Java tutorial
/* ********************************************************************** ** ** Copyright notice ** ** ** ** (c) 2005-2009 RSSOwl Development Team ** ** http://www.rssowl.org/ ** ** ** ** 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.rssowl.org/legal/epl-v10.html ** ** ** ** A copy is found in the file epl-v10.html and important notices to the ** ** license from the team is found in the textfile LICENSE.txt distributed ** ** in this package. ** ** ** ** This copyright notice MUST APPEAR in all copies of the file! ** ** ** ** Contributors: ** ** RSSOwl Development Team - initial API and implementation ** ** ** ** ********************************************************************** */ package org.rssowl.ui.internal.util; import org.eclipse.jface.dialogs.Dialog; import org.eclipse.jface.dialogs.IDialogConstants; import org.eclipse.jface.resource.JFaceResources; import org.eclipse.jface.viewers.ArrayContentProvider; import org.eclipse.jface.viewers.ComboViewer; import org.eclipse.jface.viewers.ISelectionChangedListener; import org.eclipse.jface.viewers.IStructuredSelection; import org.eclipse.jface.viewers.LabelProvider; import org.eclipse.jface.viewers.ListViewer; import org.eclipse.jface.viewers.SelectionChangedEvent; import org.eclipse.jface.viewers.StructuredSelection; import org.eclipse.jface.viewers.Viewer; import org.eclipse.jface.viewers.ViewerFilter; import org.eclipse.swt.SWT; import org.eclipse.swt.events.DisposeEvent; import org.eclipse.swt.events.DisposeListener; import org.eclipse.swt.events.MenuEvent; import org.eclipse.swt.events.MenuListener; import org.eclipse.swt.events.SelectionAdapter; import org.eclipse.swt.events.SelectionEvent; import org.eclipse.swt.graphics.FontMetrics; import org.eclipse.swt.graphics.GC; import org.eclipse.swt.graphics.Point; import org.eclipse.swt.graphics.Rectangle; import org.eclipse.swt.layout.GridData; import org.eclipse.swt.widgets.Button; import org.eclipse.swt.widgets.Composite; import org.eclipse.swt.widgets.Label; import org.eclipse.swt.widgets.Menu; import org.eclipse.swt.widgets.MenuItem; import org.rssowl.ui.internal.OwlUI; import org.rssowl.ui.internal.editors.feed.NewsColumn; import org.rssowl.ui.internal.editors.feed.NewsColumnViewModel; import java.util.List; /** * The <code>NewsColumnSelectionControl</code> is a <code>Composite</code> * providing the UI to define the number and order of columns to display news. * * @author bpasero */ public class NewsColumnSelectionControl extends Composite { private ListViewer fNewsColumnViewer; private FontMetrics fFontMetrics; private NewsColumnViewModel fModel; private ComboViewer fSortByViewer; private ComboViewer fSortAscendingViewer; private Button fRemoveButton; private Button fMoveUpButton; private Button fMoveDownButton; /* Sort Order */ private enum Order { ASCENDING(Messages.NewsColumnSelectionControl_ASCENDING), DESCENDING( Messages.NewsColumnSelectionControl_DESCENDING); private String fName; private Order(String name) { fName = name; } String getName() { return fName; } } /** * @param parent * @param style */ public NewsColumnSelectionControl(Composite parent, int style) { super(parent, style); initMetrics(); initComponents(); } private void initMetrics() { GC gc = new GC(this); gc.setFont(JFaceResources.getDialogFont()); fFontMetrics = gc.getFontMetrics(); gc.dispose(); } private void initComponents() { /* Apply Gridlayout */ setLayout(LayoutUtils.createGridLayout(2, 0, 0)); /* Left: List of Columns */ fNewsColumnViewer = new ListViewer(this, SWT.BORDER | SWT.MULTI | SWT.V_SCROLL); fNewsColumnViewer.getControl().setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, false)); fNewsColumnViewer.setContentProvider(new ArrayContentProvider()); fNewsColumnViewer.setLabelProvider(new