android.widget
Class FrameLayout

java.lang.Object
  android.view.View
      android.view.ViewGroup
          android.widget.FrameLayout

All Implemented Interfaces:

Drawable.Callback, KeyEvent.Callback, ViewManager, ViewParent

Direct Known Subclasses:

DatePicker, GadgetHostView, MediaController, ScrollView, TabHost, TimePicker, ViewAnimator

public class FrameLayout
extends ViewGroup

FrameLayout is designed to block out an area on the screen to display a single item. You can add multiple children to a FrameLayout, but all children are pegged to the top left of the screen. Children are drawn in a stack, with the most recently added child on top. The size of the frame layout is the size of its largest child (plus padding), visible or not (if the FrameLayout's parent permits). Views that are GONE are used for sizing only if setConsiderGoneChildrenWhenMeasuring() is set to true.

Nested Class Summary

static class

FrameLayout.LayoutParams Per-child layout information for layouts that support margins.

Nested classes/interfaces inherited from class android.view.ViewGroup

ViewGroup.MarginLayoutParams, ViewGroup.OnHierarchyChangeListener

Nested classes/interfaces inherited from class android.view.View

View.BaseSavedState, View.MeasureSpec, View.OnClickListener, View.OnCreateContextMenuListener, View.OnFocusChangeListener, View.OnKeyListener, View.OnLongClickListener, View.OnTouchListener

Field Summary

(package private) boolean

mMeasureAllChildren

Fields inherited from class android.view.ViewGroup

CLIP_TO_PADDING_MASK, FLAG_SUPPORT_STATIC_TRANSFORMATIONS, FLAG_USE_CHILD_DRAWING_ORDER, FOCUS_AFTER_DESCENDANTS, FOCUS_BEFORE_DESCENDANTS, FOCUS_BLOCK_DESCENDANTS, mDisappearingChildren, mGroupFlags, mOnHierarchyChangeListener, mPersistentDrawingCache, PERSISTENT_ALL_CACHES, PERSISTENT_ANIMATION_CACHE, PERSISTENT_NO_CACHE, PERSISTENT_SCROLLING_CACHE

Fields inherited from class android.view.View

DRAWING_CACHE_QUALITY_AUTO, DRAWING_CACHE_QUALITY_HIGH, DRAWING_CACHE_QUALITY_LOW, EMPTY_STATE_SET, ENABLED_FOCUSED_SELECTED_STATE_SET, ENABLED_FOCUSED_SELECTED_WINDOW_FOCUSED_STATE_SET, ENABLED_FOCUSED_STATE_SET, ENABLED_FOCUSED_WINDOW_FOCUSED_STATE_SET, ENABLED_SELECTED_STATE_SET, ENABLED_SELECTED_WINDOW_FOCUSED_STATE_SET, ENABLED_STATE_SET, ENABLED_WINDOW_FOCUSED_STATE_SET, FIRST_STATE_SET, FOCUS_BACKWARD, FOCUS_DOWN, FOCUS_FORWARD, FOCUS_LEFT, FOCUS_RIGHT, FOCUS_UP, FOCUSED_SELECTED_STATE_SET, FOCUSED_SELECTED_WINDOW_FOCUSED_STATE_SET, FOCUSED_STATE_SET, FOCUSED_WINDOW_FOCUSED_STATE_SET, GONE, INVISIBLE, KEEP_SCREEN_ON, LAST_STATE_SET, mBottom, mContext, mCurrentAnimation, MIDDLE_STATE_SET, mLayoutParams, mLeft, mMeasuredHeight, mMeasuredWidth, mOnClickListener, mOnCreateContextMenuListener, mOnFocusChangeListener, mOnLongClickListener, mPaddingBottom, mPaddingLeft, mPaddingRight, mPaddingTop, mParent, mRight, mScrollX, mScrollY, mTag, mTop, NO_ID, PRESSED_ENABLED_FOCUSED_SELECTED_STATE_SET, PRESSED_ENABLED_FOCUSED_SELECTED_WINDOW_FOCUSED_STATE_SET, PRESSED_ENABLED_FOCUSED_STATE_SET, PRESSED_ENABLED_FOCUSED_WINDOW_FOCUSED_STATE_SET, PRESSED_ENABLED_SELECTED_STATE_SET, PRESSED_ENABLED_SELECTED_WINDOW_FOCUSED_STATE_SET, PRESSED_ENABLED_STATE_SET, PRESSED_ENABLED_WINDOW_FOCUSED_STATE_SET, PRESSED_FIRST_STATE_SET, PRESSED_FOCUSED_SELECTED_STATE_SET, PRESSED_FOCUSED_SELECTED_WINDOW_FOCUSED_STATE_SET, PRESSED_FOCUSED_STATE_SET, PRESSED_FOCUSED_WINDOW_FOCUSED_STATE_SET, PRESSED_LAST_STATE_SET, PRESSED_MIDDLE_STATE_SET, PRESSED_SELECTED_STATE_SET, PRESSED_SELECTED_WINDOW_FOCUSED_STATE_SET, PRESSED_SINGLE_STATE_SET, PRESSED_STATE_SET, PRESSED_WINDOW_FOCUSED_STATE_SET, SCROLLBARS_INSIDE_INSET, SCROLLBARS_INSIDE_OVERLAY, SCROLLBARS_OUTSIDE_INSET, SCROLLBARS_OUTSIDE_OVERLAY, SELECTED_STATE_SET, SELECTED_WINDOW_FOCUSED_STATE_SET, SINGLE_STATE_SET, SOUND_EFFECTS_ENABLED, VIEW_LOG_TAG, VISIBLE, WINDOW_FOCUSED_STATE_SET

