BaseLoaderAssistant (Android Database API)

java.lang.Object
- universum.studios.android.database.content.BaseLoaderAssistant<D>

All Implemented Interfaces:: androidx.loader.app.LoaderManager.LoaderCallbacks<D>, LoaderAssistant<D>

Direct Known Subclasses:: DataLoaderAdapterAssistant, HeadersAdapterLoaderAssistant

public abstract class BaseLoaderAssistant<D>
extends Object
implements LoaderAssistant<D>

Base implementation of LoaderAssistant that may be used to implement loader assistants for a specific types of results.

Simple usage

 public class DetailActivity extends FragmentActivity {

      // ... activity members

      private static final int LOADER_ID = 0x01;
      private LoaderAssistant mLoaderAssistant;

      @Override
      protected void onCreateDB(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          mLoaderAssistant = new DetailLoaderAssistant(this, getLoaderManager());
          mLoaderAssistant.initLoader(LOADER_ID);
      }

      // Re-starts the cursor loader to load new data from database.
      private void reloadUi() {
          mLoaderAssistant.startLoader(LOADER_ID);
      }

      // Updates UI of this activity from the specified cursor.
      final void updateUi(@NonNull Cursor cursor) {
          // ... update here UI of DetailActivity
      }

      final class DetailLoaderAssistant extends BaseLoaderAssistant<Cursor> {

          DetailLoaderAssistant(@NonNull Context context, @NonNull LoaderManager loaderManager) {
              super(loaderManager);
          }

          @Override
          public Loader<Cursor> onCreateLoader(@IntRange(from = 0) int loaderId, @Nullable Bundle params) {
              return new LoaderBuilder(LoremIpsumEntity.class)
                      .projection(LoremIpsum.class)
                      .build(mContext);
          }

          @Override
          protected void onLoadFinished(@IntRange(from = 0) int loaderId, @NonNull Cursor cursor) {
              updateUi(cursor);
          }

          @Override
          protected void onLoadFailed(@IntRange(from = 0) int loaderId) {
              // Optional.
              // Invoked whenever the loaded cursor within onLoadFinished(Loader, Cursor) is null.
          }

          @Override
          protected void onLoaderReset(@NonNull Loader<Cursor> loader) {
              // Optional.
          }
      }
 }

Author:: Martin Albedinsky

Field Summary

Fields
Modifier and Type	Field and Description
`protected android.content.Context`	`mContext` Context that may be used to create loaders for this assistant.
`protected androidx.loader.app.LoaderManager`	`mLoaderManager` Manager used to perform loading operations.

Fields inherited from interface universum.studios.android.database.content.LoaderAssistant
EMPTY_ARGUMENTS, NO_LOADER_ID

Constructor Summary

Constructors
Constructor and Description
`BaseLoaderAssistant(android.content.Context context, androidx.loader.app.LoaderManager loaderManager)` Creates a new instance of BaseLoaderAssistant for the specified `loaderManager`.

