Table.
+ *
+ * Classes that wish to provide their own drag under effect for a Table
+ * can extend the TableDropTargetEffect and override any applicable methods
+ * in TableDropTargetEffect to display their own drag under effect.
super method to get the default drag under effect implementation.
+ *
+ * The feedback value is either one of the FEEDBACK constants defined in
+ * class DND which is applicable to instances of this class,
+ * or it must be built by bitwise OR'ing together
+ * (that is, using the int "|" operator) two or more
+ * of those DND effect constants.
+ *
TableDropTargetEffect to handle the drag under effect on the specified
+ * Table.
+ *
+ * @param table the Table over which the user positions the cursor to drop the data
+ */
+ public TableDropTargetEffect(Table table) {
+ super(table);
+ }
+
+ int checkEffect(int effect) {
+ // Some effects are mutually exclusive. Make sure that only one of the mutually exclusive effects has been specified.
+ if ((effect & DND.FEEDBACK_SELECT) != 0) effect = effect & ~DND.FEEDBACK_INSERT_AFTER & ~DND.FEEDBACK_INSERT_BEFORE;
+ if ((effect & DND.FEEDBACK_INSERT_BEFORE) != 0) effect = effect & ~DND.FEEDBACK_INSERT_AFTER;
+ return effect;
+ }
+
+ /**
+ * This implementation of dragEnter provides a default drag under effect
+ * for the feedback specified in event.feedback.
+ *
+ * For additional information see DropTargetAdapter.dragEnter.
+ *
+ * Subclasses that override this method should call super.dragEnter(event)
+ * to get the default drag under effect implementation.
+ *
+ * @param event the information associated with the drag enter event
+ *
+ * @see DropTargetAdapter
+ * @see DropTargetEvent
+ */
+ @Override
+ public void dragEnter(DropTargetEvent event) {
+ scrollBeginTime = 0;
+ scrollIndex = -1;
+ dropHighlight = null;
+ iItemInsert = -1;
+ }
+
+ /**
+ * This implementation of dragLeave provides a default drag under effect
+ * for the feedback specified in event.feedback.
+ *
+ * For additional information see DropTargetAdapter.dragLeave.
+ *
+ * Subclasses that override this method should call super.dragLeave(event)
+ * to get the default drag under effect implementation.
+ *
+ * @param event the information associated with the drag leave event
+ *
+ * @see DropTargetAdapter
+ * @see DropTargetEvent
+ */
+ @Override
+ public void dragLeave(DropTargetEvent event) {
+ Table table = (Table) control;
+ long handle = table.handle;
+ if (dropHighlight != null) {
+ LVITEM lvItem = new LVITEM ();
+ lvItem.stateMask = OS.LVIS_DROPHILITED;
+ OS.SendMessage(handle, OS.LVM_SETITEMSTATE, -1, lvItem);
+ dropHighlight = null;
+ }
+ if (iItemInsert != -1) {
+ LVINSERTMARK plvim = new LVINSERTMARK ();
+ plvim.cbSize = LVINSERTMARK.sizeof;
+ plvim.iItem = -1;
+ OS.SendMessage(handle, OS.LVM_SETINSERTMARK, 0, plvim);
+ iItemInsert = -1;
+ }
+ scrollBeginTime = 0;
+ scrollIndex = -1;
+ }
+
+ /**
+ * This implementation of dragOver provides a default drag under effect
+ * for the feedback specified in event.feedback. The class description
+ * lists the FEEDBACK constants that are applicable to the class.
+ *
+ * For additional information see DropTargetAdapter.dragOver.
+ *
+ * Subclasses that override this method should call super.dragOver(event)
+ * to get the default drag under effect implementation.
