Android - An Open Handset Alliance Project

android.view
public abstract class

android.view.ViewGroup

java.lang.Object
	android.view.View		Drawable.Callback KeyEvent.Callback
		android.view.ViewGroup	ViewManager ViewParent

A ViewGroup is a special view that can contain other views (called children). The view group is the base class for layouts and views containers. This class also defines the ViewGroup.LayoutParams class which serves as the base class for layouts parameters.

Nested Classes

ViewGroup.LayoutParams	LayoutParams are used by views to tell their parents how they want to be laid out.
ViewGroup.MarginLayoutParams	Per-child layout information for layouts that support margins.
ViewGroup.OnHierarchyChangeListener	Interface definition for a callback to be invoked when the hierarchy within this view changed.

Known Direct Subclasses

AbsoluteLayout, AdapterView, FrameLayout, LinearLayout, RelativeLayout

Known Indirect Subclasses

AbsListView, DatePicker, DialerFilter, ExpandableListView, Gallery, GridView, ImageSwitcher, ListMenuItemView, ListView, RadioGroup, ScaleLayout, ScrollView, Spinner, TabHost, TabWidget, TableLayout, TableRow, TextSwitcher, Ticker, TimePicker, TwoLineListItem, ViewAnimator, ViewFlipper, ViewSwitcher, WebView

AbsListView	Common code shared between ListView and GridView.
DatePicker	A view for selecting a month / year / day based on a calendar like layout.
DialerFilter	Also see ViewGroup.LayoutParams for layout attributes.
ExpandableListView	A view that shows items in a vertically scrolling two-level list.
Gallery	A view that shows items in a center-locked, horizontally scrolling list.
GridView	A view that shows items in two-dimensional scrolling grid.
ImageSwitcher	Also see ViewGroup.LayoutParams for layout attributes.
ListMenuItemView	The item view for each item in the ListView-based MenuViews.
ListView	A view that shows items in a vertically scrolling list.
RadioGroup	This class is used to create a multiple-exclusion scope for a set of radio buttons.
ScaleLayout	Also see ViewGroup.LayoutParams for layout attributes.
ScrollView	Also see ViewGroup.LayoutParams for layout attributes.
Spinner	A view that displays one child at a time and lets the user pick among them.
TabHost	Container for a tabbed window view.
TabWidget	Displays a list of tab labels representing each page in the parent's tab collection.
TableLayout	A layout that arranges its children into rows and columns.
TableRow	A layout that arranges its children horizontally.
TextSwitcher	A TextSwitcher is a specialized ViewSwitcher that contains only children of type TextView.
Ticker	A Ticker is a view that scrolls its child horizontally within its bounds.
TimePicker	A view for selecting the time of day, in either 24 hour or AM/PM mode.
TwoLineListItem	A view group with two children, intended for use in ListViews.
ViewAnimator	Also see ViewGroup.LayoutParams for layout attributes.
ViewFlipper	Shows only one child at a time.
ViewSwitcher	Shows only one child at a time.
WebView	The Android SDK provides a custom scheme to load assets from the application's .apk file in WebView.

Summary

XML Attributes

Attribute name	Related methods
android:clipChildren	setClipChildren(boolean)	Defines whether a child is limited to draw inside of its bounds or not.
android:clipToPadding	setClipToPadding(boolean)	Defines whether the ViewGroup will clip its drawing surface so as to exclude the padding area.

