Java tutorial
/******************************************************************************* * Copyright (c) 2002, 2015 Innoopract Informationssysteme GmbH 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: * Innoopract Informationssysteme GmbH - initial API and implementation * EclipseSource - ongoing development ******************************************************************************/ package org.eclipse.swt.widgets; import static org.eclipse.rap.rwt.internal.textsize.TextSizeUtil.getCharHeight; import static org.eclipse.rap.rwt.internal.textsize.TextSizeUtil.textExtent; import static org.eclipse.swt.internal.widgets.MarkupUtil.isMarkupEnabledFor; import static org.eclipse.swt.internal.widgets.MarkupValidator.isValidationDisabledFor; import org.eclipse.rap.rwt.RWT; import org.eclipse.rap.rwt.internal.lifecycle.WidgetLCA; import org.eclipse.rap.rwt.internal.theme.Size; import org.eclipse.rap.rwt.internal.theme.ThemeAdapter; import org.eclipse.rap.rwt.theme.BoxDimensions; import org.eclipse.swt.SWT; import org.eclipse.swt.SWTException; import org.eclipse.swt.events.SelectionEvent; import org.eclipse.swt.events.SelectionListener; import org.eclipse.swt.graphics.Font; import org.eclipse.swt.graphics.Image; import org.eclipse.swt.graphics.Point; import org.eclipse.swt.graphics.Rectangle; import org.eclipse.swt.internal.widgets.MarkupValidator; import org.eclipse.swt.internal.widgets.buttonkit.ButtonLCA; import org.eclipse.swt.internal.widgets.buttonkit.ButtonThemeAdapter; /** * Instances of this class represent a selectable user interface object that * issues notification when pressed and released. * <dl> * <dt><b>Styles:</b></dt> * <dd><!--ARROW, -->CHECK, PUSH, RADIO, TOGGLE, FLAT, WRAP</dd> * <dd><!--UP, DOWN, -->LEFT, RIGHT, CENTER</dd> * <dt><b>Events:</b></dt> * <dd>Selection</dd> * </dl> * <p> * Note: Only one of the styles ARROW, CHECK, PUSH, RADIO, and TOGGLE * may be specified. * </p><p> * Note: Only one of the styles LEFT, RIGHT, and CENTER may be specified. * </p><p> * Note: Only one of the styles UP, DOWN, LEFT, and RIGHT may be specified * when the ARROW style is specified. * </p><p> * IMPORTANT: This class is intended to be subclassed <em>only</em> * within the SWT implementation. * </p> * @since 1.0 */ public class Button extends Control { private String text = ""; private boolean selected; private boolean grayed; private Image image; private boolean isDefault; /** * Constructs a new instance of this class given its parent * 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 composite 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#ARROW--> * @see SWT#CHECK * @see SWT#PUSH * @see SWT#RADIO * @see SWT#TOGGLE * @see SWT#FLAT * @see SWT#LEFT * @see SWT#RIGHT * @see SWT#CENTER * @see Widget#checkSubclass * @see Widget#getStyle */ // TODO [rst] Remove comments from javadoc when fully implemented public Button(Composite parent, int style) { super(parent, checkStyle(style)); } @Override void initState() { if ((style & (SWT.PUSH | SWT.TOGGLE)) == 0) { addState(THEME_BACKGROUND); } } //////////////// // Getter/setter /** * Sets the receiver's text. * <p> * This method sets the button label. The label may include * the mnemonic character but must not contain line delimiters. * </p> * * <p> * Mnemonics are indicated by an '&' that causes the next * character to be the mnemonic. When the user presses a * key sequence that matches the mnemonic, a selection * event occurs. On most platforms, the mnemonic appears * underlined but may be emphasised in a platform specific * manner. The mnemonic indicator character '&' can be * escaped by doubling it in the string, causing a single * '&' to be displayed. * </p> * * @param text the new text * * @exception IllegalArgumentException <ul> * <li>ERROR_NULL_ARGUMENT - if the text 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> */ public void setText(String text) { checkWidget(); if (text == null) { SWT.error(SWT.ERROR_NULL_ARGUMENT); } if ((style & SWT.ARROW) == 0) { if (isMarkupEnabledFor(this) && !isValidationDisabledFor(this)) { MarkupValidator.getInstance().validate(text); } this.text = text; } } /** * Returns the receiver's text, which will be an empty * string if it has never been set<!