/*******************************************************************************
 * Copyright (c) 2000, 2004 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.internal.*;
import org.eclipse.swt.internal.photon.*;
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>
 */
public class TabItem extends Item {
	TabFolder parent;
	Control control;
	String toolTipText;

/**
 * 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);
	this.parent = parent;
	parent.createItem (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 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 either negative or greater than the parent's current tab count</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);
	this.parent = parent;
	parent.createItem (this, index);
}

protected void checkSubclass () {
	if (!isValidSubclass ()) error (SWT.ERROR_INVALID_SUBCLASS);
}

/**
 * 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;
}

void releaseChild () {
	super.releaseChild ();
	int index = parent.indexOf (this);
	if (index == parent.getSelectionIndex ()) {
		if (control != null) control.setVisible (false);
	}
	parent.destroyItem (this);
}

void releaseWidget () {
	super.releaseWidget ();
	control = null;
	parent = null;
	toolTipText = null;
}

/**
 * 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);
	if (index != parent.getSelectionIndex ()) {
		if (newControl != null) 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();
	//NOT SUPPORTED
}

/**
 * Sets the receiver's text.  The string may include
 * the mnemonic character.
 * </p>
 * <p>
 * Mnemonics are indicated by an '&amp' 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 '&amp' can be
 * escaped by doubling it in the string, causing a single
 *'&amp' 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();
	if (string == null) error (SWT.ERROR_NULL_ARGUMENT);
	super.setText (string);
	char [] text = new char [string.length ()];
	string.getChars (0, text.length, text, 0);
	fixMnemonic (text);
	byte [] buffer = Converter.wcsToMbcs (null, text, true);
	int index = parent.indexOf (this);
	int [] args = {OS.Pt_ARG_PG_PANEL_TITLES, 0, 0};
	OS.PtGetResources (parent.handle, args.length / 3, args);
	int count = args [2];
	int oldPtr = args [1];
	int newPtr = OS.malloc (count * 4);
	int [] str = new int [1];
	int [] address = new int [1];
	for (int i=0; i<count; i++) {
		if (i == index) {
			str [0] = OS.malloc (buffer.length);
			OS.memmove (str [0], buffer, buffer.length);
		} else {
			OS.memmove (address, oldPtr + (i * 4), 4);
			str [0] = OS.strdup (address [0]);
		}
		OS.memmove (newPtr + (i * 4), str, 4);
	}
	OS.PtSetResource (parent.handle, OS.Pt_ARG_PG_PANEL_TITLES, newPtr, count);
	for (int i=0; i<count; i++) {
		OS.memmove (address, newPtr + (i * 4), 4);
		OS.free (address [0]);
	}
	OS.free (newPtr);
}

/**
 * Sets the receiver's tool tip text to the argument, which
 * may be null indicating that no tool tip text should be shown.
 *
 * @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;
}

}