Constructor Summary

FrameLayout(Context context)

FrameLayout(Context context, AttributeSet attrs)

FrameLayout(Context context, AttributeSet attrs, int defStyle)

Method Summary

protected boolean	checkLayoutParams(ViewGroup.LayoutParams p)
void	draw(Canvas canvas) Manually render this view (and all of its children) to the given Canvas.
protected 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.
boolean	gatherTransparentRegion(Region region) This is used by the RootView to perform an optimization when the view hierarchy contains one or several SurfaceView.
protected FrameLayout.LayoutParams	generateDefaultLayoutParams() Returns a set of layout parameters with a width of ViewGroup.LayoutParams.FILL_PARENT, and a height of ViewGroup.LayoutParams.FILL_PARENT.
FrameLayout.LayoutParams	generateLayoutParams(AttributeSet attrs) Returns a new set of layout parameters based on the supplied attributes set.
protected ViewGroup.LayoutParams	generateLayoutParams(ViewGroup.LayoutParams p) Returns a safe set of layout parameters based on the supplied layout params.
boolean	getConsiderGoneChildrenWhenMeasuring() Determines whether to measure all children or just those in the VISIBLE or INVISIBLE state when measuring.
Drawable	getForeground() Returns the drawable used as the foreground of this FrameLayout.
protected void	onLayout(boolean changed, int left, int top, int right, int bottom) Called from layout when this view should assign a size and position to each of its children.
protected void	onMeasure(int widthMeasureSpec, int heightMeasureSpec) Measure the view and its content to determine the measured width and the measured height.
protected void	onSizeChanged(int w, int h, int oldw, int oldh) This is called during layout when the size of this view has changed.
void	setForeground(Drawable drawable) Supply a Drawable that is to be rendered on top of all of the child views in the frame layout.
void	setForegroundGravity(int foregroundGravity) Describes how the foreground is positioned.
void	setMeasureAllChildren(boolean measureAll) Determines whether to measure all children or just those in the VISIBLE or INVISIBLE state when measuring.
protected boolean	verifyDrawable(Drawable who) If your view subclass is displaying its own Drawable objects, it should override this function and return true for any Drawable it is displaying.

