Android - An Open Handset Alliance Project

android.view
public class

android.view.SurfaceView

java.lang.Object
	android.view.View		Drawable.Callback KeyEvent.Callback
		android.view.SurfaceView

Provides a dedicated drawing surface embedded inside of a view hierarchy. You can control the format of this surface and, if you like, its size; the SurfaceView takes care of placing the surface at the correct location on the screen

The surface is Z ordered so that it is behind the window holding its SurfaceView; the SurfaceView punches a hole in its window to allow its surface to be displayed. The view hierarchy will take care of correctly compositing with the Surface any siblings of the SurfaceView that would normally appear on top of it. This can be used to place overlays such as buttons on top of the Surface, though note however that it can have an impact on performance since a full alpha-blended composite will be performed each time the Surface changes.

Access to the underlying surface is provided via the SurfaceHolder interface, which can be retrieved by calling getHolder().

The Surface will be created for you while the SurfaceView's window is visible; you should implement surfaceCreated(SurfaceHolder) and surfaceDestroyed(SurfaceHolder) to discover when the Surface is created and destroyed as the window is shown and hidden.

One of the purposes of this class is to provide a surface in which a secondary thread can render in to the screen. If you are going to use it this way, you need to be aware of some threading semantics:

All SurfaceView and SurfaceHolder.Callback methods will be called from the thread running the SurfaceView's window (typically the main thread of the application). They thus need to correctly synchronize with any state that is also touched by the drawing thread.
You must ensure that the drawing thread only touches the underlying Surface while it is valid -- between SurfaceHolder.Callback.surfaceCreated() and SurfaceHolder.Callback.surfaceDestroyed().

Known Direct Subclasses

VideoView

Summary

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 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 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

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

Public Methods

				void	draw(Canvas canvas)
					Manually render this view (and all of its children) to the given Canvas.
				boolean	gatherTransparentRegion(Region region)
					This is used by the RootView to perform an optimization when the view hierarchy contains one or several SurfaceView.
				SurfaceHolder	getHolder()
					Return the SurfaceHolder providing access and control over this SurfaceView's underlying surface.

Protected Methods

				void	onAttachedToWindow()
					This is called when the view is attached to a window.
				void	onDetachedFromWindow()
					This is called when the view is detached from a window.
				void	onMeasure(int widthMeasureSpec, int heightMeasureSpec)
					Measure the view and its content to determine the measured width and the measured height.
				void	onScrollChanged(int l, int t, int oldl, int oldt)
					This is called in response to an internal scroll in this view (i.e., the view scrolled its own contents).
				void	onSizeChanged(int w, int h, int oldw, int oldh)
					This is called during layout when the size of this view has changed.
				void	onWindowVisibilityChanged(int visibility)
					Called when the window containing has change its visibility (between GONE, INVISIBLE, and VISIBLE).

