Java tutorial
/******************************************************************************* * Copyright (c) 2002, 2016 Innoopract Informationssysteme GmbH. * 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.custom; import static org.eclipse.swt.internal.widgets.MarkupUtil.isToolTipMarkupEnabledFor; 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.textsize.TextSizeUtil; import org.eclipse.rap.rwt.theme.BoxDimensions; import org.eclipse.swt.SWT; import org.eclipse.swt.SWTException; import org.eclipse.swt.graphics.Font; import org.eclipse.swt.graphics.Image; import org.eclipse.swt.graphics.Rectangle; import org.eclipse.swt.internal.custom.ctabitemkit.CTabItemLCA; import org.eclipse.swt.internal.widgets.IWidgetFontAdapter; import org.eclipse.swt.internal.widgets.MarkupValidator; import org.eclipse.swt.widgets.Control; import org.eclipse.swt.widgets.Item; import org.eclipse.swt.widgets.Widget; /** * Instances of this class represent a selectable user interface object * that represent a page in a notebook widget. * * <dl> * <dt><b>Styles:</b></dt> * <dd>SWT.CLOSE</dd> * <dt><b>Events:</b></dt> * <dd>(none)</dd> * </dl> * <p> * IMPORTANT: This class is <em>not</em> intended to be subclassed. * </p> */ public class CTabItem extends Item { static final String ELLIPSIS = "..."; private transient IWidgetFontAdapter widgetFontAdapter; final CTabFolder parent; private Control control; private String toolTipText; private Font font; String shortenedText; int shortenedTextWidth; boolean showing = false; boolean showClose; int x; int y; int width; int height; Rectangle closeRect = new Rectangle(0, 0, 0, 0); /** * Constructs a new instance of this class given its parent * (which must be a <code>CTabFolder</code>) and a style value * describing its behavior and appearance. The item is added * to the end of the items maintained by its parent. * <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 CTabFolder 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> * </ul> * * @see SWT * @see Widget#getStyle() */ public CTabItem(CTabFolder parent, int style) { this(parent, style, checkNull(parent).getItemCount()); } /** * Constructs a new instance of this class given its parent * (which must be a <code>CTabFolder</code>), a style value * describing its behavior and appearance, and the index * at which to place it in the items maintained by its parent. * <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 CTabFolder which will be the parent of the new instance (cannot be null) * @param style the style of control to construct * @param index the zero-relative index to store the receiver in its parent * * @exception IllegalArgumentException <ul> * <li>ERROR_NULL_ARGUMENT - if the parent is null</li> * <li>ERROR_INVALID_RANGE - if the index is not between 0 and the number of elements in the parent (inclusive)</li> * </ul> * @exception SWTException <ul> * <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the parent</li> * </ul> * * @see SWT * @see Widget#getStyle() */ public CTabItem(CTabFolder parent, int style, int index) { super(parent, checkStyle(style)); this.showClose = (style & SWT.CLOSE) != 0; this.parent = parent; parent.createItem(this, index); } @Override @SuppressWarnings("unchecked") public <T> T getAdapter(Class<T> adapter) { if (adapter == IWidgetFontAdapter.class) { if (widgetFontAdapter == null) { widgetFontAdapter = new IWidgetFontAdapter() { @Override public Font getUserFont() { return CTabItem.this.font; } }; } return (T) widgetFontAdapter; } if (adapter == WidgetLCA.class) { return (T) CTabItemLCA.INSTANCE; } return super.getAdapter(adapter); } /** * Returns the receiver's parent, which must be a <code>CTabFolder</code>. * * @return the receiver's parent * * @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 CTabFolder getParent() { checkWidget(); return parent; } ///////////////////////////////////////// // Getter/setter for principal properties @Override public void setText(String text) { checkWidget(); if (text == null) { SWT.error(SWT.ERROR_NULL_ARGUMENT); } if (!text.equals(getText())) { super.setText(text); shortenedText = null; shortenedTextWidth = 0; parent.updateItems(); } } @Override public void setImage(Image image) { checkWidget(); if (image != getImage()) { super.setImage(image); if (!parent.updateTabHeight(false)) { parent.updateItems(); } } } /** * Sets the font that the receiver will use to paint textual information * for this item to the font specified by the argument, or to the default font * for that kind of control if the argument is null. * * <p>Changing font works, but tab size is not adjusted accordingly.