rework ControlSwitcher -> PageBookModelBinding

3 files changed, 211 insertions, 157 deletions

diff --git a/common/plugins/org.eclipse.jpt.common.ui/src/org/eclipse/jpt/common/ui/internal/swt/bind/PageBookModelBinding.java b/common/plugins/org.eclipse.jpt.common.ui/src/org/eclipse/jpt/common/ui/internal/swt/bind/PageBookModelBinding.java
new file mode 100644
index 0000000000..a7d8af3c73
--- /dev/null
+++ b/common/plugins/org.eclipse.jpt.common.ui/src/org/eclipse/jpt/common/ui/internal/swt/bind/PageBookModelBinding.java
@@ -0,0 +1,166 @@
+/*******************************************************************************
+ * Copyright (c) 2008, 2013 Oracle. All rights reserved.
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v1.0, which accompanies this distribution
+ * and is available at http://www.eclipse.org/legal/epl-v10.html.
+ *
+ * Contributors:
+ *     Oracle - initial API and implementation
+ ******************************************************************************/
+package org.eclipse.jpt.common.ui.internal.swt.bind;
+
+import org.eclipse.jpt.common.ui.internal.listeners.SWTPropertyChangeListenerWrapper;
+import org.eclipse.jpt.common.ui.internal.swt.events.DisposeAdapter;
+import org.eclipse.jpt.common.ui.internal.swt.widgets.ControlTools;
+import org.eclipse.jpt.common.utility.internal.ObjectTools;
+import org.eclipse.jpt.common.utility.model.event.PropertyChangeEvent;
+import org.eclipse.jpt.common.utility.model.listener.PropertyChangeAdapter;
+import org.eclipse.jpt.common.utility.model.listener.PropertyChangeListener;
+import org.eclipse.jpt.common.utility.model.value.PropertyValueModel;
+import org.eclipse.jpt.common.utility.transformer.Transformer;
+import org.eclipse.swt.SWT;
+import org.eclipse.swt.events.DisposeEvent;
+import org.eclipse.swt.events.DisposeListener;
+import org.eclipse.swt.widgets.Control;
+import org.eclipse.swt.widgets.Label;
+import org.eclipse.ui.part.PageBook;
+
+/**
+ * This binding can be used to keep a page book's current page synchronized
+ * with a model.
+ * @see PropertyValueModel
+ * @see PageBook
+ */
+final class PageBookModelBinding<T> {
+	// ***** model
+	/**
+	 * The value model that determines the page to be displayed.
+	 */
+	private final PropertyValueModel<T> valueModel;
+
+	/**
+	 * A listener that allows us to synchronize the page book's current page
+	 * with the value model.
+	 */
+	private final PropertyChangeListener valueModelListener;
+
+	// ***** transformer
+	/**
+	 * The transformer that converts the model's value to the control
+	 * to be displayed by the page book. If the transformer returns
+	 * <code>null</code>, the page book will display the null page.
+	 */
+	private final Transformer<? super T, Control> transformer;
+
+	// ***** UI
+	/**
+	 * The page book whose current page is determined by the value model.
+	 */
+	private final PageBook pageBook;
+
+	/**
+	 * A listener that allows us to stop listening to stuff when the page book
+	 * is disposed. (Critical for preventing memory leaks.)
+	 */
+	private final DisposeListener pageBookDisposeListener;
+
+	/**
+	 * The control to be displayed in the page book if the control transformer
+	 * returns <code>null</code>.
+	 */
+	private final Control defaultPage;
+
+
+	// ********** construction **********
+
+	/**
+	 * Constructor - the model, transformer, and page book are required.
