eu.davidea.flexibleadapter.common

Class FlexibleItemDecoration

java.lang.Object

RecyclerView.ItemDecoration

eu.davidea.flexibleadapter.common.FlexibleItemDecoration

public class FlexibleItemDecoration
extends RecyclerView.ItemDecoration

This item decorator implements identical drawing technique of DividerItemDecorator from Android API, and at the same time, it adds several useful functionalities:

• Supports all RecyclerView LayoutManagers that implement (Linear, Grid or StaggeredGrid).
• Can add equal space offset at all sides of an item.
• Can customize the offset for each view type.
• Can customize the offset at the 4 edges: first and last column / first and last row.
• Recognizes the sections of FlexibleAdapter and can add gap offset between them.
• Recognizes the orientation of the current Layout.
• Supports the default Android divider android.R.attr.listDivider.
• Supports a custom divider by DrawableRes id.
• Supports drawing the divider over or underneath the items.
• Supports drawing the divider for specific viewTypes.

Tip: Call the method FlexibleAdapter#invalidateItemDecorations(long) to rebuild the invalidated offsets due to the changes coming from events like moveItem or any layout change that modifies the order of the items.

Since:

20/07/2015 Created in main package
23/04/2017 Drawing of the divider over or underneath the items
26/05/2017 Rewrote the full class to support equal spaces between items in all situations
10/09/2017 Optional view types for divider
17/12/2017 Moved into UI package

Field Summary

Fields

Modifier and Type	Field and Description
protected static int[]	ATTRS
protected android.graphics.Rect	mBounds
protected android.graphics.drawable.Drawable	mDivider
protected boolean	mDrawOver

Constructor Summary

Constructors

Constructor and Description
FlexibleItemDecoration(android.content.Context context) Constructor which saves the Context to calculate the dpi OR to retrieve the divider later on.

Method Summary

Modifier and Type	Method and Description
FlexibleItemDecoration	addItemViewType(int viewType) Applies the general offset also to the specified viewType.
FlexibleItemDecoration	addItemViewType(int viewType, int offset) As addItemViewType(int) but with custom offset equals to all sides that will affect only this viewType.
FlexibleItemDecoration	addItemViewType(int viewType, int left, int top, int right, int bottom) As addItemViewType(int) but with custom offset that will affect only this viewType.
protected void	draw(android.graphics.Canvas c, RecyclerView parent)
protected void	drawHorizontal(android.graphics.Canvas canvas, RecyclerView parent)
protected void	drawVertical(android.graphics.Canvas canvas, RecyclerView parent)
void	getItemOffsets(android.graphics.Rect outRect, android.view.View view, RecyclerView recyclerView, RecyclerView.State state)
int	getOffset() Returns the current general offset in dpi.
void	onDraw(android.graphics.Canvas c, RecyclerView parent, RecyclerView.State state)
void	onDrawOver(android.graphics.Canvas c, RecyclerView parent, RecyclerView.State state)
FlexibleItemDecoration	removeDivider() Removes any divider previously set.
FlexibleItemDecoration	removeItemViewType(int viewType) In case a viewType should not have anymore the applied offset.
protected boolean	shouldDrawDivider(RecyclerView.ViewHolder viewHolder) Allows to define for which items the divider should be drawn.
FlexibleItemDecoration	withBottomEdge(boolean withBottomEdge) Adds an offset to the items at the Bottom edge.
FlexibleItemDecoration	withDefaultDivider(java.lang.Integer... viewTypes) Default Android divider will be used.
FlexibleItemDecoration	withDivider(int resId, java.lang.Integer... viewTypes) Custom divider.
FlexibleItemDecoration	withDrawDividerOnLastItem(boolean lastItem) Allows to draw the Divider after the last item.
FlexibleItemDecoration	withDrawOver(boolean drawOver) Changes the mode to draw the divider.
FlexibleItemDecoration	withEdge(boolean withEdge) Adds an offset to the items at the 4 edges (left, top, right and bottom).
FlexibleItemDecoration	withLeftEdge(boolean withLeftEdge) Adds an offset to the items at the Left edge.
FlexibleItemDecoration	withOffset(int offset) Applies the same physical offset to all sides of the item AND between items.
FlexibleItemDecoration	withRightEdge(boolean withRightEdge) Adds an offset to the items at the Right edge.
FlexibleItemDecoration	withSectionGapOffset(int sectionOffset) Adds an extra offset at the end of each section.
FlexibleItemDecoration	withSectionGapOnLastItem(boolean lastItem) Allows to disable the SectionGap after the last item.
FlexibleItemDecoration	withTopEdge(boolean withTopEdge) Adds an offset to the items at the Top edge.

