Java tutorial
/******************************************************************************* * Copyright (c) 2006, 2007 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 * Brad Reynolds - bug 116920 *******************************************************************************/ package net.efano.sandbox.jface.snippets; import java.text.NumberFormat; import java.text.ParseException; import org.eclipse.core.databinding.observable.Realm; import org.eclipse.core.databinding.observable.list.WritableList; import org.eclipse.core.databinding.observable.value.ComputedValue; import org.eclipse.core.databinding.observable.value.IObservableValue; import org.eclipse.core.databinding.observable.value.WritableValue; import org.eclipse.jface.databinding.swt.SWTObservables; import org.eclipse.jface.internal.databinding.provisional.swt.TableUpdater; import org.eclipse.jface.layout.GridLayoutFactory; import org.eclipse.swt.SWT; import org.eclipse.swt.custom.ControlEditor; import org.eclipse.swt.custom.TableCursor; import org.eclipse.swt.events.KeyAdapter; import org.eclipse.swt.events.KeyEvent; import org.eclipse.swt.events.SelectionAdapter; import org.eclipse.swt.events.SelectionEvent; import org.eclipse.swt.widgets.Display; import org.eclipse.swt.widgets.Shell; import org.eclipse.swt.widgets.Table; import org.eclipse.swt.widgets.TableColumn; import org.eclipse.swt.widgets.TableItem; import org.eclipse.swt.widgets.Text; /** * @since 1.1 * */ public class SpreadSheet { private static final int COUNTER_UPDATE_DELAY = 1000; private static final int NUM_COLUMNS = 6; private static final int NUM_ROWS = 16; /** * 0 for no output, 1 for some, 2 for more */ private static int DEBUG_LEVEL = 0; /** * If true, there will be a automatic counter at B1. */ private static boolean FUNKY_COUNTER = false; /** * // * If true, all formulas (except for row 1 and column A) will be the * sum of the values of their left and top neighbouring cells. */ private static boolean FUNKY_FORMULAS = true; static WritableValue[][] cellFormulas = new WritableValue[NUM_ROWS][NUM_COLUMNS]; static ComputedValue[][] cellValues = new ComputedValue[NUM_ROWS][NUM_COLUMNS]; static class ComputedCellValue extends ComputedValue { private final IObservableValue cellFormula; private boolean calculating; ComputedCellValue(IObservableValue cellFormula) { this.cellFormula = cellFormula; } protected Object calculate() { if (calculating) { return "#cycle"; } try { calculating = true; return evaluate(cellFormula.getValue()); } finally { calculating = false; } } private Object evaluate(Object value) { if (DEBUG_LEVEL >= 2) { System.out.println("evaluating " + this + " ..."); } if (value == null) { return ""; } try { String s = (String) value; if (!s.startsWith("=")) { return s; } String addition = s.substring(1); int indexOfPlus = addition.indexOf('+'); String operand1 = addition.substring(0, indexOfPlus); double value1 = eval(operand1); String operand2 = addition.substring(indexOfPlus + 1); double value2 = eval(operand2); return NumberFormat.getNumberInstance().format(value1 + value2); } catch (Exception ex) { return ex.getMessage(); } } /** * @param s * @return * @throws ParseException */ private double eval(String s) throws ParseException { if (s.length() == 0) { return 0; } char character = s.charAt(0); if (Character.isLetter(character)) { character = Character.toLowerCase(character); // reference to other cell int columnIndex = character - 'a'; int rowIndex = 0; rowIndex = NumberFormat.getNumberInstance().parse(s.substring(1)).intValue() - 1; String value = (String) cellValues[rowIndex][columnIndex].getValue(); return value.length() == 0 ? 