universum.studios.android.recycler.decoration

Class ItemDividerDecoration

java.lang.Object

android.support.v7.widget.RecyclerView.ItemDecoration

universum.studios.android.recycler.decoration.RecyclerViewItemDecoration

universum.studios.android.recycler.decoration.ItemDividerDecoration

public class ItemDividerDecoration
extends RecyclerViewItemDecoration

A RecyclerViewItemDecoration implementation that may be used to draw a divider (drawable or color), vertically or horizontally, between items displayed in a RecyclerView widget.

Xml attributes

ItemDividerDecoration 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	ItemDividerDecoration.Orientation Defines an annotation for determining allowed orientations for ItemDividerDecoration.

Nested classes/interfaces inherited from class universum.studios.android.recycler.decoration.RecyclerViewItemDecoration

RecyclerViewItemDecoration.Precondition

Field Summary

Fields

Modifier and Type	Field and Description
static int	HORIZONTAL Horizontal orientation flag copied from LinearLayout.HORIZONTAL for convenience.
static int	VERTICAL Vertical orientation flag copied from LinearLayout.VERTICAL for convenience.

Constructor Summary

Constructors

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

Method Summary

Modifier and Type	Method and Description
Drawable	getDivider() Returns the divider drawable that is drawn by this decoration between items.
int	getDividerOffsetEnd() Returns the amount by which to offset the divider at the end.
int	getDividerOffsetStart() Returns the amount by which to offset the divider at the start.
int	getDividerThickness() Returns the thickness in which should be the divider drawn between items.
void	getItemOffsets(Rect rect, View view, RecyclerView parent, RecyclerView.State state)
int	getOrientation() Returns the orientation in which is the divider drawable drawn between items.
void	onDraw(Canvas canvas, RecyclerView parent, RecyclerView.State state)
protected void	onDrawHorizontally(Canvas canvas, RecyclerView parent, RecyclerView.State state) Called from RecyclerView.ItemDecoration.onDrawOver(Canvas, RecyclerView, RecyclerView.State) in order to draw this decoration in vertical orientation.
protected void	onDrawVertically(Canvas canvas, RecyclerView parent, RecyclerView.State state) Called from RecyclerView.ItemDecoration.onDrawOver(Canvas, RecyclerView, RecyclerView.State) in order to draw this decoration in horizontal orientation.
void	setDivider(Drawable divider) Sets a drawable of the divider to be drawn between items of the associated RecyclerView in the orientation specified for this decoration.
void	setDividerOffset(int start, int end) Specifies amounts by which to offset the divider.
void	setDividerThickness(int thickness) Sets a thickness in which should be the divider specified for this decoration drawn.
void	setOrientation(int orientation) Sets an orientation in which should be the divider specified for this decoration drawn.
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.
protected void	updateItemOffsets(Rect rect, boolean rtlDirection) Called to update the given rect with the current divider thickness and divider offsets specified for this decoration according to the orientation also specified for this decoration.

Methods inherited from class universum.studios.android.recycler.decoration.RecyclerViewItemDecoration

getPrecondition, setPrecondition, setSkipFirst, setSkipLast, skipsFirst, skipsLast

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

getItemOffsets, onDraw, onDrawOver, onDrawOver

Methods inherited from class java.lang.Object

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

Field Detail

HORIZONTAL

public static final int HORIZONTAL

Horizontal orientation flag copied from LinearLayout.HORIZONTAL for convenience.

See Also:

Constant Field Values

VERTICAL

public static final int VERTICAL

Vertical orientation flag copied from LinearLayout.VERTICAL for convenience.

See Also:

Constant Field Values

Constructor Detail

ItemDividerDecoration

public ItemDividerDecoration()

Same as ItemDividerDecoration(Context) with null context.

ItemDividerDecoration

public ItemDividerDecoration(int orientation,
                             @NonNull
                             Drawable divider)

Creates a new instance of ItemDividerDecoration with the specified orientation and divider.

Parameters:

orientation - The desired orientation in which should be the divider drawn. One of orientation defined by @Orientation annotation.

divider - Drawable of the desired divider to be drawn. If this is a ColorDrawable the divider's thickness need to be specified via setDividerThickness(int) as the color drawable does not have its intrinsic dimensions specified.

See Also:

setOrientation(int), setDivider(Drawable)

ItemDividerDecoration

public ItemDividerDecoration(@Nullable
                             Context context)

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

ItemDividerDecoration

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

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

ItemDividerDecoration

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

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

ItemDividerDecoration

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

Creates a new instance of ItemDividerDecoration 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

setOrientation

public void setOrientation(int orientation)

Sets an orientation in which should be the divider specified for this decoration drawn.

