The Tor Browser: browser/base/content/newtab/drag.js@b8a032363ba2 (annotated)

browser/base/content/newtab/drag.js@b8a032363ba2 (annotated)

browser/base/content/newtab/drag.js

Thu, 22 Jan 2015 13:21:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 22 Jan 2015 13:21:57 +0100
branch: TOR_BUG_9701
changeset 15: b8a032363ba2
permissions: -rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

 #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 implements site dragging functionality.
  */
 let gDrag = {
   /**
    * The site offset to the drag start point.
    */
   _offsetX: null,
   _offsetY: null,
   /**
    * The site that is dragged.
    */
   _draggedSite: null,
   get draggedSite() this._draggedSite,
   /**
    * The cell width/height at the point the drag started.
    */
   _cellWidth: null,
   _cellHeight: null,
   get cellWidth() this._cellWidth,
   get cellHeight() this._cellHeight,
   /**
    * Start a new drag operation.
    * @param aSite The site that's being dragged.
    * @param aEvent The 'dragstart' event.
    */
   start: function Drag_start(aSite, aEvent) {
     this._draggedSite = aSite;
     // Mark nodes as being dragged.
     let selector = ".newtab-site, .newtab-control, .newtab-thumbnail";
     let parentCell = aSite.node.parentNode;
     let nodes = parentCell.querySelectorAll(selector);
     for (let i = 0; i < nodes.length; i++)
       nodes[i].setAttribute("dragged", "true");
     parentCell.setAttribute("dragged", "true");
     this._setDragData(aSite, aEvent);
     // Store the cursor offset.
     let node = aSite.node;
     let rect = node.getBoundingClientRect();
     this._offsetX = aEvent.clientX - rect.left;
     this._offsetY = aEvent.clientY - rect.top;
     // Store the cell dimensions.
     let cellNode = aSite.cell.node;
     this._cellWidth = cellNode.offsetWidth;
     this._cellHeight = cellNode.offsetHeight;
     gTransformation.freezeSitePosition(aSite);
   },
   /**
    * Handles the 'drag' event.
    * @param aSite The site that's being dragged.
    * @param aEvent The 'drag' event.
    */
   drag: function Drag_drag(aSite, aEvent) {
     // Get the viewport size.
     let {clientWidth, clientHeight} = document.documentElement;
     // We'll want a padding of 5px.
     let border = 5;
     // Enforce minimum constraints to keep the drag image inside the window.
     let left = Math.max(scrollX + aEvent.clientX - this._offsetX, border);
     let top = Math.max(scrollY + aEvent.clientY - this._offsetY, border);
     // Enforce maximum constraints to keep the drag image inside the window.
     left = Math.min(left, scrollX + clientWidth - this.cellWidth - border);
     top = Math.min(top, scrollY + clientHeight - this.cellHeight - border);
     // Update the drag image's position.
     gTransformation.setSitePosition(aSite, {left: left, top: top});
   },
   /**
    * Ends the current drag operation.
    * @param aSite The site that's being dragged.
    * @param aEvent The 'dragend' event.
    */
   end: function Drag_end(aSite, aEvent) {
     let nodes = gGrid.node.querySelectorAll("[dragged]")
     for (let i = 0; i < nodes.length; i++)
       nodes[i].removeAttribute("dragged");
     // Slide the dragged site back into its cell (may be the old or the new cell).
     gTransformation.slideSiteTo(aSite, aSite.cell, {unfreeze: true});
     this._draggedSite = null;
   },
   /**
    * Checks whether we're responsible for a given drag event.
    * @param aEvent The drag event to check.
    * @return Whether we should handle this drag and drop operation.
    */
   isValid: function Drag_isValid(aEvent) {
     let link = gDragDataHelper.getLinkFromDragEvent(aEvent);
     // Check that the drag data is non-empty.
     // Can happen when dragging places folders.
     if (!link || !link.url) {
       return false;
     }
     // Check that we're not accepting URLs which would inherit the caller's
     // principal (such as javascript: or data:).
     return gLinkChecker.checkLoadURI(link.url);
   },
   /**
    * Initializes the drag data for the current drag operation.
    * @param aSite The site that's being dragged.
    * @param aEvent The 'dragstart' event.
    */
   _setDragData: function Drag_setDragData(aSite, aEvent) {
     let {url, title} = aSite;
     let dt = aEvent.dataTransfer;
     dt.mozCursor = "default";
     dt.effectAllowed = "move";
     dt.setData("text/plain", url);
     dt.setData("text/uri-list", url);
     dt.setData("text/x-moz-url", url + "\n" + title);
     dt.setData("text/html", "<a href=\"" + url + "\">" + url + "</a>");
     // Create and use an empty drag element. We don't want to use the default
     // drag image with its default opacity.
     let dragElement = document.createElementNS(HTML_NAMESPACE, "div");
     dragElement.classList.add("newtab-drag");
     let scrollbox = document.getElementById("newtab-scrollbox");
     scrollbox.appendChild(dragElement);
     dt.setDragImage(dragElement, 0, 0);
     // After the 'dragstart' event has been processed we can remove the
     // temporary drag element from the DOM.
     setTimeout(function () scrollbox.removeChild(dragElement), 0);
   }
 };