public abstract class

LayoutInflater

extends Object
java.lang.Object
   ↳ android.view.LayoutInflater

Class Overview

This class is used to instantiate layout XML file into its corresponding View objects. It is never be used directly -- use getLayoutInflater() or getSystemService(String) to retrieve a standard LayoutInflater instance that is already hooked up to the current context and correctly configured for the device you are running on. For example: 

LayoutInflater inflater = (LayoutInflater)context.getSystemService
      Context.LAYOUT_INFLATER_SERVICE);

To create a new LayoutInflater with an additional LayoutInflater.Factory for your own views, you can use cloneInContext(Context) to clone an existing ViewFactory, and then call setFactory(LayoutInflater.Factory) on it to include your Factory.

For performance reasons, view inflation relies heavily on pre-processing of XML files that is done at build time. Therefore, it is not currently possible to use LayoutInflater with an XmlPullParser over a plain XML file at runtime; it only works with an XmlPullParser returned from a compiled resource (R.something file.)

See Also

Summary

Nested Classes
public abstract class LayoutInflater.Factory  
public abstract class LayoutInflater.Filter Hook to allow clients of the LayoutInflater to restrict the set of Views that are allowed to be inflated. 
Protected Constructors
LayoutInflater(Context context)
Create a new LayoutInflater instance associated with a particular Context.
LayoutInflater(LayoutInflater original, Context newContext)
Create a new LayoutInflater instance that is a copy of an existing LayoutInflater, optionally with its Context changed.
Public Methods
abstract LayoutInflater cloneInContext(Context newContext)
Create a copy of the existing LayoutInflater object, with the copy pointing to a different Context than the original.
final View createView(String name, String prefix, AttributeSet attrs)
Low-level function for instantiating a view by name.
static LayoutInflater from(Context context)
Obtains the LayoutInflater from the given context.
Context getContext()
Return the context we are running in, for access to resources, class loader, etc.
final LayoutInflater.Factory getFactory()
Return the current factory (or null).
LayoutInflater.Filter getFilter()
View inflate(XmlPullParser parser, ViewGroup root, boolean attachToRoot)
Inflate a new view hierarchy from the specified XML node.
View inflate(int resource, ViewGroup root)
Inflate a new view hierarchy from the specified xml resource.
View inflate(int resource, ViewGroup root, boolean attachToRoot)
Inflate a new view hierarchy from the specified xml resource.
View inflate(XmlPullParser parser, ViewGroup root)
Inflate a new view hierarchy from the specified xml node.
void setFactory(LayoutInflater.Factory factory)
Attach a custom Factory interface for creating views while using this LayoutInflater.
void setFilter(LayoutInflater.Filter filter)
Sets the LayoutInflater.Filter to by this LayoutInflater.
Protected Methods
View onCreateView(String name, AttributeSet attrs)
This routine is responsible for creating the correct subclass of View given the xml element name.
[Expand]
Inherited Methods
From class java.lang.Object

Protected Constructors

protected LayoutInflater (Context context)

Create a new LayoutInflater instance associated with a particular Context. Applications will almost always want to use Context.getSystemService() to retrieve the standard Context.INFLATER_SERVICE.

Parameters
context The Context in which this LayoutInflater will create its Views; most importantly, this supplies the theme from which the default values for their attributes are retrieved.

protected LayoutInflater (LayoutInflater original, Context newContext)

Create a new LayoutInflater instance that is a copy of an existing LayoutInflater, optionally with its Context changed. For use in implementing cloneInContext(Context).

Parameters
original The original LayoutInflater to copy.
newContext The new Context to use.

Public Methods

public abstract LayoutInflater cloneInContext (Context newContext)

Create a copy of the existing LayoutInflater object, with the copy pointing to a different Context than the original. This is used by ContextThemeWrapper to create a new LayoutInflater to go along with the new Context theme.

Parameters
newContext The new Context to associate with the new LayoutInflater. May be the same as the original Context if desired.
Returns
  • Returns a brand spanking new LayoutInflater object associated with the given Context.

public final View createView (String name, String prefix, AttributeSet attrs)

Low-level function for instantiating a view by name. This attempts to instantiate a view class of the given name found in this LayoutInflater's ClassLoader.

There are two things that can happen in an error case: either the exception describing the error will be thrown, or a null will be returned. You must deal with both possibilities -- the former will happen the first time createView() is called for a class of a particular name, the latter every time there-after for that class name.

