android.view
Class ViewRoot

java.lang.Object
  android.os.Handler
      android.view.ViewRoot

All Implemented Interfaces:

View.AttachInfo.SoundEffectPlayer, ViewParent

final class ViewRoot
extends Handler
implements ViewParent, View.AttachInfo.SoundEffectPlayer

The top of a view hierarchy, implementing the needed protocol between View and the WindowManager. This is for the most part an internal implementation detail of WindowManagerImpl.

Nested Class Summary

static class	ViewRoot.CalledFromWrongThreadException
(package private) static class	ViewRoot.RunQueue
(package private) static class	ViewRoot.TrackballAxis Maintains state information for a single trackball axis, generating discrete (DPAD) movements based on raw trackball motion.
(package private) static class	ViewRoot.W

Field Summary

(package private) int	mAddNesting
(package private) static int	MAX_TRACKBALL_DELAY Maximum time we allow the user to roll the trackball enough to generate a key event, before resetting the counters.
(package private) ViewRoot.W	mWindow
(package private) static boolean	PROFILE_DRAWING
(package private) static ViewRoot.RunQueue	sRunQueue
(package private) static ThreadLocal<Handler>	sUiThreads

Constructor Summary

ViewRoot()

Method Summary

void	bringChildToFront(View child) Change the z order of the child so it's on top of all other children
(package private) void	checkThread()
void	childDrawableStateChanged(View child) This method is called on the parent when a child's drawable state has changed.
void	clearChildFocus(View child) Called when a child of this parent is giving up focus
void	createContextMenu(ContextMenu menu) Have the parent populate the specified context menu if it has anything to add (and then recurse on its parent).
void	debug()
void	die(boolean immediate)
void	dispatchAppVisibility(boolean visible)
(package private) void	dispatchDetachedFromWindow()
void	dispatchGetNewSurface()
void	dispatchKey(KeyEvent event)
void	dispatchPointer(MotionEvent event, long eventTime)
void	dispatchResized(int w, int h, boolean reportDraw)
void	dispatchTrackball(MotionEvent event, long eventTime)
(package private) boolean	ensureTouchMode(boolean inTouchMode) Something in the current window tells us we need to change the touch mode.
protected void	finalize() Called by the virtual machine when there are no longer any (non-weak) references to the receiver.
void	focusableViewAvailable(View v) Tells the parent that a new focusable view has become available.
View	focusSearch(View focused, int direction) Find the nearest view in the specified direction that wants to take focus
boolean	getChildVisibleRect(View child, Rect r, Point offset)
(package private) int	getHostVisibility()
static long	getInstanceCount()
(package private) WindowLeaked	getLocation()
ViewParent	getParent() Returns the parent if it exists, or null.
View	getView()
protected Rect	getWindowFrame()
(package private) void	handleAppVisibility(boolean visible)
(package private) void	handleGetNewSurface()
void	handleMessage(Message msg) Subclasses must implement this to receive messages.
void	invalidateChild(View child, Rect dirty) All or part of a child is dirty and needs to be redrawn.
ViewParent	invalidateChildInParent(int[] location, Rect dirty) All or part of a child is dirty and needs to be redrawn.
(package private) static boolean	isDirectional(int keyCode)
(package private) static boolean	isInTouchMode() Indicates whether we are in touch mode.
boolean	isLayoutRequested() Indicates whether layout was requested on this view parent.
void	playSoundEffect(int effectId)
void	profile() Call this to profile the next traversal call.
void	recomputeViewAttributes(View child) Tell view hierarchy that the global view attributes need to be re-evaluated.
void	requestChildFocus(View child, View focused) Called when a child of this parent wants focus
void	requestDisallowInterceptTouchEvent(boolean disallowIntercept) Called when a child does not want this parent and its ancestors to intercept touch events with ViewGroup.onInterceptTouchEvent(MotionEvent).
void	requestLayout() Called when something has changed which has invalidated the layout of a child of this view parent.
void	requestTransparentRegion(View child) Called when a child wants the view hierarchy to gather and report transparent regions to the window compositor.
void	scheduleTraversals()
void	setLayoutParams(WindowManager.LayoutParams attrs)
void	setView(View view, WindowManager.LayoutParams attrs, View panelParentView) We have one child
boolean	showContextMenuForChild(View originalView) Bring up a context menu for the specified view or its ancestors.
void	unscheduleTraversals()
void	windowFocusChanged(boolean hasFocus, boolean inTouchMode)

Methods inherited from class android.os.Handler

dispatchMessage, dump, getLooper, hasMessages, hasMessages, obtainMessage, obtainMessage, obtainMessage, obtainMessage, obtainMessage, post, postAtFrontOfQueue, postAtTime, postAtTime, postDelayed, removeCallbacks, removeCallbacks, removeCallbacksAndMessages, removeMessages, removeMessages, sendEmptyMessage, sendEmptyMessageAtTime, sendEmptyMessageDelayed, sendMessage, sendMessageAtFrontOfQueue, sendMessageAtTime, sendMessageDelayed, toString

Methods inherited from class java.lang.Object

clone, equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

PROFILE_DRAWING

static final boolean PROFILE_DRAWING

See Also:

Constant Field Values

MAX_TRACKBALL_DELAY

static final int MAX_TRACKBALL_DELAY

Maximum time we allow the user to roll the trackball enough to generate a key event, before resetting the counters.