LabelProvider() { @Override public String getText(Object element) { NewsColumn column = (NewsColumn) element; return column.getName(); } }); fNewsColumnViewer.addSelectionChangedListener(new ISelectionChangedListener() { public void selectionChanged(SelectionChangedEvent event) { updateMoveEnablement(); updateRemoveEnablement(); } }); /* Right: Buttons to manage Columns */ Composite buttonContainer = new Composite(this, SWT.None); buttonContainer.setLayout(LayoutUtils.createGridLayout(1, 0, 0)); buttonContainer.setLayoutData(new GridData(SWT.BEGINNING, SWT.BEGINNING, false, false)); /* Add */ final Menu menu = new Menu(getShell(), SWT.POP_UP); menu.addMenuListener(new MenuListener() { public void menuShown(MenuEvent e) { MenuItem[] items = menu.getItems(); for (MenuItem item : items) { item.dispose(); } NewsColumn[] newsColumns = NewsColumn.values(); for (final NewsColumn column : newsColumns) { if (column.isSelectable() && !fModel.contains(column)) { MenuItem item = new MenuItem(menu, SWT.PUSH); item.setText(column.getName()); item.addSelectionListener(new SelectionAdapter() { @Override public void widgetSelected(SelectionEvent e) { fModel.addColumn(column); fNewsColumnViewer.add(column); updateRemoveEnablement(); fNewsColumnViewer.setSelection(new StructuredSelection(column)); } }); } } } public void menuHidden(MenuEvent e) { } }); final Button addButton = new Button(buttonContainer, SWT.DOWN); setButtonLayoutData(addButton); addButton.setText(Messages.NewsColumnSelectionControl_ADD); addButton.addSelectionListener(new SelectionAdapter() { @Override public void widgetSelected(SelectionEvent e) { Rectangle rect = addButton.getBounds(); Point pt = new Point(rect.x, rect.y + rect.height); pt = addButton.toDisplay(pt); menu.setLocation(pt.x, pt.y); menu.setVisible(true); } }); addButton.addDisposeListener(new DisposeListener() { public void widgetDisposed(DisposeEvent e) { OwlUI.safeDispose(menu); } }); /* Remove */ fRemoveButton = new Button(buttonContainer, SWT.PUSH); setButtonLayoutData(fRemoveButton); fRemoveButton.setText(Messages.NewsColumnSelectionControl_REMOVE); fRemoveButton.setEnabled(false); fRemoveButton.addSelectionListener(new SelectionAdapter() { @Override public void widgetSelected(SelectionEvent e) { onDelete(); } }); /* Move Up */ fMoveUpButton = new Button(buttonContainer, SWT.PUSH); setButtonLayoutData(fMoveUpButton); fMoveUpButton.setText(Messages.NewsColumnSelectionControl_MOVE_UP); fMoveUpButton.setEnabled(false); fMoveUpButton.addSelectionListener(new SelectionAdapter() { @Override public void widgetSelected(SelectionEvent e) { onMove(true); } }); /* Move Down */ fMoveDownButton = new Button(buttonContainer, SWT.PUSH); setButtonLayoutData(fMoveDownButton); fMoveDownButton.setText(Messages.NewsColumnSelectionControl_MOVE_DOWN); fMoveDownButton.setEnabled(false); fMoveDownButton.addSelectionListener(new SelectionAdapter() { @Override public void widgetSelected(SelectionEvent e) { onMove(false); } }); /* Bottom: Sort Column */ Composite sortByContainer = new Composite(this, SWT.None); sortByContainer.setLayout(LayoutUtils.createGridLayout(3, 0, 0)); sortByContainer.setLayoutData(new GridData(SWT.FILL, SWT.BEGINNING, true, false, 2, 1)); Label sortByLabel = new Label(sortByContainer, SWT.NONE); sortByLabel.setText(Messages.NewsColumnSelectionControl_SORT_BY); fSortByViewer = new ComboViewer(sortByContainer, SWT.READ_ONLY | SWT.BORDER); fSortByViewer.getCombo().setVisibleItemCount(20); fSortByViewer.setContentProvider(new ArrayContentProvider()); fSortByViewer.setLabelProvider(new LabelProvider() { @Override public String getText(Object element) { NewsColumn column = (NewsColumn) element; return column.getName(); } }); fSortByViewer.addFilter(new ViewerFilter() { @Override public boolean