android.view
public
static
class
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:
- an exact number
- FILL_PARENT, which means 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)
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.
Known Direct Subclasses
Known Indirect Subclasses
Summary
XML Attributes
Constants
|
|
|
Value |
|
int |
FILL_PARENT |
Special value for the height or width requested by a View. |
-1 |
0xffffffff |
int |
WRAP_CONTENT |
Special value for the height or width requested by a View. |
-2 |
0xfffffffe |
Fields
Public Constructors
Protected Methods
clone,
equals,
finalize,
getClass,
hashCode,
notify,
notifyAll,
toString,
wait,
wait,
wait
Details
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), db (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.
Constant | Value | Description |
fill_parent | -1 | The view should be as big as its parent (minus padding). |
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.
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), db (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.
Constant | Value | Description |
fill_parent | -1 | The view should be as big as its parent (minus padding). |
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.
Constants
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 fill the available space
within the parent, taking the parent's padding into account.
Constant Value:
-1
(0xffffffff)
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
public
int
height
Information about how tall the view wants to be. Can be an exact
size, or one of the constants FILL_PARENT or WRAP_CONTENT.
public
int
width
Information about how wide the view wants to be. Can be an exact
size, or one of the constants FILL_PARENT or WRAP_CONTENT.
Public Constructors
public
ViewGroup.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:
Parameters
c
| the application environment |
attrs
| the set of attributes from which to extract the layout
parameters' values
|
public
ViewGroup.LayoutParams(int width, int height)
Creates a new set of layout parameters with the specified width
and height.
Copy constructor. Clones the width and height values of the source.
Parameters
source
| The layout params to copy from.
|
Protected Methods
protected
void
setBaseAttributes(TypedArray a, int widthAttr, int heightAttr)
Extracts the layout parameters from the supplied attributes.
Parameters
a
| the style attributes to extract the parameters from |
widthAttr
| the identifier of the width attribute |
heightAttr
| the identifier of the height attribute
|