@Override
public void performDragOver(DropTargetEvent event) {
if (!ArtifactTransfer.getInstance().isSupportedType(event.currentDataType)) {
event.detail = DND.DROP_NONE;
return;
}
final ArtifactData artData = ArtifactTransfer.getInstance().nativeToJava(event.currentDataType);
if (artData == null) {
event.detail = DND.DROP_NONE;
return;
}
for (Artifact art : artData.getArtifacts()) {
if (art.isOfType(CoreArtifactTypes.UniversalGroup)) {
event.detail = DND.DROP_NONE;
return;
}
}
Tree tree = treeViewer.getTree();
TreeItem dragOverTreeItem = tree.getItem(treeViewer.getTree().toControl(event.x, event.y));
event.feedback = DND.FEEDBACK_EXPAND;
event.detail = DND.DROP_NONE;
// Set as COPY if drag item over group (copy versus move will be determined on drop
if (dragOverTreeItem != null
&& ((GroupExplorerItem) dragOverTreeItem.getData()).isUniversalGroup()) {
event.detail = DND.DROP_COPY;
tree.setInsertMark(null, false);
}
// Handle re-ordering within same group
else if (dragOverTreeItem != null
&& !((GroupExplorerItem) dragOverTreeItem.getData()).isUniversalGroup()) {
GroupExplorerItem dragOverGroupItem = (GroupExplorerItem) dragOverTreeItem.getData();
IStructuredSelection selectedItem = (IStructuredSelection) treeViewer.getSelection();
Object obj = selectedItem.getFirstElement();
if (obj instanceof GroupExplorerItem) {
GroupExplorerItem droppingGroupItem = (GroupExplorerItem) obj;
// the group to move must belong to the same group as the member to insert before/after
if (dragOverGroupItem.getParentItem().equals(droppingGroupItem.getParentItem())) {
if (isFeedbackAfter) {
event.feedback = DND.FEEDBACK_INSERT_AFTER;
} else {
event.feedback = DND.FEEDBACK_INSERT_BEFORE;
}
event.detail = DND.DROP_MOVE;
}
} else {
if (isFeedbackAfter) {
event.feedback = DND.FEEDBACK_INSERT_AFTER;
} else {
event.feedback = DND.FEEDBACK_INSERT_BEFORE;
}
event.detail = DND.DROP_COPY;
}
} else {
tree.setInsertMark(null, false);
}
}
@Override
protected void javaToNative(Object data, TransferData transferData) {
if (!(data instanceof ArtifactData)) {
return;
}
ArtifactData artData = (ArtifactData) data;
/**
* The resource serialization format is: (int) number of artifacts Then, the following for each
* resource: (int) artID (int) tagID Then the following (int) urlLength (int) sourceLength
* (chars) url (chars) source
*/
try {
ByteArrayOutputStream out = new ByteArrayOutputStream();
DataOutputStream dataOut = new DataOutputStream(out);
// write the number of resources
dataOut.writeInt(artData.getArtifacts().length);
for (Artifact artifact : artData.getArtifacts()) {
writeArtifact(dataOut, artifact);
}
dataOut.writeInt(artData.getUrl().length());
dataOut.writeInt(artData.getSource().length());
dataOut.writeChars(artData.getUrl());
dataOut.writeChars(artData.getSource());
// cleanup
dataOut.close();
out.close();
byte[] bytes = out.toByteArray();
super.javaToNative(bytes, transferData);
} catch (Exception e) {
// it's best to send nothing if there were problems
}
}