/*******************************************************************************

 * Copyright (c) 2000, 2007 IBM Corporation and others.

 * Portion Copyright (c) 2008 Nokia Corporation and/or its subsidiary(-ies).

 * 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

 *     Nokia Corporation - Qt implementation

 *******************************************************************************/

package org.eclipse.swt.widgets;

import org.eclipse.swt.SWT;

import org.eclipse.swt.internal.qt.OS;

import org.eclipse.swt.internal.qt.TextUtils;

import org.eclipse.swt.internal.qt.WidgetConstant;

import org.eclipse.swt.internal.qt.WidgetState;

import org.eclipse.swt.graphics.Image;

import org.eclipse.swt.graphics.Point;

import org.eclipse.swt.graphics.Rectangle;

import org.eclipse.swt.events.ModifyListener;

import org.eclipse.swt.events.SelectionListener;

import org.eclipse.swt.events.VerifyListener;

/**

 * Instances of this class are selectable user interface

 * objects that allow the user to enter and modify text.

 * <p>

 * <dl>

 * <dt><b>Styles:</b></dt>

 * <dd>CANCEL, CENTER, LEFT, MULTI, PASSWORD, SEARCH, SINGLE, RIGHT, READ_ONLY, WRAP</dd>

 * <dt><b>Events:</b></dt>

 * <dd>DefaultSelection, Modify, Verify</dd>

 * </dl>

 * <p>

 * Note: Only one of the styles MULTI and SINGLE may be specified,

 * and only one of the styles LEFT, CENTER, and RIGHT may be specified.

 * </p><p>

 * IMPORTANT: This class is <em>not</em> intended to be subclassed.

 * </p>

 */

public class Text extends Scrollable {

    /*

     *  The text limit set by the application. In MULTI case limiting for the text length 

     *  is implemented on Java side as QTextEdit does not have support for it. 

     */

    private int textLimit;

    /*

     * The double click enabled flag.

     */

    private boolean doubleClick;

    int variant;

    /**

    * The maximum number of characters that can be entered

    * into a text widget.

    * <p>

    * Note that this value is platform dependent, based upon

    * the native widget implementation.

    * </p>

    */

    public final static int LIMIT;

    /**

    * The delimiter used by multi-line text widgets.  When text

    * is queried and from the widget, it will be delimited using

    * this delimiter.

    */

    public final static String DELIMITER;

    /*

    * These values can be different on different platforms.

    * Therefore they are not initialized in the declaration

    * to stop the compiler from inlining.

    */

    static {

        LIMIT = 0x7FFFFFFF;

        DELIMITER = "\n";

    }

/**

 * 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#SINGLE

 * @see SWT#MULTI

 * @see SWT#READ_ONLY

 * @see SWT#WRAP

 * @see Widget#checkSubclass

 * @see Widget#getStyle

 */

public Text (Composite parent, int style) {

    this(parent, style, 0, null, false);

}

/**

 * <p>

 * <b>IMPORTANT:</b> This constructor is <em>not</em> part of the SWT

 * public API. It should never be referenced from application code. 

 * </p>

 */

protected Text (Composite parent, int style, int extraStyle, Object packageProxy, boolean isExtended) {

    super (parent, checkStyle (style), extraStyle, packageProxy, isExtended);

}

static int checkStyle (int style) {

    if ((style & SWT.SINGLE) != 0 && (style & SWT.MULTI) != 0) {

        style &= ~SWT.MULTI;

    }

    style = checkBits (style, SWT.LEFT, SWT.CENTER, SWT.RIGHT, 0, 0, 0);

    if ((style & SWT.SINGLE) != 0) style &= ~(SWT.H_SCROLL | SWT.V_SCROLL | SWT.WRAP);

    if ((style & SWT.WRAP) != 0) {

        style |= SWT.MULTI;

        style &= ~SWT.H_SCROLL;

    }

    if ((style & SWT.MULTI) != 0) style &= ~SWT.PASSWORD;

    if ((style & (SWT.SINGLE | SWT.MULTI)) != 0) return style;

    if ((style & (SWT.H_SCROLL | SWT.V_SCROLL)) != 0) return style | SWT.MULTI;

    return style | SWT.SINGLE;

}

void createHandle_pp (int index) {

    if(variant == 0) {

        variant = ((getStyle() & SWT.SINGLE) != 0 ? TextUtils.LINE_EDIT : TextUtils.TEXT_EDIT);

    }

    int alignment = OS.QT_ALIGNLEFT;

    if ((style & SWT.CENTER) != 0) { 

        alignment = OS.QT_ALIGNHCENTER; 

