Complete - task 91: Consider allowing singleton PresenterWidgets

http://code.google.com/p/gwt-platform/issues/detail?id=91

See AbstractPresenterModule#bindSingletonPresenterWidget


Former-commit-id: 5ad36b6

src/com/philbeaudoin/gwtp/mvp/client/PresenterWidgetImpl.java

@@ -27,9 +27,9 @@
 import com.philbeaudoin.gwtp.mvp.client.proxy.ResetPresentersEvent;
 
 /**
-* @author Philippe Beaudoin
-* @author Christian Goudreau
-*/
+ * @author Philippe Beaudoin
+ * @author Christian Goudreau
+ */
 public abstract class PresenterWidgetImpl<V extends View>
 extends HandlerContainerImpl implements PresenterWidget {
 
@@ -305,15 +305,16 @@ public void addContent( Object slot, PresenterWidget content ) {
    *             what to do with this slot.
    */
   public void clearContent( Object slot ) {
-    if( isVisible() ) {
-      // This presenter is visible, its time to call onReveal
+    List<PresenterWidgetImpl<?>> slotChildren = activeChildren.get( slot );
+    if( slotChildren != null ) {
+      // This presenter is visible, its time to call onHide
       // on the newly added child (and recursively on this child children)
-      List<PresenterWidgetImpl<?>> slotChildren = activeChildren.get( slot );
-      if( slotChildren != null ) {
-        for( PresenterWidgetImpl<?> activeChild : slotChildren )
+      if( isVisible() ) {
+        for( PresenterWidgetImpl<?> activeChild : slotChildren ) {
           activeChild.notifyHide();
-        slotChildren.clear();
+        }
       }
+      slotChildren.clear();
     }
     getView().setContent( slot, null );
   }

src/com/philbeaudoin/gwtp/mvp/client/gin/AbstractPresenterModule.java

@@ -18,6 +18,7 @@
 
 import com.google.gwt.inject.client.AbstractGinModule;
 import com.google.inject.Singleton;
+import com.philbeaudoin.gwtp.mvp.client.PresenterImpl;
 import com.philbeaudoin.gwtp.mvp.client.View;
 import com.philbeaudoin.gwtp.mvp.client.Presenter;
 import com.philbeaudoin.gwtp.mvp.client.PresenterWidget;
@@ -66,7 +67,31 @@ protected <P, V> void bindPresenterWidgetFactory(
     bind(presenterFactory).to(presenterFactoryImpl).in(Singleton.class);
     bind(viewFactory).to(viewFactoryImpl).in(Singleton.class);
   }
-
+
+  /**
+   * Convenience method for binding a singleton {@link PresenterWidget} with its {@link View}.
+   * <p />
+   * <b>Important!</b> If you want to use the same {@link PresenterWidget} in many different places,
+   * you should consider making it non-singleton with {@link #bindPresenterWidget}. It is possible
+   * to use the same singleton {@link PresenterWidget} in different presenters, as long as these
+   * are not simultaneously visible. Also, if you do this, you must make sure to set the singleton
+   * presenter widget as content in its containing presenter {@link PresenterImpl#onReveal} and to
+   * remove it in the {@link PresenterImpl#onHide}.
+   *
+   * @param <P>         The {@link PresenterWidget} type.
+   * @param <V>         The {@link View} type.
+   * @param presenter   The {@link PresenterWidget} (a singleton).
+   * @param view     The {@link View} interface.
+   * @param viewImpl The {@link View} implementation (a singleton).
+   */
+  protected <P extends PresenterWidget, V extends View> void bindSingletonPresenterWidget( 
+      Class<P> presenter, 
+      Class<V> view,
+      Class<? extends V> viewImpl ) {
+    bind( presenter ).in(Singleton.class);
+    bind( view ).to( viewImpl ).in(Singleton.class);
+  }
+
   /**
    * Convenience method for binding a singleton presenter with its view and 
    * its proxy, when using automatically generated proxy classes.
@@ -127,7 +152,7 @@ protected <P extends Presenter, V extends View, Proxy_ extends Proxy<P>> void bi
    * <p />
    * <b>Important!</b> This is only be meant to be used by presenters associated 
    * with non-singleton views, for example when the same view class is reused with 
-   * many presenters. As such, you will need to also use the {@link #bindNonSingletonView} method.
+   * many presenters. As such, you will need to also use the {@link #bindSharedView} method.
    * If the view class is use only by one presenter, you should consider using
    * {@link #bindPresenter(Class, Class, Class, Class)} instead.
    *
@@ -152,7 +177,7 @@ protected <P extends Presenter, Proxy_ extends Proxy<P>> void bindPresenter(
    * <p />
    * <b>Important!</b> This is only be meant to be used by presenters associated 
    * with non-singleton views, for example when the same view class is reused with 
-   * many presenters. As such, you will need to also use the {@link #bindNonSingletonView} method.
+   * many presenters. As such, you will need to also use the {@link #bindSharedView} method.
    * If the view class is use only by one presenter, you should consider using
    * {@link #bindPresenter(Class, Class, Class, Class, Class)} instead.
    *
@@ -187,7 +212,7 @@ protected <P extends Presenter,Proxy_ extends Proxy<P>> void bindPresenter(
    * @param view     The {@link View} interface.
    * @param viewImpl The {@link View} implementation (not a singleton).
    */
-  protected <V extends View> void bindNonSingletonView( 
+  protected <V extends View> void bindSharedView( 
       Class<V> view,
       Class<? extends V> viewImpl ) {
     bind( view ).to( viewImpl );