diff options
Diffstat (limited to 'jpa/plugins/org.eclipse.jpt.ui/src/org/eclipse/jpt/ui/internal/widgets/EnumComboViewer.java')
| -rw-r--r-- | jpa/plugins/org.eclipse.jpt.ui/src/org/eclipse/jpt/ui/internal/widgets/EnumComboViewer.java | 369 |
1 files changed, 369 insertions, 0 deletions
diff --git a/jpa/plugins/org.eclipse.jpt.ui/src/org/eclipse/jpt/ui/internal/widgets/EnumComboViewer.java b/jpa/plugins/org.eclipse.jpt.ui/src/org/eclipse/jpt/ui/internal/widgets/EnumComboViewer.java new file mode 100644 index 0000000000..0810236b7a --- /dev/null +++ b/jpa/plugins/org.eclipse.jpt.ui/src/org/eclipse/jpt/ui/internal/widgets/EnumComboViewer.java @@ -0,0 +1,369 @@ +/******************************************************************************* + * Copyright (c) 2008, 2010 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.ui.internal.widgets; + +import com.ibm.icu.text.Collator; +import java.util.Arrays; +import java.util.Comparator; +import org.eclipse.jface.viewers.ComboViewer; +import org.eclipse.jface.viewers.ISelection; +import org.eclipse.jface.viewers.ISelectionChangedListener; +import org.eclipse.jface.viewers.LabelProvider; +import org.eclipse.jface.viewers.SelectionChangedEvent; +import org.eclipse.jface.viewers.StructuredSelection; +import org.eclipse.jpt.ui.WidgetFactory; +import org.eclipse.jpt.ui.internal.JptUiMessages; +import org.eclipse.jpt.ui.internal.util.SWTUtil; +import org.eclipse.jpt.utility.model.Model; +import org.eclipse.jpt.utility.model.value.PropertyValueModel; +import org.eclipse.osgi.util.NLS; +import org.eclipse.swt.widgets.Composite; + +/** + * This pane simply shows a combo where its data is populating through + * {@link #choices()} and a default value can also be added. + * <p> + * Here the layout of this pane: + * <pre> + * ----------------------------------------------------------------------------- + * | ------------------------------------------------------------------------- | + * | | I |v| | + * | ------------------------------------------------------------------------- | + * -----------------------------------------------------------------------------</pre> + * + * @version 2.0 + * @since 1.0 + */ +@SuppressWarnings("nls") +abstract class EnumComboViewer<T extends Model, V> extends Pane<T> +{ + /** + * The main widget of this pane. + */ + private ComboViewer comboViewer; + + /** + * A constant used to represent the <code>null</code> value. + */ + public static final String NULL_VALUE = "null"; + + /** + * Creates a new <code>EnumComboViewer</code>. + * + * @param parentPane The parent container of this one + * @param parent The parent container + * @param widgetFactory The factory used to create various widgets + */ + EnumComboViewer(Pane<? extends T> parentPane, + Composite parent) { + + super(parentPane, parent); + } + + /** + * Creates a new <code>EnumComboViewer</code>. + * + * @param parentPane The parent container of this one + * @param parent The parent container + * @param widgetFactory The factory used to create various widgets + */ + EnumComboViewer(Pane<?> parentPane, + PropertyValueModel<? extends T> subjectHolder, + Composite parent) { + + super(parentPane, subjectHolder, parent); + } + + /** + * Creates a new <code>EnumComboViewer</code>. + * + * @param subjectHolder The holder of this pane's subject + * @param parent The parent container + * @param widgetFactory The factory used to create various widgets + */ + EnumComboViewer(PropertyValueModel<? extends T> subjectHolder, + Composite parent, + WidgetFactory widgetFactory) { + + super(subjectHolder, parent, widgetFactory); + } + + /** + * Creates the list of choices and add an extra element that represents the + * default value. + * + * @return The combo's choices including the default value + */ + private Object[] buildChoices() { + V[] choices = getChoices(); + if (sortChoices()) { + Arrays.sort(choices, buildComparator()); + } + + Object[] extendedChoices = new Object[choices.length + 1]; + System.arraycopy(choices, 0, extendedChoices, 1, choices.length); + extendedChoices[0] = NULL_VALUE; + + return extendedChoices; + } + + /** + * Return true to sort the choices in alphabetical order + * @return + */ + protected boolean sortChoices() { + return true; + } + + /** + * Creates the <code>ComboViewer</code> with the right combo widgets. + * + * @param container The container of the combo + * @return A new <code>ComboViewer</code> containing the right combo widget + */ + protected ComboViewer addComboViewer(Composite container) { + return addComboViewer(container, buildLabelProvider()); + } + + private Comparator<Object> buildComparator() { + return new Comparator<Object>() { + final LabelProvider labelProvider = buildLabelProvider(); + + public int compare(Object value1, Object value2) { + String displayString1 = labelProvider.getText(value1); + String displayString2 = labelProvider.getText(value2); + return Collator.getInstance().compare(displayString1, displayString2); + } + }; + } + + /** + * Retrieves the localized string from the given NLS class by creating the + * key. That key is the concatenation of the composite's short class name + * with the toString() of the given value separated by an underscore. + * + * @param nlsClass The NLS class used to retrieve the localized text + * @param compositeClass The class used for creating the key, its short class + * name is the beginning of the key + * @param value The value used to append its toString() to the generated key + * @return The localized text associated with the value + */ + protected final String buildDisplayString(Class<?