Methods inherited from class android.view.View

awakenScrollBars, awakenScrollBars, bringToFront, buildDrawingCache, clearAnimation, clearFocus, computeHorizontalScrollExtent, computeHorizontalScrollOffset, computeHorizontalScrollRange, computeScroll, computeVerticalScrollExtent, computeVerticalScrollOffset, computeVerticalScrollRange, copyWindowBitmap, dispatchDraw, dispatchFreeze, dispatchKeyEvent, dispatchThaw, dispatchTouchEvent, dispatchTrackballEvent, dispatchUnhandledMove, dispatchWindowFocusChanged, dispatchWindowVisibilityChanged, draw, drawableStateChanged, finalize, findFocus, findViewById, findViewWithTag, focusSearch, freeze, getAbsoluteLocationOnScreen, getAnimation, getBackground, getBaseline, getBlockDescendantFocus, getBlockUnmatchedKeyUps, getBottom, getBottomFadingEdgeStrength, getContext, getContextMenuInfo, getDefaultSize, getDrawableState, getDrawingCache, getDrawingCacheQuality, getDrawingRect, getDrawingTime, getFocusType, getFocusables, getFocusedRect, getGlobalVisibleRect, getGlobalVisibleRect, getHandler, getHeight, getHitRect, getHorizontalFadingEdgeLength, getHorizontalScrollbarHeight, getId, getInstanceCount, getLayoutParams, getLeft, getLeftFadingEdgeStrength, getLocalVisibleRect, getLocationInWindow, getLocationOnScreen, getMeasuredHeight, getMeasuredWidth, getOnFocusChangeListener, getPaddingBottom, getPaddingLeft, getPaddingRight, getPaddingTop, getParent, getResources, getRight, getRightFadingEdgeStrength, getRootView, getScrollX, getScrollY, getTag, getTop, getTopFadingEdgeStrength, getVerticalFadingEdgeLength, getVerticalScrollbarWidth, getViewRootInstanceCount, getVisibility, getWidth, getWindowFrame, getWindowSession, getWindowToken, getWindowVisibility, hasBackground, hasFocus, hasWindowFocus, inTouchMode, initializeFadingEdge, initializeScrollbars, invalidate, invalidate, invalidate, invalidateDrawable, isClickable, isDrawingCacheEnabled, isEnabled, isFocusable, isFocusableInTouchMode, isFocused, isFreezeDisabled, isHorizontalFadingEdgeEnabled, isHorizontalScrollBarEnabled, isLayoutRequested, isPressed, isSelected, isVerticalFadingEdgeEnabled, isVerticalScrollBarEnabled, layout, measure, mergeDrawableStates, onAttachedToWindow, onCreateDrawableState, onDetachedFromWindow, onDraw, onDrawBackground, onFinishInflate, onFocusChanged, onFreeze, onKeyDown, onKeyMultiple, onKeyUp, onLayout, onMeasure, onPopulateContextMenu, onScrollChanged, onSizeChanged, onThaw, onTouchEvent, onTrackballEvent, onWindowFocusChanged, onWindowVisibilityChanged, performClick, performLongClick, populateContextMenu, post, postDelayed, postInvalidate, postInvalidateDelayed, press, refreshDrawableState, requestFocus, requestFocus, requestFocus, requestLayout, requestRectangleOnScreen, requestRectangleOnScreen, resolveSize, scheduleDrawable, scrollBy, scrollTo, setAnimation, setBackground, setBackground, setBackgroundColor, setBlockDescendantFocus, setBlockUnmatchedKeyUps, setClickable, setDrawingCacheEnabled, setDrawingCacheQuality, setEnabled, setFadingEdgeLength, setFocusType, setFocusable, setFocusableInTouchMode, setFreezeDisabled, setHorizontalFadingEdgeEnabled, setHorizontalScrollBarEnabled, setId, setLayoutParams, setMeasuredDimension, setOnClickListener, setOnFocusChangeListener, setOnKeyListener, setOnLongClickListener, setOnPopulateContextMenuListener, setPadding, setPreferredHeight, setPreferredWidth, setSelected, setTag, setVerticalFadingEdgeEnabled, setVerticalScrollBarEnabled, setVisibility, setWillNotCacheDrawing, setWillNotDraw, startAnimation, thaw, unpress, unscheduleDrawable, unscheduleDrawable, verifyDrawable, willNotCacheDrawing, willNotDraw