select(Viewer viewer, Object parentElement, Object element) { if (element == NewsColumn.RELEVANCE) return false; return true; } }); fSortByViewer.addSelectionChangedListener(new ISelectionChangedListener() { public void selectionChanged(SelectionChangedEvent event) { IStructuredSelection selection = (IStructuredSelection) event.getSelection(); NewsColumn column = (NewsColumn) selection.getFirstElement(); fModel.setSortColumn(column); } }); fSortAscendingViewer = new ComboViewer(sortByContainer, SWT.READ_ONLY | SWT.BORDER); fSortAscendingViewer.getCombo().setVisibleItemCount(2); fSortAscendingViewer.setContentProvider(new ArrayContentProvider()); fSortAscendingViewer.setLabelProvider(new LabelProvider() { @Override public String getText(Object element) { return (((Order) element)).getName(); } }); fSortAscendingViewer.addSelectionChangedListener(new ISelectionChangedListener() { public void selectionChanged(SelectionChangedEvent event) { IStructuredSelection selection = (IStructuredSelection) event.getSelection(); Order order = (Order) selection.getFirstElement(); fModel.setAscending(order == Order.ASCENDING ? true : false); } }); } private void onMove(boolean up) { IStructuredSelection selection = (IStructuredSelection) fNewsColumnViewer.getSelection(); Object element = selection.getFirstElement(); List<NewsColumn> columns = fModel.getColumns(); int index = columns.indexOf(element); if (up && index > 0) { columns.remove(element); columns.add(index - 1, (NewsColumn) element); } else if (index < columns.size() - 1) { columns.remove(element); columns.add(index + 1, (NewsColumn) element); } fNewsColumnViewer.refresh(); fNewsColumnViewer.getList().showSelection(); updateMoveEnablement(); } private void updateMoveEnablement() { boolean enableMoveUp = true; boolean enableMoveDown = true; int[] selectionIndices = fNewsColumnViewer.getList().getSelectionIndices(); if (selectionIndices.length == 1) { enableMoveUp = selectionIndices[0] != 0; enableMoveDown = selectionIndices[0] != fNewsColumnViewer.getList().getItemCount() - 1; } else { enableMoveUp = false; enableMoveDown = false; } fMoveUpButton.setEnabled(enableMoveUp); fMoveDownButton.setEnabled(enableMoveDown); } private void updateRemoveEnablement() { fRemoveButton.setEnabled( fNewsColumnViewer.getList().getItemCount() > 1 && !fNewsColumnViewer.getSelection().isEmpty()); } /** * @param model the news column model to show in the selection control. */ public void setInput(NewsColumnViewModel model) { fModel = model; fNewsColumnViewer.setInput(model.getColumns()); fSortByViewer.setInput(NewsColumn.values()); fSortByViewer.setSelection(new StructuredSelection(model.getSortColumn())); fSortAscendingViewer.setInput(Order.values()); fSortAscendingViewer .setSelection(new StructuredSelection(model.isAscending() ? Order.ASCENDING : Order.DESCENDING)); } /** * @return the news column model from this selection control */ public NewsColumnViewModel getModel() { return fModel; } private GridData setButtonLayoutData(Button button) { GridData data = new GridData(GridData.HORIZONTAL_ALIGN_FILL); int widthHint = Dialog.convertHorizontalDLUsToPixels(fFontMetrics, IDialogConstants.BUTTON_WIDTH); Point minSize = button.computeSize(SWT.DEFAULT, SWT.DEFAULT, true); data.widthHint = Math.max(widthHint, minSize.x); button.setLayoutData(data); return data; } private void onDelete() { IStructuredSelection selection = (IStructuredSelection) fNewsColumnViewer.getSelection(); List<?> elements = selection.toList(); for (Object element : elements) { fModel.removeColumn((NewsColumn) element); fNewsColumnViewer.remove(element); } if (fModel.getColumns().isEmpty()) { fModel.addColumn(NewsColumn.TITLE); fNewsColumnViewer.add(NewsColumn.TITLE); } updateRemoveEnablement(); updateMoveEnablement(); } }