+	 */
+	PageBookModelBinding(PropertyValueModel<T> valueModel, Transformer<? super T, Control> transformer, PageBook pageBook, Control defaultPage) {
+		super();
+		if ((valueModel == null) || (transformer == null) || (pageBook == null)) {
+			throw new NullPointerException();
+		}
+		this.valueModel = valueModel;
+		this.transformer = transformer;
+		this.pageBook = pageBook;
+
+		this.defaultPage = (defaultPage != null) ? defaultPage : this.buildDefaultDefaultPage();
+		if (this.defaultPage.getParent() != this.pageBook) {
+			throw new IllegalArgumentException("The null page's parent must be the page book: " + defaultPage); //$NON-NLS-1$
+		}
+
+		this.valueModelListener = this.buildValueModelListener();
+		this.valueModel.addPropertyChangeListener(PropertyValueModel.VALUE, this.valueModelListener);
+
+		this.pageBookDisposeListener = this.buildPageBookDisposeListener();
+		this.pageBook.addDisposeListener(this.pageBookDisposeListener);
+
+		this.showPage(this.valueModel.getValue());
+	}
+
+	private Control buildDefaultDefaultPage() {
+		// SWT.SHADOW_NONE makes the line separator invisible
+		return new Label(this.pageBook, SWT.SEPARATOR | SWT.SHADOW_NONE | SWT.HORIZONTAL);
+	}
+
+	private PropertyChangeListener buildValueModelListener() {
+		return new SWTPropertyChangeListenerWrapper(new ValueModelListener());
+	}
+
+	/* CU private */ class ValueModelListener
+		extends PropertyChangeAdapter
+	{
+		@Override
+		@SuppressWarnings("unchecked")
+		public void propertyChanged(PropertyChangeEvent event) {
+			PageBookModelBinding.this.showPage((T) event.getNewValue());
+		}
+	}
+
+	private DisposeListener buildPageBookDisposeListener() {
+		return new PageBookDisposeListener();
+	}
+
+	/* CU private */ class PageBookDisposeListener
+		extends DisposeAdapter
+	{
+		@Override
+		public void widgetDisposed(DisposeEvent event) {
+			PageBookModelBinding.this.pageBookDisposed();
+		}
+	}
+
+
+	// ********** model events **********
+
+	/**
+	 * Show the page corresponding to the specified model value.
+	 */
+	/* CU private */ void showPage(T value) {
+		if (this.pageBook.isDisposed()) {
+			return;
+		}
+		Control page = this.transformer.transform(value);
+		this.pageBook.showPage((page != null) ? page : this.defaultPage);
+		ControlTools.reflow(this.pageBook);
+	}
+
+
+	// ********** UI events **********
+
+	/* CU private */ void pageBookDisposed() {
+		// the page book is not yet "disposed" when we receive this event
+		// so we can still remove our listener
+		this.pageBook.removeDisposeListener(this.pageBookDisposeListener);
+		this.valueModel.removePropertyChangeListener(PropertyValueModel.VALUE, this.valueModelListener);
+	}
+
+
+	// ********** misc **********
+
+    @Override
+	public String toString() {
+		return ObjectTools.toString(this, this.valueModel);
+	}
+}
diff --git a/common/plugins/org.eclipse.jpt.common.ui/src/org/eclipse/jpt/common/ui/internal/swt/bind/SWTBindTools.java b/common/plugins/org.eclipse.jpt.common.ui/src/org/eclipse/jpt/common/ui/internal/swt/bind/SWTBindTools.java
index 7afdc59df9..5dcbc7054d 100644
--- a/common/plugins/org.eclipse.jpt.common.ui/src/org/eclipse/jpt/common/ui/internal/swt/bind/SWTBindTools.java
+++ b/common/plugins/org.eclipse.jpt.common.ui/src/org/eclipse/jpt/common/ui/internal/swt/bind/SWTBindTools.java
@@ -28,6 +28,7 @@ import org.eclipse.swt.widgets.List;
 import org.eclipse.swt.widgets.Text;
 import org.eclipse.swt.widgets.Widget;
 import org.eclipse.ui.forms.widgets.Section;
+import org.eclipse.ui.part.PageBook;
 
 /**
  * Various SWT tools.