XML Attributes inherited from class android.view.View

Attribute name	Related methods
android:background	setBackground(int)	A drawable to use as the background.
android:clickable	setClickable(boolean)	Defines whether this view reacts to click events.
android:drawingCacheQuality	setDrawingCacheQuality(int)	Defines the quality of translucent drawing caches.
android:fadingEdge	setVerticalFadingEdgeEnabled(boolean)	Defines which edges should be fadeded on scrolling.
android:fadingEdgeLength	getVerticalFadingEdgeLength()	Defines the length of the fading edges.
android:fitStatusBar		Boolean internal attribute to adjust view layout based on the status bar location.
android:focusType	setFocusType(int)	Sets the circumstances under which this view will take focus.
android:focusable	setFocusable(boolean)	Boolean that controls whether a view can take focus.
android:focusableInTouchMode	setFocusableInTouchMode(boolean)	Boolean that controls whether a view can take focus while in touch mode.
android:freezeDisabled	setFreezeDisabled(boolean)	If set, no icicle will be saved for this view when it is being frozen.
android:id	setId(int)	Supply an identifier name for this view, to later retrieve it with View.findViewById() or Activity.findViewById().
android:nextFocusDown		Defines the next view to give focus to when the next focus is FOCUS_DOWN If the reference refers to a view that does not exist or is part of a hierarchy that is invisible, a RuntimeException will result when the reference is accessed.
android:nextFocusLeft		Defines the next view to give focus to when the next focus is FOCUS_LEFT.
android:nextFocusRight		Defines the next view to give focus to when the next focus is FOCUS_RIGHT If the reference refers to a view that does not exist or is part of a hierarchy that is invisible, a RuntimeException will result when the reference is accessed.
android:nextFocusUp		Defines the next view to give focus to when the next focus is FOCUS_UP If the reference refers to a view that does not exist or is part of a hierarchy that is invisible, a RuntimeException will result when the reference is accessed.
android:padding	setPadding(int,int,int,int)	Sets the padding, in pixels, of all four edges.
android:paddingBottom	setPadding(int,int,int,int)	Sets the padding, in pixels, of the bottom edge; see padding.
android:paddingLeft	setPadding(int,int,int,int)	Sets the padding, in pixels, of the left edge; see padding.
android:paddingRight	setPadding(int,int,int,int)	Sets the padding, in pixels, of the right edge; see padding.
android:paddingTop	setPadding(int,int,int,int)	Sets the padding, in pixels, of the top edge; see padding.
android:scrollX		The initial horizontal scroll offset, in pixels.
android:scrollY		The initial vertical scroll offset, in pixels.
android:scrollbarDefaultDelayBeforeFade		Delay in milliseconds before the scrollbars disappear.
android:scrollbarFadeDuration		Duration in milliseconds of the fade when the scrollbars disappear.
android:scrollbarSize		Sets the width of vertical scrollbars and height of horizontal scrollbars.
android:scrollbarThumbHorizontal		Drawable for horizontal scrollbars' thumb.
android:scrollbarThumbVertical		Drawable for vertical scrollbars' thumb.
android:scrollbarTrackHorizontal		Drawable for horizontal scrollbars' track.
android:scrollbarTrackVertical		Drawable for vertical scrollbars' track.
android:scrollbars		Defines which scrollbars should be displayed on scrolling or not.
android:visibility	setVisibility(int)	Controls the initial visibility of the view.

Constants

			Value
int	FLAG_SUPPORT_STATIC_TRANSFORMATIONS	When set, this ViewGroup supports static transformations on children; this causes getChildStaticTransformation(View, android.view.animation.Transformation) to be invoked when a child is drawn.	2048	0x00000800
int	PERSISTENT_ALL_CACHES	Used to indicate that all drawing caches should be kept in memory.	3	0x00000003
int	PERSISTENT_ANIMATION_CACHE	Used to indicate that the animation drawing cache should be kept in memory.	1	0x00000001
int	PERSISTENT_NO_CACHE	Used to indicate that no drawing cache should be kept in memory.	0	0x00000000
int	PERSISTENT_SCROLLING_CACHE	Used to indicate that the scrolling drawing cache should be kept in memory.	2	0x00000002

Constants inherited from class android.view.View

DRAWING_CACHE_QUALITY_AUTO, DRAWING_CACHE_QUALITY_HIGH, DRAWING_CACHE_QUALITY_LOW, FOCUS_BACKWARD, FOCUS_DOWN, FOCUS_FORWARD, FOCUS_LEFT, FOCUS_RIGHT, FOCUS_UP, GONE, INVISIBLE, NORMAL_FOCUS, NO_ID, VIEW_LOG_TAG, VISIBLE, WEAK_FOCUS

