Swing/DnDBetweenLists のバックアップの現在との差分(No.12)
- category: swing
folder: DnDBetweenLists
title: JList間でのドラッグ&ドロップによるアイテムの移動
tags: [JList, DragAndDrop, TransferHandler]
author: aterai
pubdate: 2010-08-09T16:02:07+09:00
description: JList間でのドラッグ&ドロップによるアイテムの移動や並べ替えを行います。
image:
hreflang:
href: http://java-swing-tips.blogspot.com/2010/08/drag-and-drop-between-jlists.html href: https://java-swing-tips.blogspot.com/2010/08/drag-and-drop-between-jlists.html lang: en
概要
JList
間でのドラッグ&ドロップによるアイテムの移動や並べ替えを行います。
Screenshot
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サンプルコード
class ListItemTransferHandler extends TransferHandler {
private JList source = null;
protected final DataFlavor localObjectFlavor;
protected JList<?> source;
protected int[] indices;
protected int addIndex = -1;
protected int addCount;
#spanadd
#spanend
protected ListItemTransferHandler() {
super();
localObjectFlavor = new DataFlavor(List.class, "List of items");
}
#spanadd
#spanend
@Override protected Transferable createTransferable(JComponent c) {
source = (JList) c;
source = (JList<?>) c;
indices = source.getSelectedIndices();
transferedObjects = source.getSelectedValues();
return new DataHandler(transferedObjects, localObjectFlavor.getMimeType());
List<?> transferredObjects = source.getSelectedValuesList();
return new Transferable() {
@Override public DataFlavor[] getTransferDataFlavors() {
return new DataFlavor[] {localObjectFlavor};
}
#spanadd
#spanend
@Override public boolean isDataFlavorSupported(DataFlavor flavor) {
return Objects.equals(localObjectFlavor, flavor);
}
#spanadd
#spanend
@Override public Object getTransferData(DataFlavor flavor)
throws UnsupportedFlavorException, IOException {
if (isDataFlavorSupported(flavor)) {
return transferredObjects;
} else {
throw new UnsupportedFlavorException(flavor);
}
}
};
}
@Override public boolean importData(TransferSupport info) {
if (!canImport(info)) return false;
JList target = (JList) info.getComponent();
JList.DropLocation dl = (JList.DropLocation) info.getDropLocation();
#spanadd
#spanend
@Override public boolean canImport(TransferHandler.TransferSupport info) {
return info.isDrop() && info.isDataFlavorSupported(localObjectFlavor);
}
#spanadd
#spanend
@Override public int getSourceActions(JComponent c) {
return TransferHandler.MOVE;
}
#spanadd
#spanend
@SuppressWarnings("unchecked")
@Override public boolean importData(TransferHandler.TransferSupport info) {
TransferHandler.DropLocation tdl = info.getDropLocation();
if (!(tdl instanceof JList.DropLocation)) {
return false;
}
JList.DropLocation dl = (JList.DropLocation) tdl;
JList<?> target = (JList<?>) info.getComponent();
DefaultListModel listModel = (DefaultListModel) target.getModel();
int max = listModel.getSize();
int index = dl.getIndex();
int max = listModel.getSize();
if (index < 0 || index > max) index = max;
index = index < 0 ? max : index;
index = Math.min(index, max);
addIndex = index;
try {
Object[] values = (Object[]) info.getTransferable().getTransferData(localObjectFlavor);
for (int i = 0; i < values.length; i++) {
int idx = index++;
listModel.add(idx, values[i]);
target.addSelectionInterval(idx, idx);
List<?> values = (List<?>) info.getTransferable().getTransferData(
localObjectFlavor);
for (Object o : values) {
int i = index++;
listModel.add(i, o);
target.addSelectionInterval(i, i);
}
//---->
addCount = (target == source) ? values.length : 0;
//<----
// ---->
addCount = target.equals(source) ? values.size() : 0;
// <----
return true;
} catch (UnsupportedFlavorException | IOException ex) {
ex.printStackTrace();
}
return false;
}
#spandel
//...
#spanend
// ...
View in GitHub: Java, Kotlin解説
上記のサンプルでは、一つのJList
内でのアイテムの並べ替えを行うTransferHandlerを使ったJListのドラッグ&ドロップによる並べ替えを元にListItemTransferHandler
を作成し、JList
間でのアイテム移動も可能にしています。
- ドロップ先がドラッグ元と同じコンポーネントかどうかを調査する処理を変更