Home » openjdk-7 » java » awt » dnd » [javadoc | source]

    1   /*
    2    * Copyright (c) 1998, 1999, Oracle and/or its affiliates. All rights reserved.
    3    * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
    4    *
    5    * This code is free software; you can redistribute it and/or modify it
    6    * under the terms of the GNU General Public License version 2 only, as
    7    * published by the Free Software Foundation.  Oracle designates this
    8    * particular file as subject to the "Classpath" exception as provided
    9    * by Oracle in the LICENSE file that accompanied this code.
   10    *
   11    * This code is distributed in the hope that it will be useful, but WITHOUT
   12    * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
   13    * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
   14    * version 2 for more details (a copy is included in the LICENSE file that
   15    * accompanied this code).
   16    *
   17    * You should have received a copy of the GNU General Public License version
   18    * 2 along with this work; if not, write to the Free Software Foundation,
   19    * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
   20    *
   21    * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
   22    * or visit www.oracle.com if you need additional information or have any
   23    * questions.
   24    */
   25   
   26   package java.awt.dnd;
   27   
   28   import java.awt.Insets;
   29   import java.awt.Point;
   30   
   31   /**
   32    * During DnD operations it is possible that a user may wish to drop the
   33    * subject of the operation on a region of a scrollable GUI control that is
   34    * not currently visible to the user.
   35    * <p>
   36    * In such situations it is desirable that the GUI control detect this
   37    * and institute a scroll operation in order to make obscured region(s)
   38    * visible to the user. This feature is known as autoscrolling.
   39    * <p>
   40    * If a GUI control is both an active <code>DropTarget</code>
   41    * and is also scrollable, it
   42    * can receive notifications of autoscrolling gestures by the user from
   43    * the DnD system by implementing this interface.
   44    * <p>
   45    * An autoscrolling gesture is initiated by the user by keeping the drag
   46    * cursor motionless with a border region of the <code>Component</code>,
   47    * referred to as
   48    * the "autoscrolling region", for a predefined period of time, this will
   49    * result in repeated scroll requests to the <code>Component</code>
   50    * until the drag <code>Cursor</code> resumes its motion.
   51    *
   52    * @since 1.2
   53    */
   54   
   55   public interface Autoscroll {
   56   
   57       /**
   58        * This method returns the <code>Insets</code> describing
   59        * the autoscrolling region or border relative
   60        * to the geometry of the implementing Component.
   61        * <P>
   62        * This value is read once by the <code>DropTarget</code>
   63        * upon entry of the drag <code>Cursor</code>
   64        * into the associated <code>Component</code>.
   65        * <P>
   66        * @return the Insets
   67        */
   68   
   69       public Insets getAutoscrollInsets();
   70   
   71       /**
   72        * notify the <code>Component</code> to autoscroll
   73        * <P>
   74        * @param cursorLocn A <code>Point</code> indicating the
   75        * location of the cursor that triggered this operation.
   76        */
   77   
   78       public void autoscroll(Point cursorLocn);
   79   
   80   }

Home » openjdk-7 » java » awt » dnd » [javadoc | source]