-- or if the receiver is * an <code>ARROW</code> button-->. * * @return the receiver's text * * @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> */ // TODO [rst] Remove comments from javadoc when fully implemented public String getText() { checkWidget(); return text; } /** * Returns <code>true</code> if the receiver is selected, * and false otherwise. * <p> * When the receiver is of type <code>CHECK</code> or <code>RADIO</code>, * it is selected when it is checked. When it is of type <code>TOGGLE</code>, * it is selected when it is pushed in. If the receiver is of any other type, * this method returns false. * * @return the selection state * * @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 boolean getSelection() { checkWidget(); boolean result = false; if ((style & (SWT.CHECK | SWT.RADIO | SWT.TOGGLE)) != 0) { result = selected; } return result; } /** * Sets the selection state of the receiver, if it is of type <code>CHECK</code>, * <code>RADIO</code>, or <code>TOGGLE</code>. * * <p> * When the receiver is of type <code>CHECK</code> or <code>RADIO</code>, * it is selected when it is checked. When it is of type <code>TOGGLE</code>, * it is selected when it is pushed in. * * @param selected the new selection state * * @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(boolean selected) { checkWidget(); if ((style & (SWT.CHECK | SWT.RADIO | SWT.TOGGLE)) != 0) { this.selected = selected; } } /** * Returns <code>true</code> if the receiver is grayed, * and false otherwise. When the widget does not have * the <code>CHECK</code> style, return false. * * @return the grayed state of the checkbox * * @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> * * @since 1.2 */ public boolean getGrayed() { checkWidget(); boolean result = false; if ((style & SWT.CHECK) != 0) { result = grayed; } return result; } /** * Sets the grayed state of the receiver. This state change * only applies if the control was created with the SWT.CHECK * style. * * @param grayed the new grayed state * * @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> * * @since 1.2 */ public void setGrayed(boolean grayed) { checkWidget(); if ((style & SWT.CHECK) != 0) { this.grayed = grayed; } } /** * Returns the receiver's image if it has one, or null * if it does not. * * @return the receiver's image * * @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 Image getImage() { checkWidget(); return image; } /** * Sets the receiver's image to the argument, which may be * <code>null</code> indicating that no image should be displayed. * * @param image the image to display on the receiver (may be <code>null</code>) * * @exception IllegalArgumentException <ul> * <li>ERROR_INVALID_ARGUMENT - if the image 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> */ public void setImage(Image image) { checkWidget(); if (image != null && image.isDisposed()) { SWT.error(SWT.ERROR_INVALID_ARGUMENT); } if ((style & SWT.ARROW) == 0) { this.image = image; } } /** * Returns a value which describes the position of the * text or image in the receiver. The value will be one of * <code>LEFT</code>, <code>RIGHT</code> or <code>CENTER</code> * unless the receiver is an <code>ARROW</code> button, in * which case, the alignment will indicate the direction of * the arrow (one of <code>LEFT</code>, <code>RIGHT</code>, * <code>UP</code> or <code>DOWN</code>) * * @return the alignment * * @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> */ // TODO [rst] Remove comments from javadoc when fully implemented public int getAlignment() { checkWidget(); int result; if ((style & SWT.ARROW) != 0) { if ((style & SWT.UP) != 0) { result = SWT.UP; } else if ((style & SWT.DOWN) != 0) { result = SWT.DOWN; } else if ((style & SWT.LEFT) != 0) { result = SWT.LEFT; } else if ((style & SWT.RIGHT) != 0) { result = SWT.RIGHT; } else { result = SWT.UP; } } else { if ((style & SWT.LEFT) != 0) { result = SWT.LEFT; } else if ((style & SWT.CENTER) != 0) { result = SWT.CENTER; } else if ((style & SWT.RIGHT) != 0) { result = SWT.RIGHT; } else { result = SWT.LEFT; } } return result; } /** * Controls how text, images and arrows will be displayed * in the receiver. The argument should be one of * <code>LEFT</code>, <code>RIGHT</code> or <code>CENTER</code> * <!