0 : NumberFormat.getNumberInstance().parse(value).doubleValue(); } return NumberFormat.getNumberInstance().parse(s).doubleValue(); } } protected static int counter; 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.setText("Data Binding Snippet 006"); final Table table = new Table(shell, SWT.BORDER | SWT.MULTI | SWT.FULL_SELECTION | SWT.VIRTUAL); table.setLinesVisible(true); table.setHeaderVisible(true); for (int i = 0; i < NUM_COLUMNS; i++) { TableColumn tableColumn = new TableColumn(table, SWT.NONE); tableColumn.setText(Character.toString((char) ('A' + i))); tableColumn.setWidth(60); } WritableList list = new WritableList(); for (int i = 0; i < NUM_ROWS; i++) { list.add(new Object()); for (int j = 0; j < NUM_COLUMNS; j++) { cellFormulas[i][j] = new WritableValue(); cellValues[i][j] = new ComputedCellValue(cellFormulas[i][j]); if (!FUNKY_FORMULAS || i == 0 || j == 0) { cellFormulas[i][j].setValue(""); } else { cellFormulas[i][j] .setValue("=" + cellReference(i - 1, j) + "+" + cellReference(i, j - 1)); } } } new TableUpdater(table, list) { protected void updateItem(int rowIndex, TableItem item, Object element) { if (DEBUG_LEVEL >= 1) { System.out.println("updating row " + rowIndex); } for (int j = 0; j < NUM_COLUMNS; j++) { item.setText(j, (String) cellValues[rowIndex][j].getValue()); } } }; if (FUNKY_COUNTER) { // counter in A1 display.asyncExec(new Runnable() { public void run() { cellFormulas[0][1].setValue("" + counter++); display.timerExec(COUNTER_UPDATE_DELAY, this); } }); } // create a TableCursor to navigate around the table final TableCursor cursor = new TableCursor(table, SWT.NONE); // create an editor to edit the cell when the user hits "ENTER" // while over a cell in the table final ControlEditor editor = new ControlEditor(cursor); editor.grabHorizontal = true; editor.grabVertical = true; cursor.addSelectionListener(new SelectionAdapter() { // when the TableEditor is over a cell, select the // corresponding row // in // the table public void widgetSelected(SelectionEvent e) { table.setSelection(new TableItem[] { cursor.getRow() }); } // when the user hits "ENTER" in the TableCursor, pop up a // text // editor so that // they can change the text of the cell public void widgetDefaultSelected(SelectionEvent e) { final Text text = new Text(cursor, SWT.NONE); TableItem row = cursor.getRow(); int rowIndex = table.indexOf(row); int columnIndex = cursor.getColumn(); text.setText((String) cellFormulas[rowIndex][columnIndex].getValue()); text.addKeyListener(new KeyAdapter() { public void keyPressed(KeyEvent e) { // close the text editor and copy the data over // when the user hits "ENTER" if (e.character == SWT.CR) { TableItem row = cursor.getRow(); int rowIndex = table.indexOf(row); int columnIndex = cursor.getColumn(); cellFormulas[rowIndex][columnIndex].setValue(text.getText()); text.dispose(); } // close the text editor when the user hits // "ESC" if (e.character == SWT.ESC) { text.dispose(); } } }); editor.setEditor(text); text.setFocus(); } }); // Hide the TableCursor when the user hits the "MOD1" or "MOD2" // key. // This alows the user to select multiple items in the table. cursor.addKeyListener(new KeyAdapter() { public void keyPressed(KeyEvent e) { if (e.keyCode == SWT.MOD1 || e.keyCode == SWT.MOD2 || (e.stateMask & SWT.MOD1) != 0 || (e.stateMask & SWT.MOD2) != 0) { cursor.setVisible(false); } } }); // Show the TableCursor when the user releases the "MOD2" or // "MOD1" key. // This signals the end of the multiple selection task. table.addKeyListener(new KeyAdapter() { public void keyReleased(KeyEvent e) { if (e.keyCode == SWT.MOD1 && (e.stateMask & SWT.MOD2) != 0) return; if (e.keyCode == SWT.MOD2 && (e.stateMask & SWT.MOD1) != 0) return; if (e.keyCode != SWT.MOD1 && (e.stateMask & SWT.MOD1) != 0) return; if (e.keyCode != SWT.MOD2 && (e.stateMask & SWT.MOD2) != 0) return; TableItem[] selection = table.getSelection(); TableItem row = (selection.length == 0) ? table.getItem(table.getTopIndex()) : selection[0]; table.showItem(row); cursor.setSelection(row, 0); cursor.setVisible(true); cursor.setFocus(); } }); GridLayoutFactory.fillDefaults().generateLayout(shell); shell.setSize(400, 300); shell.open(); // The SWT event loop while (!shell.isDisposed()) { if (!display.readAndDispatch()) { display.sleep(); } } } }); display.dispose(); } private static String cellReference(int rowIndex, int columnIndex) { String cellReference = "" + ((char) ('A' + columnIndex)) + (rowIndex + 1); return cellReference; } }