tests/org.eclipse.jface.tests.databinding/src/org/eclipse/jface/tests/databinding/CalculatedValueTest.java

/*******************************************************************************
 * Copyright (c) 2006 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.jface.tests.databinding;

import junit.framework.TestCase;

import org.eclipse.jface.databinding.observable.value.ComputedValue;
import org.eclipse.jface.databinding.observable.value.WritableValue;
import org.eclipse.jface.examples.databinding.ModelObject;
import org.eclipse.jface.internal.databinding.provisional.DataBindingContext;
import org.eclipse.jface.internal.databinding.provisional.beans.BeanObservableFactory;

/**
 * @since 1.0
 * 
 */
public class CalculatedValueTest extends TestCase {
	public void test_ctor() throws Exception {
		ComputedValue cv = new ComputedValue() {
			protected Object calculate() {
				return new Integer(42);
			}
		};
		assertEquals("value type should be Integer.TYPE", Integer.TYPE, cv
				.getValueType());
	}

	public void test_getValue() throws Exception {
		ComputedValue cv = new ComputedValue() {
			protected Object calculate() {
				return new Integer(42);
			}
		};
		assertEquals("Calculated value should be 42", new Integer(42), cv
				.getValue());
	}

	public void test_handleChange() throws Exception {
		final int[] seed = new int[] { 42 };
		ComputedValue cv = new ComputedValue() {
			protected Object calculate() {
				return calcNewValue(seed);
			}
		};
		assertEquals("CalculatedValue should be " + calcNewValue(seed),
				calcNewValue(seed), cv.getValue());
		seed[0]++;
		// cv.getObservableChangeListener().handleChange(new ChangeEvent(this,
		// ChangeEvent.CHANGE, null, null));
		assertEquals("CalculatedValue should be " + calcNewValue(seed),
				calcNewValue(seed), cv.getValue());
	}

	private Object calcNewValue(int[] seed) {
		return new Integer(seed[0] + 2);
	}

	public void test_hookAndUnhookDependantObservableValues() throws Exception {
		final int[] seed = new int[] { 42 };
		ComputedValue cv = new ComputedValue() {
			protected Object calculate() {
				return calcNewValue(seed);
			}
		};
		WritableValue test1 = new WritableValue(Integer.TYPE);
		WritableValue test2 = new WritableValue(Integer.TYPE);

		// Hook observables...
		// cv.setDependencies(new IObservableValue[] {test1, test2});
		assertEquals("CalculatedValue should be " + calcNewValue(seed),
				calcNewValue(seed), cv.getValue());

		seed[0]++;
		test1.setValue(new Integer(0));
		assertEquals("CalculatedValue should be " + calcNewValue(seed),
				calcNewValue(seed), cv.getValue());

		seed[0]++;
		test2.setValue(new Integer(0));
		assertEquals("CalculatedValue should be " + calcNewValue(seed),
				calcNewValue(seed), cv.getValue());

		// Unhook observables...
		WritableValue test3 = new WritableValue(Integer.TYPE);
		WritableValue test4 = new WritableValue(Integer.TYPE);
		// cv.setDependencies(new IObservableValue[] {test3, test4});

		Integer oldValue = (Integer) cv.getValue();

		seed[0]++; // Calculation has changed
		test2.setValue(new Integer(0)); // should not update yet
		assertEquals("CalculatedValue should be " + oldValue, oldValue, cv
				.getValue());
		test3.setValue(new Integer(0)); // This should update
		assertEquals("CalculatedValue should be " + calcNewValue(seed),
				calcNewValue(seed), cv.getValue());

		seed[0]++;
		test4.setValue(new Integer(0));
		assertEquals("CalculatedValue should be " + calcNewValue(seed),
				calcNewValue(seed), cv.getValue());
	}

	private static class TestModel extends ModelObject {
		private int a = 0;

		/**
		 * @return Returns the a.
		 */
		public int getA() {
			return a;
		}

		/**
		 * @param a
		 *            The a to set.
		 */
		public void setA(int a) {
			int oldValue = this.a;
			this.a = a;
			firePropertyChange("a", oldValue, a);
		}
	}

	public void test_convertToObservables() throws Exception {
		final int[] seed = new int[] { 42 };
		ComputedValue cv = new ComputedValue() {
			protected Object calculate() {
				return calcNewValue(seed);
			}
		};
		TestModel test1 = new TestModel();
		TestModel test2 = new TestModel();

		// Hook beans...
		DataBindingContext dbc = new DataBindingContext();
		dbc.addObservableFactory(new BeanObservableFactory(dbc, null, null));

		// cv.setDependencies(dbc, new Object[] {new Property(test1, "a"), new
		// Property(test2, "a")});
		assertEquals("CalculatedValue should be " + calcNewValue(seed),
				calcNewValue(seed), cv.getValue());

		seed[0]++;
		test1.setA(1);
		assertEquals("CalculatedValue should be " + calcNewValue(seed),
				calcNewValue(seed), cv.getValue());

		seed[0]++;
		test2.setA(2);
		assertEquals("CalculatedValue should be " + calcNewValue(seed),
				calcNewValue(seed), cv.getValue());

		// Unhook beans...
		TestModel test3 = new TestModel();
		TestModel test4 = new TestModel();
		// cv.setDependencies(dbc, new Object[] {new Property(test3, "a"), new
		// Property(test4, "a")});

		Integer oldValue = (Integer) cv.getValue();

		seed[0]++;
		test2.setA(3);
		assertEquals("CalculatedValue should be " + oldValue, oldValue, cv
				.getValue());
		test3.setA(4);
		assertEquals("CalculatedValue should be " + calcNewValue(seed),
				calcNewValue(seed), cv.getValue());

		seed[0]++;
		test4.setA(5);
		assertEquals("CalculatedValue should be " + calcNewValue(seed),
				calcNewValue(seed), cv.getValue());
	}
}