ViewGroup.LayoutParams
public
static
class
ViewGroup.LayoutParams
extends Object
java.lang.Object | |
↳ | android.view.ViewGroup.LayoutParams |
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
Developer Guides
For more information about creating user interface layouts, read the XML Layouts developer guide.
Summary
XML attributes | ||
---|---|---|
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 | |
---|---|
LayoutParams(Context c, AttributeSet attrs)
Creates a new set of layout parameters. |
|
LayoutParams(ViewGroup.LayoutParams source)
Copy constructor. |
|
LayoutParams(int width, int height)
Creates a new set of layout parameters with the specified width and height. |
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. |
Inherited methods | |
---|---|
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), and
mm (millimeters).
Must be one of the following constant values.
Constant | Value | Description |
---|---|---|
fill_parent | ffffffff | 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 | ffffffff | The view should be as big as its parent (minus padding). Introduced in API Level 8. |
wrap_content | fffffffe | The view should be only big enough to enclose its content (plus padding). |
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), and
mm (millimeters).
Must be one of the following constant values.
Constant | Value | Description |
---|---|---|
fill_parent | ffffffff | 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 | ffffffff | The view should be as big as its parent (minus padding). Introduced in API Level 8. |
wrap_content | fffffffe | The view should be only big enough to enclose its content (plus padding). |
Constants
FILL_PARENT
public static final int FILL_PARENT
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)
MATCH_PARENT
public static final int MATCH_PARENT
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)
WRAP_CONTENT
public static final int WRAP_CONTENT
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
height
public int height
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.
layoutAnimationParameters
public LayoutAnimationController.AnimationParameters layoutAnimationParameters
Used to animate layouts.
width
public int width
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
LayoutParams
public LayoutParams (Context c, AttributeSet attrs)
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:
layout_width
: the width, either an exact value,WRAP_CONTENT
, orFILL_PARENT
(replaced byMATCH_PARENT
in API Level 8)layout_height
: the height, either an exact value,WRAP_CONTENT
, orFILL_PARENT
(replaced byMATCH_PARENT
in API Level 8)
Parameters | |
---|---|
c |
Context : the application environment |
attrs |
AttributeSet : the set of attributes from which to extract the layout
parameters' values |
LayoutParams
public LayoutParams (ViewGroup.LayoutParams source)
Copy constructor. Clones the width and height values of the source.
Parameters | |
---|---|
source |
ViewGroup.LayoutParams : The layout params to copy from. |
LayoutParams
public LayoutParams (int width, int height)
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 methods
resolveLayoutDirection
public void resolveLayoutDirection (int layoutDirection)
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
View.LAYOUT_DIRECTION_LTR
View.LAYOUT_DIRECTION_RTL |
Protected methods
setBaseAttributes
protected void setBaseAttributes (TypedArray a, int widthAttr, int heightAttr)
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 |
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Last updated 2024-12-18 UTC.