gecko/browser/base/content/newtab/drop.js

151 lines
4.1 KiB
JavaScript

#ifdef 0
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this file,
* You can obtain one at http://mozilla.org/MPL/2.0/. */
#endif
// A little delay that prevents the grid from being too sensitive when dragging
// sites around.
const DELAY_REARRANGE_MS = 100;
/**
* This singleton implements site dropping functionality.
*/
let gDrop = {
/**
* The last drop target.
*/
_lastDropTarget: null,
/**
* Handles the 'dragenter' event.
* @param aCell The drop target cell.
*/
enter: function Drop_enter(aCell) {
this._delayedRearrange(aCell);
},
/**
* Handles the 'dragexit' event.
* @param aCell The drop target cell.
* @param aEvent The 'dragexit' event.
*/
exit: function Drop_exit(aCell, aEvent) {
if (aEvent.dataTransfer && !aEvent.dataTransfer.mozUserCancelled) {
this._delayedRearrange();
} else {
// The drag operation has been cancelled.
this._cancelDelayedArrange();
this._rearrange();
}
},
/**
* Handles the 'drop' event.
* @param aCell The drop target cell.
* @param aEvent The 'dragexit' event.
*/
drop: function Drop_drop(aCell, aEvent) {
// The cell that is the drop target could contain a pinned site. We need
// to find out where that site has gone and re-pin it there.
if (aCell.containsPinnedSite())
this._repinSitesAfterDrop(aCell);
// Pin the dragged or insert the new site.
this._pinDraggedSite(aCell, aEvent);
this._cancelDelayedArrange();
// Update the grid and move all sites to their new places.
gUpdater.updateGrid();
},
/**
* Re-pins all pinned sites in their (new) positions.
* @param aCell The drop target cell.
*/
_repinSitesAfterDrop: function Drop_repinSitesAfterDrop(aCell) {
let sites = gDropPreview.rearrange(aCell);
// Filter out pinned sites.
let pinnedSites = sites.filter(function (aSite) {
return aSite && aSite.isPinned();
});
// Re-pin all shifted pinned cells.
pinnedSites.forEach(function (aSite) aSite.pin(sites.indexOf(aSite)), this);
},
/**
* Pins the dragged site in its new place.
* @param aCell The drop target cell.
* @param aEvent The 'dragexit' event.
*/
_pinDraggedSite: function Drop_pinDraggedSite(aCell, aEvent) {
let index = aCell.index;
let draggedSite = gDrag.draggedSite;
if (draggedSite) {
// Pin the dragged site at its new place.
if (aCell != draggedSite.cell)
draggedSite.pin(index);
} else {
let link = gDragDataHelper.getLinkFromDragEvent(aEvent);
if (link) {
// A new link was dragged onto the grid. Create it by pinning its URL.
gPinnedLinks.pin(link, index);
// Make sure the newly added link is not blocked.
gBlockedLinks.unblock(link);
}
}
},
/**
* Time a rearrange with a little delay.
* @param aCell The drop target cell.
*/
_delayedRearrange: function Drop_delayedRearrange(aCell) {
// The last drop target didn't change so there's no need to re-arrange.
if (this._lastDropTarget == aCell)
return;
let self = this;
function callback() {
self._rearrangeTimeout = null;
self._rearrange(aCell);
}
this._cancelDelayedArrange();
this._rearrangeTimeout = setTimeout(callback, DELAY_REARRANGE_MS);
// Store the last drop target.
this._lastDropTarget = aCell;
},
/**
* Cancels a timed rearrange, if any.
*/
_cancelDelayedArrange: function Drop_cancelDelayedArrange() {
if (this._rearrangeTimeout) {
clearTimeout(this._rearrangeTimeout);
this._rearrangeTimeout = null;
}
},
/**
* Rearrange all sites in the grid depending on the current drop target.
* @param aCell The drop target cell.
*/
_rearrange: function Drop_rearrange(aCell) {
let sites = gGrid.sites;
// We need to rearrange the grid only if there's a current drop target.
if (aCell)
sites = gDropPreview.rearrange(aCell);
gTransformation.rearrangeSites(sites, {unfreeze: !aCell});
}
};