org.eclipse.swt.dnd.TableDropTargetEffect Maven / Gradle / Ivy
/*******************************************************************************
* Copyright (c) 2007, 2012 IBM Corporation and others.
* 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
*******************************************************************************/
package org.eclipse.swt.dnd;
import org.eclipse.swt.graphics.*;
import org.eclipse.swt.internal.win32.*;
import org.eclipse.swt.widgets.*;
/**
* This class provides a default drag under effect (eg. select, insert and scroll)
* when a drag occurs over a 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.
*
* Subclasses that override any methods of this class must call the corresponding
* 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.
*
*
*
* - Feedback:
* - FEEDBACK_SELECT, FEEDBACK_SCROLL
*
*
*
* @see DropTargetAdapter
* @see DropTargetEvent
* @see Sample code and further information
*
* @since 3.3
*/
public class TableDropTargetEffect extends DropTargetEffect {
static final int SCROLL_HYSTERESIS = 200; // milli seconds
int scrollIndex = -1;
long scrollBeginTime;
TableItem dropHighlight;
int iItemInsert = -1;
/**
* Creates a new 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
*/
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
*/
public void dragLeave(DropTargetEvent event) {
Table table = (Table) control;
int /*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 (!OS.IsWinCE && OS.WIN32_VERSION >= OS.VERSION(5, 1)) {
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
*/
public void dragOver(DropTargetEvent event) {
Table table = (Table) getControl();
int effect = checkEffect(event.feedback);
int /*long*/ handle = table.handle;
Point coordinates = new Point(event.x, event.y);
coordinates = table.toControl(coordinates);
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)/*64*/OS.SendMessage (handle, OS.LVM_GETTOPINDEX, 0, 0));
int count = (int)/*64*/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 (!OS.IsWinCE && OS.WIN32_VERSION >= OS.VERSION(5, 1)) {
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;
}
}
}
}
}