Java tutorial
/******************************************************************************* * Copyright (c) 2006, 2015 IBM Corporation and others. * * This program and the accompanying materials * are made available under the terms of the Eclipse Public License 2.0 * which accompanies this distribution, and is available at * https://www.eclipse.org/legal/epl-2.0/ * * SPDX-License-Identifier: EPL-2.0 * * Contributors: * IBM Corporation - initial API and implementation * Tom Schindl <tom.schindl@bestsolution.at> - initial API and implementation * - fix in bug: 195908,198035,215069,215735,227421 *******************************************************************************/ package org.eclipse.jface.viewers; import java.util.Objects; import org.eclipse.swt.custom.StyleRange; import org.eclipse.swt.graphics.Color; import org.eclipse.swt.graphics.Font; import org.eclipse.swt.graphics.Image; import org.eclipse.swt.graphics.Rectangle; import org.eclipse.swt.widgets.Control; import org.eclipse.swt.widgets.Item; import org.eclipse.swt.widgets.Widget; /** * The ViewerCell is the JFace representation of a cell entry in a ViewerRow. * * @since 3.3 * */ public class ViewerCell { private int columnIndex; private ViewerRow row; private Object element; /** * Constant denoting the cell above current one (value is 1). */ public static int ABOVE = 1; /** * Constant denoting the cell below current one (value is 2). */ public static int BELOW = 1 << 1; /** * Constant denoting the cell to the left of the current one (value is 4). */ public static int LEFT = 1 << 2; /** * Constant denoting the cell to the right of the current one (value is 8). */ public static int RIGHT = 1 << 3; /** * Create a new instance of the receiver on the row. * * @param row * @param columnIndex */ ViewerCell(ViewerRow row, int columnIndex, Object element) { this.row = row; this.columnIndex = columnIndex; this.element = element; } /** * Get the index of the cell. * * @return the index */ public int getColumnIndex() { return columnIndex; } /** * Get the bounds of the cell. * * @return {@link Rectangle} */ public Rectangle getBounds() { return row.getBounds(columnIndex); } /** * Get the element this row represents. * * @return {@link Object} */ public Object getElement() { if (element != null) { return element; } if (row != null) { return row.getElement(); } return null; } /** * Return the text for the cell. * * @return {@link String} */ public String getText() { return row.getText(columnIndex); } /** * Return the Image for the cell. * * @return {@link Image} or <code>null</code> */ public Image getImage() { return row.getImage(columnIndex); } /** * Set the background color of the cell. * * @param background color to set */ public void setBackground(Color background) { row.setBackground(columnIndex, background); } /** * Set the foreground color of the cell. * * @param foreground color to set */ public void setForeground(Color foreground) { row.setForeground(columnIndex, foreground); } /** * Set the font of the cell. * * @param font font to set */ public void setFont(Font font) { row.setFont(columnIndex, font); } /** * Set the text for the cell. * * @param text text to set */ public void setText(String text) { row.setText(columnIndex, text); } /** * Set the Image for the cell. * * @param image image to set */ public void setImage(Image image) { row.setImage(columnIndex, image); } /** * Set the style ranges to be applied on the text label Note: Requires * {@link StyledCellLabelProvider} with owner draw enabled. * * @param styleRanges * the styled ranges * * @since 3.4 */ public void setStyleRanges(StyleRange[] styleRanges) { row.setStyleRanges(columnIndex, styleRanges); } /** * Returns the style ranges to be applied on the text label or * <code>null</code> if no style ranges have been set. * * @return styleRanges the styled ranges * * @since 3.4 */ public StyleRange[] getStyleRanges() { return row.getStyleRanges(columnIndex); } /** * Set the columnIndex. * * @param column the column index to set */ void setColumn(int column) { columnIndex = column; } /** * Set the row to rowItem and the columnIndex to column. * * @param rowItem the row item to set * @param column the column index to set * @param element the element to set */ void update(ViewerRow rowItem, int