/*******************************************************************************
* Copyright (c) 2000, 2009 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.swt.widgets;
import org.eclipse.swt.*;
import org.eclipse.swt.graphics.*;
/**
* Instances of this class represent a selectable user interface object
* corresponding to a tab for a page in a tab folder.
* <dl>
* <dt><b>Styles:</b></dt>
* <dd>(none)</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/#tabfolder">TabFolder, TabItem 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 TabItem extends Item {
TabFolder parent;
int x,y,width,height = 0;
String toolTipText;
Control control; // the tab page
// internal constants
static final int LEFT_HORIZONTAL_MARGIN = 8;
static final int RIGHT_HORIZONTAL_MARGIN = 2;
static final int VERTICAL_MARGIN = 1; // space between tab shadow and tab content
static final int ICON_MARGIN = 6;
static final int SHADOW_WIDTH = 2; // width of the tab shadow
static final int DEFAULT_TEXT_WIDTH = 36; // preferred text width if there is no text.
/**
* Constructs a new instance of this class given its parent
* (which must be a <code>TabFolder</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 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
* @see Widget#checkSubclass
* @see Widget#getStyle
*/
public TabItem (TabFolder parent, int style) {
super (parent, style);
parent.createChild (this, parent.getItemCount());
}
/**
* Constructs a new instance of this class given its parent
* (which must be a <code>TabFolder</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 composite control 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>
* <li>ERROR_INVALID_SUBCLASS - if this class is not an allowed subclass</li>
* </ul>
*
* @see SWT
* @see Widget#checkSubclass
* @see Widget#getStyle
*/
public TabItem (TabFolder parent, int style, int index) {
super (parent, style);
parent.createChild (this, index);
}
protected void checkSubclass () {
if (!isValidSubclass ()) error (SWT.ERROR_INVALID_SUBCLASS);
}
public void dispose() {
if (isDisposed()) return;
super.dispose();
parent.destroyChild(this);
parent = null;
control = null;
toolTipText = null;
}
/**
* Expand the receiver's bounds by the specified number of pixels on
* the left,top,right,and bottom.
*/
void expand(int left, int top, int right, int bottom) {
if (hasLocation()) {
x = x - left;
y = y - top;
width = width + left + right;
height = height + top + bottom;
}
}
/**
* Returns a rectangle describing the receiver's size and location
* relative to its parent.
*
* @return the receiver's bounding 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>
*
* @since 3.4
*/
public Rectangle getBounds () {
checkWidget();
return new Rectangle(x, y, width, height);
}
/**
* Returns the control that is used to fill the client area of
* the tab folder when the user selects the tab item. If no
* control has been set, return <code>null</code>.
* <p>
* @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;
}
/**
* Returns the receiver's parent, which must be a <code>TabFolder</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 TabFolder getParent () {
checkWidget();
return parent;
}
/**
* 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();
return toolTipText;
}
/**
* Answer true if the receiver has been laid out.
*/
boolean hasLocation() {
return !(width == 0 && height == 0 && x == 0 && y == 0);
}
/**
* Answer the image height.
*/
private int imageHeight() {
Image image = getImage();
if (parent.getImageHeight() != -1) {
return parent.getImageHeight();
} else if (image != null && !image.isDisposed()) {
return image.getBounds().height;
}
else {
return 0;
}
}
/**
* Answer the icon width.
*/
private int imageWidth() {
Image image = getImage();
if (image != null && !image.isDisposed()) {
return image.getBounds().width;
} else {
return 0;
}
}
/**
* Paint the receiver.
*/
void paint(GC gc, boolean isSelected) {
// high light colored line across left and top
gc.setForeground(display.getSystemColor(SWT.COLOR_WIDGET_HIGHLIGHT_SHADOW));
gc.drawLine(x, y + height - 2, x, y + 2);
gc.drawLine(x, y + 2, x + 2, y);
gc.drawLine(x + 2, y, x + width - 3, y);
// light color next to the left and below the top line.
