/*

 * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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 * questions.

 */

package javax.swing;

import sun.reflect.misc.ReflectUtil;

import sun.swing.SwingUtilities2;

import sun.swing.UIAction;

import java.applet.*;

import java.awt.*;

import java.awt.event.*;

import java.awt.dnd.DropTarget;

import java.lang.reflect.*;

import javax.accessibility.*;

import javax.swing.event.MenuDragMouseEvent;

import javax.swing.plaf.UIResource;

import javax.swing.text.View;

import java.security.AccessController;

import sun.security.action.GetPropertyAction;

import sun.awt.AppContext;

/**

 * A collection of utility methods for Swing.

 *

 * @author unknown

 */

public class SwingUtilities implements SwingConstants

{

    // These states are system-wide, rather than AppContext wide.

    private static boolean canAccessEventQueue = false;

    private static boolean eventQueueTested = false;

    /**

     * Indicates if we should change the drop target when a

     * {@code TransferHandler} is set.

     */

    private static boolean suppressDropSupport;

    /**

     * Indiciates if we've checked the system property for suppressing

     * drop support.

     */

    private static boolean checkedSuppressDropSupport;

    /**

     * Returns true if <code>setTransferHandler</code> should change the

     * <code>DropTarget</code>.

     */

    private static boolean getSuppressDropTarget() {

        if (!checkedSuppressDropSupport) {

            suppressDropSupport = Boolean.valueOf(

                AccessController.doPrivileged(

                    new GetPropertyAction("suppressSwingDropSupport")));

            checkedSuppressDropSupport = true;

        }

        return suppressDropSupport;

    }

    /**

     * Installs a {@code DropTarget} on the component as necessary for a

     * {@code TransferHandler} change.

     */

    static void installSwingDropTargetAsNecessary(Component c,

                                                         TransferHandler t) {

        if (!getSuppressDropTarget()) {

            DropTarget dropHandler = c.getDropTarget();

            if ((dropHandler == null) || (dropHandler instanceof UIResource)) {

                if (t == null) {

                    c.setDropTarget(null);

                } else if (!GraphicsEnvironment.isHeadless()) {

                    c.setDropTarget(new TransferHandler.SwingDropTarget(c));

                }

            }

        }

    }

    /**

     * Return true if <code>a</code> contains <code>b</code>

     */

    public static final boolean isRectangleContainingRectangle(Rectangle a,Rectangle b) {

        return b.x >= a.x && (b.x + b.width) <= (a.x + a.width) &&

                b.y >= a.y && (b.y + b.height) <= (a.y + a.height);

    }

    /**

     * Return the rectangle (0,0,bounds.width,bounds.height) for the component <code>aComponent</code>

     */

    public static Rectangle getLocalBounds(Component aComponent) {

        Rectangle b = new Rectangle(aComponent.getBounds());

        b.x = b.y = 0;

        return b;

    }

    /**

     * Returns the first <code>Window </code> ancestor of <code>c</code>, or

     * {@code null} if <code>c</code> is not contained inside a <code>Window</code>.

     *

     * @param c <code>Component</code> to get <code>Window</code> ancestor

     *        of.

     * @return the first <code>Window </code> ancestor of <code>c</code>, or

     *         {@code null} if <code>c</code> is not contained inside a

     *         <code>Window</code>.

     * @since 1.3

     */

    public static Window getWindowAncestor(Component c) {

        for(Container p = c.getParent(); p != null; p = p.getParent()) {

            if (p instanceof Window) {

                return (Window)p;

            }

        }

        return null;

    }

    /**

     * Converts the location <code>x</code> <code>y</code> to the

     * parents coordinate system, returning the location.

     */

    static Point convertScreenLocationToParent(Container parent,int x, int y) {

        for (Container p = parent; p != null; p = p.getParent()) {

            if (p instanceof Window) {

                Point point = new Point(x, y);

                SwingUtilities.convertPointFromScreen(point, parent);

                return point;

            }

        }

        throw new Error("convertScreenLocationToParent: no window ancestor");

    }

    /**

     * Convert a <code>aPoint</code> in <code>source</code> coordinate system to

     * <code>destination</code> coordinate system.

     * If <code>source</code> is {@code null}, <code>aPoint</code> is assumed to be in <code>destination</code>'s

     * root component coordinate system.

