ViewPager

SCROLL_STATE_DRAGGING

int SCROLL_STATE_DRAGGING

Indicates that the pager is currently being dragged by the user.

Constant Value: 1 (0x00000001)

SCROLL_STATE_IDLE

int SCROLL_STATE_IDLE

Indicates that the pager is in an idle, settled state. The current page is fully in view and no animation is in progress.

Constant Value: 0 (0x00000000)

SCROLL_STATE_SETTLING

int SCROLL_STATE_SETTLING

Indicates that the pager is in the process of settling to a final position.

Constant Value: 2 (0x00000002)

ViewPager

ViewPager (Context context)

ViewPager

ViewPager (Context context, 
                AttributeSet attrs)

addOnAdapterChangeListener

void addOnAdapterChangeListener (ViewPager.OnAdapterChangeListener listener)

Add a listener that will be invoked whenever the adapter for this ViewPager changes.

addOnPageChangeListener

void addOnPageChangeListener (ViewPager.OnPageChangeListener listener)

Add a listener that will be invoked whenever the page changes or is incrementally scrolled. See ViewPager.OnPageChangeListener.

Components that add a listener should take care to remove it when finished. Other components that take ownership of a view may call clearOnPageChangeListeners() to remove all attached listeners.

arrowScroll

boolean arrowScroll (int direction)

Handle scrolling in response to a left or right arrow click.

beginFakeDrag

boolean beginFakeDrag ()

Start a fake drag of the pager.

A fake drag can be useful if you want to synchronize the motion of the ViewPager with the touch scrolling of another view, while still letting the ViewPager control the snapping motion and fling behavior. (e.g. parallax-scrolling tabs.) Call fakeDragBy(float) to simulate the actual drag motion. Call endFakeDrag() to complete the fake drag and fling as necessary.

During a fake drag the ViewPager will ignore all touch events. If a real drag is already in progress, this method will return false.

clearOnPageChangeListeners

void clearOnPageChangeListeners ()

Remove all listeners that are notified of any changes in scroll state or position.

endFakeDrag

void endFakeDrag ()

End a fake drag of the pager.

executeKeyEvent

boolean executeKeyEvent (KeyEvent event)

You can call this function yourself to have the scroll view perform scrolling from a key event, just as if the event had been dispatched to it by the view hierarchy.

fakeDragBy

void fakeDragBy (float xOffset)

Fake drag by an offset in pixels. You must have called beginFakeDrag() first.

getAdapter

PagerAdapter getAdapter ()

Retrieve the current adapter supplying pages.

getCurrentItem

int getCurrentItem ()

getOffscreenPageLimit

int getOffscreenPageLimit ()

Returns the number of pages that will be retained to either side of the current page in the view hierarchy in an idle state. Defaults to 1.

getPageMargin

int getPageMargin ()

Return the margin between pages.

isFakeDragging

boolean isFakeDragging ()

Returns true if a fake drag is in progress.

onRestoreInstanceState

void onRestoreInstanceState (Parcelable state)

onSaveInstanceState

Parcelable onSaveInstanceState ()

removeOnAdapterChangeListener

void removeOnAdapterChangeListener (ViewPager.OnAdapterChangeListener listener)

Remove a listener that was previously added via addOnAdapterChangeListener(OnAdapterChangeListener).

removeOnPageChangeListener

void removeOnPageChangeListener (ViewPager.OnPageChangeListener listener)

Remove a listener that was previously added via addOnPageChangeListener(OnPageChangeListener).

setAdapter

void setAdapter (PagerAdapter adapter)

Set a PagerAdapter that will supply views for this pager as needed.

setCurrentItem

void setCurrentItem (int item)

Set the currently selected page. If the ViewPager has already been through its first layout with its current adapter there will be a smooth animated transition between the current item and the specified item.

setCurrentItem

void setCurrentItem (int item, 
                boolean smoothScroll)

Set the currently selected page.

setOffscreenPageLimit

void setOffscreenPageLimit (int limit)

Set the number of pages that should be retained to either side of the current page in the view hierarchy in an idle state. Pages beyond this limit will be recreated from the adapter when needed.

This is offered as an optimization. If you know in advance the number of pages you will need to support or have lazy-loading mechanisms in place on your pages, tweaking this setting can have benefits in perceived smoothness of paging animations and interaction. If you have a small number of pages (3-4) that you can keep active all at once, less time will be spent in layout for newly created view subtrees as the user pages back and forth.

You should keep this limit low, especially if your pages have complex layouts. This setting defaults to 1.

setOnPageChangeListener

void setOnPageChangeListener (ViewPager.OnPageChangeListener listener)

This method was deprecated in API level 24.1.0.
Use addOnPageChangeListener(OnPageChangeListener) and removeOnPageChangeListener(OnPageChangeListener) instead.

Set a listener that will be invoked whenever the page changes or is incrementally scrolled. See ViewPager.OnPageChangeListener.

setPageMargin

void setPageMargin (int marginPixels)

Set the margin between pages.

setPageMarginDrawable

void setPageMarginDrawable (int resId)

Set a drawable that will be used to fill the margin between pages.

setPageMarginDrawable

void setPageMarginDrawable (Drawable d)

Set a drawable that will be used to fill the margin between pages.

setPageTransformer

void setPageTransformer (boolean reverseDrawingOrder, 
                ViewPager.PageTransformer transformer, 
                int pageLayerType)

Sets a ViewPager.PageTransformer that will be called for each attached page whenever the scroll position is changed. This allows the application to apply custom property transformations to each page, overriding the default sliding behavior.

setPageTransformer

void setPageTransformer (boolean reverseDrawingOrder, 
                ViewPager.PageTransformer transformer)

Sets a ViewPager.PageTransformer that will be called for each attached page whenever the scroll position is changed. This allows the application to apply custom property transformations to each page, overriding the default sliding behavior.

Note: By default, calling this method will cause contained pages to use LAYER_TYPE_HARDWARE. This layer type allows custom alpha transformations, but it will cause issues if any of your pages contain a SurfaceView and you have not called setZOrderOnTop(boolean) to put that SurfaceView above your app content. To disable this behavior, call setPageTransformer(boolean, PageTransformer, int) and pass LAYER_TYPE_NONE for pageLayerType.

canScroll

boolean canScroll (View v, 
                boolean checkV, 
                int dx, 
                int x, 
                int y)

Tests scrollability within child views of v given a delta of dx.

onLayout

void onLayout (boolean changed, 
                int l, 
                int t, 
                int r, 
                int b)

onPageScrolled

void onPageScrolled (int position, 
                float offset, 
                int offsetPixels)

This method will be invoked when the current page is scrolled, either as part of a programmatically initiated smooth scroll or a user initiated touch scroll. If you override this method you must call through to the superclass implementation (e.g. super.onPageScrolled(position, offset, offsetPixels)) before onPageScrolled returns.