    } else if ((style & SWT.RIGHT) != 0) {

        alignment = OS.QT_ALIGNRIGHT;

    }

    if (variant == TextUtils.LINE_EDIT) {

        scrollAreaHandle = 0;

        topHandle = handle = OS.QLineEdit_new();

        OS.QLineEdit_setAlignment(handle, alignment | OS.QT_ALIGNVCENTER);

        OS.QLineEdit_setMaxLength(handle, LIMIT);

        if ((style & SWT.PASSWORD) != 0) {

            OS.QLineEdit_setEchoMode(handle, OS.QLINEEDIT_ECHOMODE_PASSWORD);

        }

    } else {

        frameHandle = topHandle = scrollAreaHandle = OS.QTextEdit_new();

        handle = OS.QAbstractScrollArea_viewPort(scrollAreaHandle);

        OS.QTextEdit_setAlignment(scrollAreaHandle, alignment);

        forceTextLayout();

    }

    OS.QWidget_setGeometry(topHandle, 0, 0, 0, 0);

    state |= WidgetState.HANDLE;

    if ((style & SWT.READ_ONLY) != 0) {

        setEditable(false);

    }

}

void createWidget (int index) {

    super.createWidget(index);

    doubleClick = true;

    textLimit = 0;

}

/**

 * Adds the listener to the collection of listeners who will

 * be notified when the receiver's text is modified, by sending

 * it one of the messages defined in the <code>ModifyListener</code>

 * interface.

 *

 * @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 ModifyListener

 * @see #removeModifyListener

 */

public void addModifyListener(ModifyListener listener) {

    checkWidget();

    if (listener == null) {

        error(SWT.ERROR_NULL_ARGUMENT);

    }

    TypedListener typedListener = new TypedListener(listener);

    addListener(SWT.Modify, typedListener);

}

/**

 * Adds the listener to the collection of listeners who will

 * be notified when the control is selected by the user, by sending

 * it one of the messages defined in the <code>SelectionListener</code>

 * interface.

 * <p>

 * <code>widgetSelected</code> is not called for texts.

 * <code>widgetDefaultSelected</code> is typically called when ENTER is pressed in a single-line text,

 * or when ENTER is pressed in a search text. If the receiver has the <code>SWT.SEARCH | SWT.CANCEL</code> style

 * and the user cancels the search, the event object detail field contains the value <code>SWT.CANCEL</code>.

 * </p>

 *

 * @param listener the listener which should be notified when the control is selected by the user

 *

 * @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) { 

        error(SWT.ERROR_NULL_ARGUMENT);

    }

    TypedListener typedListener = new TypedListener(listener);

    addListener(SWT.Selection,typedListener);

    addListener(SWT.DefaultSelection,typedListener);

}

/**

 * Adds the listener to the collection of listeners who will

 * be notified when the receiver's text is verified, by sending

 * it one of the messages defined in the <code>VerifyListener</code>

 * interface.

 *

 * @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 VerifyListener

 * @see #removeVerifyListener

 */

public void addVerifyListener(VerifyListener listener) {

    checkWidget();

    if (listener == null) {

        error(SWT.ERROR_NULL_ARGUMENT);

    }

    TypedListener typedListener = new TypedListener(listener);

    addListener(SWT.Verify, typedListener);

}

/**

 * Appends a string.

 * <p>

 * The new text is appended to the text at

 * the end of the widget.

 * </p>

 *

 * @param string the string to be appended

 *

 * @exception IllegalArgumentException <ul>

 *    <li>ERROR_NULL_ARGUMENT - if the string 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 append (String string) {

    checkWidget();

    TextUtils.append(variant, topHandle, string, textLimit, this);

}

void checkBorder_pp () {

    super.checkBorder_pp();

    if (variant == TextUtils.LINE_EDIT) {

        OS.QLineEdit_setFrame(topHandle, (style & SWT.BORDER) != 0);

    }

}

/**

 * Clears the selection.

 *

 * @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 clearSelection () {

    checkWidget();

    TextUtils.clearSelection(variant, topHandle);

}

    public Point computeSize(int wHint, int hHint, boolean changed) {

        checkWidget();

        if (changed) {

            OS.QWidget_updateGeometry(topHandle);

        }

        if (wHint != SWT.DEFAULT && wHint < 0)

            wHint = SWT.DEFAULT;

        if (hHint != SWT.DEFAULT && hHint < 0)

            hHint = SWT.DEFAULT;

        Point preferredSize;

        if (wHint != SWT.DEFAULT && hHint != SWT.DEFAULT) {

            preferredSize = new Point(wHint, hHint);