@@ -206,6 +207,50 @@ public final class SWTBindTools {
 	}
 
 
+	// ********** page book **********
+
+	/**
+	 * Bind the specified control model to the specified page book. The model's
+	 * value will determine which page the page book displays.
+	 */
+	public static void bind(PropertyValueModel<Control> controlModel, PageBook pageBook) {
+		bind(controlModel, pageBook, null);
+	}
+
+	/**
+	 * Bind the specified control model to the specified page book. The model's
+	 * value will determine which page the page book displays. If the model's
+	 * value is <code>null</code>, the page book will display the specified
+	 * default page.
+	 */
+	public static void bind(PropertyValueModel<Control> controlModel, PageBook pageBook, Control defaultPage) {
+		bind(controlModel, TransformerTools.<Control>passThruTransformer(), pageBook, defaultPage);
+	}
+
+	/**
+	 * Bind the specified model to the specified page book. The model's value will
+	 * determine which page the page book displays. The specified transformer
+	 * will convert the model's value into the control to be displayed in the
+	 * page book.
+	 */
+	public static <T> void bind(PropertyValueModel<T> valueModel, Transformer<? super T, Control> transformer, PageBook pageBook) {
+		bind(valueModel, transformer, pageBook, null);
+	}
+
+	/**
+	 * Bind the specified model to the specified page book. The model's value will
+	 * determine which page the page book displays. The specified transformer
+	 * will convert the model's value into the control to be displayed in the
+	 * page book. If the transformer converts the model's value into
+	 * <code>null</code>, the page book will display the specified default
+	 * page.
+	 */
+	@SuppressWarnings("unused")
+	public static <T> void bind(PropertyValueModel<T> valueModel, Transformer<? super T, Control> transformer, PageBook pageBook, Control defaultPage) {
+		new PageBookModelBinding<T>(valueModel, transformer, pageBook, defaultPage);
+	}
+
+
 	// ********** 'enabled' state **********
 
 	/**
diff --git a/common/plugins/org.eclipse.jpt.common.ui/src/org/eclipse/jpt/common/ui/internal/util/ControlSwitcher.java b/common/plugins/org.eclipse.jpt.common.ui/src/org/eclipse/jpt/common/ui/internal/util/ControlSwitcher.java
deleted file mode 100644
index 932f992a54..0000000000
--- a/common/plugins/org.eclipse.jpt.common.ui/src/org/eclipse/jpt/common/ui/internal/util/ControlSwitcher.java
+++ /dev/null
@@ -1,157 +0,0 @@
-/*******************************************************************************
- * Copyright (c) 2008, 2011 Oracle. All rights reserved.
- * This program and the accompanying materials are made available under the
- * terms of the Eclipse Public License v1.0, which accompanies this distribution
- * and is available at http://www.eclipse.org/legal/epl-v10.html.
- *
- * Contributors:
- *     Oracle - initial API and implementation
- ******************************************************************************/
-package org.eclipse.jpt.common.ui.internal.util;
-
-import org.eclipse.jpt.common.ui.internal.listeners.SWTPropertyChangeListenerWrapper;
-import org.eclipse.jpt.common.ui.internal.swt.widgets.ControlTools;
-import org.eclipse.jpt.common.utility.internal.transformer.AbstractTransformer;
-import org.eclipse.jpt.common.utility.model.event.PropertyChangeEvent;
-import org.eclipse.jpt.common.utility.model.listener.PropertyChangeListener;
-import org.eclipse.jpt.common.utility.model.value.PropertyValueModel;
-import org.eclipse.jpt.common.utility.transformer.Transformer;
-import org.eclipse.swt.SWT;
-import org.eclipse.swt.widgets.Control;
-import org.eclipse.swt.widgets.Label;
-import org.eclipse.ui.part.PageBook;
-
-/**
- * This controller is responsible to switch the active page based on a value. A
- * <code>Transformer</code> is used to transformed that value into a
- * <code>Control</code>.
- *
- * @version 2.3
- * @since 2.0
- */
-public final class ControlSwitcher
-{
-	/**
-	 * The widget that is used to show the active <code>Control</code>.
