private void commitPosition(int pos) {
lastElementX_ = pos;
// check to see if we're overlapping with another tab
for (int i = 0; i < dragTabsHost_.getChildCount(); i++) {
// skip non-element DOM nodes
Node node = dragTabsHost_.getChild(i);
if (node.getNodeType() != Node.ELEMENT_NODE) {
continue;
}
// skip the current candidate (no point in testing it for swap)
if (i == candidatePos_) {
continue;
}
// skip the element we're dragging and elements that are not tabs
Element ele = (Element) node;
if (ele == dragElement_ || ele.getClassName().indexOf("gwt-TabLayoutPanelTab") < 0) {
continue;
}
int left = DomUtils.leftRelativeTo(dragTabsHost_, ele);
int right = left + ele.getClientWidth();
int minOverlap = Math.min(initDragWidth_ / 2, ele.getClientWidth() / 2);
// a little complicated: compute the number of overlapping pixels
// with this element; if the overlap is more than half of our width
// (or the width of the candidate), it's swapping time
if (Math.min(lastElementX_ + initDragWidth_, right) - Math.max(lastElementX_, left)
>= minOverlap) {
dragTabsHost_.removeChild(dragPlaceholder_);
if (candidatePos_ > i) {
dragTabsHost_.insertBefore(dragPlaceholder_, ele);
} else {
dragTabsHost_.insertAfter(dragPlaceholder_, ele);
}
candidatePos_ = i;
// account for the extra element when moving to the right of the
// original location
if (dragElement_ != null && startPos_ != null) {
destPos_ = startPos_ <= candidatePos_ ? candidatePos_ - 1 : candidatePos_;
} else {
destPos_ = candidatePos_;
}
}
}
}
private void beginDrag(Event evt) {
String docId = initDragParams_.getDocId();
int dragTabWidth = initDragWidth_;
// set drag element state
dragTabsHost_ = getTabBarElement();
dragScrollHost_ = dragTabsHost_.getParentElement();
outOfBounds_ = 0;
candidatePos_ = null;
startPos_ = null;
// attempt to determine which tab the cursor is over
Point hostPos = DomUtils.getRelativePosition(Document.get().getBody(), dragTabsHost_);
int dragX = evt.getClientX() - hostPos.getX();
for (int i = 0; i < dragTabsHost_.getChildCount(); i++) {
Node node = dragTabsHost_.getChild(i);
if (node.getNodeType() == Node.ELEMENT_NODE) {
int left =
DomUtils.leftRelativeTo(dragTabsHost_, Element.as(node))
- dragScrollHost_.getScrollLeft();
int right = left + Element.as(node).getOffsetWidth();
if (left <= dragX && dragX <= right) {
candidatePos_ = i;
break;
}
}
}
// let the rest of the IDE know we're dragging (this will enable us to
// disable drag targets that might otherwise be happy to accept the
// data)
curState_ = STATE_DRAGGING;
events_.fireEvent(
new DocTabDragStateChangedEvent(DocTabDragStateChangedEvent.STATE_DRAGGING));
// the relative position of the last node determines how far we
// can drag
dragMax_ =
DomUtils.leftRelativeTo(dragTabsHost_, getLastChildElement(dragTabsHost_))
+ getLastChildElement(dragTabsHost_).getClientWidth();
lastCursorX_ = evt.getClientX();
// account for cursor starting out of bounds (e.g. dragging into
// empty space on the right of the panel)
if (lastCursorX_ > dragMax_ + (initDragParams_.getCursorOffset()))
outOfBounds_ = (lastCursorX_ - dragMax_) - initDragParams_.getCursorOffset();
// attempt to ascertain whether the element being dragged is one of
// our own documents
for (DocTab tab : docTabs_) {
if (tab.getDocId() == docId) {
dragElement_ = tab.getElement().getParentElement().getParentElement();
break;
}
}
// if we couldn't find the horizontal drag position in any tab, append
// to the end
if (candidatePos_ == null) {
candidatePos_ = dragTabsHost_.getChildCount();
}
destPos_ = candidatePos_;
// if we're dragging one of our own documents, figure out its physical
// position
if (dragElement_ != null) {
for (int i = 0; i < dragTabsHost_.getChildCount(); i++) {
if (dragTabsHost_.getChild(i) == dragElement_) {
startPos_ = i;
break;
}
}
}
// compute the start location for the drag
if (candidatePos_ >= dragTabsHost_.getChildCount()) {
Element lastTab = getLastChildElement(dragTabsHost_);
lastElementX_ = DomUtils.leftRelativeTo(dragTabsHost_, lastTab) + lastTab.getOffsetWidth();
} else {
lastElementX_ =
DomUtils.leftRelativeTo(
dragTabsHost_, Element.as(dragTabsHost_.getChild(candidatePos_)));
}
// if we're dragging one of our own tabs, snap it out of the
// tabset
if (dragElement_ != null) {
dragElement_.getStyle().setPosition(Position.ABSOLUTE);
dragElement_.getStyle().setLeft(lastElementX_, Unit.PX);
dragElement_.getStyle().setZIndex(100);
Scheduler.get()
.scheduleDeferred(
new ScheduledCommand() {
@Override
public void execute() {
dragElement_.getStyle().setDisplay(Display.NONE);
}
});
}
// create the placeholder that shows where this tab will go when the
// mouse is released
dragPlaceholder_ = Document.get().createDivElement();
dragPlaceholder_.getStyle().setWidth(dragTabWidth - 4, Unit.PX);
dragPlaceholder_.getStyle().setHeight(dragTabsHost_.getClientHeight() - 3, Unit.PX);
dragPlaceholder_.getStyle().setDisplay(Display.INLINE_BLOCK);
dragPlaceholder_.getStyle().setPosition(Position.RELATIVE);
dragPlaceholder_.getStyle().setFloat(Float.LEFT);
dragPlaceholder_.getStyle().setBorderStyle(BorderStyle.DOTTED);
dragPlaceholder_.getStyle().setBorderColor("#A1A2A3");
dragPlaceholder_.getStyle().setBorderWidth(1, Unit.PX);
dragPlaceholder_.getStyle().setMarginLeft(1, Unit.PX);
dragPlaceholder_.getStyle().setMarginRight(1, Unit.PX);
dragPlaceholder_.getStyle().setProperty("borderTopLeftRadius", "4px");
dragPlaceholder_.getStyle().setProperty("borderTopRightRadius", "4px");
dragPlaceholder_.getStyle().setProperty("borderBottom", "0px");
if (candidatePos_ < dragTabsHost_.getChildCount()) {
dragTabsHost_.insertBefore(dragPlaceholder_, dragTabsHost_.getChild(candidatePos_));
} else {
dragTabsHost_.appendChild(dragPlaceholder_);
}
}