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Diffstat (limited to 'components/newtab/updater.js')
| -rw-r--r-- | components/newtab/updater.js | 177 |
1 files changed, 177 insertions, 0 deletions
diff --git a/components/newtab/updater.js b/components/newtab/updater.js new file mode 100644 index 0000000..2bab74d --- /dev/null +++ b/components/newtab/updater.js @@ -0,0 +1,177 @@ +#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 + +/** + * This singleton provides functionality to update the current grid to a new + * set of pinned and blocked sites. It adds, moves and removes sites. + */ +var gUpdater = { + /** + * Updates the current grid according to its pinned and blocked sites. + * This removes old, moves existing and creates new sites to fill gaps. + * @param aCallback The callback to call when finished. + */ + updateGrid: function Updater_updateGrid(aCallback) { + let links = gLinks.getLinks().slice(0, gGrid.cells.length); + + // Find all sites that remain in the grid. + let sites = this._findRemainingSites(links); + + // Remove sites that are no longer in the grid. + this._removeLegacySites(sites, () => { + // Freeze all site positions so that we can move their DOM nodes around + // without any visual impact. + this._freezeSitePositions(sites); + + // Move the sites' DOM nodes to their new position in the DOM. This will + // have no visual effect as all the sites have been frozen and will + // remain in their current position. + this._moveSiteNodes(sites); + + // Now it's time to animate the sites actually moving to their new + // positions. + this._rearrangeSites(sites, () => { + // Try to fill empty cells and finish. + this._fillEmptyCells(links, aCallback); + + // Update other pages that might be open to keep them synced. + gAllPages.update(gPage); + }); + }); + }, + + /** + * Takes an array of links and tries to correlate them to sites contained in + * the current grid. If no corresponding site can be found (i.e. the link is + * new and a site will be created) then just set it to null. + * @param aLinks The array of links to find sites for. + * @return Array of sites mapped to the given links (can contain null values). + */ + _findRemainingSites: function Updater_findRemainingSites(aLinks) { + let map = {}; + + // Create a map to easily retrieve the site for a given URL. + gGrid.sites.forEach(function (aSite) { + if (aSite) + map[aSite.url] = aSite; + }); + + // Map each link to its corresponding site, if any. + return aLinks.map(function (aLink) { + return aLink && (aLink.url in map) && map[aLink.url]; + }); + }, + + /** + * Freezes the given sites' positions. + * @param aSites The array of sites to freeze. + */ + _freezeSitePositions: function Updater_freezeSitePositions(aSites) { + aSites.forEach(function (aSite) { + if (aSite) + gTransformation.freezeSitePosition(aSite); + }); + }, + + /** + * Moves the given sites' DOM nodes to their new positions. + * @param aSites The array of sites to move. + */ + _moveSiteNodes: function Updater_moveSiteNodes(aSites) { + let cells = gGrid.cells; + + // Truncate the given array of sites to not have more sites than cells. + // This can happen when the user drags a bookmark (or any other new kind + // of link) onto the grid. + let sites = aSites.slice(0, cells.length); + + sites.forEach(function (aSite, aIndex) { + let cell = cells[aIndex]; + let cellSite = cell.site; + + // The site's position didn't change. + if (!aSite || cellSite != aSite) { + let cellNode = cell.node; + + // Empty the cell if necessary. + if (cellSite) + cellNode.removeChild(cellSite.node); + + // Put the new site in place, if any. + if (aSite) + cellNode.appendChild(aSite.node); + } + }, this); + }, + + /** + * Rearranges the given sites and slides them to their new positions. + * @param aSites The array of sites to re-arrange. + * @param aCallback The callback to call when finished. + */ + _rearrangeSites: function Updater_rearrangeSites(aSites, aCallback) { + let options = {callback: aCallback, unfreeze: true}; + gTransformation.rearrangeSites(aSites, options); + }, + + /** + * Removes all sites from the grid that are not in the given links array or + * exceed the grid. + * @param aSites The array of sites remaining in the grid. + * @param aCallback The callback to call when finished. + */ + _removeLegacySites: function Updater_removeLegacySites(aSites, aCallback) { + let batch = []; + + // Delete sites that were removed from the grid. + gGrid.sites.forEach(function (aSite) { + // The site must be valid and not in the current grid. + if (!aSite || aSites.indexOf(aSite) != -1) + return; + + batch.push(new Promise(resolve => { + // Fade out the to-be-removed site. + gTransformation.hideSite(aSite, function () { + let node = aSite.node; + + // Remove the site from the DOM. + node.parentNode.removeChild(node); + resolve(); + }); + })); + }); + + Promise.all(batch).then(aCallback); + }, + + /** + * Tries to fill empty cells with new links if available. + * @param aLinks The array of links. + * @param aCallback The callback to call when finished. + */ + _fillEmptyCells: function Updater_fillEmptyCells(aLinks, aCallback) { + let {cells, sites} = gGrid; + + // Find empty cells and fill them. + Promise.all(sites.map((aSite, aIndex) => { + if (aSite || !aLinks[aIndex]) + return null; + + return new Promise(resolve => { + // Create the new site and fade it in. + let site = gGrid.createSite(aLinks[aIndex], cells[aIndex]); + + // Set the site's initial opacity to zero. + site.node.style.opacity = 0; + + // Flush all style changes for the dynamically inserted site to make + // the fade-in transition work. + window.getComputedStyle(site.node).opacity; + gTransformation.showSite(site, resolve); + }); + })).then(aCallback).catch(console.exception); + } +}; |