</p> * * @param font the new font (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> * * @since 1.0 */ public void setFont(Font font) { checkWidget(); if (font != null && font.isDisposed()) { SWT.error(SWT.ERROR_INVALID_ARGUMENT); } if (font != this.font) { this.font = font; if (!parent.updateTabHeight(false)) { parent.updateItems(); } } } /** * Returns the font that the receiver will use to paint textual information. * * @return the receiver's font * * @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 1.0 */ public Font getFont() { checkWidget(); Font result = font; if (font == null) { boolean isSelected = parent.indexOf(this) == parent.getSelectionIndex(); result = parent.getItemFont(isSelected); } return result; } /** * Gets the control that is displayed in the content area of the tab item. * * @return the control * * @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 Control getControl() { checkWidget(); return control; } /** * Sets the control that is used to fill the client area of * the tab folder when the user selects the tab item. * * @param control the new control (or null) * * @exception IllegalArgumentException <ul> * <li>ERROR_INVALID_ARGUMENT - if the control has been disposed</li> * <li>ERROR_INVALID_PARENT - if the control is not in the same widget tree</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 setControl(Control control) { checkWidget(); if (control != null) { if (control.isDisposed()) { SWT.error(SWT.ERROR_INVALID_ARGUMENT); } if (control.getParent() != parent) { SWT.error(SWT.ERROR_INVALID_PARENT); } } if (this.control != null && !this.control.isDisposed()) { this.control.setVisible(false); } this.control = control; if (this.control != null) { int index = parent.indexOf(this); if (index == parent.getSelectionIndex()) { this.control.setBounds(parent.getClientArea()); this.control.setVisible(true); } else { this.control.setVisible(false); } } } /** * Sets the receiver's tool tip text to the argument, which * may be null indicating that no tool tip text should be shown. * * @param toolTipText the new tool tip text (or null) * * @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 setToolTipText(String toolTipText) { checkWidget(); if (toolTipText != null && isToolTipMarkupEnabledFor(this) && !isValidationDisabledFor(this)) { MarkupValidator.getInstance().validate(toolTipText); } this.toolTipText = toolTipText; } /** * Returns the receiver's tool tip text, or null if it has * not been set. * * @return the receiver's tool tip 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> */ public String getToolTipText() { checkWidget(); String result = toolTipText; if (result == null && shortenedText != null) { String text = getText(); if (!shortenedText.equals(text)) { result = text; } } return result; } /** * Sets to <code>true</code> to indicate that the receiver's close button should be shown. * If the parent (CTabFolder) was created with SWT.CLOSE style, changing this value has * no effect. * * @param close the new state of the close button * * @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 1.3 */ public void setShowClose(boolean close) { checkWidget(); if ((parent.getStyle() & SWT.CLOSE) == 0 && showClose != close) { showClose = close; parent.updateItems(); } } /** * Returns <code>true</code> to indicate that the receiver's close button should be shown. * Otherwise return <code>false</code>. The initial value is defined by the style (SWT.CLOSE) * that was used to create the receiver. * * @return <code>true</code> if the close button should be shown * * @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 1.3 */ public boolean getShowClose() { checkWidget(); return showClose; } //////////////////////// // Bounds and visibility /** * Returns <code>true</code> if the item will be rendered in the visible area of the CTabFolder. Returns false otherwise. * * @return <code>true</code> if the item will be rendered in the visible area of the CTabFolder. Returns false otherwise. * * @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 1.0 */ public boolean isShowing() { checkWidget(); return showing; } /** * Returns a rectangle describing the receiver's size and location * relative to its parent. * * @return the receiver's bounding column rectangle * * @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 Rectangle getBounds() { checkWidget(); return new Rectangle(x, y, width, height); } /////////////////// // Widget overrides @Override public void dispose() { if (!isDisposed()) { // if (!isValidThread ()) error (SWT.ERROR_THREAD_INVALID_ACCESS); parent.destroyItem(this); super.dispose(); } } @Override public void setData(String key, Object value) { handleBadge(key, value); if (!RWT.TOOLTIP_MARKUP_ENABLED.equals(key) || !isToolTipMarkupEnabledFor(this)) { super.setData(key, value); } } private static void handleBadge(String key, Object value) { if (RWT.BADGE.equals(key) && value != null && !(value instanceof String)) { SWT.error(SWT.ERROR_INVALID_ARGUMENT); } } /////////////////////////////////////////////////////////////////////// // Helping methods used by CTabFolder to control item size and location int preferredHeight(boolean isSelected) { Image image = getImage(); String text = getText(); BoxDimensions padding = parent.getItemPadding(isSelected); int height = (image == null) ? 