Java tutorial
/******************************************************************************* * Copyright (c) 2000, 2005 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.egit.ui.internal; import org.eclipse.core.runtime.Assert; import org.eclipse.jface.dialogs.Dialog; import org.eclipse.jface.dialogs.IDialogConstants; import org.eclipse.swt.SWT; import org.eclipse.swt.graphics.FontMetrics; import org.eclipse.swt.graphics.GC; import org.eclipse.swt.layout.GridData; import org.eclipse.swt.layout.GridLayout; import org.eclipse.swt.widgets.Button; import org.eclipse.swt.widgets.Composite; import org.eclipse.swt.widgets.Control; import org.eclipse.swt.widgets.Group; import org.eclipse.swt.widgets.Label; import org.eclipse.swt.widgets.Text; import org.eclipse.ui.dialogs.PreferenceLinkArea; import org.eclipse.ui.preferences.IWorkbenchPreferenceContainer; /** * A collection of factory methods for creating common SWT controls */ public class SWTUtils { /** */ public static final int MARGINS_DEFAULT = -1; /** */ public static final int MARGINS_NONE = 0; /** */ public static final int MARGINS_DIALOG = 1; /** * Creates a preference link which will open in the specified container * * @param container * @param parent * @param pageId * @param text * * @return the created link */ public static PreferenceLinkArea createPreferenceLink(IWorkbenchPreferenceContainer container, Composite parent, String pageId, String text) { final PreferenceLinkArea area = new PreferenceLinkArea(parent, SWT.NONE, pageId, text, container, null); return area; } /** * Creates a grid data with the specified metrics * * @param width * @param height * @param hFill * @param vFill * * @return the created grid data */ public static GridData createGridData(int width, int height, boolean hFill, boolean vFill) { return createGridData(width, height, hFill ? SWT.FILL : SWT.BEGINNING, vFill ? SWT.FILL : SWT.CENTER, hFill, vFill); } /** * Creates a grid data with the specified metrics * * @param width * @param height * @param hAlign * @param vAlign * @param hGrab * @param vGrab * * @return the created grid data */ public static GridData createGridData(int width, int height, int hAlign, int vAlign, boolean hGrab, boolean vGrab) { final GridData gd = new GridData(hAlign, vAlign, hGrab, vGrab); gd.widthHint = width; gd.heightHint = height; return gd; } /** * Creates a horizontal grid data with the default metrics * * @return the created grid data */ public static GridData createHFillGridData() { return createHFillGridData(1); } /** * Creates a horizontal grid data with the specified span * * @param span * * @return the created grid data */ public static GridData createHFillGridData(int span) { final GridData gd = createGridData(0, SWT.DEFAULT, SWT.FILL, SWT.CENTER, true, false); gd.horizontalSpan = span; return gd; } /** * Creates a horizontal fill composite with the specified margins * * @param parent * @param margins * * @return the created composite */ public static Composite createHFillComposite(Composite parent, int margins) { return createHFillComposite(parent, margins, 1); } /** * Creates a horizontal fill composite with the specified margins and * columns * * @param parent * @param margins * @param columns * * @return the created composite */ public static Composite createHFillComposite(Composite parent, int margins, int columns) { final Composite composite = new Composite(parent, SWT.NONE); composite.setFont(parent.getFont()); composite.setLayoutData(createHFillGridData()); composite.setLayout(createGridLayout(columns, new PixelConverter(parent), margins)); return composite; } /** * Creates a horizontal/vertical fill composite with the specified margins * * @param parent * @param margins * * @return the created composite */ public static Composite createHVFillComposite(Composite parent, int margins) { return createHVFillComposite(parent, margins, 1); } /** * Creates a horizontal/vertical fill composite with the specified margins * and columns * * @param parent * @param margins * @param columns * * @return the created composite */ public static Composite createHVFillComposite(Composite parent, int margins, int columns) { final Composite composite = new Composite(parent, SWT.NONE); composite.setFont(parent.getFont()); composite.setLayoutData(createHVFillGridData()); composite.setLayout(createGridLayout(columns, new PixelConverter(parent), margins)); return composite; } /** * Creates a horizontal fill group with the specified text and margins * * @param parent * @param text * @param margins * @return the created group */ public static Group createHFillGroup(Composite parent, String text, int margins) { return createHFillGroup(parent, text, margins, 1); } /** * Creates a horizontal fill group with the