See Also:

Constant Field Values

sUiThreads

static final ThreadLocal<Handler> sUiThreads

sRunQueue

static final ViewRoot.RunQueue sRunQueue

mWindow

final ViewRoot.W mWindow

mAddNesting

int mAddNesting

Constructor Detail

ViewRoot

public ViewRoot()

Method Detail

finalize

protected void finalize()
                 throws Throwable

Description copied from class: Object

Called by the virtual machine when there are no longer any (non-weak) references to the receiver. Subclasses can use this facility to guarantee that any associated resources are cleaned up before the receiver is garbage collected. Uncaught exceptions which are thrown during the running of the method cause it to terminate immediately, but are otherwise ignored.

Note: The virtual machine assumes that the implementation in class Object is empty.

Overrides:

finalize in class Object

Throws:

Throwable - The virtual machine ignores any exceptions which are thrown during finalization.

getInstanceCount

public static long getInstanceCount()

profile

public void profile()

Call this to profile the next traversal call. FIXME for perf testing only. Remove eventually

isInTouchMode

static boolean isInTouchMode()

Indicates whether we are in touch mode. Calling this method triggers an IPC call and should be avoided whenever possible.

Returns:

True, if the device is in touch mode, false otherwise.

setView

public void setView(View view,
                    WindowManager.LayoutParams attrs,
                    View panelParentView)

We have one child

getView

public View getView()

getLocation

final WindowLeaked getLocation()

setLayoutParams

public void setLayoutParams(WindowManager.LayoutParams attrs)

handleAppVisibility

void handleAppVisibility(boolean visible)

handleGetNewSurface

void handleGetNewSurface()

requestLayout

public void requestLayout()

Called when something has changed which has invalidated the layout of a child of this view parent. This will schedule a layout pass of the view tree.

Specified by:

requestLayout in interface ViewParent

isLayoutRequested

public boolean isLayoutRequested()

Indicates whether layout was requested on this view parent.

Specified by:

isLayoutRequested in interface ViewParent

Returns:

true if layout was requested, false otherwise

invalidateChild

public void invalidateChild(View child,
                            Rect dirty)

Description copied from interface: ViewParent

All or part of a child is dirty and needs to be redrawn.

Specified by:

invalidateChild in interface ViewParent

Parameters:

child - The child which is dirty

dirty - The area within the child that is invalid

getParent

public ViewParent getParent()

Description copied from interface: ViewParent

Returns the parent if it exists, or null.

Specified by:

getParent in interface ViewParent

Returns:

a ViewParent or null if this ViewParent does not have a parent

invalidateChildInParent

public ViewParent invalidateChildInParent(int[] location,
                                          Rect dirty)

Description copied from interface: ViewParent

All or part of a child is dirty and needs to be redrawn. The location array is an array of two int values which respectively define the left and the top position of the dirty child. This method must return the parent of this ViewParent if the specified rectangle must be invalidated in the parent. If the specified rectangle does not require invalidation in the parent or if the parent does not exist, this method must return null. When this method returns a non-null value, the location array must have been updated with the left and top coordinates of this ViewParent.

Specified by:

invalidateChildInParent in interface ViewParent

Parameters:

location - An array of 2 ints containing the left and top coordinates of the child to invalidate

dirty - The area within the child that is invalid

Returns:

the parent of this ViewParent or null

getChildVisibleRect

public boolean getChildVisibleRect(View child,
                                   Rect r,
                                   Point offset)

Specified by:

getChildVisibleRect in interface ViewParent

bringChildToFront

public void bringChildToFront(View child)

Description copied from interface: ViewParent

Change the z order of the child so it's on top of all other children

Specified by:

bringChildToFront in interface ViewParent

scheduleTraversals

public void scheduleTraversals()

unscheduleTraversals

public void unscheduleTraversals()

getHostVisibility

int getHostVisibility()

requestTransparentRegion

public void requestTransparentRegion(View child)

Description copied from interface: ViewParent

Called when a child wants the view hierarchy to gather and report transparent regions to the window compositor. Views that "punch" holes in the view hierarchy, such as SurfaceView can use this API to improve performance of the system. When no such a view is present in the hierarchy, this optimization in unnecessary and might slightly reduce the view hierarchy performance.

