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

 * 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.graphics.Point;

import org.eclipse.swt.graphics.Rectangle;

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

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

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

/**

 * Instances of this class are controls which are capable

 * of containing other controls.

 * <dl>

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

 * <dd>NO_BACKGROUND, NO_FOCUS, NO_MERGE_PAINTS, NO_REDRAW_RESIZE, NO_RADIO_GROUP</dd>

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

 * <dd>(none)</dd>

 * </dl>

 * <p>

 * Note: The <code>NO_BACKGROUND</code>, <code>NO_FOCUS</code>, <code>NO_MERGE_PAINTS</code>,

 * and <code>NO_REDRAW_RESIZE</code> styles are intended for use with <code>Canvas</code>.

 * They can be used with <code>Composite</code> if you are drawing your own, but their

 * behavior is undefined if they are used with subclasses of <code>Composite</code> other

 * than <code>Canvas</code>.

 * </p><p>

 * This class may be subclassed by custom control implementors

 * who are building controls that are constructed from aggregates

 * of other controls.

 * </p>

 *

 * @see Canvas

 */

public class Composite extends Scrollable {

    Layout layout;

    Control[] tabList;

    int layoutCount;

    int backgroundMode;

/**

 * Prevents uninitialized instances from being created outside the package.

 */

Composite () {

}

/**

 * 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 widget which will be the parent of the new instance (cannot be null)

 * @param style the style of widget 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#NO_BACKGROUND

 * @see SWT#NO_FOCUS

 * @see SWT#NO_MERGE_PAINTS

 * @see SWT#NO_REDRAW_RESIZE

 * @see SWT#NO_RADIO_GROUP

 * @see Widget#getStyle

 */

public Composite (Composite parent, int style) {

    super (parent, style);

}

/**

 * <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 Composite(Composite parent, int style, int extraStyle, Object packageProxy, 

        boolean isExtended) {

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

}

void addControl_pp (Control control) {

}

void checkBuffered () {

    if ((state & WidgetState.CANVAS) == 0) {

        super.checkBuffered ();

    }

}

void checkNoBackground() {

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

        if(handle != 0) {

            OS.QWidget_setAttribute(handle, OS.QT_WA_NOSYSTEMBACKGROUND, true);

        }

    }

}

void checkNoFocus() {

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

        OS.QWidget_setFocusPolicy(handle, OS.QT_FOCUSPOLICY_NOFOCUS);

        int topHandle;

        if((topHandle = this.topHandle) != handle) {

            OS.QWidget_setFocusPolicy(topHandle, OS.QT_FOCUSPOLICY_NOFOCUS);

        }

    }

}

void checkNoRedrawResize() {

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

        if(handle != 0) {

            OS.QWidget_setAttribute(handle, OS.QT_WA_STATICCONTENTS, true);

        }

    }

}

protected void checkSubclass () {

    /* Do nothing - Subclassing is allowed */

}

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

    checkWidget ();

    if ((state & WidgetState.CANVAS) != 0) {

        Point size;

        if (layout != null) {

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

                changed |= (state & WidgetState.LAYOUT_CHANGED) != 0;

                state &= ~WidgetState.LAYOUT_CHANGED;

                size = layout.computeSize (this, wHint, hHint, changed);

            } else {

                size = new Point (wHint, hHint);

            }

        } else {

            size = minimumSize (wHint, hHint, changed);

        }

        if (size.x == 0) size.x = WidgetConstant.DEFAULT_WIDTH;

        if (size.y == 0) size.y = WidgetConstant.DEFAULT_HEIGHT;

        if (wHint != SWT.DEFAULT) size.x = wHint;

        if (hHint != SWT.DEFAULT) size.y = hHint;

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

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

    } else {

        // If this is not a stand-alone Composite, Shell or Canvas, 

        // call Scrollable's implementation

        return super.computeSize(wHint, hHint, changed);

    }

}

Control [] computeTabList () {

    Control result [] = super.computeTabList ();

    if (result.length == 0) return result;

    Control [] list = tabList != null ? _getTabList () : _getChildren ();

    for (int i=0; i<list.length; i++) {

        Control child = list [i];

        Control [] childList = child.computeTabList ();

        if (childList.length != 0) {

            Control [] newResult = new Control [result.length + childList.length];

            System.arraycopy (result, 0, newResult, 0, result.length);

            System.arraycopy (childList, 0, newResult, result.length, childList.length);

            result = newResult;

        }

    }

    return result;

}

void createHandle_pp (int index) {

    super.createHandle_pp (index);

    frameHandle = topHandle = scrollAreaHandle = OS.QScrollArea_new(0);

    handle = OS.QAbstractScrollArea_viewPort(scrollAreaHandle);

    // Composite by itself must not by default accept focus by clicking.

    int policy = OS.QWidget_focusPolicy(topHandle) & ~OS.QT_FOCUSPOLICY_CLICKFOCUS;