			Value
int	DRAWING_CACHE_QUALITY_AUTO	Enables automatic quality mode for the drawing cache.	0	0x00000000
int	DRAWING_CACHE_QUALITY_HIGH	Enables high quality mode for the drawing cache.	1048576	0x00100000
int	DRAWING_CACHE_QUALITY_LOW	Enables low quality mode for the drawing cache.	524288	0x00080000
int	FOCUS_BACKWARD	Use with focusSearch(int).	1	0x00000001
int	FOCUS_DOWN	Use with focusSearch(int).	130	0x00000082
int	FOCUS_FORWARD	Use with focusSearch(int).	2	0x00000002
int	FOCUS_LEFT	Use with focusSearch(int).	17	0x00000011
int	FOCUS_RIGHT	Use with focusSearch(int).	66	0x00000042
int	FOCUS_UP	Use with focusSearch(int).	33	0x00000021
int	GONE	This view is invisible, and it doesn't take any space for layout purposes.	8	0x00000008
int	INVISIBLE	This view is invisible, but it still takes up space for layout purposes.	4	0x00000004
int	NORMAL_FOCUS	This view wants keystrokes.	0	0x00000000
int	NO_ID	Used to mark a View that has no ID.	-1	0xffffffff
String	VIEW_LOG_TAG	The logging tag used by this class with android.util.Log.	"View"
int	VISIBLE	This view is visible.	0	0x00000000
int	WEAK_FOCUS	This view wants keystrokes, but only if none of its children has focus.	2	0x00000002

Fields

protected	ArrayList	mDisappearingChildren	Views which have been hidden or removed which need to be animated on their way out
protected	int	mGroupFlags
protected	OnHierarchyChangeListener	mOnHierarchyChangeListener	Listener used to propagate events indicating when children are added and/or removed from a view group.
protected	int	mPersistentDrawingCache	Indicates which types of drawing caches are to be kept in memory.

Fields inherited from class android.view.View

mBottom, mContext, mLayoutParams, mLeft, mLocation, mOnClickListener, mOnFocusChangeListener, mOnLongClickListener, mOnPopulateContextMenuListener, mPaddingBottom, mPaddingLeft, mPaddingRight, mPaddingTop, mParent, mRight, mScrollX, mScrollY, mTag, mTop

protected		int	mBottom	The distance in pixels from the top edge of this view's parent to the bottom edge of this view.
protected		Context	mContext	The application environment this view lives in.
protected		LayoutParams	mLayoutParams	The layout parameters associated with this view and used by the parent ViewGroup to determine how this view should be laid out.
protected		int	mLeft	The distance in pixels from the left edge of this view's parent to the left edge of this view.
protected	final	int[]	mLocation	Used to store a pair of coordinates, for instance returned values returned by getLocationInWindow(int[]).
protected		OnClickListener	mOnClickListener	Listener used to dispatch click events.
protected		OnFocusChangeListener	mOnFocusChangeListener	Listener used to dispatch focus change events.
protected		OnLongClickListener	mOnLongClickListener	Listener used to dispatch long click events.
protected		OnPopulateContextMenuListener	mOnPopulateContextMenuListener	Listener used to build the context menu.
protected		int	mPaddingBottom	The bottom padding in pixels, that is the distance in pixels between the bottom edge of this view and the bottom edge of its content.
protected		int	mPaddingLeft	The left padding in pixels, that is the distance in pixels between the left edge of this view and the left edge of its content.
protected		int	mPaddingRight	The right padding in pixels, that is the distance in pixels between the right edge of this view and the right edge of its content.
protected		int	mPaddingTop	The top padding in pixels, that is the distance in pixels between the top edge of this view and the top edge of its content.
protected		ViewParent	mParent	The parent this view is attached to.
protected		int	mRight	The distance in pixels from the left edge of this view's parent to the right edge of this view.
protected		int	mScrollX	The offset, in pixels, by which the content of this view is scrolled horizontally.
protected		int	mScrollY	The offset, in pixels, by which the content of this view is scrolled vertically.
protected		Object	mTag	The view's tag.
protected		int	mTop	The distance in pixels from the top edge of this view's parent to the top edge of this view.

