Android position definition ( Gravity ) of layout

public class

Gravity

extends Object

java.lang.Object
↳	android.view.Gravity

Class Overview

Standard constants and tools for placing an object within a potentially larger container.

Summary

Constants
int	AXIS_CLIP	Raw bit controlling whether the right/bottom edge is clipped to its container, based on the gravity direction being applied.
int	AXIS_PULL_AFTER	Raw bit controlling how the right/bottom edge is placed.
int	AXIS_PULL_BEFORE	Raw bit controlling how the left/top edge is placed.
int	AXIS_SPECIFIED	Raw bit indicating the gravity for an axis has been specified.
int	AXIS_X_SHIFT	Bits defining the horizontal axis.
int	AXIS_Y_SHIFT	Bits defining the vertical axis.
int	BOTTOM	Push object to the bottom of its container, not changing its size.
int	CENTER	Place the object in the center of its container in both the vertical and horizontal axis, not changing its size.
int	CENTER_HORIZONTAL	Place object in the horizontal center of its container, not changing its size.
int	CENTER_VERTICAL	Place object in the vertical center of its container, not changing its size.
int	CLIP_HORIZONTAL	Flag to clip the edges of the object to its container along the horizontal axis.
int	CLIP_VERTICAL	Flag to clip the edges of the object to its container along the vertical axis.
int	DISPLAY_CLIP_HORIZONTAL	Special constant to enable clipping to an overall display along the horizontal dimension.
int	DISPLAY_CLIP_VERTICAL	Special constant to enable clipping to an overall display along the vertical dimension.
int	FILL	Grow the horizontal and vertical size of the object if needed so it completely fills its container.
int	FILL_HORIZONTAL	Grow the horizontal size of the object if needed so it completely fills its container.
int	FILL_VERTICAL	Grow the vertical size of the object if needed so it completely fills its container.
int	HORIZONTAL_GRAVITY_MASK	Binary mask to get the horizontal gravity of a gravity.
int	LEFT	Push object to the left of its container, not changing its size.
int	NO_GRAVITY	Constant indicating that no gravity has been set
int	RIGHT	Push object to the right of its container, not changing its size.
int	TOP	Push object to the top of its container, not changing its size.
int	VERTICAL_GRAVITY_MASK	Binary mask to get the vertical gravity of a gravity.

Public Constructors
	Gravity()

Public Methods
static void	apply(int gravity, int w, int h, Rect container, Rect outRect) Apply a gravity constant to an object.
static void	apply(int gravity, int w, int h, Rect container, int xAdj, int yAdj, Rect outRect) Apply a gravity constant to an object.
static void	applyDisplay(int gravity, Rect display, Rect inoutObj) Apply additional gravity behavior based on the overall "display" that an object exists in.
static boolean	isHorizontal(int gravity) Indicate whether the supplied gravity has an horizontal pull.
static boolean	isVertical(int gravity) Indicate whether the supplied gravity has a vertical pull.

[Expand] Inherited Methods

From class java.lang.Object Object clone() Creates and returns a copy of this Object. boolean equals(Object o) Compares this instance with the specified object and indicates if they are equal. void finalize() Is called before the object's memory is being reclaimed by the VM. final Class<? extends Object> getClass() Returns the unique instance of Class which represents this object's class. int hashCode() Returns an integer hash code for this object. final void notify() Causes a thread which is waiting on this object's monitor (by means of calling one of the wait() methods) to be woken up. final void notifyAll() Causes all threads which are waiting on this object's monitor (by means of calling one of the wait() methods) to be woken up. String toString() Returns a string containing a concise, human-readable description of this object. final void wait(long millis, int nanos) Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object or until the specified timeout expires. final void wait(long millis) Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object or until the specified timeout expires. final void wait() Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object.

Constants

public static final int AXIS_CLIP

Since: API Level 3

Raw bit controlling whether the right/bottom edge is clipped to its container, based on the gravity direction being applied.

Constant Value: 8 (0x00000008)

public static final int AXIS_PULL_AFTER

Since: API Level 1

Raw bit controlling how the right/bottom edge is placed.

Constant Value: 4 (0x00000004)

public static final int AXIS_PULL_BEFORE

Since: API Level 1

Raw bit controlling how the left/top edge is placed.

Constant Value: 2 (0x00000002)

public static final int AXIS_SPECIFIED

Since: API Level 1

Raw bit indicating the gravity for an axis has been specified.

Constant Value: 1 (0x00000001)

public static final int AXIS_X_SHIFT

Since: API Level 1

Bits defining the horizontal axis.

Constant Value: 0 (0x00000000)

public static final int AXIS_Y_SHIFT

Since: API Level 1

Bits defining the vertical axis.

Constant Value: 4 (0x00000004)

public static final int BOTTOM

Since: API Level 1

Push object to the bottom of its container, not changing its size.

Constant Value: 80 (0x00000050)

public static final int CENTER

Since: API Level 1

Place the object in the center of its container in both the vertical and horizontal axis, not changing its size.

Constant Value: 17 (0x00000011)

public static final int CENTER_HORIZONTAL

Since: API Level 1

Place object in the horizontal center of its container, not changing its size.