     * If <code>destination</code> is {@code null}, <code>aPoint</code> will be converted to <code>source</code>'s

     * root component coordinate system.

     * If both <code>source</code> and <code>destination</code> are {@code null}, return <code>aPoint</code>

     * without any conversion.

     */

    public static Point convertPoint(Component source,Point aPoint,Component destination) {

        Point p;

        if(source == null && destination == null)

            return aPoint;

        if(source == null) {

            source = getWindowAncestor(destination);

            if(source == null)

                throw new Error("Source component not connected to component tree hierarchy");

        }

        p = new Point(aPoint);

        convertPointToScreen(p,source);

        if(destination == null) {

            destination = getWindowAncestor(source);

            if(destination == null)

                throw new Error("Destination component not connected to component tree hierarchy");

        }

        convertPointFromScreen(p,destination);

        return p;

    }

    /**

     * Convert the point <code>(x,y)</code> in <code>source</code> coordinate system to

     * <code>destination</code> coordinate system.

     * If <code>source</code> is {@code null}, <code>(x,y)</code> is assumed to be in <code>destination</code>'s

     * root component coordinate system.

     * If <code>destination</code> is {@code null}, <code>(x,y)</code> will be converted to <code>source</code>'s

     * root component coordinate system.

     * If both <code>source</code> and <code>destination</code> are {@code null}, return <code>(x,y)</code>

     * without any conversion.

     */

    public static Point convertPoint(Component source,int x, int y,Component destination) {

        Point point = new Point(x,y);

        return convertPoint(source,point,destination);

    }

    /**

     * Convert the rectangle <code>aRectangle</code> in <code>source</code> coordinate system to

     * <code>destination</code> coordinate system.

     * If <code>source</code> is {@code null}, <code>aRectangle</code> is assumed to be in <code>destination</code>'s

     * root component coordinate system.

     * If <code>destination</code> is {@code null}, <code>aRectangle</code> will be converted to <code>source</code>'s

     * root component coordinate system.

     * If both <code>source</code> and <code>destination</code> are {@code null}, return <code>aRectangle</code>

     * without any conversion.

     */

    public static Rectangle convertRectangle(Component source,Rectangle aRectangle,Component destination) {

        Point point = new Point(aRectangle.x,aRectangle.y);

        point =  convertPoint(source,point,destination);

        return new Rectangle(point.x,point.y,aRectangle.width,aRectangle.height);

    }

    /**

     * Convenience method for searching above <code>comp</code> in the

     * component hierarchy and returns the first object of class <code>c</code> it

     * finds. Can return {@code null}, if a class <code>c</code> cannot be found.

     */

    public static Container getAncestorOfClass(Class<?> c, Component comp)

    {

        if(comp == null || c == null)

            return null;

        Container parent = comp.getParent();

        while(parent != null && !(c.isInstance(parent)))

            parent = parent.getParent();

        return parent;

    }

    /**

     * Convenience method for searching above <code>comp</code> in the

     * component hierarchy and returns the first object of <code>name</code> it

     * finds. Can return {@code null}, if <code>name</code> cannot be found.

     */

    public static Container getAncestorNamed(String name, Component comp) {

        if(comp == null || name == null)

            return null;

        Container parent = comp.getParent();

        while(parent != null && !(name.equals(parent.getName())))

            parent = parent.getParent();

        return parent;

    }

    /**

     * Returns the deepest visible descendent Component of <code>parent</code>

     * that contains the location <code>x</code>, <code>y</code>.

     * If <code>parent</code> does not contain the specified location,

     * then <code>null</code> is returned.  If <code>parent</code> is not a

     * container, or none of <code>parent</code>'s visible descendents

     * contain the specified location, <code>parent</code> is returned.

     *

     * @param parent the root component to begin the search

     * @param x the x target location

     * @param y the y target location

     */

    public static Component getDeepestComponentAt(Component parent, int x, int y) {

        if (!parent.contains(x, y)) {

            return null;

        }

        if (parent instanceof Container) {

            Component components[] = ((Container)parent).getComponents();

            for (Component comp : components) {

                if (comp != null && comp.isVisible()) {

                    Point loc = comp.getLocation();

                    if (comp instanceof Container) {

                        comp = getDeepestComponentAt(comp, x - loc.x, y - loc.y);

                    } else {

                        comp = comp.getComponentAt(x - loc.x, y - loc.y);

                    }

                    if (comp != null && comp.isVisible()) {

                        return comp;

                    }

                }

            }

        }

        return parent;

    }

    /**

     * Returns a MouseEvent similar to <code>sourceEvent</code> except that its x

     * and y members have been converted to <code>destination</code>'s coordinate

     * system.  If <code>source</code> is {@code null}, <code>sourceEvent</code> x and y members

     * are assumed to be into <code>destination</code>'s root component coordinate system.