Methods inherited from class java.lang.Object

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

Field Detail

mDivider

protected android.graphics.drawable.Drawable mDivider

mBounds

protected final android.graphics.Rect mBounds

mDrawOver

protected boolean mDrawOver

ATTRS

protected static final int[] ATTRS

Constructor Detail

FlexibleItemDecoration

public FlexibleItemDecoration(android.content.Context context)

Constructor which saves the Context to calculate the dpi OR to retrieve the divider later on.

Parameters:

context - current Context, it will be used to calculate dpi OR to retrieve the divider

Since:

1.0.0-b1

Method Detail

withDefaultDivider

public FlexibleItemDecoration withDefaultDivider(java.lang.Integer... viewTypes)

Default Android divider will be used.

Parameters:

viewTypes - the specific ViewTypes for which the divider will be drawn OR do not specify any to draw divider for all ViewTypes (default behavior).

Returns:

this FlexibleItemDecoration instance so the call can be chained

Since:

1.0.0-b1

See Also:

withDivider(int, Integer...), withDrawOver(boolean), removeDivider()

withDivider

public FlexibleItemDecoration withDivider(int resId,
                                          java.lang.Integer... viewTypes)

Custom divider.

Parameters:

resId - drawable resourceId that should be used as a divider

viewTypes - the specific ViewTypes for which the divider will be drawn OR do not specify any to draw divider for all ViewTypes (default behavior).

Returns:

this FlexibleItemDecoration instance so the call can be chained

Since:

1.0.0-b1

See Also:

withDefaultDivider(Integer...), withDrawOver(boolean), removeDivider()

withDrawDividerOnLastItem

public FlexibleItemDecoration withDrawDividerOnLastItem(boolean lastItem)

Allows to draw the Divider after the last item.

Default is false (don't draw).

Parameters:

lastItem - true to draw, false to not draw

Returns:

this FlexibleItemDecoration instance so the call can be chained

Since:

1.0.0-b1

removeDivider

public FlexibleItemDecoration removeDivider()

Removes any divider previously set.

Returns:

this FlexibleItemDecoration instance so the call can be chained

Since:

1.0.0-b1

withDrawOver

public FlexibleItemDecoration withDrawOver(boolean drawOver)

Changes the mode to draw the divider.

- When false, any content will be drawn before the item views are drawn, and will thus appear underneath the views.
- When true, any content will be drawn after the item views are drawn, and will thus appear over the views.

Default value is false (drawn underneath).

Parameters:

drawOver - true to draw after the item has been added, false to draw underneath the item

Returns:

this Divider, so the call can be chained

Since:

1.0.0-b1

onDraw

public void onDraw(android.graphics.Canvas c,
                   RecyclerView parent,
                   RecyclerView.State state)

onDrawOver

public void onDrawOver(android.graphics.Canvas c,
                       RecyclerView parent,
                       RecyclerView.State state)

draw

protected void draw(android.graphics.Canvas c,
                    RecyclerView parent)

drawVertical

protected void drawVertical(android.graphics.Canvas canvas,
                            RecyclerView parent)

drawHorizontal

protected void drawHorizontal(android.graphics.Canvas canvas,
                              RecyclerView parent)

shouldDrawDivider

protected boolean shouldDrawDivider(RecyclerView.ViewHolder viewHolder)

Allows to define for which items the divider should be drawn.

Override to define custom logic. By default all viewTypes will have the divider.

Parameters:

viewHolder - the ViewHolder under analysis

Returns:

true to draw the divider, false to skip the drawing

withSectionGapOffset

public FlexibleItemDecoration withSectionGapOffset(int sectionOffset)

Adds an extra offset at the end of each section.

Works only with FlexibleAdapter.

Parameters:

sectionOffset - the extra offset at the end of each section

Returns:

this FlexibleItemDecoration instance so the call can be chained

Since:

1.0.0-b1

withSectionGapOnLastItem

public FlexibleItemDecoration withSectionGapOnLastItem(boolean lastItem)

Allows to disable the SectionGap after the last item.

Default is true (draw).

Parameters:

lastItem - true to draw, false to not draw

Returns:

this FlexibleItemDecoration instance so the call can be chained

Since:

1.0.0-b1

withEdge

public FlexibleItemDecoration withEdge(boolean withEdge)

Adds an offset to the items at the 4 edges (left, top, right and bottom).

