bundles/org.eclipse.swt.win32.win32.x86_64/src/org/eclipse/swt/dnd/TableDropTargetEffect.java

   1 /*******************************************************************************
   2  * Copyright (c) 2007, 2012 IBM Corporation and others.
   3  *
   4  * This program and the accompanying materials
   5  * are made available under the terms of the Eclipse Public License 2.0
   6  * which accompanies this distribution, and is available at
   7  * https://www.eclipse.org/legal/epl-2.0/
   8  *
   9  * SPDX-License-Identifier: EPL-2.0
  10  *
  11  * Contributors:
  12  *     IBM Corporation - initial API and implementation
  13  *******************************************************************************/
  14 package org.eclipse.swt.dnd;
  15
  16 import org.eclipse.swt.graphics.*;
  17 import org.eclipse.swt.internal.*;
  18 import org.eclipse.swt.internal.win32.*;
  19 import org.eclipse.swt.widgets.*;
  20
  21 /**
  22  * This class provides a default drag under effect (eg. select, insert and scroll)
  23  * when a drag occurs over a <code>Table</code>.
  24  *
  25  * <p>Classes that wish to provide their own drag under effect for a <code>Table</code>
  26  * can extend the <code>TableDropTargetEffect</code> and override any applicable methods
  27  * in <code>TableDropTargetEffect</code> to display their own drag under effect.</p>
  28  *
  29  * Subclasses that override any methods of this class must call the corresponding
  30  * <code>super</code> method to get the default drag under effect implementation.
  31  *
  32  * <p>The feedback value is either one of the FEEDBACK constants defined in
  33  * class <code>DND</code> which is applicable to instances of this class,
  34  * or it must be built by <em>bitwise OR</em>'ing together
  35  * (that is, using the <code>int</code> "|" operator) two or more
  36  * of those <code>DND</code> effect constants.
  37  * </p>
  38  * <dl>
  39  * <dt><b>Feedback:</b></dt>
  40  * <dd>FEEDBACK_SELECT, FEEDBACK_SCROLL</dd>
  41  * </dl>
  42  *
  43  * @see DropTargetAdapter
  44  * @see DropTargetEvent
  45  * @see <a href="http://www.eclipse.org/swt/">Sample code and further information</a>
  46  *
  47  * @since 3.3
  48  */
  49 public class TableDropTargetEffect extends DropTargetEffect {
  50         static final int SCROLL_HYSTERESIS = 200; // milli seconds
  51
  52         int scrollIndex = -1;
  53         long scrollBeginTime;
  54         TableItem dropHighlight;
  55         int iItemInsert = -1;
  56
  57         /**
  58          * Creates a new <code>TableDropTargetEffect</code> to handle the drag under effect on the specified
  59          * <code>Table</code>.
  60          *
  61          * @param table the <code>Table</code> over which the user positions the cursor to drop the data
  62          */
  63         public TableDropTargetEffect(Table table) {
  64                 super(table);
  65         }
  66
  67         int checkEffect(int effect) {
  68                 // Some effects are mutually exclusive.  Make sure that only one of the mutually exclusive effects has been specified.
  69                 if ((effect & DND.FEEDBACK_SELECT) != 0) effect = effect & ~DND.FEEDBACK_INSERT_AFTER & ~DND.FEEDBACK_INSERT_BEFORE;
  70                 if ((effect & DND.FEEDBACK_INSERT_BEFORE) != 0) effect = effect & ~DND.FEEDBACK_INSERT_AFTER;
  71                 return effect;
  72         }
  73
  74         /**
  75          * This implementation of <code>dragEnter</code> provides a default drag under effect
  76          * for the feedback specified in <code>event.feedback</code>.
  77          *
  78          * For additional information see <code>DropTargetAdapter.dragEnter</code>.
  79          *
  80          * Subclasses that override this method should call <code>super.dragEnter(event)</code>
  81          * to get the default drag under effect implementation.
