Attachment 132350 Details for Bug 238222 – demonstrate the problem using an overriden updatevaluestrategy

demonstrate the problem using an overriden updatevaluestrategy

SnippetUpdtStrategEx.java (text/plain), 5.94 KB, created by Sylvere Richard

on 2009-04-19 13:00:52 EDT

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Filename:

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Creator: Sylvere Richard

Created: 2009-04-19 13:00:52 EDT

Size: 5.94 KB

patch

obsolete

>/*******************************************************************************
> * Copyright (c) 2000, 2004 IBM Corporation and others.
> * 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:
> *     IBM Corporation - initial API and implementation
> *******************************************************************************/
>package org.eclipse.swt.snippets;
>
>/*
> *
> * For a list of all SWT example snippets see
> * http://www.eclipse.org/swt/snippets/
> */
>import org.eclipse.core.databinding.Binding;
>import org.eclipse.core.databinding.DataBindingContext;
>import org.eclipse.core.databinding.UpdateValueStrategy;
>import org.eclipse.core.databinding.beans.PojoObservables;
>import org.eclipse.core.databinding.conversion.Converter;
>import org.eclipse.core.databinding.observable.Realm;
>import org.eclipse.core.databinding.observable.value.IObservableValue;
>import org.eclipse.core.runtime.IStatus;
>import org.eclipse.jface.databinding.swt.SWTObservables;
>import org.eclipse.swt.SWT;
>import org.eclipse.swt.layout.FormAttachment;
>import org.eclipse.swt.layout.FormData;
>import org.eclipse.swt.layout.FormLayout;
>import org.eclipse.swt.widgets.Button;
>import org.eclipse.swt.widgets.Composite;
>import org.eclipse.swt.widgets.Display;
>import org.eclipse.swt.widgets.Label;
>import org.eclipse.swt.widgets.Shell;
>import org.eclipse.swt.widgets.Text;
>
>public class SnippetUpdtStrategEx {
>
>	/**
>	 * the model bound to the UI.
>	 * 
>	 */
>	private static class MyModel {
>
>		private String myText;
>
>		public String getMyText() {
>			return myText;
>		}
>
>		public void setMyText(String myText) {
>			this.myText = myText;
>		}
>	}
>
>	/**
>	 * 
>	 * Represents the updatevaluestrategy that will be used to manually update
>	 * the target
>	 * 
>	 */
>	private static class UpdateValueStrategyEx extends UpdateValueStrategy {
>		private Binding binding;
>
>		/**
>		 * 
>		 * @param policy
>		 */
>		public UpdateValueStrategyEx(int policy) {
>			super(policy);
>		}
>
>		public void setBinding(Binding binding) {
>			this.binding = binding;
>		}
>
>		@Override
>		protected IStatus doSet(IObservableValue observableValue, Object value) {
>			IStatus status = super.doSet(observableValue, value);
>			if (binding != null)
>				binding.updateModelToTarget();
>			return status;
>		}
>
>	}
>
>	/**
>	 * 
>	 * A composite that will contains a text to validate.
>	 * 
>	 */
>	private static class MainCompo extends Composite {
>		private final MyModel model = new MyModel();
>
>		private Text text;
>
>		private Button button;
>
>		/**
>		 * 
>		 * @param parent
>		 * @param style
>		 */
>		public MainCompo(Composite parent, int style) {
>			super(parent, style);
>			doLayout();
>		}
>
>		private void doLayout() {
>			setLayout(new FormLayout());
>
>			Label lbl = new Label(this, SWT.NONE);
>			lbl.setText("Enter a text without 'aa' :");
>
>			text = new Text(this, SWT.BORDER);
>
>			button = new Button(this, SWT.NONE);
>			button.setText("Hello");
>
>			FormData data = new FormData();
>			data.left = new FormAttachment(0, 100, 5);
>			data.top = new FormAttachment(text, 0, SWT.CENTER);
>			lbl.setLayoutData(data);
>
>			data = new FormData();
>			data.left = new FormAttachment(lbl, 5, SWT.RIGHT);
>			data.top = new FormAttachment(0, 100, 5);
>			data.right = new FormAttachment(100, 100, -5);
>			text.setLayoutData(data);
>
>			data = new FormData();
>			data.left = new FormAttachment(lbl, 5, SWT.RIGHT);
>			data.top = new FormAttachment(text, 5);
>			button.setLayoutData(data);
>
>		}
>
>		/**
>		 * we bind text to MyModel.myText
>		 */
>		public void binding(final DataBindingContext dbc) {
>			// let's go binding text to MyModel.myText
>			// we will do validation
>			// In case the string typed by the user contains 'aa', we do the
>			// roundtrip to go
>			// back to the last correct value.
>			// Unfortunately, this solution does not work if we type two times
>			//the same bad text
>			
>
>			final UpdateValueStrategyEx strgTargetToModel = new UpdateValueStrategyEx(
>					UpdateValueStrategy.POLICY_UPDATE);
>			final UpdateValueStrategy strgModelToTarget = new UpdateValueStrategy(
>					UpdateValueStrategy.POLICY_UPDATE);
>			Binding b = dbc.bindValue(SWTObservables.observeText(text,
>					SWT.FocusOut), PojoObservables
>					.observeValue(model, "myText"), strgTargetToModel,
>					strgModelToTarget);
>
>			//don't forget to set the binding
>			strgTargetToModel.setBinding(b);
>			strgTargetToModel.setConverter(new Converter(String.class, String.class) {
>				
>				@Override
>				public Object convert(Object fromObject) {
>					if (fromObject == null) {
>						
>						return "";
>					}
>					String strVal = (String) fromObject;
>					// error, contains 'aa'
>					if (strVal.indexOf("aa") != -1) {
>						//force the update with the last valid value
>						return model.getMyText();
>					}
>					return strVal;
>				}
>			});
>			
>
>		}
>
>	}
>
>	/**
>	 * Main entry point
>	 * 
>	 * @param args
>	 */
>	public static void main(String[] args) {
>		final Display display = new Display();
>
>		Realm.runWithDefault(SWTObservables.getRealm(display), new Runnable() {
>			public void run() {
>				Shell shell = new Shell(display);
>				shell.setBounds(0, 0, 400, 200);
>				shell.setLayout(new FormLayout());
>				MainCompo compo = new MainCompo(shell, SWT.NONE);
>				FormData data = new FormData();
>				data.left = new FormAttachment(0, 100, 0);
>				data.right = new FormAttachment(100, 100, 0);
>				data.top = new FormAttachment(0, 100, 0);
>				data.bottom = new FormAttachment(100, 100, 0);
>				compo.setLayoutData(data);
>
>				final DataBindingContext dbc = new DataBindingContext();
>				compo.binding(dbc);
>				shell.open();
>
>				while (!shell.isDisposed()) {
>					if (!display.readAndDispatch())
>						display.sleep();
>				}
>			}
>		});
>		display.dispose();
>	}
>}

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Attachments on bug 238222: 131571 | 131572 | 132350 | 132819