    OS.QWidget_setFocusPolicy(topHandle, policy);

    // Stand-alone Composites, Shells, Canvases set the CANVAS flag

    state |= (WidgetState.HANDLE | WidgetState.CANVAS);

}

boolean doHandleMouseEvent(int type, int widgetHandle, int button, int x, int y, int state, int buttons) {

    boolean cancel = super.doHandleMouseEvent(type, widgetHandle, button, x, y, state, buttons);

    // From the CANVAS flag it's known if this is a Shell/stand-alone Composite/Canvas. 

    if((this.state & WidgetState.CANVAS) != 0) {

        // Set focus for a Canvas with no children. 

        if(type == SWT.MouseDown) {

            if ((style & SWT.NO_FOCUS) == 0 && hooksKeys ()) {

                Control[] children = getChildren();

                if (children == null || children.length == 0) {

                    setFocus (OS.QT_OTHERFOCUSREASON);

                }

            }

        }

    }

    return cancel;

}

Composite findDeferredControl () {

    return layoutCount > 0 ? this : parent.findDeferredControl ();

}

Menu [] findMenus (Control control) {

    if (control == this) return new Menu [0];

    Menu result [] = super.findMenus (control);

    Control [] children = _getChildren ();

    for (int i=0; i<children.length; i++) {

        Control child = children [i];

        Menu [] menuList = child.findMenus (control);

        if (menuList.length != 0) {

            Menu [] newResult = new Menu [result.length + menuList.length];

            System.arraycopy (result, 0, newResult, 0, result.length);

            System.arraycopy (menuList, 0, newResult, result.length, menuList.length);

            result = newResult;

        }

    }

    return result;

}

void fixTabList (Control control) {

    if (tabList == null) return;

    int count = 0;

    for (int i=0; i<tabList.length; i++) {

        if (tabList [i] == control) count++;

    }

    if (count == 0) return;

    Control [] newList = null;

    int length = tabList.length - count;

    if (length != 0) {

        newList = new Control [length];

        int index = 0;

        for (int i=0; i<tabList.length; i++) {

            if (tabList [i] != control) {

                newList [index++] = tabList [i];

            }

        }

    }

    tabList = newList;

}

/**

 * Returns the receiver's background drawing mode. This

 * will be one of the following constants defined in class

 * <code>SWT</code>:

 * <code>INHERIT_NONE</code>, <code>INHERIT_DEFAULT</code>,

 * <code>INHERTIT_FORCE</code>.

 *

 * @return the background mode

 *

 * @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 SWT

 * 

 * @since 3.2

 */

public int getBackgroundMode () {

    checkWidget ();

    return backgroundMode;

}

/**

 * Returns a (possibly empty) array containing the receiver's children.

 * Children are returned in the order that they are drawn.  The topmost

 * control appears at the beginning of the array.  Subsequent controls

 * draw beneath this control and appear later in the array.

 * <p>

 * Note: This is not the actual structure used by the receiver

 * to maintain its list of children, so modifying the array will

 * not affect the receiver. 

 * </p>

 *

 * @return an array of children

 * 

 * @see Control#moveAbove

 * @see Control#moveBelow

 *

 * @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 [] getChildren () {

    checkWidget();

    return _getChildren ();

}

Control [] _getChildren() {

    // For some reason MultiPageDialog's children are not children of the handle

    int widgetHandle = packageProxy != null ? packageProxy.handleWithChildren() : handleWithChildren_pp();

    int[] list = OS.QObject_children(widgetHandle); 

    int count = list.length;

    if (count == 0) return new Control [0];

    Control [] children = new Control [count];

    int childControls = 0;

    for(int i = 0; i < count; ++i) {

        int handle = list[i];

        if (handle != 0) {

            Widget widget = Display.getWidget (handle);

            if (widget != null && widget != this) {

                if (widget instanceof Control && !(widget instanceof Shell)) {

                    children [childControls++] = (Control) widget;

                }

            }

        }

    }

    if (childControls == count) return children;

    Control [] newChildren = new Control [childControls];

    System.arraycopy (children, 0, newChildren, 0, childControls);

    return newChildren;

}

/**

 * Returns layout which is associated with the receiver, or

 * null if one has not been set.

 *

 * @return the receiver's layout 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 Layout getLayout () {

    checkWidget();

    return layout;

}

/**

 * Gets the (possibly empty) tabbing order for the control.

