belongs to Maven artifact com.android.support:recyclerview-v7:28.0.0-alpha1
LinearSmoothScroller
public
class
LinearSmoothScroller
extends RecyclerView.SmoothScroller
| java.lang.Object | ||
| ↳ | android.support.v7.widget.RecyclerView.SmoothScroller | |
| ↳ | android.support.v7.widget.LinearSmoothScroller | |
RecyclerView.SmoothScroller implementation which uses a LinearInterpolator until
the target position becomes a child of the RecyclerView and then uses a
DecelerateInterpolator to slowly approach to target position.
If the RecyclerView.LayoutManager you are using does not implement the
RecyclerView.SmoothScroller.ScrollVectorProvider interface, then you must override the
computeScrollVectorForPosition(int) method. All the LayoutManagers bundled with
the support library implement this interface.
Summary
Constants | |
|---|---|
int |
SNAP_TO_ANY
Decides if the child should be snapped from start or end, depending on where it currently is in relation to its parent. |
int |
SNAP_TO_END
Align child view's right or bottom with parent view's right or bottom |
int |
SNAP_TO_START
Align child view's left or top with parent view's left or top |
Fields | |
|---|---|
protected
final
DecelerateInterpolator |
mDecelerateInterpolator
|
protected
int |
mInterimTargetDx
|
protected
int |
mInterimTargetDy
|
protected
final
LinearInterpolator |
mLinearInterpolator
|
protected
PointF |
mTargetVector
|
Public constructors | |
|---|---|
LinearSmoothScroller(Context context)
|
|
Public methods | |
|---|---|
int
|
calculateDtToFit(int viewStart, int viewEnd, int boxStart, int boxEnd, int snapPreference)
Helper method for |
int
|
calculateDxToMakeVisible(View view, int snapPreference)
Calculates the horizontal scroll amount necessary to make the given view fully visible inside the RecyclerView. |
int
|
calculateDyToMakeVisible(View view, int snapPreference)
Calculates the vertical scroll amount necessary to make the given view fully visible inside the RecyclerView. |
Protected methods | |
|---|---|
float
|
calculateSpeedPerPixel(DisplayMetrics displayMetrics)
Calculates the scroll speed. |
int
|
calculateTimeForDeceleration(int dx)
Calculates the time for deceleration so that transition from LinearInterpolator to DecelerateInterpolator looks smooth. |
int
|
calculateTimeForScrolling(int dx)
Calculates the time it should take to scroll the given distance (in pixels) |
int
|
getHorizontalSnapPreference()
When scrolling towards a child view, this method defines whether we should align the left or the right edge of the child with the parent RecyclerView. |
int
|
getVerticalSnapPreference()
When scrolling towards a child view, this method defines whether we should align the top or the bottom edge of the child with the parent RecyclerView. |
void
|
onSeekTargetStep(int dx, int dy, RecyclerView.State state, RecyclerView.SmoothScroller.Action action)
RecyclerView will call this method each time it scrolls until it can find the target position in the layout. |
void
|
onStart()
Called when smooth scroll is started. |
void
|
onStop()
Called when smooth scroller is stopped. |
void
|
onTargetFound(View targetView, RecyclerView.State state, RecyclerView.SmoothScroller.Action action)
Called when the target position is laid out. |
void
|
updateActionForInterimTarget(RecyclerView.SmoothScroller.Action action)
When the target scroll position is not a child of the RecyclerView, this method calculates a direction vector towards that child and triggers a smooth scroll. |
Inherited methods | |
|---|---|
From
class
android.support.v7.widget.RecyclerView.SmoothScroller
| |
From
class
java.lang.Object
| |
Constants
SNAP_TO_ANY
int SNAP_TO_ANY
Decides if the child should be snapped from start or end, depending on where it currently is in relation to its parent.
For instance, if the view is virtually on the left of RecyclerView, using
SNAP_TO_ANY is the same as using SNAP_TO_START
See also:
Constant Value: 0 (0x00000000)
SNAP_TO_END
int SNAP_TO_END
Align child view's right or bottom with parent view's right or bottom
See also:
Constant Value: 1 (0x00000001)
SNAP_TO_START
int SNAP_TO_START
Align child view's left or top with parent view's left or top
See also:
Constant Value: -1 (0xffffffff)
Fields
Public constructors
LinearSmoothScroller
LinearSmoothScroller (Context context)
| Parameters | |
|---|---|
context |
Context |
Public methods
calculateDtToFit
int calculateDtToFit (int viewStart,
int viewEnd,
int boxStart,
int boxEnd,
int snapPreference)
Helper method for calculateDxToMakeVisible(android.view.View, int) and
calculateDyToMakeVisible(android.view.View, int)
| Parameters | |
|---|---|
viewStart |
int |
viewEnd |
int |
boxStart |
int |
boxEnd |
int |
snapPreference |
int |
| Returns | |
|---|---|
int |
|
calculateDxToMakeVisible
int calculateDxToMakeVisible (View view, int snapPreference)
Calculates the horizontal scroll amount necessary to make the given view fully visible inside the RecyclerView.
| Parameters | |
|---|---|
view |
View: The view which we want to make fully visible |
snapPreference |
int: The edge which the view should snap to when entering the visible
area. One of SNAP_TO_START, SNAP_TO_END or
SNAP_TO_END |
| Returns | |
|---|---|
int |
The vertical scroll amount necessary to make the view visible with the given snap preference. |
calculateDyToMakeVisible
int calculateDyToMakeVisible (View view, int snapPreference)
Calculates the vertical scroll amount necessary to make the given view fully visible inside the RecyclerView.
| Parameters | |
|---|---|
view |
View: The view which we want to make fully visible |
snapPreference |
int: The edge which the view should snap to when entering the visible
area. One of SNAP_TO_START, SNAP_TO_END or
SNAP_TO_ANY. |
| Returns | |
|---|---|
int |
The vertical scroll amount necessary to make the view visible with the given s |