column, Object element) { row = rowItem; columnIndex = column; this.element = element; } /** * Return the item for the receiver. * * @return {@link Item} */ public Widget getItem() { return row.getItem(); } /** * Get the control for this cell. * * @return {@link Control} */ public Control getControl() { return row.getControl(); } /** * Get the current index. This can be different from the original index when * columns are reordered * * @return the current index (as shown in the UI) * @since 3.4 */ public int getVisualIndex() { return row.getVisualIndex(getColumnIndex()); } /** * Returns the specified neighbor of this cell, or <code>null</code> if no * neighbor exists in the given direction. Direction constants can be * combined by bitwise OR; for example, this method will return the cell to * the upper-left of the current cell by passing {@link #ABOVE} | * {@link #LEFT}. If <code>sameLevel</code> is <code>true</code>, only cells * in sibling rows (under the same parent) will be considered. * * @param directionMask * the direction mask used to identify the requested neighbor * cell * @param sameLevel * if <code>true</code>, only consider cells from sibling rows * @return the requested neighbor cell, or <code>null</code> if not found */ public ViewerCell getNeighbor(int directionMask, boolean sameLevel) { ViewerRow row; if ((directionMask & ABOVE) == ABOVE) { row = this.row.getNeighbor(ViewerRow.ABOVE, sameLevel); } else if ((directionMask & BELOW) == BELOW) { row = this.row.getNeighbor(ViewerRow.BELOW, sameLevel); } else { row = this.row; } if (row != null) { int columnIndex; columnIndex = getVisualIndex(); int modifier = 0; if ((directionMask & LEFT) == LEFT) { modifier = -1; } else if ((directionMask & RIGHT) == RIGHT) { modifier = 1; } else { return row.getCellAtVisualIndex(columnIndex); } columnIndex += modifier; if (columnIndex >= 0 && columnIndex < row.getColumnCount()) { ViewerCell cell = row.getCellAtVisualIndex(columnIndex); while (cell != null && columnIndex < row.getColumnCount() - 1 && columnIndex > 0) { if (cell.isVisible()) { break; } columnIndex += modifier; cell = row.getCellAtVisualIndex(columnIndex); } return cell; } } return null; } /** * @return the row */ public ViewerRow getViewerRow() { return row; } /** * The location and bounds of the area where the text is drawn depends on * various things (image displayed, control with SWT.CHECK) * * @return The bounds of the of the text area. May return <code>null</code> * if the underlying widget implementation doesn't provide this * information * @since 3.4 */ public Rectangle getTextBounds() { return row.getTextBounds(columnIndex); } /** * Returns the location and bounds of the area where the image is drawn * * @return The bounds of the of the image area. May return <code>null</code> * if the underlying widget implementation doesn't provide this * information * @since 3.4 */ public Rectangle getImageBounds() { return row.getImageBounds(columnIndex); } /** * Gets the foreground color of the cell. * * @return the foreground of the cell or <code>null</code> for the default * foreground * * @since 3.4 */ public Color getForeground() { return row.getForeground(columnIndex); } /** * Gets the background color of the cell. * * @return the background of the cell or <code>null</code> for the default * background * * @since 3.4 */ public Color getBackground() { return row.getBackground(columnIndex); } /** * Gets the font of the cell. * * @return the font of the cell or <code>null</code> for the default font * * @since 3.4 */ public Font getFont() { return row.getFont(columnIndex); } @Override public int hashCode() { final int prime = 31; int result = 1; result = prime * result + columnIndex; return prime * result + Objects.hashCode(row); } @Override public boolean equals(Object obj) { if (this == obj) return true; if (obj == null) return false; if (getClass() != obj.getClass()) return false; final ViewerCell other = (ViewerCell) obj; return columnIndex == other.columnIndex && Objects.equals(row, other.row); } private boolean isVisible() { return row.isColumnVisible(columnIndex); } /** * Scroll the cell into view * * @return true if the cell was scrolled into view * @since 3.5 */ public boolean scrollIntoView() { return row.scrollCellIntoView(columnIndex); } }