  82          *
  83          * @param event  the information associated with the drag enter event
  84          *
  85          * @see DropTargetAdapter
  86          * @see DropTargetEvent
  87          */
  88         @Override
  89         public void dragEnter(DropTargetEvent event) {
  90                 scrollBeginTime = 0;
  91                 scrollIndex = -1;
  92                 dropHighlight = null;
  93                 iItemInsert = -1;
  94         }
  95
  96         /**
  97          * This implementation of <code>dragLeave</code> provides a default drag under effect
  98          * for the feedback specified in <code>event.feedback</code>.
  99          *
 100          * For additional information see <code>DropTargetAdapter.dragLeave</code>.
 101          *
 102          * Subclasses that override this method should call <code>super.dragLeave(event)</code>
 103          * to get the default drag under effect implementation.
 104          *
 105          * @param event  the information associated with the drag leave event
 106          *
 107          * @see DropTargetAdapter
 108          * @see DropTargetEvent
 109          */
 110         @Override
 111         public void dragLeave(DropTargetEvent event) {
 112                 Table table = (Table) control;
 113                 long handle = table.handle;
 114                 if (dropHighlight != null) {
 115                         LVITEM lvItem = new LVITEM ();
 116                         lvItem.stateMask = OS.LVIS_DROPHILITED;
 117                         OS.SendMessage(handle, OS.LVM_SETITEMSTATE, -1, lvItem);
 118                         dropHighlight = null;
 119                 }
 120                 if (iItemInsert != -1) {
 121                         LVINSERTMARK plvim = new LVINSERTMARK ();
 122                         plvim.cbSize = LVINSERTMARK.sizeof;
 123                         plvim.iItem = -1;
 124                         OS.SendMessage(handle, OS.LVM_SETINSERTMARK, 0, plvim);
 125                         iItemInsert = -1;
 126                 }
 127                 scrollBeginTime = 0;
 128                 scrollIndex = -1;
 129         }
 130
 131         /**
 132          * This implementation of <code>dragOver</code> provides a default drag under effect
 133          * for the feedback specified in <code>event.feedback</code>. The class description
 134          * lists the FEEDBACK constants that are applicable to the class.
 135          *
 136          * For additional information see <code>DropTargetAdapter.dragOver</code>.
 137          *
 138          * Subclasses that override this method should call <code>super.dragOver(event)</code>
 139          * to get the default drag under effect implementation.
 140          *
 141          * @param event  the information associated with the drag over event
 142          *
 143          * @see DropTargetAdapter
 144          * @see DropTargetEvent
 145          * @see DND#FEEDBACK_SELECT
 146          * @see DND#FEEDBACK_SCROLL
 147          */
 148         @Override
 149         public void dragOver(DropTargetEvent event) {
 150                 Table table = (Table) getControl();
 151                 int effect = checkEffect(event.feedback);
 152                 long handle = table.handle;
 153                 Point coordinates = new Point(event.x, event.y);
 154                 coordinates = DPIUtil.autoScaleUp(table.toControl(coordinates)); // To Pixels
 155                 LVHITTESTINFO pinfo = new LVHITTESTINFO();
 156                 pinfo.x = coordinates.x;
 157                 pinfo.y = coordinates.y;
 158                 OS.SendMessage(handle, OS.LVM_HITTEST, 0, pinfo);
 159                 if ((effect & DND.FEEDBACK_SCROLL) == 0) {
 160                         scrollBeginTime = 0;
 161                         scrollIndex = -1;
 162                 } else {
 163                         if (pinfo.iItem != -1 && scrollIndex == pinfo.iItem && scrollBeginTime != 0) {
 164                                 if (System.currentTimeMillis() >= scrollBeginTime) {
 165                                         int top = Math.max (0, (int)OS.SendMessage (handle, OS.LVM_GETTOPINDEX, 0, 0));
 166                                         int count = (int)OS.SendMessage (handle, OS.LVM_GETITEMCOUNT, 0, 0);
 167                                         int index = (scrollIndex - 1 < top) ? Math.max(0, scrollIndex - 1) : Math.min(count - 1, scrollIndex + 1);