// Since tabs expand horizontally when selected, we actually draw
// the background color to erase any debris from a selected tab.
gc.setForeground(display.getSystemColor(SWT.COLOR_WIDGET_LIGHT_SHADOW));
gc.drawLine(x + 1, y + height - 2, x + 1, y + 2);
gc.drawLine(x + 2, y + 1, x + width - 3, y + 1);
// dark colored line at right
gc.setForeground(display.getSystemColor(SWT.COLOR_WIDGET_FOREGROUND));
gc.drawLine(x + width - 1, y + 2, x + width - 1, y + height - 1);
// dark pixel on top of shadowed line, inside dark line
gc.drawLine(x + width - 2, y + 1, x + width - 2, y + 1);
// shadowed line on right inside the dark line
gc.setForeground(display.getSystemColor(SWT.COLOR_WIDGET_NORMAL_SHADOW));
gc.drawLine(x + width - 2, y + 2, x + width - 2, y + height - 1);
if (parent.isFocusControl() && isSelected) {
// draw a focus rectangle
gc.drawFocus(x + 3, y + 3, width - 6, height - 3);
}
// icon and bitmap. Should probably be checking style bits to determine
// exactly what to paint. Do we just draw the icon when the icon/text combination
// is too wide to fit all tabs?
gc.setForeground(parent.getForeground());
int xDraw = x + LEFT_HORIZONTAL_MARGIN;
int yCenter;
int decorationHeight = SHADOW_WIDTH * 2 + VERTICAL_MARGIN * 2;
Image image = getImage();
Rectangle sourceBounds = null;
if (image != null) {
sourceBounds = image.getBounds();
yCenter = y + SHADOW_WIDTH + VERTICAL_MARGIN + (height - decorationHeight - imageHeight()) / 2;
gc.drawImage(
image,
sourceBounds.x, sourceBounds.y, sourceBounds.width, sourceBounds.height,
xDraw, yCenter, sourceBounds.width, parent.getImageHeight());
}
xDraw = xDraw + ICON_MARGIN;
if (sourceBounds != null) {
xDraw += sourceBounds.width;
}
yCenter = y + SHADOW_WIDTH + VERTICAL_MARGIN + (height - decorationHeight - textHeight(gc)) / 2;
int flags = SWT.DRAW_MNEMONIC | SWT.DRAW_TRANSPARENT;
gc.drawText(getText(), xDraw, yCenter, flags);
}
/**
* Answer the preferred height of the receiver for the GC.
*/
int preferredHeight(GC gc) {
int height = textHeight(gc);
if (imageHeight() > height) height = imageHeight();
height += VERTICAL_MARGIN * 2 + SHADOW_WIDTH * 2;
return height;
}
/**
* Answer the preferred width of the receiver for the GC.
*/
int preferredWidth(GC gc) {
return imageWidth() + textWidth(gc) + LEFT_HORIZONTAL_MARGIN +
RIGHT_HORIZONTAL_MARGIN + ICON_MARGIN + SHADOW_WIDTH * 2;
}
/**
* Sets the control that is used to fill the client area of
* the tab folder when the user selects the tab item.
* <p>
* @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()) error (SWT.ERROR_INVALID_ARGUMENT);
if (control.parent != parent) error (SWT.ERROR_INVALID_PARENT);
}
if (this.control != null && this.control.isDisposed ()) {
this.control = null;
}
Control oldControl = this.control, newControl = control;
this.control = control;
int index = parent.indexOf (this), selectionIndex = parent.getSelectionIndex();
if (index != selectionIndex) {
if (newControl != null) {
if (selectionIndex != -1) {
Control selectedControl = parent.getItem(selectionIndex).getControl();
if (selectedControl == newControl) return;
}
newControl.setVisible(false);
return;
}
}
if (newControl != null) {
newControl.setBounds (parent.getClientArea ());
newControl.setVisible (true);
}
if (oldControl != null) oldControl.setVisible (false);
}
public void setImage (Image image) {
checkWidget();
Image oldImage = this.image;
super.setImage(image);
if (image == null || !image.equals(oldImage)) {
parent.itemChanged(this);
}
}
/**
* Sets the receiver's text. The string may include
* the mnemonic character.
* </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 string 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 string) {
checkWidget();
String oldText = text;
if (string == null) error (SWT.ERROR_NULL_ARGUMENT);
super.setText(string);
if (!string.equals(oldText)) {
parent.itemChanged(this);
}
}
/**
* 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;
}
/**
* Answer the text height.
*/
private int textHeight(GC gc) {
String text = getText();
if (text == null) {
return 0;
} else {
int flags = SWT.DRAW_MNEMONIC;
return gc.textExtent(text, flags).y;
}
}
/**
* Answer the text width.
*/
private int textWidth(GC gc) {
String text = getText();
int textWidth = 0;
if (text != null) {
int flags = SWT.DRAW_MNEMONIC;
textWidth = gc.textExtent(text, flags).x;
}
if (textWidth == 0) {
textWidth = DEFAULT_TEXT_WIDTH;
}
return textWidth;
}
}