Note: An offset OR an itemType with offsets must be added.

Default value is false (no edge).

Parameters:

withEdge - true to enable, false otherwise

Returns:

this FlexibleItemDecoration instance so the call can be chained

Since:

1.0.0-b1

See Also:

withOffset(int), addItemViewType(int, int)

withLeftEdge

public FlexibleItemDecoration withLeftEdge(boolean withLeftEdge)

Adds an offset to the items at the Left edge.

Note: An offset OR an itemType with offsets must be added.

Default value is false (no edge).

Parameters:

withLeftEdge - true to add offset to the items at the Left of the first column.

Returns:

this FlexibleItemDecoration instance so the call can be chained

Since:

1.0.0-b1

See Also:

withOffset(int), addItemViewType(int, int)

withTopEdge

public FlexibleItemDecoration withTopEdge(boolean withTopEdge)

Adds an offset to the items at the Top edge.

Note: An offset OR an itemType with offsets must be added.

Default value is false (no edge).

Parameters:

withTopEdge - true to add offset to the items at the Top of the first row.

Returns:

this FlexibleItemDecoration instance so the call can be chained

Since:

1.0.0-b1

See Also:

withOffset(int), addItemViewType(int, int)

withBottomEdge

public FlexibleItemDecoration withBottomEdge(boolean withBottomEdge)

Adds an offset to the items at the Bottom edge.

Note: An offset OR an itemType with offsets must be added.

Default value is false (no edge).

Parameters:

withBottomEdge - true to add offset to the items at the Bottom of the last row.

Returns:

this FlexibleItemDecoration instance so the call can be chained

Since:

1.0.0-b1

See Also:

withOffset(int), addItemViewType(int, int)

withRightEdge

public FlexibleItemDecoration withRightEdge(boolean withRightEdge)

Adds an offset to the items at the Right edge.

Note: An offset OR an itemType with offsets must be added.

Default value is false (no edge).

Parameters:

withRightEdge - true to add offset to the items at the Right of the last column.

Returns:

this FlexibleItemDecoration instance so the call can be chained

Since:

1.0.0-b1

See Also:

withOffset(int), addItemViewType(int, int)

getOffset

public int getOffset()

Returns the current general offset in dpi.

Returns:

the offset previously set in dpi

withOffset

public FlexibleItemDecoration withOffset(int offset)

Applies the same physical offset to all sides of the item AND between items.

Parameters:

offset - the offset in dpi to apply

Returns:

this FlexibleItemDecoration instance so the call can be chained

Since:

1.0.0-b1

addItemViewType

public FlexibleItemDecoration addItemViewType(int viewType)

Applies the general offset also to the specified viewType.

Call withOffset(int) to set a general offset.

Parameters:

viewType - the viewType affected

Returns:

this FlexibleItemDecoration instance so the call can be chained

Since:

1.0.0-b1

See Also:

withOffset(int), addItemViewType(int, int), removeItemViewType(int)

addItemViewType

public FlexibleItemDecoration addItemViewType(int viewType,
                                              int offset)

As addItemViewType(int) but with custom offset equals to all sides that will affect only this viewType.

Parameters:

viewType - the viewType affected

Returns:

this FlexibleItemDecoration instance so the call can be chained

Since:

1.0.0-b1

See Also:

withOffset(int), removeItemViewType(int)

addItemViewType

public FlexibleItemDecoration addItemViewType(int viewType,
                                              int left,
                                              int top,
                                              int right,
                                              int bottom)

As addItemViewType(int) but with custom offset that will affect only this viewType.

Parameters:

viewType - the viewType affected

left - the offset to the left of the item

top - the offset to the top of the item

right - the offset to the right of the item

bottom - the offset to the bottom of the item

Returns:

this FlexibleItemDecoration instance so the call can be chained

Since:

1.0.0-b1

See Also:

addItemViewType(int, int), removeItemViewType(int)

removeItemViewType

public FlexibleItemDecoration removeItemViewType(int viewType)

In case a viewType should not have anymore the applied offset.

Parameters:

viewType - the viewType to remove from the decoration management

Returns:

this FlexibleItemDecoration instance so the call can be chained

Since:

1.0.0-b1

getItemOffsets

public void getItemOffsets(android.graphics.Rect outRect,
                           android.view.View view,
                           RecyclerView recyclerView,
                           RecyclerView.State state)

Since:

1.0.0-b1