 168                                         boolean scroll = true;
 169                                         if (pinfo.iItem == top) {
 170                                                 scroll = pinfo.iItem != index;
 171                                         } else {
 172                                                 RECT itemRect = new RECT ();
 173                                                 itemRect.left = OS.LVIR_BOUNDS;
 174                                                 if (OS.SendMessage (handle, OS.LVM_GETITEMRECT, pinfo.iItem, itemRect) != 0) {
 175                                                         RECT rect = new RECT ();
 176                                                         OS.GetClientRect (handle, rect);
 177                                                         POINT pt = new POINT ();
 178                                                         pt.x = itemRect.left;
 179                                                         pt.y = itemRect.top;
 180                                                         if (OS.PtInRect (rect, pt)) {
 181                                                                 pt.y = itemRect.bottom;
 182                                                                 if (OS.PtInRect (rect, pt)) scroll = false;
 183                                                         }
 184                                                 }
 185                                         }
 186                                         if (scroll) {
 187                                                 OS.SendMessage (handle, OS.LVM_ENSUREVISIBLE, index, 0);
 188                                                 table.redraw();
 189                                         }
 190                                         scrollBeginTime = 0;
 191                                         scrollIndex = -1;
 192                                 }
 193                         } else {
 194                                 scrollBeginTime = System.currentTimeMillis() + SCROLL_HYSTERESIS;
 195                                 scrollIndex = pinfo.iItem;
 196                         }
 197                 }
 198
 199                 if (pinfo.iItem != -1 && (effect & DND.FEEDBACK_SELECT) != 0) {
 200                         TableItem item = table.getItem(pinfo.iItem);
 201                         if (dropHighlight != item) {
 202                                 LVITEM lvItem = new LVITEM();
 203                                 lvItem.stateMask = OS.LVIS_DROPHILITED;
 204                                 OS.SendMessage(handle, OS.LVM_SETITEMSTATE, -1, lvItem);
 205                                 lvItem.state = OS.LVIS_DROPHILITED;
 206                                 OS.SendMessage(handle, OS.LVM_SETITEMSTATE, pinfo.iItem, lvItem);
 207                                 dropHighlight = item;
 208                         }
 209                 } else {
 210                         if (dropHighlight != null) {
 211                                 LVITEM lvItem = new LVITEM ();
 212                                 lvItem.stateMask = OS.LVIS_DROPHILITED;
 213                                 OS.SendMessage(handle, OS.LVM_SETITEMSTATE, -1, lvItem);
 214                                 dropHighlight = null;
 215                         }
 216                 }
 217                 if (pinfo.iItem != -1 && (effect & (DND.FEEDBACK_INSERT_BEFORE | DND.FEEDBACK_INSERT_AFTER)) != 0) {
 218                                 LVINSERTMARK plvim = new LVINSERTMARK ();
 219                                 plvim.cbSize = LVINSERTMARK.sizeof;
 220                                 plvim.dwFlags = (effect & DND.FEEDBACK_INSERT_AFTER) != 0 ? OS.LVIM_AFTER : 0;
 221                                 plvim.iItem = pinfo.iItem;
 222                                 if (OS.SendMessage(handle, OS.LVM_SETINSERTMARK, 0, plvim) != 0) {
 223                                         iItemInsert = pinfo.iItem;
 224                                 }
 225                 } else {
 226                         if (iItemInsert != -1) {
 227                                 LVINSERTMARK plvim = new LVINSERTMARK ();
 228                                 plvim.cbSize = LVINSERTMARK.sizeof;
 229                                 plvim.iItem = -1;
 230                                 OS.SendMessage(handle, OS.LVM_SETINSERTMARK, 0, plvim);
 231                                 iItemInsert = -1;
 232                         }
 233                 }
 234         }
 235 }