| /******************************************************************************* |
| * Copyright (c) 2008 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.jface.layout; |
| |
| import org.eclipse.swt.graphics.Font; |
| import org.eclipse.swt.graphics.FontMetrics; |
| import org.eclipse.swt.graphics.GC; |
| import org.eclipse.swt.widgets.Control; |
| |
| import org.eclipse.jface.dialogs.Dialog; |
| |
| /** |
| * PixelConverter performs various conversions from device-independent units |
| * (such as DLUs or characters) to pixels. It can be associated with a control or |
| * a font. In the case of a control, the font used by the control at the time |
| * the PixelConverter is created is used for the pixel calculations. In the case |
| * of a specific font, the supplied font is used for the calculations. |
| * |
| * The control and/or font must not be disposed at the time the PixelConverter |
| * is created. |
| * |
| * @since 3.5 |
| */ |
| public class PixelConverter { |
| |
| private final FontMetrics fontMetrics; |
| |
| /** |
| * Create a PixelConverter which will convert device-independent units to |
| * pixels using the font of the specified control. |
| * |
| * @param control |
| * the control whose font should be used for pixel conversions. |
| * Note that the font used by the control at the time this |
| * constructor is called is the font that will be used for all |
| * calculations. If the font of the specified control is changed |
| * after this PixelConverter is created, then the conversions |
| * from this instance will not produce the desired effect. |
| */ |
| public PixelConverter(Control control) { |
| this(control.getFont()); |
| } |
| |
| /** |
| * Create a PixelConverter which will convert device-independent units to |
| * pixels using the specified font. |
| * |
| * @param font |
| * the font that should be used for pixel conversions. |
| */ |
| public PixelConverter(Font font) { |
| GC gc = new GC(font.getDevice()); |
| gc.setFont(font); |
| fontMetrics = gc.getFontMetrics(); |
| gc.dispose(); |
| } |
| |
| /** |
| * Returns the number of pixels corresponding to the height of the given |
| * number of characters. |
| * |
| * @param chars |
| * the number of characters |
| * @return the number of pixels |
| */ |
| public int convertHeightInCharsToPixels(int chars) { |
| return Dialog.convertHeightInCharsToPixels(fontMetrics, chars); |
| } |
| |
| /** |
| * Returns the number of pixels corresponding to the given number of |
| * horizontal dialog units. |
| * |
| * @param dlus |
| * the number of horizontal dialog units |
| * @return the number of pixels |
| */ |
| public int convertHorizontalDLUsToPixels(int dlus) { |
| return Dialog.convertHorizontalDLUsToPixels(fontMetrics, dlus); |
| } |
| |
| /** |
| * Returns the number of pixels corresponding to the given number of |
| * vertical dialog units. |
| * |
| * @param dlus |
| * the number of vertical dialog units |
| * @return the number of pixels |
| */ |
| public int convertVerticalDLUsToPixels(int dlus) { |
| return Dialog.convertVerticalDLUsToPixels(fontMetrics, dlus); |
| } |
| |
| /** |
| * Returns the number of pixels corresponding to the width of the given |
| * number of characters. |
| * |
| * @param chars |
| * the number of characters |
| * @return the number of pixels |
| */ |
| public int convertWidthInCharsToPixels(int chars) { |
| return Dialog.convertWidthInCharsToPixels(fontMetrics, chars); |
| } |
| |
| } |