		boolean	awakenScrollBars()
			Trigger the scrollbars to draw.
		boolean	awakenScrollBars(int startDelay)
			Trigger the scrollbars to draw.
		void	bringToFront()
			Change the view's z order in the tree, so it's on top of other sibling views
		void	buildDrawingCache()
			Forces the drawing cache to be built if the drawing cache is enabled and if it has not been built yet.
		void	clearAnimation()
			Cancels any animations for this view.
		void	clearFocus()
			Called when this view wants to give up focus.
		int	computeHorizontalScrollExtent()
			Compute the horizontal extent of the horizontal scrollbar's thumb within the horizontal range.
		int	computeHorizontalScrollOffset()
			Compute the horizontal offset of the horizontal scrollbar's thumb within the horizontal range.
		int	computeHorizontalScrollRange()
			Compute the horizontal range that the horizontal scrollbar represents.
		void	computeScroll()
			Called by a parent to request that a child update its values for mScrollX and mScrollY if necessary.
		int	computeVerticalScrollExtent()
			Compute the vertical extent of the horizontal scrollbar's thumb within the vertical range.
		int	computeVerticalScrollOffset()
			Compute the vertical offset of the vertical scrollbar's thumb within the horizontal range.
		int	computeVerticalScrollRange()
			Compute the vertical range that the vertical scrollbar represents.
		Bitmap	copyWindowBitmap()
			Return a copy of the bitmap holding the overall contents of the window this view is attached to.
		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.
		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.
		boolean	dispatchTouchEvent(MotionEvent event)
			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.
		void	draw(Canvas canvas)
			Manually render this view (and all of its children) to the given Canvas.
		void	drawableStateChanged()
			This function is called whenever the state of the view changes in such a way that it impacts the state of drawables being shown.
		void	finalize()
			Called by the virtual machine when there are no longer any (non-weak) references to the receiver.
		View	findFocus()
			Find the view in the hierarchy rooted at this view that currently has focus.
final		View	findViewById(int id)
			Look for a child view with the given id.
final		View	findViewWithTag(Object tag)
			Look for a child view with the given tag.
		View	focusSearch(int direction)
			Find the nearest view in the specified direction that can take focus.
		void	freeze(SparseArray container)
			Store this view hierarchy's frozen state into the given container.
		void	getAbsoluteLocationOnScreen(int[] location)
			Computes the coordinates of this view on the screen.
		Animation	getAnimation()
			Get the animation currently associated with this view.
		Drawable	getBackground()
			Gets the background drawable
		int	getBaseline()
			Return the offset of the widget's text baseline from the widget's top boundary.
		boolean	getBlockDescendantFocus()
			Indicated if this view will block its descendants from receiving or requesting focus.
		boolean	getBlockUnmatchedKeyUps()
			Indicates whether this view will receive key up events for which it did not receive the corresponding key down.
final		int	getBottom()
			Bottom position of this view relative to its parent.
		float	getBottomFadingEdgeStrength()
			Returns the strength, or intensity, of the bottom faded edge.
final		Context	getContext()
			Returns the context the view is running in, through which it can access the current theme, resources, etc.
		Object	getContextMenuInfo()
			Views should implement this if they have extra information to associate with the context menu.
		int	getDefaultSize(int size, int measureSpec)
			Utility to return a default size.
final		int[]	getDrawableState()
			Return an array of resource IDs of the drawable states representing the current state of the view.
		Bitmap	getDrawingCache()
			Returns the bitmap in which this view drawing is cached.
		int	getDrawingCacheQuality()
			Returns the quality of the drawing cache.
		void	getDrawingRect(Rect outRect)
			Return the visible drawing bounds of your view.
		long	getDrawingTime()
			Return the time at which the drawing of the view hierarchy started.
		int	getFocusType()
			Gets the conditions under which this view will take focus.
		ArrayList	getFocusables()
			Find and return all focusable views that are descendants of this view, possibly including this view if it is focusable itself.
		void	getFocusedRect(Rect r)
			When a view has focus and the user navigates away from it, the next view is searched for starting from the rectangle filled in by this method.
		boolean	getGlobalVisibleRect(Rect r, Point globalOffset)
			If some part of this view is not clipped by any of its parents, then return that area in r in global (root) coordinates.
final		boolean	getGlobalVisibleRect(Rect r)
		Handler	getHandler()
final		int	getHeight()
			Return the height of your view.
		void	getHitRect(Rect outRect)
			Hit rectangle in parent's coordinates
		int	getHorizontalFadingEdgeLength()
		int	getHorizontalScrollbarHeight()
		int	getId()
			Returns this view's identifier.
	static	long	getInstanceCount()
		LayoutParams	getLayoutParams()
			Get the LayoutParams associated with this view.
final		int	getLeft()
			Left position of this view relative to its parent.
		float	getLeftFadingEdgeStrength()
			Returns the strength, or intensity, of the left faded edge.
final		boolean	getLocalVisibleRect(Rect r)
		void	getLocationInWindow(int[] location)
			Computes the coordinates of this view in its window.
		void	getLocationOnScreen(int[] location)
			Computes the coordinates of this view on the screen.
final		int	getMeasuredHeight()
			The height of this view as measured in the most recent call to measure().
final		int	getMeasuredWidth()
			The width of this view as measured in the most recent call to measure().
		OnFocusChangeListener	getOnFocusChangeListener()
			Returns the focus-change callback registered for this view.
		int	getPaddingBottom()
			Returns the bottom padding of this view.
		int	getPaddingLeft()
			Returns the left padding of this view.
		int	getPaddingRight()
			Returns the right padding of this view.
		int	getPaddingTop()
			Returns the top padding of this view.
final		ViewParent	getParent()
			Gets the parent of this view.
		Resources	getResources()
			Returns the resources associated with this view.
final		int	getRight()
			Right position of this view relative to its parent.
		float	getRightFadingEdgeStrength()
			Returns the strength, or intensity, of the right faded edge.
		View	getRootView()
			Finds the topmost view in the current view hierarchy.
final		int	getScrollX()
			Return the scrolled left position of this view.
final		int	getScrollY()
			Return the scrolled top position of this view.