     * If <code>destination</code> is <code>null</code>, the

     * returned MouseEvent will be in <code>source</code>'s coordinate system.

     * <code>sourceEvent</code> will not be changed. A new event is returned.

     * the <code>source</code> field of the returned event will be set

     * to <code>destination</code> if destination is non-{@code null}

     * use the translateMouseEvent() method to translate a mouse event from

     * one component to another without changing the source.

     */

    public static MouseEvent convertMouseEvent(Component source,

                                               MouseEvent sourceEvent,

                                               Component destination) {

        Point p = convertPoint(source,new Point(sourceEvent.getX(),

                                                sourceEvent.getY()),

                               destination);

        Component newSource;

        if(destination != null)

            newSource = destination;

        else

            newSource = source;

        MouseEvent newEvent;

        if (sourceEvent instanceof MouseWheelEvent) {

            MouseWheelEvent sourceWheelEvent = (MouseWheelEvent)sourceEvent;

            newEvent = new MouseWheelEvent(newSource,

                                           sourceWheelEvent.getID(),

                                           sourceWheelEvent.getWhen(),

                                           sourceWheelEvent.getModifiers()

                                                   | sourceWheelEvent.getModifiersEx(),

                                           p.x,p.y,

                                           sourceWheelEvent.getXOnScreen(),

                                           sourceWheelEvent.getYOnScreen(),

                                           sourceWheelEvent.getClickCount(),

                                           sourceWheelEvent.isPopupTrigger(),

                                           sourceWheelEvent.getScrollType(),

                                           sourceWheelEvent.getScrollAmount(),

                                           sourceWheelEvent.getWheelRotation());

        }

        else if (sourceEvent instanceof MenuDragMouseEvent) {

            MenuDragMouseEvent sourceMenuDragEvent = (MenuDragMouseEvent)sourceEvent;

            newEvent = new MenuDragMouseEvent(newSource,

                                              sourceMenuDragEvent.getID(),

                                              sourceMenuDragEvent.getWhen(),

                                              sourceMenuDragEvent.getModifiers()

                                                      | sourceMenuDragEvent.getModifiersEx(),

                                              p.x,p.y,

                                              sourceMenuDragEvent.getXOnScreen(),

                                              sourceMenuDragEvent.getYOnScreen(),

                                              sourceMenuDragEvent.getClickCount(),

                                              sourceMenuDragEvent.isPopupTrigger(),

                                              sourceMenuDragEvent.getPath(),

                                              sourceMenuDragEvent.getMenuSelectionManager());

        }

        else {

            newEvent = new MouseEvent(newSource,

                                      sourceEvent.getID(),

                                      sourceEvent.getWhen(),

                                      sourceEvent.getModifiers()

                                              | sourceEvent.getModifiersEx(),

                                      p.x,p.y,

                                      sourceEvent.getXOnScreen(),

                                      sourceEvent.getYOnScreen(),

                                      sourceEvent.getClickCount(),

                                      sourceEvent.isPopupTrigger(),

                                      sourceEvent.getButton());

        }

        return newEvent;

    }

    /**

     * Convert a point from a component's coordinate system to

     * screen coordinates.

     *

     * @param p  a Point object (converted to the new coordinate system)

     * @param c  a Component object

     */

    public static void convertPointToScreen(Point p,Component c) {

            Rectangle b;

            int x,y;

            do {

                if(c instanceof JComponent) {

                    x = c.getX();

                    y = c.getY();

                } else if(c instanceof java.applet.Applet ||

                          c instanceof java.awt.Window) {

                    try {

                        Point pp = c.getLocationOnScreen();

                        x = pp.x;

                        y = pp.y;

                    } catch (IllegalComponentStateException icse) {

                        x = c.getX();

                        y = c.getY();

                    }

                } else {

                    x = c.getX();

                    y = c.getY();

