RecyclerView.State

public State()

public boolean didStructureChange()

public T <T> get(int resourceId)

Gets the Object mapped from the specified id, or null if no such data exists.

public int getItemCount()

Returns the total number of items that can be laid out. Note that this number is not necessarily equal to the number of items in the adapter, so you should always use this number for your position calculations and never access the adapter directly.

RecyclerView listens for Adapter's notify events and calculates the effects of adapter data changes on existing Views. These calculations are used to decide which animations should be run.

To support predictive animations, RecyclerView may rewrite or reorder Adapter changes to present the correct state to LayoutManager in pre-layout pass.

For example, a newly added item is not included in pre-layout item count because pre-layout reflects the contents of the adapter before the item is added. Behind the scenes, RecyclerView offsets getViewForPosition calls such that LayoutManager does not know about the new item's existence in pre-layout. The item will be available in second layout pass and will be included in the item count. Similar adjustments are made for moved and removed items as well.

You can get the adapter's item count via getItemCount method.

public int getRemainingScrollHorizontal()

Returns remaining horizontal scroll distance of an ongoing scroll animation(fling/ smoothScrollTo/SmoothScroller) in pixels. Returns zero if getScrollState is other than SCROLL_STATE_SETTLING.

public int getRemainingScrollVertical()

Returns remaining vertical scroll distance of an ongoing scroll animation(fling/ smoothScrollTo/SmoothScroller) in pixels. Returns zero if getScrollState is other than SCROLL_STATE_SETTLING.

public int getTargetScrollPosition()

If scroll is triggered to make a certain item visible, this value will return the adapter index of that item.

public boolean hasTargetScrollPosition()

Returns if current scroll has a target position.

public boolean isMeasuring()

Returns true if the RecyclerView is currently measuring the layout. This value is true only if the LayoutManager opted into the auto measure API and RecyclerView has non-exact measurement specs.

Note that if the LayoutManager supports predictive animations and it is calculating the pre-layout step, this value will be false even if the RecyclerView is in onMeasure call. This is because pre-layout means the previous state of the RecyclerView and measurements made for that state cannot change the RecyclerView's size. LayoutManager is always guaranteed to receive another call to onLayoutChildren when this happens.

public boolean isPreLayout()

Returns true if the RecyclerView is in the pre-layout step where it is having its LayoutManager layout items where they will be at the beginning of a set of predictive item animations.

public void put(int resourceId, Object data)

Adds a mapping from the specified id to the specified value, replacing the previous mapping from the specified key if there was one.

public void remove(int resourceId)

Removes the mapping from the specified id, if there was any.

public String toString()

public boolean willRunPredictiveAnimations()

Returns whether RecyclerView will run predictive animations in this layout pass or not.

public boolean willRunSimpleAnimations()

Returns whether RecyclerView will run simple animations in this layout pass or not.