Java tutorial
/******************************************************************************* * Copyright (c) 2000, 2011 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.custom; import org.eclipse.swt.*; import org.eclipse.swt.graphics.*; import org.eclipse.swt.widgets.*; import org.eclipse.swt.accessibility.*; import org.eclipse.swt.events.*; /** * A TableCursor provides a way for the user to navigate around a Table * using the keyboard. It also provides a mechanism for selecting an * individual cell in a table. * <p> * For a detailed example of using a TableCursor to navigate to a cell and then edit it see * http://git.eclipse.org/c/platform/eclipse.platform.swt.git/tree/examples/org.eclipse.swt.snippets/src/org/eclipse/swt/snippets/Snippet96.java . * * <dl> * <dt><b>Styles:</b></dt> * <dd>BORDER</dd> * <dt><b>Events:</b></dt> * <dd>Selection, DefaultSelection</dd> * </dl> * * @since 2.0 * * @see <a href="http://www.eclipse.org/swt/snippets/#tablecursor">TableCursor snippets</a> * @see <a href="http://www.eclipse.org/swt/">Sample code and further information</a> */ public class TableCursor extends Canvas { Table table; TableItem row = null; TableColumn column = null; Listener listener, tableListener, resizeListener, disposeItemListener, disposeColumnListener; Color background = null; Color foreground = null; /* By default, invert the list selection colors */ static final int BACKGROUND = SWT.COLOR_LIST_SELECTION_TEXT; static final int FOREGROUND = SWT.COLOR_LIST_SELECTION; /** * Constructs a new instance of this class given its parent * table and a style value describing its behavior and appearance. * <p> * The style value is either one of the style constants defined in * class <code>SWT</code> which is applicable to instances of this * class, or must be built by <em>bitwise OR</em>'ing together * (that is, using the <code>int</code> "|" operator) two or more * of those <code>SWT</code> style constants. The class description * lists the style constants that are applicable to the class. * Style bits are also inherited from superclasses. * </p> * * @param parent a Table control which will be the parent of the new instance (cannot be null) * @param style the style of control to construct * * @exception IllegalArgumentException <ul> * <li>ERROR_NULL_ARGUMENT - if the parent is null</li> * </ul> * @exception SWTException <ul> * <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the parent</li> * <li>ERROR_INVALID_SUBCLASS - if this class is not an allowed subclass</li> * </ul> * * @see SWT#BORDER * @see Widget#checkSubclass() * @see Widget#getStyle() */ public TableCursor(Table parent, int style) { super(parent, style); table = parent; setBackground(null); setForeground(null); listener = new Listener() { public void handleEvent(Event event) { switch (event.type) { case SWT.Dispose: onDispose(event); break; case SWT.FocusIn: case SWT.FocusOut: redraw(); break; case SWT.KeyDown: keyDown(event); break; case SWT.Paint: paint(event); break; case SWT.Traverse: { event.doit = true; switch (event.detail) { case SWT.TRAVERSE_ARROW_NEXT: case SWT.TRAVERSE_ARROW_PREVIOUS: case SWT.TRAVERSE_RETURN: event.doit = false; break; } break; } } } }; int[] events = new int[] { SWT.Dispose, SWT.FocusIn, SWT.FocusOut, SWT.KeyDown, SWT.Paint, SWT.Traverse }; for (int i = 0; i < events.length; i++) { addListener(events[i], listener); } tableListener = new Listener() { public void handleEvent(Event event) { switch (event.type) { case SWT.MouseDown: tableMouseDown(event); break; case SWT.FocusIn: tableFocusIn(event); break; } } }; table.addListener(SWT.FocusIn, tableListener); table.addListener(SWT.MouseDown, tableListener); disposeItemListener = new Listener() { public void handleEvent(Event event) { unhookRowColumnListeners(); row = null; column = null; _resize(); } }; disposeColumnListener = new Listener() { public void handleEvent(Event event) { unhookRowColumnListeners(); row = null; column = null; _resize(); } }; resizeListener = new Listener() { public void handleEvent(Event event) { _resize(); } }; ScrollBar hBar = table.getHorizontalBar(); if (hBar != null) { hBar.addListener(SWT.Selection, resizeListener); } ScrollBar vBar = table.getVerticalBar(); if (vBar != null) { vBar.addListener(SWT.Selection, resizeListener); } getAccessible().addAccessibleControlListener(new AccessibleControlAdapter() { @Override public void getRole(AccessibleControlEvent e) { e.detail = ACC.ROLE_TABLECELL; } }); getAccessible().addAccessibleListener(new AccessibleAdapter() { @Override public void getName(AccessibleEvent e) { if (row == null) return; int columnIndex = column == null ? 