Java tutorial
/******************************************************************************* * Copyright (c) 2000, 2012 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 *******************************************************************************/ package org.eclipse.swt.custom; import org.eclipse.swt.*; import org.eclipse.swt.graphics.*; import org.eclipse.swt.widgets.*; /** * 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> * * @see <a href="http://www.eclipse.org/swt/snippets/#ctabfolder">CTabFolder, CTabItem snippets</a> * @see <a href="http://www.eclipse.org/swt/">Sample code and further information</a> * @noextend This class is not intended to be subclassed by clients. */ public class CTabItem extends Item { CTabFolder parent; int x, y, width, height = 0; Control control; // the tab page String toolTipText; String shortenedText; int shortenedTextWidth; // Appearance Font font; Image disabledImage; Rectangle closeRect = new Rectangle(0, 0, 0, 0); int closeImageState = SWT.BACKGROUND; int state = SWT.NONE; boolean showClose = false; boolean showing = false; /** * 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, 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, style); showClose = (style & SWT.CLOSE) != 0; parent.createItem(this, index); } @Override public void dispose() { if (isDisposed()) return; //if (!isValidThread ()) error (SWT.ERROR_THREAD_INVALID_ACCESS); parent.destroyItem(this); super.dispose(); parent = null; control = null; toolTipText = null; shortenedText = null; font = null; } /** * 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() { /* * This call is intentionally commented out, to allow this getter method to be * called from a thread which is different from one that created the widget. */ //checkWidget(); parent.runUpdate(); return new Rectangle(x, y, width, height); } /** * 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; } /** * Get the image displayed in the tab if the tab is disabled. * * @return the disabled image 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> * * @deprecated the disabled image is not used */ @Deprecated public Image getDisabledImage() { checkWidget(); return disabledImage; } /** * 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 3.0 */ public Font getFont() { checkWidget(); if (font != null) return font; return parent.getFont(); } /** * 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() { /* * This call is intentionally commented out, to allow this getter method to be * called from a thread which is different from one that created the widget. */ //checkWidget(); return parent; } /** * 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 3.4 */ public boolean getShowClose() { checkWidget(); return showClose; } /** * 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(); if (toolTipText == null && shortenedText != null) { String text = getText(); if (!shortenedText.equals(text)) return text; } return toolTipText; } /** * 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 3.0 */ public boolean isShowing() { checkWidget(); return showing; } /** * 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 { int selectedIndex = parent.getSelectionIndex(); Control selectedControl = null; if (selectedIndex != -1) { selectedControl = parent.getItem(selectedIndex).control; } if (this.control != selectedControl) { this.control.setVisible(false); } } } } /** * Sets the image that is displayed if the tab item is disabled. * Null will clear the image. * * @param image the image to be displayed when the item is disabled 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> * * @deprecated This image is not used */ @Deprecated public void setDisabledImage(Image image) { checkWidget(); if (image != null && image.isDisposed()) { SWT.error(SWT.ERROR_INVALID_ARGUMENT); } this.disabledImage = image; } boolean setFocus() { return control != null && !control.isDisposed() && control.setFocus(); } /** * 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. * * @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 3.0 */ public void setFont(Font font) { checkWidget(); if (font != null && font.isDisposed()) { SWT.error(SWT.ERROR_INVALID_ARGUMENT); } if (font == null && this.font == null) return; if (font != null && font.equals(this.font)) return; this.font = font; parent.updateFolder(CTabFolder.UPDATE_TAB_HEIGHT | CTabFolder.REDRAW_TABS); } @Override public void setImage(Image image) { checkWidget(); if (image != null && image.isDisposed()) { SWT.error(SWT.ERROR_INVALID_ARGUMENT); } Image oldImage = getImage(); if (image == null && oldImage == null) return; if (image != null && image.equals(oldImage)) return; super.setImage(image); parent.updateFolder(CTabFolder.UPDATE_TAB_HEIGHT | CTabFolder.REDRAW_TABS); } /** * 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 3.4 */ public void setShowClose(boolean close) { checkWidget(); if (showClose == close) return; showClose = close; parent.updateFolder(CTabFolder.REDRAW_TABS); } /** * Sets the text to display on the tab. * A carriage return '\n' allows to display multi line text. * * @param string the tab name * * @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> */ @Override public void setText(String string) { checkWidget(); if (string == null) SWT.error(SWT.ERROR_NULL_ARGUMENT); if (string.equals(getText())) return; super.setText(string); shortenedText = null; shortenedTextWidth = 0; parent.updateFolder(CTabFolder.UPDATE_TAB_HEIGHT | CTabFolder.REDRAW_TABS); } /** * Sets the receiver's tool tip text to the argument, which * may be null indicating that the default tool tip for the * control will be shown. For a control that has a default * tool tip, such as the Tree control on Windows, setting * the tool tip text to an empty string replaces the default, * causing no tool tip text to be shown. * <p> * The mnemonic indicator (character '&') is not displayed in a tool tip. * To display a single '&' in the tool tip, the character '&' can be * escaped by doubling it in the string. * </p> * * @param string 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 string) { checkWidget(); toolTipText = string; } }