Methods inherited from class android.view.ViewGroup

addFocusables, addStatesFromChildren, addTouchables, addView, addView, addView, addView, addView, addViewInLayout, addViewInLayout, attachLayoutAnimationParameters, attachViewToParent, bringChildToFront, canAnimate, childDrawableStateChanged, cleanupLayoutState, clearChildFocus, clearDisappearingChildren, clearFocus, debug, detachAllViewsFromParent, detachViewFromParent, detachViewFromParent, detachViewsFromParent, dispatchDraw, dispatchFreezeSelfOnly, dispatchKeyEvent, dispatchKeyEventPreIme, dispatchKeyShortcutEvent, dispatchRestoreInstanceState, dispatchSaveInstanceState, dispatchSetPressed, dispatchSetSelected, dispatchThawSelfOnly, dispatchTouchEvent, dispatchTrackballEvent, dispatchUnhandledMove, dispatchWindowFocusChanged, dispatchWindowVisibilityChanged, drawChild, findFocus, findViewTraversal, findViewWithTagTraversal, fitSystemWindows, focusableViewAvailable, focusSearch, getChildAt, getChildCount, getChildDrawingOrder, getChildMeasureSpec, getChildStaticTransformation, getChildVisibleRect, getDescendantFocusability, getFocusedChild, getLayoutAnimation, getLayoutAnimationListener, getPersistentDrawingCache, hasFocus, hasFocusable, indexOfChild, invalidateChild, invalidateChildInParent, isAlwaysDrawnWithCacheEnabled, isAnimationCacheEnabled, isChildrenDrawnWithCacheEnabled, measureChild, measureChildren, measureChildWithMargins, offsetChildrenTopAndBottom, offsetDescendantRectToMyCoords, offsetRectIntoDescendantCoords, onAnimationEnd, onAnimationStart, onCreateDrawableState, onInterceptTouchEvent, onRequestFocusInDescendants, recomputeViewAttributes, removeAllViews, removeAllViewsInLayout, removeDetachedView, removeView, removeViewAt, removeViewInLayout, removeViews, removeViewsInLayout, requestChildFocus, requestChildRectangleOnScreen, requestDisallowInterceptTouchEvent, requestFocus, requestTransparentRegion, scheduleLayoutAnimation, setAddStatesFromChildren, setAlwaysDrawnWithCacheEnabled, setAnimationCacheEnabled, setChildrenDrawingCacheEnabled, setChildrenDrawnWithCacheEnabled, setClipChildren, setClipToPadding, setDescendantFocusability, setLayoutAnimation, setLayoutAnimationListener, setOnHierarchyChangeListener, setPadding, setPersistentDrawingCache, setStaticTransformationsEnabled, showContextMenuForChild, startLayoutAnimation, updateViewLayout

Methods inherited from class android.view.View

applyDrawableToTransparentRegion, bringToFront, buildDrawingCache, cancelLongPress, clearAnimation, computeHorizontalScrollExtent, computeHorizontalScrollOffset, computeHorizontalScrollRange, computeScroll, computeVerticalScrollExtent, computeVerticalScrollOffset, computeVerticalScrollRange, createContextMenu, debug, debugIndent, destroyDrawingCache, finalize, findViewById, findViewWithTag, focusSearch, forceLayout, getAnimation, getApplicationWindowToken, getBackground, getBaseline, getBottom, getBottomFadingEdgeStrength, getBottomPaddingOffset, getContext, getContextMenuInfo, getDefaultSize, getDrawableState, getDrawingCache, getDrawingCacheBackgroundColor, getDrawingCacheQuality, getDrawingRect, getDrawingTime, getFocusables, getFocusedRect, getGlobalVisibleRect, getGlobalVisibleRect, getHandler, getHeight, getHitRect, getHorizontalFadingEdgeLength, getHorizontalScrollbarHeight, getId, getKeepScreenOn, getLayoutParams, getLeft, getLeftFadingEdgeStrength, getLeftPaddingOffset, getLocalVisibleRect, getLocationInWindow, getLocationOnScreen, getMeasuredHeight, getMeasuredWidth, getNextFocusDownId, getNextFocusLeftId, getNextFocusRightId, getNextFocusUpId, getOnFocusChangeListener, getPaddingBottom, getPaddingLeft, getPaddingRight, getPaddingTop, getParent, getResources, getRight, getRightFadingEdgeStrength, getRightPaddingOffset, getRootView, getScrollBarStyle, getScrollX, getScrollY, getSolidColor, getSuggestedMinimumHeight, getSuggestedMinimumWidth, getTag, getTop, getTopFadingEdgeStrength, getTopPaddingOffset, getTouchables, getTouchDelegate, getVerticalFadingEdgeLength, getVerticalScrollbarWidth, getViewTreeObserver, getVisibility, getWidth, getWindowAttachCount, getWindowToken, getWindowVisibility, getWindowVisibleDisplayFrame, hasWindowFocus, inflate, initializeFadingEdge, initializeScrollbars, invalidate, invalidate, invalidate, invalidateDrawable, isClickable, isDrawingCacheEnabled, isDuplicateParentStateEnabled, isEnabled, isFocusable, isFocusableInTouchMode, isFocused, isHorizontalFadingEdgeEnabled, isHorizontalScrollBarEnabled, isInEditMode, isInTouchMode, isLayoutRequested, isLongClickable, isPaddingOffsetRequired, isPressed, isRootNamespace, isSaveEnabled, isSelected, isShown, isSoundEffectsEnabled, isVerticalFadingEdgeEnabled, isVerticalScrollBarEnabled, layout, measure, mergeDrawableStates, offsetLeftAndRight, offsetTopAndBottom, onAttachedToWindow, onCheckIsTextEditor, onCreateContextMenu, onCreateInputConnection, onDetachedFromWindow, onDraw, onFinishInflate, onFocusChanged, onKeyDown, onKeyMultiple, onKeyPreIme, onKeyShortcut, onKeyUp, onRestoreInstanceState, onSaveInstanceState, onScrollChanged, onSetAlpha, onTouchEvent, onTrackballEvent, onWindowFocusChanged, onWindowVisibilityChanged, performClick, performLongClick, playSoundEffect, post, postDelayed, postInvalidate, postInvalidate, postInvalidateDelayed, postInvalidateDelayed, refreshDrawableState, removeCallbacks, requestFocus, requestFocus, requestFocusFromTouch, requestLayout, requestRectangleOnScreen, requestRectangleOnScreen, resolveSize, restoreHierarchyState, saveHierarchyState, scheduleDrawable, scrollBy, scrollTo, setAnimation, setBackgroundColor, setBackgroundDrawable, setBackgroundResource, setClickable, setDrawingCacheBackgroundColor, setDrawingCacheEnabled, setDrawingCacheQuality, setDuplicateParentStateEnabled, setEnabled, setFadingEdgeLength, setFocusable, setFocusableInTouchMode, setFrame, setHorizontalFadingEdgeEnabled, setHorizontalScrollBarEnabled, setId, setIsRootNamespace, setKeepScreenOn, setLayoutParams, setLongClickable, setMeasuredDimension, setMinimumHeight, setMinimumWidth, setNextFocusDownId, setNextFocusLeftId, setNextFocusRightId, setNextFocusUpId, setOnClickListener, setOnCreateContextMenuListener, setOnFocusChangeListener, setOnKeyListener, setOnLongClickListener, setOnTouchListener, setPressed, setSaveEnabled, setScrollBarStyle, setScrollContainer, setSelected, setSoundEffectsEnabled, setTag, setTouchDelegate, setVerticalFadingEdgeEnabled, setVerticalScrollBarEnabled, setVisibility, setWillNotCacheDrawing, setWillNotDraw, showContextMenu, startAnimation, unscheduleDrawable, unscheduleDrawable, willNotCacheDrawing, willNotDraw