0 : table.indexOf(column); e.result = row.getText(columnIndex); } }); } /** * Adds the listener to the collection of listeners who will * be notified when the user changes the receiver's selection, by sending * it one of the messages defined in the <code>SelectionListener</code> * interface. * <p> * When <code>widgetSelected</code> is called, the item field of the event object is valid. * If the receiver has <code>SWT.CHECK</code> style set and the check selection changes, * the event object detail field contains the value <code>SWT.CHECK</code>. * <code>widgetDefaultSelected</code> is typically called when an item is double-clicked. * </p> * * @param listener the listener which should be notified when the user changes the receiver's selection * * @exception IllegalArgumentException <ul> * <li>ERROR_NULL_ARGUMENT - if the listener is null</li> * </ul> * @exception SWTException <ul> * <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li> * <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li> * </ul> * * @see SelectionListener * @see SelectionEvent * @see #removeSelectionListener(SelectionListener) * */ public void addSelectionListener(SelectionListener listener) { checkWidget(); if (listener == null) SWT.error(SWT.ERROR_NULL_ARGUMENT); TypedListener typedListener = new TypedListener(listener); addListener(SWT.Selection, typedListener); addListener(SWT.DefaultSelection, typedListener); } void onDispose(Event event) { removeListener(SWT.Dispose, listener); notifyListeners(SWT.Dispose, event); event.type = SWT.None; table.removeListener(SWT.FocusIn, tableListener); table.removeListener(SWT.MouseDown, tableListener); unhookRowColumnListeners(); ScrollBar hBar = table.getHorizontalBar(); if (hBar != null) { hBar.removeListener(SWT.Selection, resizeListener); } ScrollBar vBar = table.getVerticalBar(); if (vBar != null) { vBar.removeListener(SWT.Selection, resizeListener); } } void keyDown(Event event) { if (row == null) return; switch (event.character) { case SWT.CR: notifyListeners(SWT.DefaultSelection, new Event()); return; } int rowIndex = table.indexOf(row); int columnIndex = column == null ? 0 : table.indexOf(column); switch (event.keyCode) { case SWT.ARROW_UP: setRowColumn(Math.max(0, rowIndex - 1), columnIndex, true); break; case SWT.ARROW_DOWN: setRowColumn(Math.min(rowIndex + 1, table.getItemCount() - 1), columnIndex, true); break; case SWT.ARROW_LEFT: case SWT.ARROW_RIGHT: { int columnCount = table.getColumnCount(); if (columnCount == 0) break; int[] order = table.getColumnOrder(); int index = 0; while (index < order.length) { if (order[index] == columnIndex) break; index++; } if (index == order.length) index = 0; int leadKey = (getStyle() & SWT.RIGHT_TO_LEFT) != 0 ? SWT.ARROW_RIGHT : SWT.ARROW_LEFT; if (event.keyCode == leadKey) { setRowColumn(rowIndex, order[Math.max(0, index - 1)], true); } else { setRowColumn(rowIndex, order[Math.min(columnCount - 1, index + 1)], true); } break; } case SWT.HOME: setRowColumn(0, columnIndex, true); break; case SWT.END: { int i = table.getItemCount() - 1; setRowColumn(i, columnIndex, true); break; } case SWT.PAGE_UP: { int index = table.getTopIndex(); if (index == rowIndex) { Rectangle rect = table.getClientArea(); TableItem item = table.getItem(index); Rectangle itemRect = item.getBounds(0); rect.height -= itemRect.y; int height = table.getItemHeight(); int page = Math.max(1, rect.height / height); index = Math.max(0, index - page + 1); } setRowColumn(index, columnIndex, true); break; } case SWT.PAGE_DOWN: { int index = table.getTopIndex(); Rectangle rect = table.getClientArea(); TableItem item = table.getItem(index); Rectangle itemRect = item.getBounds(0); rect.height -= itemRect.y; int height = table.getItemHeight(); int page = Math.max(1, rect.height / height); int end = table.getItemCount() - 1; index = Math.min(end, index + page - 1); if (index == rowIndex) { index = Math.min(end, index + page - 1); } setRowColumn(index, columnIndex, true); break; } } } void paint(Event event) { if (row == null) return; int columnIndex = column == null ? 