+ *
+ * @param event the information associated with the drag over event
+ *
+ * @see DropTargetAdapter
+ * @see DropTargetEvent
+ * @see DND#FEEDBACK_SELECT
+ * @see DND#FEEDBACK_SCROLL
+ */
+ @Override
+ public void dragOver(DropTargetEvent event) {
+ Table table = (Table) getControl();
+ int effect = checkEffect(event.feedback);
+ long handle = table.handle;
+ Point coordinates = new Point(event.x, event.y);
+ coordinates = DPIUtil.autoScaleUp(table.toControl(coordinates)); // To Pixels
+ LVHITTESTINFO pinfo = new LVHITTESTINFO();
+ pinfo.x = coordinates.x;
+ pinfo.y = coordinates.y;
+ OS.SendMessage(handle, OS.LVM_HITTEST, 0, pinfo);
+ if ((effect & DND.FEEDBACK_SCROLL) == 0) {
+ scrollBeginTime = 0;
+ scrollIndex = -1;
+ } else {
+ if (pinfo.iItem != -1 && scrollIndex == pinfo.iItem && scrollBeginTime != 0) {
+ if (System.currentTimeMillis() >= scrollBeginTime) {
+ int top = Math.max (0, (int)OS.SendMessage (handle, OS.LVM_GETTOPINDEX, 0, 0));
+ int count = (int)OS.SendMessage (handle, OS.LVM_GETITEMCOUNT, 0, 0);
+ int index = (scrollIndex - 1 < top) ? Math.max(0, scrollIndex - 1) : Math.min(count - 1, scrollIndex + 1);
+ boolean scroll = true;
+ if (pinfo.iItem == top) {
+ scroll = pinfo.iItem != index;
+ } else {
+ RECT itemRect = new RECT ();
+ itemRect.left = OS.LVIR_BOUNDS;
+ if (OS.SendMessage (handle, OS.LVM_GETITEMRECT, pinfo.iItem, itemRect) != 0) {
+ RECT rect = new RECT ();
+ OS.GetClientRect (handle, rect);
+ POINT pt = new POINT ();
+ pt.x = itemRect.left;
+ pt.y = itemRect.top;
+ if (OS.PtInRect (rect, pt)) {
+ pt.y = itemRect.bottom;
+ if (OS.PtInRect (rect, pt)) scroll = false;
+ }
+ }
+ }
+ if (scroll) {
+ OS.SendMessage (handle, OS.LVM_ENSUREVISIBLE, index, 0);
+ table.redraw();
+ }
+ scrollBeginTime = 0;
+ scrollIndex = -1;
+ }
+ } else {
+ scrollBeginTime = System.currentTimeMillis() + SCROLL_HYSTERESIS;
+ scrollIndex = pinfo.iItem;
+ }
+ }
+
+ if (pinfo.iItem != -1 && (effect & DND.FEEDBACK_SELECT) != 0) {
+ TableItem item = table.getItem(pinfo.iItem);
+ if (dropHighlight != item) {
+ LVITEM lvItem = new LVITEM();
+ lvItem.stateMask = OS.LVIS_DROPHILITED;
+ OS.SendMessage(handle, OS.LVM_SETITEMSTATE, -1, lvItem);
+ lvItem.state = OS.LVIS_DROPHILITED;
+ OS.SendMessage(handle, OS.LVM_SETITEMSTATE, pinfo.iItem, lvItem);
+ dropHighlight = item;
+ }
+ } else {
+ if (dropHighlight != null) {
+ LVITEM lvItem = new LVITEM ();
+ lvItem.stateMask = OS.LVIS_DROPHILITED;
+ OS.SendMessage(handle, OS.LVM_SETITEMSTATE, -1, lvItem);
+ dropHighlight = null;
+ }
+ }
+ if (pinfo.iItem != -1 && (effect & (DND.FEEDBACK_INSERT_BEFORE | DND.FEEDBACK_INSERT_AFTER)) != 0) {
+ LVINSERTMARK plvim = new LVINSERTMARK ();
+ plvim.cbSize = LVINSERTMARK.sizeof;
+ plvim.dwFlags = (effect & DND.FEEDBACK_INSERT_AFTER) != 0 ? OS.LVIM_AFTER : 0;
+ plvim.iItem = pinfo.iItem;
+ if (OS.SendMessage(handle, OS.LVM_SETINSERTMARK, 0, plvim) != 0) {
+ iItemInsert = pinfo.iItem;
+ }
+ } else {
+ if (iItemInsert != -1) {
+ LVINSERTMARK plvim = new LVINSERTMARK ();
+ plvim.cbSize = LVINSERTMARK.sizeof;
+ plvim.iItem = -1;
+ OS.SendMessage(handle, OS.LVM_SETINSERTMARK, 0, plvim);
+ iItemInsert = -1;
+ }
+ }
+ }
+}