-	 */
-	private PageBook pageBook;
-
-	/**
-	 * The <code>Transformer</code> used to transform the value into a
-	 * <code>Control</code>.
-	 */
-	private Transformer<?, Control> controlTransformer;
-
-	private Label emptyLabel;
-
-	/**
-	 * Creates a new <code>ControlSwitcher</code>.
-	 *
-	 * @param switchHolder The holder of the value that will be used to retrieve
-	 * the right <code>Control</code> when passed to the given transformer
-	 * @param controlTransformer The <code>Transformer</code> used to transform the value into a
-	 * <code>Control</code>
-	 * @param pageBook The <code>PageBook</code> used for switching the <code>Control</code>
-	 */
-	public <T> ControlSwitcher(PropertyValueModel<? extends T> switchHolder,
-	                           Transformer<T, Control> controlTransformer,
-	                           PageBook pageBook)
-	{
-		super();
-		initialize(switchHolder, controlTransformer, pageBook);
-	}
-
-	public <T> ControlSwitcher(PropertyValueModel<? extends T> switchHolder,
-								Control control,
-								PageBook pageBook)
-	{
-		this(switchHolder, buildNullControlTransformer(control), pageBook);
-	}
-
-	private static <T> Transformer<T, Control> buildNullControlTransformer(Control control) {
-		return new NullControlTransformer<T>(control);
-	}
-
-	protected static class NullControlTransformer<T>
-		extends AbstractTransformer<T, Control>
-	{
-		private final Control control;
-
-		protected NullControlTransformer(Control control) {
-			this.control = control;
-		}
-
-		@Override
-		public Control transform_(T model) {
-			return this.control;
-		}
-	}
-
-	private void initialize(PropertyValueModel<?> switchHolder,
-	                        Transformer<?, Control> controlTransformer,
-	                        PageBook pageBook)
-	{
-		this.pageBook        = pageBook;
-		this.controlTransformer = controlTransformer;
-
-		this.emptyLabel = this.buildEmptyLabel();
-
-		switchHolder.addPropertyChangeListener(
-			PropertyValueModel.VALUE,
-			buildPropertyChangeListener()
-		);
-
-		switchPages(switchHolder.getValue());
-	}
-
-	//Build an empty label to display in the page book when the controlTransformer returns null.
-	//SWT.SHADOW_NONE makes the line separator not visible
-	//This is the best we can come up with for an empty page
-	private Label buildEmptyLabel() {
-		return new Label(this.pageBook, SWT.SEPARATOR | SWT.SHADOW_NONE | SWT.HORIZONTAL);
-	}
-
-	private PropertyChangeListener buildPropertyChangeListener() {
-		return new SWTPropertyChangeListenerWrapper(
-			buildPropertyChangeListener_()
-		);
-	}
-
-	private PropertyChangeListener buildPropertyChangeListener_() {
-		return new PropertyChangeListener() {
-			public void propertyChanged(PropertyChangeEvent e) {
-				switchPages(e.getNewValue());
-			}
-		};
-	}
-
-	/**
-	 * Switches the active page by transforming the given value into its
-	 * corresponding control.
-	 *
-	 * @param value The state passed to the transformer in order to retrieve the
-	 * new control
-	 */
-	private void switchPages(Object value) {
-		if (this.pageBook.isDisposed()) {
-			return;
-		}
-
-		// Retrieve the Control for the new value
-		Control page = transform(value);
-
-		if (page == null) {
-			//Note: We can't pass in null due to a bug in PageBook
-			page = this.emptyLabel;
-		}
-		this.pageBook.showPage(page);
-
-		// Revalidate the parents in order to update the layout
-		ControlTools.reflow(this.pageBook);
-	}
-
-	@SuppressWarnings("unchecked")
-	private Control transform(Object value) {
-		return ((Transformer<Object, Control>) this.controlTransformer).transform(value);
-	}
-}
\ No newline at end of file