        } else if (variant == TextUtils.LINE_EDIT) {

            if (wHint == SWT.DEFAULT && hHint == SWT.DEFAULT) {

                preferredSize = getPreferredSingleLineClientAreaSize();

            } else if (hHint == SWT.DEFAULT) {

                preferredSize = new Point(wHint,

                        getPreferredSingleLineClientAreaSize().y);

            } else {

                preferredSize = new Point(

                        getPreferredSingleLineClientAreaSize().x, hHint);

            }

        } else {

            if (wHint == SWT.DEFAULT && hHint == SWT.DEFAULT) {

                preferredSize = getPreferredClientAreaSize(-1);

            } else if (hHint == SWT.DEFAULT) {

                preferredSize = new Point(wHint, getPreferredClientAreaSize(wHint).y);

            } else {

                preferredSize = new Point(getPreferredClientAreaSize(hHint).y, hHint);

            }

        }

        Rectangle trim = computeTrim(0, 0, preferredSize.x, preferredSize.y);

        return new Point(trim.width, trim.height);

    }

public Rectangle computeTrim(int x, int y, int width, int height) {

    checkWidget();

    if (variant == TextUtils.LINE_EDIT) {

        if ((style & SWT.BORDER) != 0) {

            int border = OS.QLineEdit_swt_getBorderWidth(topHandle);

            x -= border;

            y -= border;

            width += 2 * border;

            height += 2 * border;

        } 

        return new Rectangle(x, y, width, height);

    } else {

        return super.computeTrim(x, y, width, height);

    }

}

/**

 * Copies the selected text.

 * <p>

 * The current selection is copied to the clipboard.

 * </p>

 *

 * @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 copy () {

    checkWidget();

    TextUtils.copy(variant, topHandle);

}

/**

 * Cuts the selected text.

 * <p>

 * The current selection is first copied to the

 * clipboard and then deleted from the widget.

 * </p>

 *

 * @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 cut () {

    checkWidget();

    TextUtils.cut(variant, topHandle, this);

}

void deregister_pp () {  

    super.deregister_pp ();

    if (variant == TextUtils.TEXT_EDIT) {

        Display.removeWidget(scrollAreaHandle);

    }

}

void forceTextLayout() {

    // Hack: Qt does not do the layouting of the QTextDocument until QTextEdit comes visible on the screen.

    // Need to force the layouting of the invisible QTextEdit/QTextDocument here by changing the line wrap mode.

    // (Qt's default is QTEXTEDIT_WIDGETWIDTH).

    // This is needed in order that method's like getLineHeight(), getCaretLineNumber(), getCaretLocation(),

    // setTopIndex, etc. work correctly also for invisble text widgets.

    if (isVisible()) return;

    OS.QTextEdit_setLineWrapMode(scrollAreaHandle, OS.QTEXTEDIT_NOWRAP);

    if ((style & SWT.WRAP) != 0) {

        OS.QTextEdit_setLineWrapMode(scrollAreaHandle, OS.QTEXTEDIT_WIDGETWIDTH);

    }

}

public int getBorderWidth () {

   checkWidget(); 

   if (variant == TextUtils.LINE_EDIT) {

       return (style & SWT.BORDER) != 0 ? OS.QLineEdit_swt_getBorderWidth(topHandle) : 0;

   } else {

       return super.getBorderWidth();

   }

}

/**

 * Returns the line number of the caret.

 * <p>

 * The line number of the caret is returned.

 * </p>

 *

 * @return the line number

 *

 * @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 int getCaretLineNumber () {

    checkWidget();

    if (variant == TextUtils.LINE_EDIT) {

        return 0;

    } else {

        return OS.QTextEdit_swt_getCaretLineNumber(topHandle);

    }

}

/**

 * Returns a point describing the receiver's location relative

 * to its parent (or its display if its parent is null).

 * <p>

 * The location of the caret is returned.

 * </p>

 *

 * @return a point, the location of the caret

 *

 * @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 Point getCaretLocation () {

    checkWidget();

    if (variant == TextUtils.LINE_EDIT) {

        // Not supported in Qt

        return new Point(0, 0);

    } else {

        Rectangle cursorRect = OS.QTextEdit_cursorRect(topHandle);  

        return new Point(cursorRect.x, cursorRect.y);

    }

}

/**

 * Returns the character position of the caret.

 * <p>

 * Indexing is zero based.

 * </p>

 *

 * @return the position of the caret

 *

 * @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 int getCaretPosition () {

    checkWidget();

    return TextUtils.getCaretPosition(variant, topHandle);

}

/**

 * Returns the number of characters.

 *

 * @return number of characters in the widget

 *

 * @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 int getCharCount () {

    checkWidget();