Method Summary

All Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method and Description
`boolean`	`destroyLoader(int loaderId)` Destroys a loader with the specified `loaderId` via the associated LoaderManager's `destroyLoader(int)`.
`androidx.loader.content.Loader<D>`	`getLoader(int loaderId)` Returns a loader with the specified `loaderId` via the associated LoaderManager's `getLoader(int)`.
`androidx.loader.content.Loader<D>`	`initLoader(int loaderId, android.os.Bundle arguments)` Initializes a loader with the specified `loaderId` via the associated LoaderManager's `initLoader(int, Bundle, LoaderManager.LoaderCallbacks)`.
`abstract androidx.loader.content.Loader<D>`	`onCreateLoader(int loaderId, android.os.Bundle arguments)`
`void`	`onLoaderReset(androidx.loader.content.Loader<D> loader)`
`protected void`	`onLoadFailed(int loaderId)` Invoked whenever `onLoadFinished(Loader, Object)` is fired and the received results is `null`.
`protected abstract void`	`onLoadFinished(int loaderId, D result)` Invoked whenever `onLoadFinished(Loader, Object)` is fired and the received `result` is valid (not `null`).
`void`	`onLoadFinished(androidx.loader.content.Loader<D> loader, D result)`
`androidx.loader.content.Loader<D>`	`restartLoader(int loaderId, android.os.Bundle arguments)` Re-starts a loader with the specified `loaderId` via the associated LoaderManager's `restartLoader(int, Bundle, LoaderManager.LoaderCallbacks)`.
`androidx.loader.content.Loader<D>`	`startLoader(int loaderId, android.os.Bundle arguments)` Starts a loader with the specified `loaderId` either via the associated LoaderManager's `initLoader(int, Bundle, LoaderManager.LoaderCallbacks)` or `restartLoader(int, Bundle, LoaderManager.LoaderCallbacks)` depending on whether the requested loader is already initialized or not.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - mContext
```
@NonNull
protected final android.content.Context mContext
```
    Context that may be used to create loaders for this assistant.
  - mLoaderManager
```
@NonNull
protected final androidx.loader.app.LoaderManager mLoaderManager
```
    Manager used to perform loading operations.
- Constructor Detail
  - BaseLoaderAssistant
```
public BaseLoaderAssistant(@NonNull
                           android.content.Context context,
                           @NonNull
                           androidx.loader.app.LoaderManager loaderManager)
```
    Creates a new instance of BaseLoaderAssistant for the specified loaderManager.
    
    Parameters:
    
    context - Context that may be used to create loaders for this assistant.
    
    loaderManager - The manager that is used to perform content loading operations.
- Method Detail
  - startLoader
```
@Nullable
public androidx.loader.content.Loader<D> startLoader(int loaderId,
                                                                @NonNull
                                                                android.os.Bundle arguments)
```
    Description copied from interface: LoaderAssistant
    
    Starts a loader with the specified loaderId either via the associated LoaderManager's initLoader(int, Bundle, LoaderManager.LoaderCallbacks) or restartLoader(int, Bundle, LoaderManager.LoaderCallbacks) depending on whether the requested loader is already initialized or not.
    This assistant will be used as LoaderManager.LoaderCallbacks callback.
    
    Specified by:
    
    startLoader in interface LoaderAssistant<D>
    
    Parameters:
    
    loaderId - Id of the desired loader to start.
    
    arguments - The desired arguments for the loader. Should be LoaderAssistant.EMPTY_ARGUMENTS if loader does not require any arguments.
    
    Returns:
    
    Initialized or re-started loader instance or null if this assistant does not create loader for the specified id.
    
    See Also:
    
    LoaderAssistant.initLoader(int, Bundle), LoaderAssistant.restartLoader(int, Bundle), LoaderAssistant.destroyLoader(int)
  - initLoader
```
@Nullable
public androidx.loader.content.Loader<D> initLoader(int loaderId,
                                                               @NonNull
                                                               android.os.Bundle arguments)
```
    Description copied from interface: LoaderAssistant
    
    Initializes a loader with the specified loaderId via the associated LoaderManager's initLoader(int, Bundle, LoaderManager.LoaderCallbacks).
    This assistant will be used as LoaderManager.LoaderCallbacks callback.
    
    Specified by:
    
    initLoader in interface LoaderAssistant<D>
    
    Parameters:
    
    loaderId - Id of the desired loader to initialize.
    
    arguments - The desired arguments for the loader. Should be LoaderAssistant.EMPTY_ARGUMENTS if loader does not require any arguments.
    
    Returns:
    
    Initialized loader instance or null if this assistant does not create loader for the specified id.
    
    See Also:
    
    LoaderAssistant.startLoader(int, Bundle), LoaderAssistant.restartLoader(int, Bundle), LoaderAssistant.destroyLoader(int)
  - restartLoader
```
@Nullable
public androidx.loader.content.Loader<D> restartLoader(int loaderId,
                                                                  @NonNull
                                                                  android.os.Bundle arguments)
```
    Description copied from interface: LoaderAssistant
    
    Re-starts a loader with the specified loaderId via the associated LoaderManager's restartLoader(int, Bundle, LoaderManager.LoaderCallbacks).
    This assistant will be used as LoaderManager.LoaderCallbacks callback.
    