0 : table.indexOf(column); GC gc = event.gc; gc.setBackground(getBackground()); gc.setForeground(getForeground()); gc.fillRectangle(event.x, event.y, event.width, event.height); int x = 0; Point size = getSize(); Image image = row.getImage(columnIndex); if (image != null) { Rectangle imageSize = image.getBounds(); int imageY = (size.y - imageSize.height) / 2; gc.drawImage(image, x, imageY); x += imageSize.width; } String text = row.getText(columnIndex); if (text.length() > 0) { Rectangle bounds = row.getBounds(columnIndex); Point extent = gc.stringExtent(text); // Temporary code - need a better way to determine table trim String platform = SWT.getPlatform(); if ("win32".equals(platform)) { //$NON-NLS-1$ if (table.getColumnCount() == 0 || columnIndex == 0) { x += 2; } else { int alignmnent = column.getAlignment(); switch (alignmnent) { case SWT.LEFT: x += 6; break; case SWT.RIGHT: x = bounds.width - extent.x - 6; break; case SWT.CENTER: x += (bounds.width - x - extent.x) / 2; break; } } } else { if (table.getColumnCount() == 0) { x += 5; } else { int alignmnent = column.getAlignment(); switch (alignmnent) { case SWT.LEFT: x += 5; break; case SWT.RIGHT: x = bounds.width - extent.x - 2; break; case SWT.CENTER: x += (bounds.width - x - extent.x) / 2 + 2; break; } } } int textY = (size.y - extent.y) / 2; gc.drawString(text, x, textY); } if (isFocusControl()) { Display display = getDisplay(); gc.setBackground(display.getSystemColor(SWT.COLOR_BLACK)); gc.setForeground(display.getSystemColor(SWT.COLOR_WHITE)); gc.drawFocus(0, 0, size.x, size.y); } } void tableFocusIn(Event event) { if (isDisposed()) return; if (isVisible()) { if (row == null && column == null) return; setFocus(); } } void tableMouseDown(Event event) { if (isDisposed() || !isVisible()) return; Point pt = new Point(event.x, event.y); int lineWidth = table.getLinesVisible() ? table.getGridLineWidth() : 0; TableItem item = table.getItem(pt); if ((table.getStyle() & SWT.FULL_SELECTION) != 0) { if (item == null) return; } else { int start = item != null ? table.indexOf(item) : table.getTopIndex(); int end = table.getItemCount(); Rectangle clientRect = table.getClientArea(); for (int i = start; i < end; i++) { TableItem nextItem = table.getItem(i); Rectangle rect = nextItem.getBounds(0); if (pt.y >= rect.y && pt.y < rect.y + rect.height + lineWidth) { item = nextItem; break; } if (rect.y > clientRect.y + clientRect.height) return; } if (item == null) return; } TableColumn newColumn = null; int columnCount = table.getColumnCount(); if (columnCount == 0) { if ((table.getStyle() & SWT.FULL_SELECTION) == 0) { Rectangle rect = item.getBounds(0); rect.width += lineWidth; rect.height += lineWidth; if (!rect.contains(pt)) return; } } else { for (int i = 0; i < columnCount; i++) { Rectangle rect = item.getBounds(i); rect.width += lineWidth; rect.height += lineWidth; if (rect.contains(pt)) { newColumn = table.getColumn(i); break; } } if (newColumn == null) { if ((table.getStyle() & SWT.FULL_SELECTION) == 0) return; newColumn = table.getColumn(0); } } setRowColumn(item, newColumn, true); setFocus(); return; } void setRowColumn(int row, int column, boolean notify) { TableItem item = row == -1 ? null : table.getItem(row); TableColumn col = column == -1 || table.getColumnCount() == 0 ? null : table.getColumn(column); setRowColumn(item, col, notify); } void setRowColumn(TableItem row, TableColumn column, boolean notify) { if (this.row == row && this.column == column) { return; } if (this.row != null && this.row != row) { this.row.removeListener(SWT.Dispose, disposeItemListener); this.row = null; } if (this.column != null && this.column != column) { this.column.removeListener(SWT.Dispose, disposeColumnListener); this.column.removeListener(SWT.Move, resizeListener); this.column.removeListener(SWT.Resize, resizeListener); this.column = null; } if (row != null) { if (this.row != row) { this.row = row; row.addListener(SWT.Dispose, disposeItemListener); table.showItem(row); } if (this.column != column && column != null) { this.column = column; column.addListener(SWT.Dispose, disposeColumnListener); column.addListener(SWT.Move, resizeListener); column.addListener(SWT.Resize, resizeListener); table.showColumn(column); } int columnIndex = column == null ? 0 : table.indexOf(column); setBounds(row.getBounds(columnIndex)); redraw(); if (notify) { notifyListeners(SWT.Selection, new Event()); } } getAccessible().setFocus(ACC.CHILDID_SELF); } @Override public void setVisible(boolean visible) { checkWidget(); if (visible) _resize(); super.setVisible(visible); } /** * Removes the listener from the collection of listeners who will * be notified when the user changes the receiver's selection. * * @param listener the listener which should no longer be notified * * @exception IllegalArgumentException <ul> * <li>ERROR_NULL_ARGUMENT - if the listener is null</li> * </ul> * @exception SWTException <ul> * <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li> * <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li> * </ul> * * @see SelectionListener * @see #addSelectionListener(SelectionListener) * * @since 3.0 */ public void removeSelectionListener(SelectionListener listener) { checkWidget(); if (listener == null) { SWT.error(SWT.ERROR_NULL_ARGUMENT); } removeListener(SWT.Selection, listener); removeListener(SWT.DefaultSelection, listener); } void _resize() { if (row == null) { setBounds(-200, -200, 0, 0); } else { int columnIndex = column == null ? 