Public Constructors

					ViewGroup(Context context)
					ViewGroup(Context context, AttributeSet attrs, Map inflateParams)
					ViewGroup(Context context, AttributeSet attrs, Map inflateParams, int defStyle)

Public Methods

		void	addView(View child, int index)
			Adds a child view that already has layout parameters set on it.
		void	addView(View child, int index, LayoutParams params)
			Adds a child view with the specified layout parameters.
		void	addView(View child, LayoutParams params)
			Adds a child view with the specified layout parameters.
		void	addView(View child)
			Adds a child view that already has layout parameters set on it.
		boolean	addsStatesFromChildren()
			Returns whether this ViewGroup's drawable states also include its children's drawable states.
		void	bringChildToFront(View child)
			Change the z order of the child so it's on top of all other children
		void	childDrawableStateChanged(View child)
			If {link #addsStatesFromChildren} is true, refreshes this group's drawable state (to include the states from its children).
		void	clearChildFocus(View child)
			Called when a child of this parent is giving up focus
		void	clearDisappearingChildren()
			Removes any pending animations for views that have been removed.
		void	clearFocus()
			Called when this view wants to give up focus.
		boolean	dispatchKeyEvent(KeyEvent event)
			Dispatch a key event to the next view on the focus path.
		boolean	dispatchTouchEvent(MotionEvent ev)
			Pass the touch screen motion event down to the target view, or this view if it is the target.
		boolean	dispatchTrackballEvent(MotionEvent event)
			Pass a trackball motion event down to the focused view.
		boolean	dispatchUnhandledMove(View focused, int direction)
			This method is the last chance for the focused view and its ancestors to respond to an arrow key.
		void	dispatchWindowFocusChanged(boolean hasFocus)
			Called when the window containing this view gains or loses window focus.
		void	dispatchWindowVisibilityChanged(int visibility)
			Dispatch a window visibility change down the view hierarchy.
		View	findFocus()
			Find the view in the hierarchy rooted at this view that currently has focus.
		View	focusSearch(View v, int direction)
			Find the nearest view in the specified direction that wants to take focus.
		void	focusableViewAvailable(View v)
			Tells the parent that a new focusable view has become available.
		boolean	gatherTransparentRegion(Region region)
			This is used by the RootView to perform an optimization when the view hierarchy contains one or several SurfaceView.
		LayoutParams	generateLayoutParams(AttributeSet attrs)

		View	getChildAt(int index)
			Returns the view at the specified position in the group.
		int	getChildCount()
			Returns the number of children in the group.
	static	int	getChildMeasureSpec(int spec, int padding, int childDimension)
			Does the hard part of measureChildren: figuring out the MeasureSpec to pass to a particular child.
		boolean	getChildVisibleRect(View child, Rect r, Point offset)

		View	getFocusedChild()
			Returns the focused child of this view, if any.
		LayoutAnimationController	getLayoutAnimation()
			Returns the layout animation controller used to animate the group's children.
		AnimationListener	getLayoutAnimationListener()
			Returns the animation listener to which layout animation events are sent.
		int	getPeristentDrawingCache()
			Returns an integer indicating what types of drawing caches are kept in memory.
		boolean	hasFocus()
			Returns true if this view has or contains focus
		int	indexOfChild(View child)
			Returns the position in the group of the specified child view.
final		void	invalidateChild(View child, Rect dirty)
			Don't call or override this method.
final		ViewParent	invalidateChildInParent(int[] location, Rect dirty)
			Don't call or override this method.
		boolean	isAlwaysDrawnWithCacheEnabled()
			Indicates whether this ViewGroup will always try to draw its children using their drawing cache.
		boolean	isAnimationCacheEnabled()
			Indicates whether the children's drawing cache is used during a layout animation.
		boolean	isKeepAnimations()
			Indicates whether animations set on this view group's children are kept after they're over or not.
final		void	offsetDescendantRectToMyCoords(View descendant, Rect rect)
			Offset a rectangle that is in a descendant's coordinate space into our coordinate space.
final		void	offsetRectIntoDescendantCoords(View descendant, Rect rect)
			Offset a rectangle that is in our coordinate space into an ancestor's coordinate space.
		boolean	onInterceptTouchEvent(MotionEvent ev)
			Implement this method to intercept all touch screen motion events.
		void	removeAllViews()
			Call this method to remove all child views from the ViewGroup.
		void	removeAllViewsInLayout()
			Called by a ViewGroup subclass to remove child views from itself, when it must first know its size on screen before it can calculate how many child views it will render.
		void	removeView(View view)