0 : image.getBounds().height; height = Math.max(height, TextSizeUtil.textExtent(getFont(), text, 0).y); return height + padding.top + padding.bottom; } int preferredWidth(boolean isSelected, boolean minimum) { // NOTE: preferred width does not include the "dead space" caused // by the curve. if (isDisposed()) { return 0; } int width = 0; Image image = getImage(); if (image != null && (isSelected || parent.showUnselectedImage)) { width += image.getBounds().width; } String text = null; if (minimum) { int minChars = parent.minChars; text = minChars == 0 ? null : getText(); if (text != null && text.length() > minChars) { if (useEllipses()) { int end = minChars < ELLIPSIS.length() + 1 ? minChars : minChars - ELLIPSIS.length(); text = text.substring(0, end); if (minChars > ELLIPSIS.length() + 1) { text += ELLIPSIS; } } else { int end = minChars; text = text.substring(0, end); } } } else { text = getText(); } if (text != null) { if (width > 0) { width += parent.getItemSpacing(isSelected); } if (font == null) { // w += gc.textExtent(text, FLAGS).x; width += TextSizeUtil.stringExtent(getFont(), text).x; } else { // Font gcFont = gc.getFont(); // gc.setFont(font); // w += gc.textExtent(text, FLAGS).x; // gc.setFont(gcFont); width += TextSizeUtil.stringExtent(getFont(), text).x; } } if (parent.showClose || showClose) { if (isSelected || parent.showUnselectedClose) { if (width > 0) { width += parent.getItemSpacing(isSelected); } width += CTabFolder.BUTTON_SIZE; } } BoxDimensions padding = parent.getItemPadding(isSelected); return width + padding.left + padding.right; } /* * Return whether to use ellipses or just truncate labels */ boolean useEllipses() { return parent.simple; } /* (intentionally non-JavaDoc'ed) * Return whether the image (if any) should be shown or omitted if there is * not enough space. The code is copied from the drawSelected and * drawUnselected methods in SWT. */ boolean showImage() { boolean result = false; if (parent.getSelection() == this) { int rightEdge = Math.min(x + width, parent.getRightItemEdge()); // draw Image int xDraw = x + parent.getItemPaddingLeft(true); if (parent.single && (parent.showClose || showClose)) { xDraw += CTabFolder.BUTTON_SIZE; } Image image = getImage(); if (image != null) { Rectangle imageBounds = image.getBounds(); // only draw image if it won't overlap with close button int rightPadding = parent.getItemPaddingRight(true); int maxImageWidth = rightEdge - xDraw - rightPadding; if (!parent.single && closeRect.width > 0) { maxImageWidth -= closeRect.width + parent.getItemSpacing(true); } if (imageBounds.width < maxImageWidth) { result = true; } } } else { int xDraw = x + parent.getItemPaddingLeft(false); Image image = getImage(); if (image != null && parent.showUnselectedImage) { Rectangle imageBounds = image.getBounds(); // only draw image if it won't overlap with close button int rightPadding = parent.getItemPaddingRight(false); int maxImageWidth = x + width - xDraw - rightPadding; if (parent.showUnselectedClose && (parent.showClose || showClose)) { maxImageWidth -= closeRect.width + parent.getItemSpacing(false); } if (imageBounds.width < maxImageWidth) { result = true; } } } return result; } /* (intentionally non-JavaDoc'ed) * The code of this methods is taken from SWT's CTabItem#drawSelected() and * modified to suit the specifics of RWT. */ String getShortenedText(boolean isSelected) { if (shortenedText == null) { int xDraw = x + parent.getItemPaddingLeft(isSelected); if (showImage()) { Rectangle imageBounds = getImage().getBounds(); xDraw += imageBounds.width + parent.getItemSpacing(isSelected); } int rightEdge = Math.min(x + width, parent.getRightItemEdge()); int rightPadding = parent.getItemPaddingRight(isSelected); int textWidth = rightEdge - xDraw - rightPadding; if (!parent.single && closeRect.width > 0) { textWidth -= closeRect.width + parent.getItemSpacing(isSelected); } if (textWidth > 0) { if (shortenedText == null || shortenedTextWidth != textWidth) { shortenedText = shortenText(getFont(), getText(), textWidth); shortenedTextWidth = textWidth; } } } return shortenedText == null ? "" : shortenedText; } String shortenText(Font font, String text, int width) { return useEllipses() ? shortenText(font, text, width, ELLIPSIS) : shortenText(font, text, width, ""); } @SuppressWarnings("all") static String shortenText(Font font, String text, int width, String ellipses) { if (TextSizeUtil.stringExtent(font, text).x <= width) { return text; } int ellipseWidth = TextSizeUtil.stringExtent(font, ellipses).x; int length = text.length(); int end = length - 1; while (end > 0) { text = text.substring(0, end); int l = TextSizeUtil.stringExtent(font, text).x; if (l + ellipseWidth <= width) { return text + ellipses; } end--; } return text.substring(0, 1); } ////////////////// // Helping methods private static CTabFolder checkNull(CTabFolder parent) { if (parent == null) { SWT.error(SWT.ERROR_NULL_ARGUMENT); } return parent; } private static int checkStyle(int style) { int result = SWT.NONE; if ((style & SWT.CLOSE) != 0) { result = SWT.CLOSE; } return result; } }