universum.studios.android.recycler.decoration

Class RecyclerViewItemDecoration

java.lang.Object

android.support.v7.widget.RecyclerView.ItemDecoration

universum.studios.android.recycler.decoration.RecyclerViewItemDecoration

Direct Known Subclasses:

ItemDividerDecoration, ItemSpaceDecoration

public abstract class RecyclerViewItemDecoration
extends RecyclerView.ItemDecoration

A RecyclerView.ItemDecoration implementation that is used as base class by all item decorations from the Recycler library and is also encouraged to be used as base class by custom decoration implementations.

Xml attributes

ItemDecoration Attributes

Default style attribute

none

Since:

1.0

Author:

Martin Albedinsky

See Also:

RecyclerView.addItemDecoration(RecyclerView.ItemDecoration)

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	RecyclerViewItemDecoration.Precondition Precondition represents a simple check which is performed by an item decoration before its decoration logic is performed for a specific item view.

Constructor Summary

Constructors

Constructor and Description
RecyclerViewItemDecoration() Same as RecyclerViewItemDecoration(Context) with null context.
RecyclerViewItemDecoration(Context context) Same as RecyclerViewItemDecoration(Context, AttributeSet) with null attrs.
RecyclerViewItemDecoration(Context context, AttributeSet attrs) Same as RecyclerViewItemDecoration(Context, AttributeSet, int) with 0 defStyleAttr.
RecyclerViewItemDecoration(Context context, AttributeSet attrs, int defStyleAttr) Same as RecyclerViewItemDecoration(Context, AttributeSet, int, int) with 0 defStyleRes.
RecyclerViewItemDecoration(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) Creates a new instance of RecyclerViewItemDecoration for the given context.

Method Summary

Modifier and Type	Method and Description
RecyclerViewItemDecoration.Precondition	getPrecondition() Returns the precondition specified for this decoration.
void	setPrecondition(RecyclerViewItemDecoration.Precondition precondition) Specifies a precondition that should be checked by this decoration for each item view before it is decorated.
void	setSkipFirst(boolean skip) Sets a boolean flag indicating whether this decoration should be skipped for the first item from data set of the associated RecyclerView.
void	setSkipLast(boolean skip) Sets a boolean flag indicating whether this decoration should be skipped for the last item from data set of the associated RecyclerView.
protected boolean	shouldDecorate(RecyclerView parent, RecyclerView.State state) Checks whether any subsequent decoration algorithm should be applied by this decoration for the given parent RecyclerView and its current state.
boolean	skipsFirst() Checks whether this decoration is skipped for the first item.
boolean	skipsLast() Checks whether this decoration is skipped for the last item.

Methods inherited from class android.support.v7.widget.RecyclerView.ItemDecoration

getItemOffsets, getItemOffsets, onDraw, onDraw, onDrawOver, onDrawOver

Methods inherited from class java.lang.Object

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

Constructor Detail

RecyclerViewItemDecoration

public RecyclerViewItemDecoration()

Same as RecyclerViewItemDecoration(Context) with null context.

RecyclerViewItemDecoration

public RecyclerViewItemDecoration(@Nullable
                                  Context context)

Same as RecyclerViewItemDecoration(Context, AttributeSet) with null attrs.

RecyclerViewItemDecoration

public RecyclerViewItemDecoration(@Nullable
                                  Context context,
                                  @Nullable
                                  AttributeSet attrs)

Same as RecyclerViewItemDecoration(Context, AttributeSet, int) with 0 defStyleAttr.

RecyclerViewItemDecoration

public RecyclerViewItemDecoration(@Nullable
                                  Context context,
                                  @Nullable
                                  AttributeSet attrs,
                                  @AttrRes
                                  int defStyleAttr)

Same as RecyclerViewItemDecoration(Context, AttributeSet, int, int) with 0 defStyleRes.

RecyclerViewItemDecoration

public RecyclerViewItemDecoration(@Nullable
                                  Context context,
                                  @Nullable
                                  AttributeSet attrs,
                                  @AttrRes
                                  int defStyleAttr,
                                  @StyleRes
                                  int defStyleRes)

Creates a new instance of RecyclerViewItemDecoration for the given context.

Parameters:

context - Context in which will be the new decoration presented.

attrs - Set of Xml attributes used to configure the new instance of this decoration.

defStyleAttr - An attribute which contains a reference to a default style resource for this decoration within a theme of the given context.

defStyleRes - Resource id of the default style for the new decoration.

Method Detail

setSkipFirst

public void setSkipFirst(boolean skip)

Sets a boolean flag indicating whether this decoration should be skipped for the first item from data set of the associated RecyclerView.

Default value: false

Parameters:

skip - True to not apply this decoration for the first item, false to apply it.

See Also:

skipsFirst(), setSkipLast(boolean), setPrecondition(Precondition)

skipsFirst

public boolean skipsFirst()

Checks whether this decoration is skipped for the first item.

Returns:

True if this decoration is not applied for the first item, false if it is.

See Also:

setSkipFirst(boolean)

setSkipLast

public void setSkipLast(boolean skip)

Sets a boolean flag indicating whether this decoration should be skipped for the last item from data set of the associated RecyclerView.

Default value: false

Parameters:

skip - True to not apply this decoration for the last item, false to apply it.

See Also:

skipsFirst(), setSkipFirst(boolean), setPrecondition(Precondition)

skipsLast

public boolean skipsLast()

Checks whether this decoration is skipped for the last item.

Returns:

True if this decoration is not applied for the last item, false if it is.

See Also:

setSkipLast(boolean)

setPrecondition

public final void setPrecondition(@NonNull
                                  RecyclerViewItemDecoration.Precondition precondition)

Specifies a precondition that should be checked by this decoration for each item view before it is decorated.

This precondition may be used in order to perform more item specific decoration logic.

Parameters:

precondition - The desired precondition which should be checked for each item view of the parent recycler view before it is decorated.

See Also:

getPrecondition(), setSkipFirst(boolean), setSkipLast(boolean)

getPrecondition

@NonNull
public final RecyclerViewItemDecoration.Precondition getPrecondition()

Returns the precondition specified for this decoration.

Returns:

This decoration's precondition. If not specified, this is an RecyclerViewItemDecoration.Precondition.EMPTY instance.

See Also:

setPrecondition(Precondition)

shouldDecorate

protected boolean shouldDecorate(@NonNull
                                 RecyclerView parent,
                                 @NonNull
                                 RecyclerView.State state)

Checks whether any subsequent decoration algorithm should be applied by this decoration for the given parent RecyclerView and its current state.

This implementation checks whether the given RecyclerView has its RecyclerView.LayoutManager specified by RecyclerView.getLayoutManager() != null and if there are any items to be decorated by RecyclerView.State.getItemCount() > 0. If both conditions are met, this method returns true, if not, false is returned.

Parameters:

parent - The RecyclerView into which is this decoration added.

state - Current state of the parent RecyclerView.

Returns:

True if decorating should be performed, false otherwise.