Android - An Open Handset Alliance Project

android.widget
public class

android.widget.LinearLayout

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

A Layout that arranges its children in a single column or a single row. The direction of the row can be set by calling setOrientation(). You can also specify gravity, which specifies the alignment of all the child elements by calling setGravity() or specify that specific children grow to fill up any remaining space in the layout by setting the weight member of LinearLayout.LayoutParams. The default orientation is horizontal.

Also see android.widget.LinearLayout.LayoutParams for layout attributes

Nested Classes

LinearLayout.LayoutParams Per-child layout information associated with ViewLinearLayout.

Known Direct Subclasses

RadioGroup, TabWidget, TableLayout, TableRow

Summary

XML Attributes

Attribute name	Related methods
android:animationDuration	setAnimationDuration(int)	Sets how long a transition animation should run (in milliseconds) when layout has changed.
android:baselineAligned	setBaselineAligned(boolean)	When set to false, prevents the layout from aligning its children's baselines.
android:baselineAlignedChildIndex	setBaselineAlignedChildIndex(int)	When a linear layout is part of another layout that is baseline aligned, it can specify which of its children to baseline align to (i.e which child TextView).
android:gravity	setGravity(int)	Specifies how to place an object, both its x and y axis, within a larger containing object.
android:orientation	setOrientation(int)	Should the layout be a column or a row? Use "horizontal" for a row, "vertical" for a column.

XML Attributes inherited from class android.view.ViewGroup

android:clipChildren, android:clipToPadding

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	HORIZONTAL		0	0x00000000
int	VERTICAL		1	0x00000001

Constants inherited from class android.view.ViewGroup

FLAG_SUPPORT_STATIC_TRANSFORMATIONS, PERSISTENT_ALL_CACHES, PERSISTENT_ANIMATION_CACHE, PERSISTENT_NO_CACHE, PERSISTENT_SCROLLING_CACHE

			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 boolean mAnimateNextLayout When this flag is set to true, the next layout pass should animate the children from their old position to their new one.

Fields inherited from class android.view.ViewGroup

mDisappearingChildren, mGroupFlags, mOnHierarchyChangeListener, mPersistentDrawingCache

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

					LinearLayout(Context context)
					LinearLayout(Context context, AttributeSet attrs, Map inflateParams)

Public Methods

				LayoutParams	generateLayoutParams(AttributeSet attrs)

				int	getBaseline()
					Return the offset of the widget's text baseline from the widget's top boundary.
				int	getBaselineAlignedChildIndex()
				boolean	isBaselineAligned()
					Indicates whether widgets contained within this layout are aligned on their baseline or not.
				void	setAnimateNextLayout(boolean animate)
					Sets whether the LinearLayout will animate child views when they move from one position to another
				void	setAnimationDuration(int animationDurationMillis)
					Sets how long the transition animation should run when a chid view changes position.
				void	setBaselineAligned(boolean baselineAligned)
					Defines whether widgets contained in this layout are baseline-aligned or not.
				void	setBaselineAlignedChildIndex(int i)
				void	setGravity(int gravity)
					Describes how the child views are positioned.
				void	setHorizontalGravity(int horizontalGravity)
				void	setOrientation(int orientation)
					Should the layout be a column or a row.
				void	setVerticalGravity(int verticalGravity)

Protected Methods

				boolean	checkLayoutParams(LayoutParams p)

				int	getChildrenSkipCount(View child, int index)
					Returns the number of children to skip after measuring/laying out the specified child.
				int	getLocationOffset(View child)
					Return the location offset of the specified child.
				int	getNextLocationOffset(View child)
					Return the size offset of the next sibling of the specified child.
				View	getVirtualChildAt(int index)
					Returns the view at the specified index.
				int	getVirtualChildCount()
					Returns the virtual number of children.
				void	layoutHorizontal()
				void	layoutVertical()
				void	measureChildBeforeLayout(View child, int childIndex, int widthMeasureSpec, int totalWidth, int heightMeasureSpec, int totalHeight)
					Measure the child according to the parent's measure specs.
				void	measureHorizontal(int widthMeasureSpec, int heightMeasureSpec)
				int	measureNullChild(int childIndex)
					Returns the size (width or height) that should be occupied by a null child.
				void	measureVertical(int widthMeasureSpec, int heightMeasureSpec)
				void	onLayout(boolean changed, int l, int t, int r, int b)
					Called from layout when this view should assign a size and position to each of its children.
				void	onMeasure(int widthMeasureSpec, int heightMeasureSpec)
					Measure the view and its content to determine the measured width and the measured height.

Methods inherited from class android.view.ViewGroup

addView, addView, addView, addView, addViewInLayout, addViewInLayout, addsStatesFromChildren, attachLayoutAnimationParameters, attachViewToParent, bringChildToFront, canAnimate, checkLayoutParams, childDrawableStateChanged, cleanupLayoutState, clearChildFocus, clearDisappearingChildren, clearFocus, debug, detachAllViewsFromParent, detachViewFromParent, detachViewFromParent, dispatchDraw, dispatchFreeze, dispatchFreezeSelfOnly, dispatchKeyEvent, dispatchThaw, dispatchThawSelfOnly, dispatchTouchEvent, dispatchTrackballEvent, dispatchUnhandledMove, dispatchWindowFocusChanged, dispatchWindowVisibilityChanged, findFocus, focusSearch, focusableViewAvailable, gatherTransparentRegion, generateLayoutParams, getChildAt, getChildCount, getChildMeasureSpec, getChildStaticTransformation, getChildVisibleRect, getFocusedChild, getLayoutAnimation, getLayoutAnimationListener, getPeristentDrawingCache, hasFocus, indexOfChild, invalidateChild, invalidateChildInParent, isAlwaysDrawnWithCacheEnabled, isAnimationCacheEnabled, isChildrenDrawnWithCacheEnabled, isKeepAnimations, measureChild, measureChildWithMargins, measureChildren, offsetDescendantRectToMyCoords, offsetRectIntoDescendantCoords, onCreateDrawableState, onInterceptTouchEvent, onLayout, removeAllViews, removeAllViewsInLayout, removeDetachedView, removeView, removeViewAt, removeViewInLayout, requestChildFocus, requestChildRectangleOnScreen, requestFocus, requestTransparentRegion, scheduleLayoutAnimation, setAddsStatesFromChildren, setAlwaysDrawnWithCacheEnabled, setAnimationCacheEnabled, setChildrenDrawingCacheEnabled, setChildrenDrawnWithCacheEnabled, setClipChildren, setClipToPadding, setKeepAnimations, setLayoutAnimation, setLayoutAnimationListener, setOnHierarchyChangeListener, setPadding, setPersistentDrawingCache, setSelected, showContextMenuForChild, startLayoutAnimation, updateViewLayout

		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	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.
		boolean	addsStatesFromChildren()
			Returns whether this ViewGroup's drawable states also include its children's drawable states.
		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.
		void	bringChildToFront(View child)
			Change the z order of the child so it's on top of all other children
		boolean	canAnimate()
			Indicates whether the view group has the ability to animate its children after the first layout.
		boolean	checkLayoutParams(LayoutParams p)

		void	childDrawableStateChanged(View child)
			If {link #addsStatesFromChildren} is true, refreshes this group's drawable state (to include the states from its children).
		void	cleanupLayoutState(View child)
			Prevents the specified child to be laid out during the next layout pass.
		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.
		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.
		boolean	dispatchKeyEvent(KeyEvent event)
			Dispatch a key event to the next view on the focus path.
		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	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	getChildStaticTransformation(View child, Transformation t)

		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