Constant Value: 1 (0x00000001)

public static final int CENTER_VERTICAL

Since: API Level 1

Place object in the vertical center of its container, not changing its size.

Constant Value: 16 (0x00000010)

public static final int CLIP_HORIZONTAL

Since: API Level 3

Flag to clip the edges of the object to its container along the horizontal axis.

Constant Value: 8 (0x00000008)

public static final int CLIP_VERTICAL

Since: API Level 3

Flag to clip the edges of the object to its container along the vertical axis.

Constant Value: 128 (0x00000080)

public static final int DISPLAY_CLIP_HORIZONTAL

Since: API Level 3

Special constant to enable clipping to an overall display along the horizontal dimension. This is not applied by default by apply(int, int, int, Rect, int, int, Rect); you must do so yourself by calling applyDisplay(int, Rect, Rect).

Constant Value: 16777216 (0x01000000)

public static final int DISPLAY_CLIP_VERTICAL

Since: API Level 3

Special constant to enable clipping to an overall display along the vertical dimension. This is not applied by default by apply(int, int, int, Rect, int, int, Rect); you must do so yourself by calling applyDisplay(int, Rect, Rect).

Constant Value: 268435456 (0x10000000)

public static final int FILL

Since: API Level 1

Grow the horizontal and vertical size of the object if needed so it completely fills its container.

Constant Value: 119 (0x00000077)

public static final int FILL_HORIZONTAL

Since: API Level 1

Grow the horizontal size of the object if needed so it completely fills its container.

Constant Value: 7 (0x00000007)

public static final int FILL_VERTICAL

Since: API Level 1

Grow the vertical size of the object if needed so it completely fills its container.

Constant Value: 112 (0x00000070)

public static final int HORIZONTAL_GRAVITY_MASK

Since: API Level 1

Binary mask to get the horizontal gravity of a gravity.

Constant Value: 7 (0x00000007)

public static final int LEFT

Since: API Level 1

Push object to the left of its container, not changing its size.

Constant Value: 3 (0x00000003)

public static final int NO_GRAVITY

Since: API Level 1

Constant indicating that no gravity has been set

Constant Value: 0 (0x00000000)

public static final int RIGHT

Since: API Level 1

Push object to the right of its container, not changing its size.

Constant Value: 5 (0x00000005)

public static final int TOP

Since: API Level 1

Push object to the top of its container, not changing its size.

Constant Value: 48 (0x00000030)

public static final int VERTICAL_GRAVITY_MASK

Since: API Level 1

Binary mask to get the vertical gravity of a gravity.

Constant Value: 112 (0x00000070)

Public Constructors

public Gravity ()

Since: API Level 1

Public Methods

public static void apply (int gravity, int w, int h, Rect container, Rect outRect)

Since: API Level 1

Apply a gravity constant to an object.

Parameters

gravity	The desired placement of the object, as defined by the constants in this class.
w	The horizontal size of the object.
h	The vertical size of the object.
container	The frame of the containing space, in which the object will be placed. Should be large enough to contain the width and height of the object.
outRect	Receives the computed frame of the object in its container.

public static void apply (int gravity, int w, int h, Rect container, int xAdj, int yAdj, Rect outRect)

Since: API Level 1

Apply a gravity constant to an object.

Parameters

gravity	The desired placement of the object, as defined by the constants in this class.
w	The horizontal size of the object.
h	The vertical size of the object.
container	The frame of the containing space, in which the object will be placed. Should be large enough to contain the width and height of the object.
xAdj	Offset to apply to the X axis. If gravity is LEFT this pushes it to the right; if gravity is RIGHT it pushes it to the left; if gravity is CENTER_HORIZONTAL it pushes it to the right or left; otherwise it is ignored.
yAdj	Offset to apply to the Y axis. If gravity is TOP this pushes it down; if gravity is BOTTOM it pushes it up; if gravity is CENTER_VERTICAL it pushes it down or up; otherwise it is ignored.
outRect	Receives the computed frame of the object in its container.

public static void applyDisplay (int gravity, Rect display, Rect inoutObj)

Since: API Level 3

Apply additional gravity behavior based on the overall "display" that an object exists in. This can be used after apply(int, int, int, Rect, int, int, Rect) to place the object within a visible display. By default this moves or clips the object to be visible in the display; the gravity flags DISPLAY_CLIP_HORIZONTAL and DISPLAY_CLIP_VERTICAL can be used to change this behavior.

Parameters

gravity	Gravity constants to modify the placement within the display.
display	The rectangle of the display in which the object is being placed.
inoutObj	Supplies the current object position; returns with it modified if needed to fit in the display.

public static boolean isHorizontal (int gravity)

Since: API Level 1

Indicate whether the supplied gravity has an horizontal pull.

Parameters

gravity	the gravity to check for horizontal pull

Returns

• true if the supplied gravity has an horizontal pull

public static boolean isVertical (int gravity)

Since: API Level 1

Indicate whether the supplied gravity has a vertical pull.

Parameters

gravity	the gravity to check for vertical pull

Returns

• true if the supplied gravity has a vertical pull