Specified by:

requestTransparentRegion in interface ViewParent

Parameters:

child - the view requesting the transparent region computation

requestChildFocus

public void requestChildFocus(View child,
                              View focused)

Description copied from interface: ViewParent

Called when a child of this parent wants focus

Specified by:

requestChildFocus in interface ViewParent

Parameters:

child - The child of this ViewParent that wants focus. This view will contain the focused view. It is not necessarily the view that actually has focus.

focused - The view that is a descendant of child that actually has focus

clearChildFocus

public void clearChildFocus(View child)

Description copied from interface: ViewParent

Called when a child of this parent is giving up focus

Specified by:

clearChildFocus in interface ViewParent

Parameters:

child - The view that is giving up focus

focusableViewAvailable

public void focusableViewAvailable(View v)

Description copied from interface: ViewParent

Tells the parent that a new focusable view has become available. This is to handle transitions from the case where there are no focusable views to the case where the first focusable view appears.

Specified by:

focusableViewAvailable in interface ViewParent

Parameters:

v - The view that has become newly focusable

recomputeViewAttributes

public void recomputeViewAttributes(View child)

Description copied from interface: ViewParent

Tell view hierarchy that the global view attributes need to be re-evaluated.

Specified by:

recomputeViewAttributes in interface ViewParent

Parameters:

child - View whose attributes have changed.

dispatchDetachedFromWindow

void dispatchDetachedFromWindow()

handleMessage

public void handleMessage(Message msg)

Description copied from class: Handler

Subclasses must implement this to receive messages.

Overrides:

handleMessage in class Handler

ensureTouchMode

boolean ensureTouchMode(boolean inTouchMode)

Something in the current window tells us we need to change the touch mode. For example, we are not in touch mode, and the user touches the screen. If the touch mode has changed, tell the window manager, and handle it locally.

Parameters:

inTouchMode - Whether we want to be in touch mode.

Returns:

True if the touch mode changed and focus changed was changed as a result

isDirectional

static boolean isDirectional(int keyCode)

Parameters:

keyCode - The key code

Returns:

True if the key is directional.

playSoundEffect

public void playSoundEffect(int effectId)

Specified by:

playSoundEffect in interface View.AttachInfo.SoundEffectPlayer

focusSearch

public View focusSearch(View focused,
                        int direction)

Find the nearest view in the specified direction that wants to take focus

Specified by:

focusSearch in interface ViewParent

Parameters:

focused - The view that currently has focus

direction - One of FOCUS_UP, FOCUS_DOWN, FOCUS_LEFT, and FOCUS_RIGHT

debug

public void debug()

die

public void die(boolean immediate)

dispatchResized

public void dispatchResized(int w,
                            int h,
                            boolean reportDraw)

dispatchKey

public void dispatchKey(KeyEvent event)

dispatchPointer

public void dispatchPointer(MotionEvent event,
                            long eventTime)

dispatchTrackball

public void dispatchTrackball(MotionEvent event,
                              long eventTime)

dispatchAppVisibility

public void dispatchAppVisibility(boolean visible)

dispatchGetNewSurface

public void dispatchGetNewSurface()

windowFocusChanged

public void windowFocusChanged(boolean hasFocus,
                               boolean inTouchMode)

showContextMenuForChild

public boolean showContextMenuForChild(View originalView)

Description copied from interface: ViewParent

Bring up a context menu for the specified view or its ancestors.

In most cases, a subclass does not need to override this. However, if the subclass is added directly to the window manager (for example, ViewManager.addView(View, android.view.ViewGroup.LayoutParams)) then it should override this and show the context menu.

Specified by:

showContextMenuForChild in interface ViewParent

Parameters:

originalView - The source view where the context menu was first invoked

Returns:

true if a context menu was displayed

createContextMenu

public void createContextMenu(ContextMenu menu)

Description copied from interface: ViewParent

Have the parent populate the specified context menu if it has anything to add (and then recurse on its parent).

Specified by:

createContextMenu in interface ViewParent

Parameters:

menu - The menu to populate

childDrawableStateChanged

public void childDrawableStateChanged(View child)

Description copied from interface: ViewParent

This method is called on the parent when a child's drawable state has changed.

Specified by:

childDrawableStateChanged in interface ViewParent

Parameters:

child - The child whose drawable state has changed.

getWindowFrame

protected Rect getWindowFrame()

checkThread

void checkThread()

requestDisallowInterceptTouchEvent

public void requestDisallowInterceptTouchEvent(boolean disallowIntercept)

Description copied from interface: ViewParent

Called when a child does not want this parent and its ancestors to intercept touch events with ViewGroup.onInterceptTouchEvent(MotionEvent).

This parent should pass this call onto its parents. This parent must obey this request for the duration of the touch (that is, only clear the flag after this parent has received an up or a cancel.

Specified by:

requestDisallowInterceptTouchEvent in interface ViewParent

Parameters:

disallowIntercept - True if the child does not want the parent to intercept touch events.