The Tor Browser / file revision

 #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);

   }

 };