-- * unless the receiver is an <code>ARROW</code> button, in * which case, the argument indicates the direction of * the arrow (one of <code>LEFT</code>, <code>RIGHT</code>, * <code>UP</code> or <code>DOWN</code>) * -->. * * @param alignment the new alignment * * @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> */ // TODO [rst] Remove comments from javadoc when fully implemented public void setAlignment(int alignment) { checkWidget(); if ((style & SWT.ARROW) != 0) { if ((style & (SWT.UP | SWT.DOWN | SWT.LEFT | SWT.RIGHT)) != 0) { style &= ~(SWT.UP | SWT.DOWN | SWT.LEFT | SWT.RIGHT); style |= alignment & (SWT.UP | SWT.DOWN | SWT.LEFT | SWT.RIGHT); } } else if ((alignment & (SWT.LEFT | SWT.RIGHT | SWT.CENTER)) != 0) { style &= ~(SWT.LEFT | SWT.RIGHT | SWT.CENTER); style |= alignment & (SWT.LEFT | SWT.RIGHT | SWT.CENTER); } } @Override public Point computeSize(int wHint, int hHint, boolean changed) { checkWidget(); int width = 0; int height = 0; ButtonThemeAdapter themeAdapter = getThemeAdapter(); BoxDimensions padding = themeAdapter.getPadding(this); if ((style & SWT.ARROW) != 0) { Size arrowSize = themeAdapter.getArrowSize(this); width = arrowSize.width; height = arrowSize.height; } else { boolean hasImage = image != null; boolean hasText = text.length() > 0; Font font = getFont(); if ((style & (SWT.CHECK | SWT.RADIO)) != 0) { Size checkSize = themeAdapter.getCheckSize(this); width += checkSize.width; if (hasText || hasImage) { width += themeAdapter.getCheckSpacing(this); } height = Math.max(height, checkSize.height); } if (hasImage) { Rectangle imageBounds = image.getBounds(); width += imageBounds.width; height = Math.max(height, imageBounds.height); } if (hasText && hasImage) { width += themeAdapter.getSpacing(this); } if (hasText) { Point extent; boolean markupEnabled = isMarkupEnabledFor(this); int wrapWidth = SWT.DEFAULT; if ((style & SWT.WRAP) != 0 && wHint != SWT.DEFAULT) { wrapWidth = wHint - width - (padding.left + padding.right); } extent = textExtent(font, text, wrapWidth, markupEnabled); width += extent.x; height = Math.max(height, extent.y); } if (height == 0) { height = getCharHeight(font); } } width += padding.left + padding.right; height += padding.top + padding.bottom; if (wHint != SWT.DEFAULT) { width = wHint; } if (hHint != SWT.DEFAULT) { height = hHint; } BoxDimensions border = getBorder(); width += border.left + border.right; height += border.top + border.bottom; return new Point(width, height); } /** * Adds the listener to the collection of listeners who will * be notified when the control is selected, by sending * it one of the messages defined in the <code>SelectionListener</code> * interface. * <p> * <code>widgetSelected</code> is called when the control is selected. * <code>widgetDefaultSelected</code> is not called. * </p> * * @param listener the listener which should 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 #removeSelectionListener * @see SelectionEvent */ 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); } /** * Removes the listener from the collection of listeners who will * be notified when the control is selected. * * @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 */ public void removeSelectionListener(SelectionListener listener) { checkWidget(); if (listener == null) { SWT.error(SWT.ERROR_NULL_ARGUMENT); } removeListener(SWT.Selection, listener); removeListener(SWT.DefaultSelection, listener); } @Override public void setData(String key, Object value) { if (RWT.BADGE.equals(key) && (style & SWT.PUSH) == 0) { return; } else if (RWT.MARKUP_ENABLED.equals(key) && isMarkupEnabledFor(this)) { return; } super.setData(key, value); } @Override @SuppressWarnings("unchecked") public <T> T getAdapter(Class<T> adapter) { if (adapter == WidgetLCA.class) { return (T) ButtonLCA.INSTANCE; } return super.getAdapter(adapter); } void setDefault(boolean isDefault) { this.isDefault = isDefault; } boolean getDefault() { return isDefault; } @Override boolean isTabGroup() { return true; } @Override String getNameText() { return getText(); } private static int checkStyle(int style) { int result = checkBits(style, SWT.PUSH, SWT.ARROW, SWT.CHECK, SWT.RADIO, SWT.TOGGLE, 0); if ((result & (SWT.PUSH | SWT.TOGGLE)) != 0) { result = checkBits(result, SWT.CENTER, SWT.LEFT, SWT.RIGHT, 0, 0, 0); } else if ((result & (SWT.CHECK | SWT.RADIO)) != 0) { result = checkBits(result, SWT.LEFT, SWT.RIGHT, SWT.CENTER, 0, 0, 0); } else if ((result & SWT.ARROW) != 0) { result |= SWT.NO_FOCUS; result = checkBits(result, SWT.UP, SWT.DOWN, SWT.LEFT, SWT.RIGHT, 0, 0); } return result; } private ButtonThemeAdapter getThemeAdapter() { return (ButtonThemeAdapter) getAdapter(ThemeAdapter.class); } }