0 : table.indexOf(column); setBounds(row.getBounds(columnIndex)); } } /** * Returns the index of the column over which the TableCursor is positioned. * * @return the column index for the current position * * @exception SWTException <ul> * <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li> * <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li> * </ul> */ public int getColumn() { checkWidget(); return column == null ? 0 : table.indexOf(column); } /** * Returns the background color that the receiver will use to draw. * * @return the receiver's background color */ @Override public Color getBackground() { checkWidget(); if (background == null) { return getDisplay().getSystemColor(BACKGROUND); } return background; } /** * Returns the foreground color that the receiver will use to draw. * * @return the receiver's foreground color */ @Override public Color getForeground() { checkWidget(); if (foreground == null) { return getDisplay().getSystemColor(FOREGROUND); } return foreground; } /** * Returns the row over which the TableCursor is positioned. * * @return the item for the current position, or <code>null</code> if none * * @exception SWTException <ul> * <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li> * <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li> * </ul> */ public TableItem getRow() { checkWidget(); return row; } /** * Sets the receiver's background color to the color specified * by the argument, or to the default system color for the control * if the argument is null. * <p> * Note: This operation is a hint and may be overridden by the platform. * For example, on Windows the background of a Button cannot be changed. * </p> * @param color the new color (or null) * * @exception IllegalArgumentException <ul> * <li>ERROR_INVALID_ARGUMENT - if the argument has been disposed</li> * </ul> * @exception SWTException <ul> * <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li> * <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li> * </ul> */ @Override public void setBackground(Color color) { background = color; super.setBackground(getBackground()); redraw(); } /** * Sets the receiver's foreground color to the color specified * by the argument, or to the default system color for the control * if the argument is null. * <p> * Note: This operation is a hint and may be overridden by the platform. * </p> * @param color the new color (or null) * * @exception IllegalArgumentException <ul> * <li>ERROR_INVALID_ARGUMENT - if the argument has been disposed</li> * </ul> * @exception SWTException <ul> * <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li> * <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li> * </ul> */ @Override public void setForeground(Color color) { foreground = color; super.setForeground(getForeground()); redraw(); } /** * Positions the TableCursor over the cell at the given row and column in the parent table. * * @param row the index of the row for the cell to select * @param column the index of column for the cell to select * * @exception SWTException <ul> * <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li> * <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li> * </ul> * */ public void setSelection(int row, int column) { checkWidget(); int columnCount = table.getColumnCount(); int maxColumnIndex = columnCount == 0 ? 0 : columnCount - 1; if (row < 0 || row >= table.getItemCount() || column < 0 || column > maxColumnIndex) SWT.error(SWT.ERROR_INVALID_ARGUMENT); setRowColumn(row, column, false); } /** * Positions the TableCursor over the cell at the given row and column in the parent table. * * @param row the TableItem of the row for the cell to select * @param column the index of column for the cell to select * * @exception SWTException <ul> * <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li> * <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li> * </ul> * */ public void setSelection(TableItem row, int column) { checkWidget(); int columnCount = table.getColumnCount(); int maxColumnIndex = columnCount == 0 ? 0 : columnCount - 1; if (row == null || row.isDisposed() || column < 0 || column > maxColumnIndex) SWT.error(SWT.ERROR_INVALID_ARGUMENT); setRowColumn(table.indexOf(row), column, false); } void unhookRowColumnListeners() { if (column != null) { column.removeListener(SWT.Dispose, disposeColumnListener); column.removeListener(SWT.Move, resizeListener); column.removeListener(SWT.Resize, resizeListener); column = null; } if (row != null) { row.removeListener(SWT.Dispose, disposeItemListener); row = null; } } }