in API level 1
public static final int AT_MOST

Measure specification mode: The child can be as large as it wants up to the specified size.

Constant Value: -2147483648 (0x80000000)

EXACTLY

Added in API level 1
public static final int EXACTLY

Measure specification mode: The parent has determined an exact size for the child. The child is going to be given those bounds regardless of how big it wants to be.

Constant Value: 1073741824 (0x40000000)

UNSPECIFIED

Added in API level 1
public static final int UNSPECIFIED

Measure specification mode: The parent has not imposed any constraint on the child. It can be whatever size it wants.

Constant Value: 0 (0x00000000)

Public constructors

MeasureSpec

public MeasureSpec ()

Public methods

getMode

Added in API level 1
public static int getMode (int measureSpec)

Extracts the mode from the supplied measure specification.

Parameters
measureSpec int: the measure specification to extract the mode from

Returns
int UNSPECIFIED, AT_MOST or EXACTLY Value is UNSPECIFIED, EXACTLY, or AT_MOST

getSize

Added in API level 1
public static int getSize (int measureSpec)

Extracts the size from the supplied measure specification.

Parameters
measureSpec int: the measure specification to extract the size from

Returns
int the size in pixels defined in the supplied measure specification

makeMeasureSpec

Added in API level 1
public static int makeMeasureSpec (int size, 
                int mode)

Creates a measure specification based on the supplied size and mode. The mode must always be one of the following:

Note: On API level 17 and lower, makeMeasureSpec's implementation was such that the order of arguments did not matter and overflow in either value could impact the resulting MeasureSpec. RelativeLayout was affected by this bug. Apps targeting API levels greater than 17 will get the fixed, more strict behavior.

Parameters
size int: the size of the measure specification Value is between 0 and (1 << MeasureSpec.MODE_SHIFT) - 1 inclusive

mode int: the mode of the measure specification Value is UNSPECIFIED, EXACTLY, or AT_MOST

Returns
int the measure specification based on size and mode

toString

Added in API level 1
public static String toString (int measureSpec)

Returns a String representation of the specified measure specification.

Parameters
measureSpec int: the measure specification to convert to a String

Returns
String a String with the following format: "MeasureSpec: MODE SIZE"