Methods inherited from class java.lang.Object

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

Methods inherited from interface android.view.ViewParent

createContextMenu, getParent, isLayoutRequested, requestLayout

Field Detail

mMeasureAllChildren

boolean mMeasureAllChildren

Constructor Detail

FrameLayout

public FrameLayout(Context context)

FrameLayout

public FrameLayout(Context context,
                   AttributeSet attrs)

FrameLayout

public FrameLayout(Context context,
                   AttributeSet attrs,
                   int defStyle)

Method Detail

setForegroundGravity

public void setForegroundGravity(int foregroundGravity)

Describes how the foreground is positioned. Defaults to FILL.

Parameters:

foregroundGravity - See Gravity

verifyDrawable

protected boolean verifyDrawable(Drawable who)

If your view subclass is displaying its own Drawable objects, it should override this function and return true for any Drawable it is displaying. This allows animations for those drawables to be scheduled.

Be sure to call through to the super class when overriding this function.

Overrides:

verifyDrawable in class View

Parameters:

who - The Drawable to verify. Return true if it is one you are displaying, else return the result of calling through to the super class.

Returns:

boolean If true than the Drawable is being displayed in the view; else false and it is not allowed to animate.

See Also:

View.unscheduleDrawable(android.graphics.drawable.Drawable, java.lang.Runnable), View.drawableStateChanged()

drawableStateChanged

protected 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.

Be sure to call through to the superclass when overriding this function.

Overrides:

drawableStateChanged in class ViewGroup

See Also:

Drawable.setState(int[])

generateDefaultLayoutParams

protected FrameLayout.LayoutParams generateDefaultLayoutParams()

Returns a set of layout parameters with a width of ViewGroup.LayoutParams.FILL_PARENT, and a height of ViewGroup.LayoutParams.FILL_PARENT.

Overrides:

generateDefaultLayoutParams in class ViewGroup

Returns:

a set of default layout parameters or null

setForeground

public void setForeground(Drawable drawable)

Supply a Drawable that is to be rendered on top of all of the child views in the frame layout. Any padding in the Drawable will be taken into account by ensuring that the children are inset to be placed inside of the padding area.

Parameters:

drawable - The Drawable to be drawn on top of the children.

getForeground

public Drawable getForeground()

Returns the drawable used as the foreground of this FrameLayout. The foreground drawable, if non-null, is always drawn on top of the children.

Returns:

A Drawable or null if no foreground was set.

onMeasure

protected void onMeasure(int widthMeasureSpec,
                         int heightMeasureSpec)

Measure the view and its content to determine the measured width and the measured height. This method is invoked by View.measure(int, int) and should be overriden by subclasses to provide accurate and efficient measurement of their contents.