specified text, margins and rows * * @param parent * @param text * @param margins * @param rows * * @return the created group */ public static Group createHFillGroup(Composite parent, String text, int margins, int rows) { final Group group = new Group(parent, SWT.NONE); group.setFont(parent.getFont()); group.setLayoutData(createHFillGridData()); if (text != null) group.setText(text); group.setLayout(createGridLayout(rows, new PixelConverter(parent), margins)); return group; } /** * Creates a horizontal/vertical fill group with the specified text and * margins * * @param parent * @param text * @param margins * * @return the created group */ public static Group createHVFillGroup(Composite parent, String text, int margins) { return createHVFillGroup(parent, text, margins, 1); } /** * Creates a horizontal/vertical fill group with the specified text, margins * and rows * * @param parent * @param text * @param margins * @param rows * * @return the created group */ public static Group createHVFillGroup(Composite parent, String text, int margins, int rows) { final Group group = new Group(parent, SWT.NONE); group.setFont(parent.getFont()); group.setLayoutData(createHVFillGridData()); if (text != null) group.setText(text); group.setLayout(createGridLayout(rows, new PixelConverter(parent), margins)); return group; } /** * Creates a horizontal/vertical fill grid data with the default metrics * * @return the created grid data */ public static GridData createHVFillGridData() { return createHVFillGridData(1); } /** * Creates a horizontal/vertical fill grid data with the specified span * * @param span * * @return the created grid data */ public static GridData createHVFillGridData(int span) { final GridData gd = createGridData(0, 0, true, true); gd.horizontalSpan = span; return gd; } /** * Creates a grid layout with the specified number of columns and the * standard spacings. * * @param numColumns * the number of columns * @param converter * the pixel converter * @param margins * one of <code>MARGINS_DEFAULT</code>, <code>MARGINS_NONE</code> * or <code>MARGINS_DIALOG</code>. * * @return the created grid layout */ public static GridLayout createGridLayout(int numColumns, PixelConverter converter, int margins) { Assert.isTrue(margins == MARGINS_DEFAULT || margins == MARGINS_NONE || margins == MARGINS_DIALOG); final GridLayout layout = new GridLayout(numColumns, false); layout.horizontalSpacing = converter.convertHorizontalDLUsToPixels(IDialogConstants.HORIZONTAL_SPACING); layout.verticalSpacing = converter.convertVerticalDLUsToPixels(IDialogConstants.VERTICAL_SPACING); switch (margins) { case MARGINS_NONE: layout.marginLeft = layout.marginRight = 0; layout.marginTop = layout.marginBottom = 0; break; case MARGINS_DIALOG: layout.marginLeft = layout.marginRight = converter .convertHorizontalDLUsToPixels(IDialogConstants.HORIZONTAL_MARGIN); layout.marginTop = layout.marginBottom = converter .convertVerticalDLUsToPixels(IDialogConstants.VERTICAL_MARGIN); break; case MARGINS_DEFAULT: layout.marginLeft = layout.marginRight = layout.marginWidth; layout.marginTop = layout.marginBottom = layout.marginHeight; } layout.marginWidth = layout.marginHeight = 0; return layout; } /** * Creates a label with the specified message * * @param parent * @param message * * @return the created label */ public static Label createLabel(Composite parent, String message) { return createLabel(parent, message, 1); } /** * Creates a label with the specified message and span * * @param parent * @param message * @param span * * @return the created label */ public static Label createLabel(Composite parent, String message, int span) { final Label label = new Label(parent, SWT.WRAP); if (message != null) label.setText(message); label.setLayoutData(createHFillGridData(span)); return label; } /** * Creates a check box with the specified message * * @param parent * @param message * * @return the created check box */ public static Button createCheckBox(Composite parent, String message) { return createCheckBox(parent, message, 1); } /** * Creates a check box with the specified message and span * * @param parent * @param message * @param span * * @return the created check box */ public static Button createCheckBox(Composite parent, String message, int span) { final Button button = new Button(parent, SWT.CHECK); button.setText(message); button.setLayoutData(createHFillGridData(span)); return button; } /** * Creates a radio button with the specified message * * @param parent * @param message * * @return the created radio button */ public static Button createRadioButton(Composite parent, String message) { return createRadioButton(parent, message, 1); } /** * Creates a radio button with the specified message and span * * @param parent * @param message * @param span * * @return the created radio button */ public static Button createRadioButton(Composite parent, String message, int span) { final Button button = new Button(parent, SWT.RADIO); button.setText(message); button.setLayoutData(createHFillGridData(span)); return button; } /** * Creates a text control * * @param parent * * @return the created text control */ public static Text createText(Composite parent) { return createText(parent, 1); } /** * Creates a text control with the specified span * * @param parent * @param span * * @return the created text control */ public static Text createText(Composite parent, int span) { final Text text = new Text(parent, SWT.SINGLE | SWT.BORDER); text.setLayoutData(createHFillGridData(span)); return text; } /** * Creates a place holder with the specified height and span * * @param parent * @param heightInChars * @param span * * @return the created place holder */ public static Control createPlaceholder(Composite parent, int heightInChars, int span) { Assert.isTrue(heightInChars > 0); final Control placeHolder = new Composite(parent, SWT.NONE); final GridData gd = new GridData(SWT.BEGINNING, SWT.TOP, false, false); gd.heightHint = new PixelConverter(parent).convertHeightInCharsToPixels(heightInChars); gd.horizontalSpan = span; placeHolder.setLayoutData(gd); return placeHolder; } /** * Creates a place holder with the specified height * * @param parent * @param heightInChars * @return the created place holder */ public static Control createPlaceholder(Composite parent, int heightInChars) { return createPlaceholder(parent, heightInChars, 1); } /** * Creates a pixel converter * * @param control * * @return the created pixel converter */ public static PixelConverter createDialogPixelConverter(Control control) { Dialog.applyDialogFont(control); return new PixelConverter(control); } /** * Calculates the size of the specified controls, using the specified * converter * * @param converter * @param controls * * @return the size of the control(s) */ public static int calculateControlSize(PixelConverter converter, Control[] controls) { return calculateControlSize(converter, controls, 0, controls.length - 1); } /** * Calculates the size of the specified subset of controls, using the * specified converter * * @param converter * @param controls * @param start * @param end * * @return the created control */ public static int calculateControlSize(PixelConverter converter, Control[] controls, int start, int end) { int minimum = converter.convertHorizontalDLUsToPixels(IDialogConstants.BUTTON_WIDTH); for (int i = start; i <= end; i++) { final int length = controls[i].computeSize(SWT.DEFAULT, SWT.DEFAULT).x; if (minimum < length) minimum = length; } return minimum; } /** * Equalizes the specified controls using the specified converter * * @param converter * @param controls */ public static void equalizeControls(PixelConverter converter, Control[] controls) { equalizeControls(converter, controls, 0, controls.length - 1); } /** * Equalizes the specified subset of controls using the specified converter * * @param converter * @param controls * @param start * @param end */ public static void equalizeControls(PixelConverter converter, Control[] controls, int start, int end) { final int size = calculateControlSize(converter, controls, start, end); for (int i = start; i <= end; i++) { final Control button = controls[i]; if (button.getLayoutData() instanceof GridData) { ((GridData) button.getLayoutData()).widthHint = size; } } } /** * Gets the width of the longest string in <code>strings</code>, using the * specified pixel converter * * @param converter * @param strings * * @return the width of the longest string */ public static int getWidthInCharsForLongest(PixelConverter converter, String[] strings) { int minimum = 0; for (int i = 0; i < strings.length; i++) { final int length = converter.convertWidthInCharsToPixels(strings[i].length()); if (minimum < length) minimum = length; } return minimum; } private static class PixelConverter { private final FontMetrics fFontMetrics; public PixelConverter(Control control) { GC gc = new GC(control); try { gc.setFont(control.getFont()); fFontMetrics = gc.getFontMetrics(); } finally { gc.dispose(); } } public int convertHeightInCharsToPixels(int chars) { return Dialog.convertHeightInCharsToPixels(fFontMetrics, chars); } public int convertHorizontalDLUsToPixels(int dlus) { return Dialog.convertHorizontalDLUsToPixels(fFontMetrics, dlus); } public int convertVerticalDLUsToPixels(int dlus) { return Dialog.convertVerticalDLUsToPixels(fFontMetrics, dlus); } public int convertWidthInCharsToPixels(int chars) { return Dialog.convertWidthInCharsToPixels(fFontMetrics, chars); } } }