CoordinatorLayout.Behavior

CoordinatorLayout.Behavior

CoordinatorLayout.Behavior ()

Default constructor for instantiating Behaviors.

CoordinatorLayout.Behavior

CoordinatorLayout.Behavior (Context context, 
                AttributeSet attrs)

Default constructor for inflating Behaviors from layout. The Behavior will have the opportunity to parse specially defined layout parameters. These parameters will appear on the child view tag.

blocksInteractionBelow

boolean blocksInteractionBelow (CoordinatorLayout parent, 
                V child)

Determine whether interaction with views behind the given child in the child order should be blocked.

The default implementation returns true if getScrimOpacity(CoordinatorLayout, View) would return > 0.0f.

getInsetDodgeRect

boolean getInsetDodgeRect (CoordinatorLayout parent, 
                V child, 
                Rect rect)

Called when a view is set to dodge view insets.

This method allows a behavior to update the rectangle that should be dodged. The rectangle should be in the parent's coordinate system and within the child's bounds. If not, a IllegalArgumentException is thrown.

getScrimColor

int getScrimColor (CoordinatorLayout parent, 
                V child)

Supply a scrim color that will be painted behind the associated child view.

A scrim may be used to indicate that the other elements beneath it are not currently interactive or actionable, drawing user focus and attention to the views above the scrim.

The default implementation returns BLACK.

getScrimOpacity

float getScrimOpacity (CoordinatorLayout parent, 
                V child)

Determine the current opacity of the scrim behind a given child view

A scrim may be used to indicate that the other elements beneath it are not currently interactive or actionable, drawing user focus and attention to the views above the scrim.

The default implementation returns 0.0f.

getTag

Object getTag (View child)

Get the behavior-specific tag object with the given child view. This object is stored with the child view's LayoutParams.

layoutDependsOn

boolean layoutDependsOn (CoordinatorLayout parent, 
                V child, 
                View dependency)

Determine whether the supplied child view has another specific sibling view as a layout dependency.

This method will be called at least once in response to a layout request. If it returns true for a given child and dependency view pair, the parent CoordinatorLayout will:

1. Always lay out this child after the dependent child is laid out, regardless of child order.
2. Call onDependentViewChanged(CoordinatorLayout, V, View) when the dependency view's layout or position changes.

onApplyWindowInsets

WindowInsetsCompat onApplyWindowInsets (CoordinatorLayout coordinatorLayout, 
                V child, 
                WindowInsetsCompat insets)

Called when the window insets have changed.

Any Behavior associated with the direct child of the CoordinatorLayout may elect to handle the window inset change on behalf of it's associated view.

onAttachedToLayoutParams

void onAttachedToLayoutParams (CoordinatorLayout.LayoutParams params)

Called when the Behavior has been attached to a LayoutParams instance.

This will be called after the LayoutParams has been instantiated and can be modified.

onDependentViewChanged

boolean onDependentViewChanged (CoordinatorLayout parent, 
                V child, 
                View dependency)

Respond to a change in a child's dependent view

This method is called whenever a dependent view changes in size or position outside of the standard layout flow. A Behavior may use this method to appropriately update the child view in response.

A view's dependency is determined by layoutDependsOn(CoordinatorLayout, View, View) or if child has set another view as it's anchor.

Note that if a Behavior changes the layout of a child via this method, it should also be able to reconstruct the correct position in onLayoutChild. onDependentViewChanged will not be called during normal layout since the layout of each child view will always happen in dependency order.

If the Behavior changes the child view's size or position, it should return true. The default implementation returns false.

onDependentViewRemoved

void onDependentViewRemoved (CoordinatorLayout parent, 
                V child, 
                View dependency)

Respond to a child's dependent view being removed.

This method is called after a dependent view has been removed from the parent. A Behavior may use this method to appropriately update the child view in response.

A view's dependency is determined by layoutDependsOn(CoordinatorLayout, View, View) or if child has set another view as it's anchor.

onDetachedFromLayoutParams

void onDetachedFromLayoutParams ()

Called when the Behavior has been detached from its holding LayoutParams instance.

This will only be called if the Behavior has been explicitly removed from the LayoutParams instance via setBehavior(Behavior). It will not be called if the associated view is removed from the CoordinatorLayout or similar.

onInterceptTouchEvent

boolean onInterceptTouchEvent (CoordinatorLayout parent, 
                V child, 
                MotionEvent ev)

Respond to CoordinatorLayout touch events before they are dispatched to child views.

Behaviors can use this to monitor inbound touch events until one decides to intercept the rest of the event stream to take an action on its associated child view. This method will return false until it detects the proper intercept conditions, then return true once those conditions have occurred.

Once a Behavior intercepts touch events, the rest of the event stream will be sent to the onTouchEvent(CoordinatorLayout, V, MotionEvent) method.

This method will be called regardless of the visibility of the associated child of the behavior. If you only wish to handle touch events when the child is visible, you should add a check to isShown() on the given child.

The default implementation of this method always returns false.

onLayoutChild

boolean onLayoutChild (CoordinatorLayout parent, 
                V child, 
                int layoutDirection)

Called when the parent CoordinatorLayout is about the lay out the given child view.

This method can be used to perform custom or modified layout of a child view in place of the default child layout behavior. The Behavior's implementation can delegate to the standard CoordinatorLayout measurement behavior by calling parent.onLayoutChild.

If a Behavior implements onDependentViewChanged(CoordinatorLayout, View, View) to change the position of a view in response to a dependent view changing, it should also implement onLayoutChild in such a way that respects those dependent views. onLayoutChild will always be called for a dependent view after its dependency has been laid out.

onMeasureChild

boolean onMeasureChild (CoordinatorLayout parent, 
                V child, 
                int parentWidthMeasureSpec, 
                int widthUsed, 
                int parentHeightMeasureSpec, 
                int heightUsed)

Called when the parent CoordinatorLayout is about to measure the given child view.

This method can be used to perform custom or modified measurement of a child view in place of the default child measurement behavior. The Behavior's implementation can delegate to the standard CoordinatorLayout measurement behavior by calling parent.onMeasureChild.

onNestedFling

boolean onNestedFling (CoordinatorLayout coordinatorLayout, 
                V child, 
                View target, 
                float velocityX, 
                float velocityY, 
                boolean consumed)

Called when a nested scrolling child is starting a fling or an action that would be a fling.

Any Behavior associated with the direct child of the CoordinatorLayout may elect to accept the nested scroll as part of onStartNestedScroll(CoordinatorLayout, V, View, View, int). Each Behavior that returned true will receive subsequent nested scroll events for that nested scroll.

onNestedFling is called when the current nested scrolling child view detects the proper conditions for a fling. It reports if the child itself consumed the fling. If it did not, the child is expected to show some sort of overscroll indication. This method should return true if it consumes the fling, so that a child that did not itself take an action in response can choose not to show an overfling indication.

onNestedPreFling

boolean onNestedPreFling (CoordinatorLayout coordinatorLayout, 
                V child, 
                View target, 
                float velocityX, 
                float velocityY)

Called when a nested scrolling child is about to start a fling.

Any Behavior associated with the direct child of the CoordinatorLayout may elect to accept the nested scroll as part of onStartNestedScroll(CoordinatorLayout, V, View, View, int). Each Behavior that returned true will receive subsequent nested scroll events for that nested scroll.

onNestedPreFling is called when the current nested scrolling child view detects the proper conditions for a fling, but it has not acted on it yet. A Behavior can return true to indicate that it consumed the fling. If at least one Behavior returns true, the fling should not be acted upon by the child.

onNestedPr