Parameters
name The full name of the class to be instantiated.
attrs The XML attributes supplied for this instance.
Returns
  • View The newly instantied view, or null.
Throws
ClassNotFoundException
InflateException

public static LayoutInflater from (Context context)

Obtains the LayoutInflater from the given context.

public Context getContext ()

Return the context we are running in, for access to resources, class loader, etc.

public final LayoutInflater.Factory getFactory ()

Return the current factory (or null). This is called on each element name. If the factory returns a View, add that to the hierarchy. If it returns null, proceed to call onCreateView(name).

public LayoutInflater.Filter getFilter ()

Returns
  • The LayoutInflater.Filter currently used by this LayoutInflater to restrict the set of Views that are allowed to be inflated.

public View inflate (XmlPullParser parser, ViewGroup root, boolean attachToRoot)

Inflate a new view hierarchy from the specified XML node. Throws InflateException if there is an error.

Important   For performance reasons, view inflation relies heavily on pre-processing of XML files that is done at build time. Therefore, it is not currently possible to use LayoutInflater with an XmlPullParser over a plain XML file at runtime.

Parameters
parser XML dom node containing the description of the view hierarchy.
root Optional view to be the parent of the generated hierarchy (if attachToRoot is true), or else simply an object that provides a set of LayoutParams values for root of the returned hierarchy (if attachToRoot is false.)
attachToRoot Whether the inflated hierarchy should be attached to the root parameter? If false, root is only used to create the correct subclass of LayoutParams for the root view in the XML.
Returns
  • The root View of the inflated hierarchy. If root was supplied and attachToRoot is true, this is root; otherwise it is the root of the inflated XML file.

public View inflate (int resource, ViewGroup root)

Inflate a new view hierarchy from the specified xml resource. Throws InflateException if there is an error.

Parameters
resource ID for an XML layout resource to load (e.g., R.layout.main_page)
root Optional view to be the parent of the generated hierarchy.
Returns
  • The root View of the inflated hierarchy. If root was supplied, this is the root View; otherwise it is the root of the inflated XML file.

public View inflate (int resource, ViewGroup root, boolean attachToRoot)

Inflate a new view hierarchy from the specified xml resource. Throws InflateException if there is an error.

Parameters
resource ID for an XML layout resource to load (e.g., R.layout.main_page)
root Optional view to be the parent of the generated hierarchy (if attachToRoot is true), or else simply an object that provides a set of LayoutParams values for root of the returned hierarchy (if attachToRoot is false.)
attachToRoot Whether the inflated hierarchy should be attached to the root parameter? If false, root is only used to create the correct subclass of LayoutParams for the root view in the XML.
Returns
  • The root View of the inflated hierarchy. If root was supplied and attachToRoot is true, this is root; otherwise it is the root of the inflated XML file.

public View inflate (XmlPullParser parser, ViewGroup root)

Inflate a new view hierarchy from the specified xml node. Throws InflateException if there is an error. *

Important   For performance reasons, view inflation relies heavily on pre-processing of XML files that is done at build time. Therefore, it is not currently possible to use LayoutInflater with an XmlPullParser over a plain XML file at runtime.

Parameters
parser XML dom node containing the description of the view hierarchy.
root Optional view to be the parent of the generated hierarchy.
Returns
  • The root View of the inflated hierarchy. If root was supplied, this is the root View; otherwise it is the root of the inflated XML file.

public void setFactory (LayoutInflater.Factory factory)

Attach a custom Factory interface for creating views while using this LayoutInflater. This must not be null, and can only be set once; after setting, you can not change the factory. This is called on each element name as the xml is parsed. If the factory returns a View, that is added to the hierarchy. If it returns null, the next factory default onCreateView(String, AttributeSet) method is called.

If you have an existing LayoutInflater and want to add your own factory to it, use cloneInContext(Context) to clone the existing instance and then you can use this function (once) on the returned new instance. This will merge your own factory with whatever factory the original instance is using.

public void setFilter (LayoutInflater.Filter filter)

Sets the LayoutInflater.Filter to by this LayoutInflater. If a view is attempted to be inflated which is not allowed by the LayoutInflater.Filter, the inflate(int, ViewGroup) call will throw an InflateException. This filter will replace any previous filter set on this LayoutInflater.

Parameters
filter The Filter which restricts the set of Views that are allowed to be inflated. This filter will replace any previous filter set on this LayoutInflater.

Protected Methods

protected View onCreateView (String name, AttributeSet attrs)

This routine is responsible for creating the correct subclass of View given the xml element name. Override it to handle custom view objects. If you override this in your subclass be sure to call through to super.onCreateView(name) for names you do not recognize.

Parameters
name The fully qualified class name of the View to be create.
attrs An AttributeSet of attributes to apply to the View.
Returns
  • View The View created.
Throws
ClassNotFoundException