eu.davidea.viewholders

Class ExpandableViewHolder

java.lang.Object

RecyclerView.ViewHolder

eu.davidea.viewholders.FlexibleViewHolder

eu.davidea.viewholders.ExpandableViewHolder

All Implemented Interfaces:

android.view.View.OnClickListener, android.view.View.OnLongClickListener, android.view.View.OnTouchListener, ItemTouchHelperCallback.ViewHolderCallback

public abstract class ExpandableViewHolder
extends FlexibleViewHolder

ViewHolder for a Expandable Items. It holds methods which can be used to trigger expansion or collapsing events.

This class extends FlexibleViewHolder, which means it will benefit of all implemented methods the super class holds.

Since:

16/01/2016 Created

Field Summary

Fields inherited from class eu.davidea.viewholders.FlexibleViewHolder

mActionState, mAdapter

Constructor Summary

Constructors

Constructor and Description
ExpandableViewHolder(android.view.View view, FlexibleAdapter adapter) Default constructor.
ExpandableViewHolder(android.view.View view, FlexibleAdapter adapter, boolean stickyHeader) Constructor to configure the sticky behaviour of a view.

Method Summary

Modifier and Type	Method and Description
protected void	collapseView(int position) Triggers collapse of this itemView.
protected void	expandView(int position) Triggers expansion of this itemView.
android.view.View	getContentView() In case this ViewHolder represents a Header Item, this method returns the contentView of the FrameLayout, otherwise it returns the basic itemView.
int	getFlexibleAdapterPosition() Overcomes the situation of returning an unknown position (-1) of ViewHolders created out of the LayoutManager (ex.
protected boolean	isViewCollapsibleOnClick() Allows to collapse child views of this ItemView when View.OnClickListener event occurs on the entire view.
protected boolean	isViewCollapsibleOnLongClick() Allows to collapse child views of this ItemView when View.OnLongClickListener event occurs on the entire view.
protected boolean	isViewExpandableOnClick() Allows to expand or collapse child views of this itemView when View.OnClickListener event occurs on the entire view.
void	onActionStateChanged(int position, int actionState) Here we handle the event of when the ItemTouchHelper first registers an item as being moved or swiped.
void	onClick(android.view.View view) Called when user taps once on the ItemView.
boolean	onLongClick(android.view.View view) Called when user long taps on this itemView.
void	setBackupPosition(int backupPosition) Restore the Adapter position if the original Adapter position is unknown.
protected boolean	shouldNotifyParentOnClick() Allows to notify change and rebound this itemView on expanding and collapsing events, in order to update the content (so, user can decide to display the current expanding status).
protected void	toggleExpansion() Expands or Collapses based on the current state AND on the configuration of the methods isViewExpandableOnClick() and isViewCollapsibleOnClick().

Methods inherited from class eu.davidea.viewholders.FlexibleViewHolder

getActivationElevation, getFrontView, getRearLeftView, getRearRightView, isDraggable, isSwipeable, onItemReleased, onTouch, scrollAnimators, setDragHandleView, setFullSpan, shouldActivateViewWhileSwiping, shouldAddSelectionInActionMode, toggleActivation

Methods inherited from class java.lang.Object

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

Constructor Detail

ExpandableViewHolder

public ExpandableViewHolder(android.view.View view,
                            FlexibleAdapter adapter)

Default constructor.

Parameters:

view - The View being hosted in this ViewHolder

adapter - Adapter instance of type FlexibleAdapter

Since:

5.0.0-b1

ExpandableViewHolder

public ExpandableViewHolder(android.view.View view,
                            FlexibleAdapter adapter,
                            boolean stickyHeader)

Constructor to configure the sticky behaviour of a view.

Note: StickyHeader works only if the item has been declared of type IHeader.

Parameters:

view - The View being hosted in this ViewHolder

adapter - Adapter instance of type FlexibleAdapter

stickyHeader - true if the View can be a Sticky Header, false otherwise

Since:

5.0.0-b7

Method Detail

isViewExpandableOnClick

protected boolean isViewExpandableOnClick()

Allows to expand or collapse child views of this itemView when View.OnClickListener event occurs on the entire view.

This method returns always true; Extend with "return false" to Not expand or collapse this ItemView onClick events.

Returns:

always true, if not overridden

Since:

5.0.0-b1

isViewCollapsibleOnClick

protected boolean isViewCollapsibleOnClick()

Allows to collapse child views of this ItemView when View.OnClickListener event occurs on the entire view.

This method returns always true; Extend with "return false" to Not collapse this ItemView onClick events.