CONTRACT: When overriding this method, you must call View.setMeasuredDimension(int, int) to store the measured width and height of this view. Failure to do so will trigger an IllegalStateException, thrown by View.measure(int, int). Calling the superclass' View.onMeasure(int, int) is a valid use.

The base class implementation of measure defaults to the background size, unless a larger size is allowed by the MeasureSpec. Subclasses should override View.onMeasure(int, int) to provide better measurements of their content.

If this method is overridden, it is the subclass's responsibility to make sure the measured height and width are at least the view's minimum height and width (View.getSuggestedMinimumHeight() and View.getSuggestedMinimumWidth()).

Overrides:

onMeasure in class View

Parameters:

widthMeasureSpec - horizontal space requirements as imposed by the parent. The requirements are encoded with View.MeasureSpec.

heightMeasureSpec - vertical space requirements as imposed by the parent. The requirements are encoded with View.MeasureSpec.

See Also:

View.getMeasuredWidth(), View.getMeasuredHeight(), View.setMeasuredDimension(int, int), View.getSuggestedMinimumHeight(), View.getSuggestedMinimumWidth(), View.MeasureSpec.getMode(int), View.MeasureSpec.getSize(int)

onLayout

protected void onLayout(boolean changed,
                        int left,
                        int top,
                        int right,
                        int bottom)

Called from layout when this view should assign a size and position to each of its children. Derived classes with children should override this method and call layout on each of their their children.

Specified by:

onLayout in class ViewGroup

Parameters:

changed - This is a new size or position for this view

left - Left position, relative to parent

top - Top position, relative to parent

right - Right position, relative to parent

bottom - Bottom position, relative to parent

onSizeChanged

protected void onSizeChanged(int w,
                             int h,
                             int oldw,
                             int oldh)

This is called during layout when the size of this view has changed. If you were just added to the view hierarchy, you're called with the old values of 0.

Overrides:

onSizeChanged in class View

Parameters:

w - Current width of this view.

h - Current height of this view.

oldw - Old width of this view.

oldh - Old height of this view.

draw

public void draw(Canvas canvas)

Manually render this view (and all of its children) to the given Canvas. The view must have already done a full layout before this function is called. When implementing a view, do not override this method; instead, you should implement View.onDraw(android.graphics.Canvas).

Overrides:

draw in class View

Parameters:

canvas - The Canvas to which the View is rendered.

gatherTransparentRegion

public boolean gatherTransparentRegion(Region region)

This is used by the RootView to perform an optimization when the view hierarchy contains one or several SurfaceView. SurfaceView is always considered transparent, but its children are not, therefore all View objects remove themselves from the global transparent region (passed as a parameter to this function).

Overrides:

gatherTransparentRegion in class ViewGroup

Parameters:

region - The transparent region for this ViewRoot (window).

Returns:

Returns true if the effective visibility of the view at this point is opaque, regardless of the transparent region; returns false if it is possible for underlying windows to be seen behind the view.

setMeasureAllChildren

public void setMeasureAllChildren(boolean measureAll)

Determines whether to measure all children or just those in the VISIBLE or INVISIBLE state when measuring. Defaults to false.

Parameters:

measureAll - true to consider children marked GONE, false otherwise. Default value is false.

getConsiderGoneChildrenWhenMeasuring

public boolean getConsiderGoneChildrenWhenMeasuring()

Determines whether to measure all children or just those in the VISIBLE or INVISIBLE state when measuring.

generateLayoutParams

public FrameLayout.LayoutParams generateLayoutParams(AttributeSet attrs)

Returns a new set of layout parameters based on the supplied attributes set.

Overrides:

generateLayoutParams in class ViewGroup

Parameters:

attrs - the attributes to build the layout parameters from

Returns:

an instance of ViewGroup.LayoutParams or one of its descendants

checkLayoutParams

protected boolean checkLayoutParams(ViewGroup.LayoutParams p)

Overrides:

checkLayoutParams in class ViewGroup

generateLayoutParams

protected ViewGroup.LayoutParams generateLayoutParams(ViewGroup.LayoutParams p)

Description copied from class: ViewGroup

Returns a safe set of layout parameters based on the supplied layout params. When a ViewGroup is passed a View whose layout params do not pass the test of ViewGroup.checkLayoutParams(android.view.ViewGroup.LayoutParams), this method is invoked. This method should return a new set of layout params suitable for this ViewGroup, possibly by copying the appropriate attributes from the specified set of layout params.

Overrides:

generateLayoutParams in class ViewGroup

Parameters:

p - The layout parameters to convert into a suitable set of layout parameters for this ViewGroup.

Returns:

an instance of ViewGroup.LayoutParams or one of its descendants