                }

                p.x += x;

                p.y += y;

                if(c instanceof java.awt.Window || c instanceof java.applet.Applet)

                    break;

                c = c.getParent();

            } while(c != null);

        }

    /**

     * Convert a point from a screen coordinates to a component's

     * coordinate system

     *

     * @param p  a Point object (converted to the new coordinate system)

     * @param c  a Component object

     */

    public static void convertPointFromScreen(Point p,Component c) {

        Rectangle b;

        int x,y;

        do {

            if(c instanceof JComponent) {

                x = c.getX();

                y = c.getY();

            }  else if(c instanceof java.applet.Applet ||

                       c instanceof java.awt.Window) {

                try {

                    Point pp = c.getLocationOnScreen();

                    x = pp.x;

                    y = pp.y;

                } catch (IllegalComponentStateException icse) {

                    x = c.getX();

                    y = c.getY();

                }

            } else {

                x = c.getX();

                y = c.getY();

            }

            p.x -= x;

            p.y -= y;

            if(c instanceof java.awt.Window || c instanceof java.applet.Applet)

                break;

            c = c.getParent();

        } while(c != null);

    }

    /**

     * Returns the first <code>Window </code> ancestor of <code>c</code>, or

     * {@code null} if <code>c</code> is not contained inside a <code>Window</code>.

     * <p>

     * Note: This method provides the same functionality as

     * <code>getWindowAncestor</code>.

     *

     * @param c <code>Component</code> to get <code>Window</code> ancestor

     *        of.

     * @return the first <code>Window </code> ancestor of <code>c</code>, or

     *         {@code null} if <code>c</code> is not contained inside a

     *         <code>Window</code>.

     */

    public static Window windowForComponent(Component c) {

        return getWindowAncestor(c);

    }

    /**

     * Return <code>true</code> if a component <code>a</code> descends from a component <code>b</code>

     */

    public static boolean isDescendingFrom(Component a,Component b) {

        if(a == b)

            return true;

        for(Container p = a.getParent();p!=null;p=p.getParent())

            if(p == b)

                return true;

        return false;

    }

    /**

     * Convenience to calculate the intersection of two rectangles

     * without allocating a new rectangle.

     * If the two rectangles don't intersect,

     * then the returned rectangle begins at (0,0)

     * and has zero width and height.

     *

     * @param x       the X coordinate of the first rectangle's top-left point

     * @param y       the Y coordinate of the first rectangle's top-left point

     * @param width   the width of the first rectangle

     * @param height  the height of the first rectangle

     * @param dest    the second rectangle

     *

     * @return <code>dest</code>, modified to specify the intersection

     */

    public static Rectangle computeIntersection(int x,int y,int width,int height,Rectangle dest) {

        int x1 = (x > dest.x) ? x : dest.x;

        int x2 = ((x+width) < (dest.x + dest.width)) ? (x+width) : (dest.x + dest.width);

        int y1 = (y > dest.y) ? y : dest.y;

        int y2 = ((y + height) < (dest.y + dest.height) ? (y+height) : (dest.y + dest.height));

        dest.x = x1;

        dest.y = y1;

        dest.width = x2 - x1;

        dest.height = y2 - y1;

        // If rectangles don't intersect, return zero'd intersection.

        if (dest.width < 0 || dest.height < 0) {

            dest.x = dest.y = dest.width = dest.height = 0;

        }

        return dest;

    }

    /**

     * Convenience method that calculates the union of two rectangles

     * without allocating a new rectangle.

     *

     * @param x the x-coordinate of the first rectangle

     * @param y the y-coordinate of the first rectangle

     * @param width the width of the first rectangle

     * @param height the height of the first rectangle

     * @param dest  the coordinates of the second rectangle; the union

     *    of the two rectangles is returned in this rectangle

     * @return the <code>dest</code> <code>Rectangle</code>

     */

    public static Rectangle computeUnion(int x,int y,int width,int height,Rectangle dest) {

        int x1 = (x < dest.x) ? x : dest.x;

        int x2 = ((x+width) > (dest.x + dest.width)) ? (x+width) : (dest.x + dest.width);

        int y1 = (y < dest.y) ? y : dest.y;

        int y2 = ((y+height) > (dest.y + dest.height)) ? (y+height) : (dest.y + dest.height);

        dest.x = x1;

        dest.y = y1;

        dest.width = (x2 - x1);