universum.studios.android.widget.adapter.module

Class AdapterModule

java.lang.Object

universum.studios.android.widget.adapter.module.AdapterModule

Direct Known Subclasses:

HeadersModule, SelectionModule

public abstract class AdapterModule
extends Object

This class specifies base API layer for an object which can be used as a module within an instance of Adapter. AdapterModule also specifies API supporting state saving via saveInstanceState() and its restoring via restoreInstanceState(Parcelable) and also allows its inheritance hierarchies to notify the adapter to which are these modules attached via notifyAdapter().

State saving

 public class SampleModule extends AdapterModule {

     // ...

     @NonNull
     @Override
     public Parcelable saveInstanceState() {
         final SavedState state = new SavedState(super.onSaveInstanceState());
         // ...
         // Pass here all data of this module which need to be saved to the state.
         // ...
         return state;
     }

     @Override
     public void restoreInstanceState(@NonNull Parcelable savedState) {
          if (!(savedState instanceof SavedState)) {
              // Passed savedState is not our state, let super to process it.
              super.restoreInstanceState(savedState);
              return;
          }
          final SavedState state = (SavedState) savedState;
          // Pass super state to super to process it.
          super.restoreInstanceState(savedState.getSuperState());
          // ...
          // Set here all data of this module which need to be restored from the savedState.
          // ...
     }

     // ...

     // Implementation of AdapterSavedState for this module.
     public static class SavedState extends AdapterSavedState {

         // Each implementation of saved state need to have its own CREATOR provided.
         public static final Creator<SavedState> CREATOR = new Creator<SavedState> {

              @Override
              public SavedState createFromParcel(@NonNull Parcel source) {
                  return new SavedState(source);
              }

              @Override
              public SavedState[] newArray(int size) {
                  return new SavedState[size];
              }
         }

         // Constructor used to chain the state of inheritance hierarchies.
         SavedState(@NonNull Parcelable superState) {
              super(superState);
         }

         SavedState(@NonNull Parcel source) {
              super(source);
              // Restore here state's data.
         }

         @Override
         public void writeToParcel(@NonNull Parcel dest, int flags) {
              super.writeToParcel(dest, flags);
              // Save here state's data.
         }
     }
 }
 

Author:

Martin Albedinsky

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	AdapterModule.ModuleAdapter Simple interface for "module based" adapter.

Constructor Summary

Constructors

Constructor and Description
AdapterModule()

Method Summary

Modifier and Type	Method and Description
protected void	assertAttachedToAdapterOrThrow() Asserts that this module is attached to its associated adapter, if not an exception is thrown.
void	attachToAdapter(AdapterModule.ModuleAdapter adapter) Called to attach this module to the given adapter.
boolean	isAdapterNotificationEnabled() Returns a boolean flag indicating whether the adapter to which is this module attached should be notified in case, when its data set has been changed due to changes made by this module.
protected void	notifyAdapter() Notifies the adapter to which is this module attached via AdapterModule.ModuleAdapter.notifyDataSetChanged().
protected void	onAttachedToAdapter(AdapterModule.ModuleAdapter adapter) Invoked immediately after attachToAdapter(ModuleAdapter).
boolean	requiresStateSaving() Returns a boolean flag indicating whether this module requires state saving or not.
void	setAdapterNotificationEnabled(boolean enabled) Sets a boolean flag indicating whether the adapter to which is this module attached should be notified in case, when its data set has been changed due to changes made by this module.

Methods inherited from class java.lang.Object

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

Constructor Detail

AdapterModule

public AdapterModule()

Method Detail

attachToAdapter

public final void attachToAdapter(@NonNull
                                  AdapterModule.ModuleAdapter adapter)

Called to attach this module to the given adapter.

Parameters:

adapter - Instance of the adapter by which will be this module used.

onAttachedToAdapter

protected void onAttachedToAdapter(@NonNull
                                   AdapterModule.ModuleAdapter adapter)

Invoked immediately after attachToAdapter(ModuleAdapter).

Parameters:

adapter - Instance of the adapter to which was this module just attached.

assertAttachedToAdapterOrThrow

protected final void assertAttachedToAdapterOrThrow()

Asserts that this module is attached to its associated adapter, if not an exception is thrown.

Throws:

NullPointerException - If this module is not attached to any adapter.

See Also:

attachToAdapter(ModuleAdapter)

setAdapterNotificationEnabled

public void setAdapterNotificationEnabled(boolean enabled)

Sets a boolean flag indicating whether the adapter to which is this module attached should be notified in case, when its data set has been changed due to changes made by this module.

Default value: true

Parameters:

enabled - True to enable adapter auto-notification, false to disable it.

See Also:

isAdapterNotificationEnabled()

isAdapterNotificationEnabled

public boolean isAdapterNotificationEnabled()

Returns a boolean flag indicating whether the adapter to which is this module attached should be notified in case, when its data set has been changed due to changes made by this module.

Returns:

True when adapter auto-notification is enabled, false otherwise.

See Also:

setAdapterNotificationEnabled(boolean)

notifyAdapter

protected final void notifyAdapter()

Notifies the adapter to which is this module attached via AdapterModule.ModuleAdapter.notifyDataSetChanged().

This should be called whenever the data set of the attached adapter should be reloaded due to changes made by this module.

This method does nothing if adapter's notifications are disabled for this module.

See Also:

isAdapterNotificationEnabled()

requiresStateSaving

public boolean requiresStateSaving()

Returns a boolean flag indicating whether this module requires state saving or not.

This implementation by default returns false.

Returns:

True to call saveInstanceState() upon this module to save its current state and restore it via restoreInstanceState(Parcelable) later, false otherwise.