		void	removeViewAt(int index)
			Removes the view at the specified position in the group.
		void	removeViewInLayout(View view)
			Removes a view during layout.
		void	requestChildFocus(View child, View focused)
			Called when a child of this parent wants focus
		boolean	requestChildRectangleOnScreen(View child, Rect rectangle, boolean immediate)
			Called when a child of this group wants a particular rectangle to be positioned onto the screen.
		boolean	requestFocus(int direction, Rect previouslyFocusedRect)
			Call this to try to give focus to a specific view or to one of its descendants and give it hints about the direction and a specific rectangle that the focus is coming from. This implements the focus type logic (getFocusType()), respecting this group's preference for NORMAL_FOCUS or WEAK_FOCUS.
		void	requestTransparentRegion(View child)
			Called when a child wants the view hierarchy to gather and report transparent regions to the window compositor.
		void	scheduleLayoutAnimation()
			Schedules the layout animation to be played after the next layout pass of this view group.
		void	setAddsStatesFromChildren(boolean addsStates)
			Sets whether this ViewGroup's drawable states also include its children's drawable states.
		void	setAlwaysDrawnWithCacheEnabled(boolean always)
			Indicates whether this ViewGroup will always try to draw its children using their drawing cache.
		void	setAnimationCacheEnabled(boolean enabled)
			Enables or disables the children's drawing cache during a layout animation.
		void	setClipChildren(boolean clipChildren)
			By default, children are clipped to their bounds before drawing.
		void	setClipToPadding(boolean clipToPadding)
			By default, children are clipped to the padding of the ViewGroup.
		void	setKeepAnimations(boolean keepAnimations)
			Indicates whether the view group keeps its children animations after they are over or not.
		void	setLayoutAnimation(LayoutAnimationController controller)
			Sets the layout animation controller used to animate the group's children after the first layout.
		void	setLayoutAnimationListener(AnimationListener animationListener)
			Specifies the animation listener to which layout animation events must be sent.
		void	setOnHierarchyChangeListener(OnHierarchyChangeListener listener)
			Register a callback to be invoked when a child is added to or removed from this view.
		void	setPadding(int left, int top, int right, int bottom)
			Sets the padding.
		void	setPersistentDrawingCache(int drawingCacheToKeep)
			Indicates what types of drawing caches should be kept in memory after they have been created.
		void	setSelected(boolean selected)
			Changes the selection state of this view.
		boolean	showContextMenuForChild(View v)
			Bring up a context menu for the specified view or its ancestors
		void	startLayoutAnimation()
			Runs the layout animation.
		void	updateViewLayout(View view, LayoutParams params)

Protected Methods

				boolean	addViewInLayout(View child, int index, LayoutParams params)
					Adds a view during layout.
				boolean	addViewInLayout(View child, int index, LayoutParams params, boolean preventRequestLayout)
					Adds a view during layout.
				void	attachLayoutAnimationParameters(View child, LayoutParams params, int index, int count)
					Subclasses should override this method to set layout animation parameters on the supplied child.
				void	attachViewToParent(View child, int index, LayoutParams params)
					Attaches a view to this view group.
				boolean	canAnimate()
					Indicates whether the view group has the ability to animate its children after the first layout.
				boolean	checkLayoutParams(LayoutParams p)

				void	cleanupLayoutState(View child)
					Prevents the specified child to be laid out during the next layout pass.
				void	debug(int depth)
					Prints information about this view in the log output, with the tag VIEW_LOG_TAG.
				void	detachAllViewsFromParent()
					Detaches all views from theparent.
				void	detachViewFromParent(View child)
					Detaches a view from its parent.
				void	detachViewFromParent(int index)
					Detaches a view from its parent.
				void	dispatchDraw(Canvas canvas)
					Called by draw to draw the child views.
				void	dispatchFreeze(SparseArray container)
					Called by freeze(SparseArray) to store the icicles for this view and its children.
				void	dispatchFreezeSelfOnly(SparseArray container)
					Perform dispatching of a freeze() to only this view, not to its children.
				void	dispatchThaw(SparseArray container)
					Called by thaw(SparseArray) to retrieve the icicles for this view and its children.
				void	dispatchThawSelfOnly(SparseArray container)
					Perform dispatching of a thaw() to only this view, not to its children.
				boolean	getChildStaticTransformation(View child, Transformation t)

				boolean	isChildrenDrawnWithCacheEnabled()
					Indicates whether the ViewGroup is currently drawing its children using their drawing cache.
				void	measureChild(Vi