/*******************************************************************************
 * 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.WidgetState;

/**
 * Instances of the receiver represent an unselectable
 * user interface object that is used to display progress,
 * typically in the form of a bar.
 * <dl>
 * <dt><b>Styles:</b></dt>
 * <dd>SMOOTH, HORIZONTAL, VERTICAL, INDETERMINATE</dd>
 * <dt><b>Events:</b></dt>
 * <dd>(none)</dd>
 * </dl>
 * <p>
 * Note: Only one of the styles HORIZONTAL and VERTICAL may be specified.
 * </p><p>
 * IMPORTANT: This class is intended to be subclassed <em>only</em>
 * within the SWT implementation.
 * </p>
 */
public class ProgressBar extends Control {
    int minimum = 0, maximum = 100, selection = 0;
    
/**
 * 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#SMOOTH
 * @see SWT#HORIZONTAL
 * @see SWT#VERTICAL
 * @see Widget#checkSubclass
 * @see Widget#getStyle
 */
public ProgressBar (Composite parent, int style) {
    super (parent, checkStyle(style));
}

static int checkStyle (int style) {
    style |= SWT.NO_FOCUS;
    style = checkBits (style, SWT.HORIZONTAL, SWT.VERTICAL, 0, 0, 0, 0);
    return checkBits (style, SWT.SMOOTH, SWT.INDETERMINATE, 0, 0, 0, 0);
}


void createHandle_pp (int index) {
    topHandle = handle = OS.QProgressBar_new();
    state |= WidgetState.HANDLE;
    setStyle();
}

void setStyle(){
    
    if ( ( style & SWT.VERTICAL ) != 0 )
        {
        OS.QProgressBar_setOrientation(handle,OS.QT_VERTICAL);
        }
    
    if ( ( style & SWT.INDETERMINATE ) != 0 )
        {
        OS.QProgressBar_setMaximum(handle, maximum);
        }
    OS.QProgressBar_setTextInVisible(handle);
}

/**
 * Returns the maximum value which the receiver will allow.
 *
 * @return the maximum
 *
 * @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 getMaximum () {
    checkWidget ();
    return maximum;
}

/**
 * Returns the minimum value which the receiver will allow.
 *
 * @return the minimum
 *
 * @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 getMinimum () {
    checkWidget ();
    return minimum;
}

/**
 * Returns the single 'selection' that is the receiver's position.
 *
 * @return 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 int getSelection () {
    checkWidget ();
    return selection;
}


/**
 * Sets the maximum value that the receiver will allow.  This new
 * value will be ignored if it is not greater than the receiver's current
 * minimum value.  If the new maximum is applied then the receiver's
 * selection value will be adjusted if necessary to fall within its new range.
 *
 * @param value the new maximum, which must be greater than the current minimum
 *
 * @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 setMaximum (int value) {
    checkWidget ();
    if (value <= minimum) return;
    maximum = value;
    selection = Math.min (selection, maximum);
    //According to QT Attempting to change the current value to one outside the minimum-maximum 
    //range has no effect on the current value. But in eSWT, If the new maximum is applied then 
    // the receiver's selection value will be adjusted if necessary to fall within its new range.
    // So we need to call setSelection 
    if( value <= selection && !( (style & SWT.INDETERMINATE) != 0 ) )
        OS.QProgressBar_setValue(handle,selection);
    
    if( !( (style & SWT.INDETERMINATE) != 0 ) )
        {
        OS.QProgressBar_setMaximum(handle, maximum);
        }
}

/**
 * Sets the minimum value that the receiver will allow.  This new
 * value will be ignored if it is negative or is not less than the receiver's
 * current maximum value.  If the new minimum is applied then the receiver's
 * selection value will be adjusted if necessary to fall within its new range.
 *
 * @param value the new minimum, which must be nonnegative and less than the current maximum
 *
 * @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 setMinimum (int value) {
    checkWidget ();
    if (value < 0 || value >= maximum) return;
    minimum = value;
    selection = Math.max (selection, minimum);
    if( !( (style & SWT.INDETERMINATE) != 0 ) )
        {
        OS.QProgressBar_setMinimum(handle, value);
        }
}

/**
 * Sets the single 'selection' that is the receiver's
 * position to the argument which must be greater than or equal
 * to zero.
 *
 * @param value the new selection (must be zero or greater)
 *
 * @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 setSelection (int value) {
    checkWidget ();
    selection = Math.max (minimum, Math.min (maximum, value));
    if( !( (style & SWT.INDETERMINATE) != 0 ) )
        {
        OS.QProgressBar_setValue(handle, selection);
        }
}


}