Returns:

always true, if not overridden

Since:

5.0.4

isViewCollapsibleOnLongClick

protected boolean isViewCollapsibleOnLongClick()

Allows to collapse child views of this ItemView when View.OnLongClickListener event occurs on the entire view.

This method returns always true; Extend with "return false" to Not collapse this ItemView onLongClick events.

Returns:

always true, if not overridden

Since:

5.0.0-b1

shouldNotifyParentOnClick

protected boolean shouldNotifyParentOnClick()

Allows to notify change and rebound this itemView on expanding and collapsing events, in order to update the content (so, user can decide to display the current expanding status).

This method returns always false; Override with "return true" to trigger the notification.

Returns:

true to rebound the content of this itemView on expanding and collapsing events, false to ignore the events

Since:

5.0.0-rc1

See Also:

expandView(int), collapseView(int)

toggleExpansion

protected void toggleExpansion()

Expands or Collapses based on the current state AND on the configuration of the methods isViewExpandableOnClick() and isViewCollapsibleOnClick().

Since:

5.0.0-b1

See Also:

shouldNotifyParentOnClick(), isViewExpandableOnClick(), isViewCollapsibleOnClick(), expandView(int), collapseView(int)

expandView

protected void expandView(int position)

Triggers expansion of this itemView.

If shouldNotifyParentOnClick() returns true, this view is rebound with payload Payload.EXPANDED.

Since:

5.0.0-b1

See Also:

shouldNotifyParentOnClick()

collapseView

protected void collapseView(int position)

Triggers collapse of this itemView.

If shouldNotifyParentOnClick() returns true, this view is rebound with payload Payload.COLLAPSED.

Since:

5.0.0-b1

See Also:

shouldNotifyParentOnClick()

onClick

public void onClick(android.view.View view)

Called when user taps once on the ItemView.

Note: In Expandable version, it tries to expand, but before, it checks if the view isViewExpandableOnClick().

Specified by:

onClick in interface android.view.View.OnClickListener

Overrides:

onClick in class FlexibleViewHolder

Parameters:

view - the view that receives the event

Since:

5.0.0-b1

See Also:

FlexibleViewHolder.toggleActivation()

onLongClick

public boolean onLongClick(android.view.View view)

Called when user long taps on this itemView.

Note: In Expandable version, it tries to collapse, but before, it checks if the view isViewCollapsibleOnLongClick().

Specified by:

onLongClick in interface android.view.View.OnLongClickListener

Overrides:

onLongClick in class FlexibleViewHolder

Parameters:

view - the view that receives the event

Since:

5.0.0-b1

See Also:

FlexibleViewHolder.toggleActivation()

onActionStateChanged

public void onActionStateChanged(int position,
                                 int actionState)

Here we handle the event of when the ItemTouchHelper first registers an item as being moved or swiped.

In this implementation, View activation is automatically handled if dragged: The Item will be added to the selection list if not selected yet and mode MULTI is activated.

Note: In the Expandable version, expanded items are forced to collapse.

Specified by:

onActionStateChanged in interface ItemTouchHelperCallback.ViewHolderCallback

Overrides:

onActionStateChanged in class FlexibleViewHolder

Parameters:

position - the position of the item touched

actionState - one of ItemTouchHelper#ACTION_STATE_SWIPE or ItemTouchHelper#ACTION_STATE_DRAG.

Since:

5.0.0-b1

See Also:

FlexibleViewHolder.shouldActivateViewWhileSwiping(), FlexibleViewHolder.shouldAddSelectionInActionMode()

getContentView

public final android.view.View getContentView()

In case this ViewHolder represents a Header Item, this method returns the contentView of the FrameLayout, otherwise it returns the basic itemView.

Returns:

the real contentView

Since:

5.0.0-b7

getFlexibleAdapterPosition

public final int getFlexibleAdapterPosition()

Overcomes the situation of returning an unknown position (-1) of ViewHolders created out of the LayoutManager (ex. StickyHeaders).

NOTE: Always call this method, instead of getAdapterPosition(), in case of StickyHeaders use case.

Returns:

the Adapter position result of #getAdapterPosition() OR the backup position preset and known, if the previous result was RecyclerView#NO_POSITION.

Since:

5.0.0-b6

See Also:

setBackupPosition(int)

setBackupPosition

public final void setBackupPosition(int backupPosition)

Restore the Adapter position if the original Adapter position is unknown.

Called by StickyHeaderHelper to support the clickListeners events.

Parameters:

backupPosition - the known position of this ViewHolder

Since:

5.0.0-b6