 *

 * @return tabList the ordered list of controls representing the tab order

 *

 * @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 #setTabList

 */

public Control [] getTabList () {

    checkWidget ();

    Control [] tabList = _getTabList ();

    if (tabList == null) {

        int count = 0;

        Control [] list =_getChildren ();

        for (int i=0; i<list.length; i++) {

            if (list [i].isTabGroup ()) count++;

        }

        tabList = new Control [count];

        int index = 0;

        for (int i=0; i<list.length; i++) {

            if (list [i].isTabGroup ()) {

                tabList [index++] = list [i];

            }

        }

    }

    return tabList;

}

Control [] _getTabList () {

    if (tabList == null) return tabList;

    int count = 0;

    for (int i=0; i<tabList.length; i++) {

        if (!tabList [i].isDisposed ()) count++;

    }

    if (count == tabList.length) return tabList;

    Control [] newList = new Control [count];

    int index = 0;

    for (int i=0; i<tabList.length; i++) {

        if (!tabList [i].isDisposed ()) {

            newList [index++] = tabList [i];

        }

    }

    tabList = newList;

    return tabList;

}

/*

 * This method is here because MultiPageDialog for some reason has a Composite

 * which has its children not as children of the handle. It overrides this. 

 */ 

int handleWithChildren_pp() {

    return handle; // handle == viewport

}

boolean hooksKeys () {

    return hooks (SWT.KeyDown) || hooks (SWT.KeyUp);

}

/**

 * If the receiver has a layout, asks the layout to <em>lay out</em>

 * (that is, set the size and location of) the receiver's children. 

 * If the receiver does not have a layout, do nothing.

 * <p>

 * This is equivalent to calling <code>layout(true)</code>.

 * </p>

 * <p>

 * Note: Layout is different from painting. If a child is

 * moved or resized such that an area in the parent is

 * exposed, then the parent will paint. If no child is

 * affected, the parent will not paint.

 * </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 layout () {

    checkWidget ();

    layout (true);

}

/**

 * If the receiver has a layout, asks the layout to <em>lay out</em>

 * (that is, set the size and location of) the receiver's children. 

 * If the argument is <code>true</code> the layout must not rely

 * on any information it has cached about the immediate children. If it

 * is <code>false</code> the layout may (potentially) optimize the

 * work it is doing by assuming that none of the receiver's 

 * children has changed state since the last layout.

 * If the receiver does not have a layout, do nothing.

 * <p>

 * If a child is resized as a result of a call to layout, the 

 * resize event will invoke the layout of the child.  The layout

 * will cascade down through all child widgets in the receiver's widget 

 * tree until a child is encountered that does not resize.  Note that 

 * a layout due to a resize will not flush any cached information 

 * (same as <code>layout(false)</code>).

 * </p>

 * <p>

 * Note: Layout is different from painting. If a child is

 * moved or resized such that an area in the parent is

 * exposed, then the parent will paint. If no child is

 * affected, the parent will not paint.

 * </p>

 *

 * @param changed <code>true</code> if the layout must flush its caches, and <code>false</code> 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>

 */

public void layout (boolean changed) {

    checkWidget ();

    if (layout == null) return;

    layout (changed, false);

}

void layout (boolean changed, boolean all) {

    checkWidget ();

    if (layout == null && !all) return;

    markLayout (changed, all);

    updateLayout (all);

}

void markLayout (boolean changed, boolean all) {

    if (layout != null) {

        state |= WidgetState.LAYOUT_NEEDED;

        if (changed) state |= WidgetState.LAYOUT_CHANGED;

    }

    if (all) {

        Control [] children = _getChildren ();

        for (int i=0; i<children.length; i++) {

            children [i].markLayout (changed, all);

        }

    }

}

Point minimumSize (int wHint, int hHint, boolean changed) {

    Control [] children = _getChildren ();

    int width = 0, height = 0;

    for (int i=0; i<children.length; i++) {

        Rectangle rect = children [i].getBounds ();

        width = Math.max (width, rect.x + rect.width);

        height = Math.max (height, rect.y + rect.height);

    }

    return new Point (width, height);

}

void qt_swt_event_widgetResized_pp(int widgetHandle, int oldWidth, int oldHeight, int width, int height, boolean sendResizeEvent) {

    if (isDisposed ()) return;

    if((widgetHandle == handle) && isMirrored()) {

        // In real coordinate system the children need to be moved so that they

        // appear stationary in the emulated mirrored coordinate system. 

        final int dx = width - oldWidth;

        if(dx != 0) {

            Control[] children =_getChildren();

            try {

                Display.blockedQtEventType = OS.QSWTEVENT_WIDGETMOVED;

                for (int i = 0; i < children.length; ++i) {

                    Control child = children[i];

                    if (!child.isDisposed()) {

                        final int childHandle = child.topHandle;

                        Point pos = OS.QWidget_pos(childHandle);

                        OS.QWidget_move(childHandle, pos.x + dx, pos.y);

                    }

                }

            } finally {

                Display.blockedQtEventType = OS.QEVENT_NONE;

            }

        }

    }

    super.qt_swt_event_widgetResized_pp(widgetHandle, oldWidth, oldHeight, width, height, sendResizeEvent);