Default value: VERTICAL

Parameters:

orientation - The desired orientation. Should be one of orientations defined by @Orientation annotation.

See Also:

getOrientation()

getOrientation

public int getOrientation()

Returns the orientation in which is the divider drawable drawn between items.

Returns:

This decoration's orientation.

See Also:

setOrientation(int)

setDivider

public void setDivider(@Nullable
                       Drawable divider)

Sets a drawable of the divider to be drawn between items of the associated RecyclerView in the orientation specified for this decoration.

Note that calling this method will reset any thickness value specified via setDividerThickness(int) before and the thickness of the given divider drawable will be used instead depending on the orientation specified for this decoration.

Parameters:

divider - The desired divider drawable. May be null to to not draw any divider.

See Also:

getDivider()

getDivider

@Nullable
public Drawable getDivider()

Returns the divider drawable that is drawn by this decoration between items.

Returns:

This decorations's divider drawable. May by null if no divider has been specified.

See Also:

setDivider(Drawable)

setDividerThickness

public void setDividerThickness(int thickness)

Sets a thickness in which should be the divider specified for this decoration drawn.

Note that calling this method will override the intrinsic thickness obtained form the divider drawable when setDivider(Drawable) has been called.

Parameters:

thickness - The desired thickness. May be 0 to not draw the divider.

See Also:

getDividerThickness()

getDividerThickness

public int getDividerThickness()

Returns the thickness in which should be the divider drawn between items.

Returns:

The divider's thickness.

See Also:

setDividerThickness(int)

setDividerOffset

public void setDividerOffset(int start,
                             int end)

Specifies amounts by which to offset the divider.

Both values are used with respect to layout direction of the parent RecyclerView and also with respect to the orientation specified for this decoration.

Parameters:

start - The desired amount in pixels by which to offset the divider at the start.

end - The desired amount in pixels by which to offset the divider at the end.

See Also:

getDividerOffsetStart(), getDividerOffsetEnd()

getDividerOffsetStart

public int getDividerOffsetStart()

Returns the amount by which to offset the divider at the start.

This value is used with respect to layout direction of the parent RecyclerView and also with respect to the orientation specified for this decoration.

Returns:

Offset in pixels.

See Also:

setDividerOffset(int, int)

getDividerOffsetEnd

public int getDividerOffsetEnd()

Returns the amount by which to offset the divider at the end.

This value is used with respect to layout direction of the parent RecyclerView and also with respect to the orientation specified for this decoration.

Returns:

Offset in pixels.

See Also:

setDividerOffset(int, int)

getItemOffsets

public void getItemOffsets(@NonNull
                           Rect rect,
                           @NonNull
                           View view,
                           @NonNull
                           RecyclerView parent,
                           @NonNull
                           RecyclerView.State state)

Overrides:

getItemOffsets in class RecyclerView.ItemDecoration

updateItemOffsets

protected void updateItemOffsets(@NonNull
                                 Rect rect,
                                 boolean rtlDirection)

Called to update the given rect with the current divider thickness and divider offsets specified for this decoration according to the orientation also specified for this decoration.

Parameters:

rect - The desired item offsets rect to be updated.

rtlDirection - True if offsets should be updated for RTL layout direction, false for LTR layout direction.

onDraw

public void onDraw(@NonNull
                   Canvas canvas,
                   @NonNull
                   RecyclerView parent,
                   @NonNull
                   RecyclerView.State state)

Overrides:

onDraw in class RecyclerView.ItemDecoration

shouldDecorate

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

Description copied from class: RecyclerViewItemDecoration

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.

Overrides:

shouldDecorate in class RecyclerViewItemDecoration

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.

onDrawHorizontally

protected void onDrawHorizontally(@NonNull
                                  Canvas canvas,
                                  @NonNull
                                  RecyclerView parent,
                                  @NonNull
                                  RecyclerView.State state)

Called from RecyclerView.ItemDecoration.onDrawOver(Canvas, RecyclerView, RecyclerView.State) in order to draw this decoration in vertical orientation.

Parameters:

canvas - Canvas on which to draw.

parent - RecyclerView into which is this decoration added.

state - Current state of the parent RecyclerView.

onDrawVertically

protected void onDrawVertically(@NonNull
                                Canvas canvas,
                                @NonNull
                                RecyclerView parent,
                                @NonNull
                                RecyclerView.State state)

Called from RecyclerView.ItemDecoration.onDrawOver(Canvas, RecyclerView, RecyclerView.State) in order to draw this decoration in horizontal orientation.

Parameters:

canvas - Canvas on which to draw.

parent - RecyclerView into which is this decoration added.

state - Current state of the parent RecyclerView.