> nlsClass, + Class<?> compositeClass, + Object value) { + + return SWTUtil.buildDisplayString(nlsClass, compositeClass, value); + } + + /** + * Retrieves the localized string from the given NLS class by creating the + * key. That key is the concatenation of the composite's short class name + * with the toString() of the given value separated by an underscore. + * + * @param nlsClass The NLS class used to retrieve the localized text + * @param composite The object used to retrieve the short class name that is + * the beginning of the key + * @param value The value used to append its toString() to the generated key + * @return The localized text associated with the value + */ + protected final String buildDisplayString(Class<?> nlsClass, + Object composite, + Object value) { + + return SWTUtil.buildDisplayString(nlsClass, composite, value); + } + + /** + * Creates the display string for the given element. If the element is the + * virtual <code>null</code> value then its display string will be "Default" + * appended by the actual default value, if it exists. + * + * @param value The value to convert into a human readable string + * @return The string representation of the given element + */ + @SuppressWarnings("unchecked") + private String buildDisplayString(Object value) { + if (value == NULL_VALUE) { + V defaultValue = (getSubject() != null) ? getDefaultValue() : null; + + if (defaultValue != null) { + String displayString = displayString(defaultValue); + return NLS.bind(JptUiMessages.EnumComboViewer_defaultWithDefault, displayString); + } + return nullDisplayString(); + } + + return displayString((V) value); + } + + final LabelProvider buildLabelProvider() { + return new LabelProvider() { + @Override + public String getText(Object element) { + return buildDisplayString(element); + } + }; + } + + private ISelection buildSelection() { + Object value = (getSubject() != null) ? getValue() : null; + + if (value == null) { + value = NULL_VALUE; + } + + return new StructuredSelection(value); + } + + private ISelectionChangedListener buildSelectionChangedListener() { + return new ISelectionChangedListener() { + public void selectionChanged(SelectionChangedEvent e) { + if (!isPopulating()) { + StructuredSelection selection = (StructuredSelection) e.getSelection(); + valueChanged(selection.getFirstElement()); + } + } + }; + } + + /** + * Returns the possible choices to show in the viewer. + * + * @return The items to show in the combos + */ + protected abstract V[] getChoices(); + + /** + * Returns the default value, this method is not called if the subject is + * <code>null</code>. + * + * @return The value that is declared as being the default when it is not + * defined or <code>null</code> if there is no default value + */ + protected abstract V getDefaultValue(); + + /** + * Returns the displayable string for the given value. + * + * @param value The value to translate into a human readable string + * @return The localized text representing the given value + */ + protected abstract String displayString(V value); + + /** + * Returns the displayable string for a null value. + */ + protected String nullDisplayString() { + return null; //I would rather display nothing than "Default()" + } + + /* + * (non-Javadoc) + */ + @Override + protected void doPopulate() { + super.doPopulate(); + this.populateCombo(); + } + + /** + * Returns + * + * @return + */ + final ComboViewer getComboViewer() { + return comboViewer; + } + + /** + * Retrieves the subject's value. The subject is never <code>null</code>. + * + * @return The subject' value, which can be <code>null</code> + */ + protected abstract V getValue(); + + /* + * (non-Javadoc) + */ + @Override + protected final void initializeLayout(Composite container) { + + this.comboViewer = this.addComboViewer(container); + this.comboViewer.addSelectionChangedListener(buildSelectionChangedListener()); + } + + /** + * Populates the combo by re-adding all the items. + */ + private void populateCombo() { + + removeAll(); + comboViewer.add(buildChoices()); + updateSelection(); + } + + /* + * (non-Javadoc) + */ + @Override + protected void propertyChanged(String propertyName) { + super.propertyChanged(propertyName); + this.populateCombo(); + } + + /** + * Removes all the items from the combo. + */ + abstract void removeAll(); + + /** + * Requests the given new value be set on the subject. + * + * @param value The new value to be set + */ + protected abstract void setValue(V value); + + /** + * Updates the cursor, which is required to show the entire selected item + * within the combo's area. + */ + abstract void updateCursor(); + + /** + * Updates the combo's selected item. + */ + private void updateSelection() { + comboViewer.setSelection(buildSelection()); + updateCursor(); + } + + /** + * The selection changes, notify the subclass to set the value. + * + * @param value The new selected item + */ + @SuppressWarnings("unchecked") + private void valueChanged(Object value) { + + // Convert the default "null" value to a real null + if (value == NULL_VALUE) { + value = null; + } + + setPopulating(true); + + try { + setValue((V) value); + } + finally { + setPopulating(false); + } + } +} |