    Specified by:
    
    restartLoader in interface LoaderAssistant<D>
    
    Parameters:
    
    loaderId - Id of the desired loader to re-start.
    
    arguments - The desired arguments for the loader. Should be LoaderAssistant.EMPTY_ARGUMENTS if loader does not require any arguments.
    
    Returns:
    
    Re-started loader instance or null if this assistant does not create loader for the specified id.
    
    See Also:
    
    LoaderAssistant.startLoader(int, Bundle), LoaderAssistant.initLoader(int, Bundle), LoaderAssistant.destroyLoader(int)
  - getLoader
```
@Nullable
public androidx.loader.content.Loader<D> getLoader(int loaderId)
```
    Description copied from interface: LoaderAssistant
    
    Returns a loader with the specified loaderId via the associated LoaderManager's getLoader(int).
    
    Specified by:
    
    getLoader in interface LoaderAssistant<D>
    
    Parameters:
    
    loaderId - Id of the desired loader to obtain.
    
    Returns:
    
    Requested loader or null if there is no such loader with the requested id.
    
    See Also:
    
    LoaderAssistant.startLoader(int, Bundle), LoaderAssistant.initLoader(int, Bundle), LoaderAssistant.restartLoader(int, Bundle), LoaderAssistant.destroyLoader(int)
  - destroyLoader
```
public boolean destroyLoader(int loaderId)
```
    Description copied from interface: LoaderAssistant
    
    Destroys a loader with the specified loaderId via the associated LoaderManager's destroyLoader(int).
    
    Specified by:
    
    destroyLoader in interface LoaderAssistant<D>
    
    Parameters:
    
    loaderId - Id of the desired loader to destroy.
    
    Returns:
    
    True if loader has been destroyed, false otherwise.
    
    See Also:
    
    LoaderAssistant.startLoader(int, Bundle), LoaderAssistant.initLoader(int, Bundle), LoaderAssistant.restartLoader(int, Bundle), LoaderAssistant.getLoader(int)
  - onCreateLoader
```
public abstract androidx.loader.content.Loader<D> onCreateLoader(int loaderId,
                                                                 @Nullable
                                                                 android.os.Bundle arguments)
```
    Specified by:
    
    onCreateLoader in interface androidx.loader.app.LoaderManager.LoaderCallbacks<D>
  - onLoadFinished
```
public void onLoadFinished(@NonNull
                           androidx.loader.content.Loader<D> loader,
                           @Nullable
                           D result)
```
    Specified by:
    
    onLoadFinished in interface androidx.loader.app.LoaderManager.LoaderCallbacks<D>
  - onLoadFinished
```
protected abstract void onLoadFinished(int loaderId,
                                       @NonNull
                                       D result)
```
    Invoked whenever onLoadFinished(Loader, Object) is fired and the received result is valid (not null).
    
    Parameters:
    
    loaderId - Id of the loader for which has been loading finished.
    
    result - The result received in onLoadFinished(Loader, Object).
  - onLoadFailed
```
protected void onLoadFailed(int loaderId)
```
    Invoked whenever onLoadFinished(Loader, Object) is fired and the received results is null.
    
    Parameters:
    
    loaderId - Id of the loader for which has loading failed.
  - onLoaderReset
```
public void onLoaderReset(@NonNull
                          androidx.loader.content.Loader<D> loader)
```
    Specified by:
    
    onLoaderReset in interface androidx.loader.app.LoaderManager.LoaderCallbacks<D>

Class BaseLoaderAssistant<D>

Simple usage

Field Summary

Fields inherited from interface universum.studios.android.database.content.LoaderAssistant

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

mContext

mLoaderManager

Constructor Detail

BaseLoaderAssistant

Method Detail

startLoader

initLoader

restartLoader

getLoader

destroyLoader

onCreateLoader

onLoadFinished

onLoadFinished

onLoadFailed

onLoaderReset