The Tor Browser: toolkit/devtools/LayoutHelpers.jsm@8bccb770b82d (annotated)

toolkit/devtools/LayoutHelpers.jsm@8bccb770b82d (annotated)

toolkit/devtools/LayoutHelpers.jsm

Wed, 31 Dec 2014 13:27:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 13:27:57 +0100
branch: TOR_BUG_3246
changeset 6: 8bccb770b82d
permissions: -rw-r--r--

Ignore runtime configuration files generated during quality assurance.

 /* -*- Mode: Javascript; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
 /* vim: set ft=javascript ts=2 et sw=2 tw=80: */
 /* 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/. */
 const Cu = Components.utils;
 const Ci = Components.interfaces;
 const Cr = Components.results;
 Cu.import("resource://gre/modules/XPCOMUtils.jsm");
 XPCOMUtils.defineLazyModuleGetter(this, "Services",
   "resource://gre/modules/Services.jsm");
 this.EXPORTED_SYMBOLS = ["LayoutHelpers"];
 this.LayoutHelpers = LayoutHelpers = function(aTopLevelWindow) {
   this._topDocShell = aTopLevelWindow.QueryInterface(Ci.nsIInterfaceRequestor)
                                      .getInterface(Ci.nsIWebNavigation)
                                      .QueryInterface(Ci.nsIDocShell);
 };
 LayoutHelpers.prototype = {
   /**
    * Get box quads adjusted for iframes and zoom level.
    *
    * @param {DOMNode} node
    *        The node for which we are to get the box model region quads
    * @param  {String} region
    *         The box model region to return:
    *         "content", "padding", "border" or "margin"
    */
   getAdjustedQuads: function(node, region) {
     if (!node) {
       return;
     }
     let [quads] = node.getBoxQuads({
       box: region
     });
     if (!quads) {
       return;
     }
     let [xOffset, yOffset] = this._getNodeOffsets(node);
     let scale = this.calculateScale(node);
     return {
       p1: {
         w: quads.p1.w * scale,
         x: quads.p1.x * scale + xOffset,
         y: quads.p1.y * scale + yOffset,
         z: quads.p1.z * scale
       },
       p2: {
         w: quads.p2.w * scale,
         x: quads.p2.x * scale + xOffset,
         y: quads.p2.y * scale + yOffset,
         z: quads.p2.z * scale
       },
       p3: {
         w: quads.p3.w * scale,
         x: quads.p3.x * scale + xOffset,
         y: quads.p3.y * scale + yOffset,
         z: quads.p3.z * scale
       },
       p4: {
         w: quads.p4.w * scale,
         x: quads.p4.x * scale + xOffset,
         y: quads.p4.y * scale + yOffset,
         z: quads.p4.z * scale
       },
       bounds: {
         bottom: quads.bounds.bottom * scale + yOffset,
         height: quads.bounds.height * scale,
         left: quads.bounds.left * scale + xOffset,
         right: quads.bounds.right * scale + xOffset,
         top: quads.bounds.top * scale + yOffset,
         width: quads.bounds.width * scale,
         x: quads.bounds.x * scale + xOffset,
         y: quads.bounds.y * scale + yOffset
       }
     };
   },
   calculateScale: function(node) {
     let win = node.ownerDocument.defaultView;
     let winUtils = win.QueryInterface(Ci.nsIInterfaceRequestor)
                       .getInterface(Ci.nsIDOMWindowUtils);
     return winUtils.fullZoom;
   },
   /**
    * Compute the absolute position and the dimensions of a node, relativalely
    * to the root window.
    *
    * @param nsIDOMNode aNode
    *        a DOM element to get the bounds for
    * @param nsIWindow aContentWindow
    *        the content window holding the node
    */
   getRect: function LH_getRect(aNode, aContentWindow) {
     let frameWin = aNode.ownerDocument.defaultView;
     let clientRect = aNode.getBoundingClientRect();
     // Go up in the tree of frames to determine the correct rectangle.
     // clientRect is read-only, we need to be able to change properties.
     let rect = {top: clientRect.top + aContentWindow.pageYOffset,
             left: clientRect.left + aContentWindow.pageXOffset,
             width: clientRect.width,
             height: clientRect.height};
     // We iterate through all the parent windows.
     while (true) {
       // Are we in the top-level window?
       if (this.isTopLevelWindow(frameWin)) {
         break;
       }
       let frameElement = this.getFrameElement(frameWin);
       if (!frameElement) {
         break;
       }
       // We are in an iframe.
       // We take into account the parent iframe position and its
       // offset (borders and padding).
       let frameRect = frameElement.getBoundingClientRect();
       let [offsetTop, offsetLeft] =
         this.getIframeContentOffset(frameElement);
       rect.top += frameRect.top + offsetTop;
       rect.left += frameRect.left + offsetLeft;
       frameWin = this.getParentWindow(frameWin);
     }
     return rect;
   },
   /**
    * Returns iframe content offset (iframe border + padding).
    * Note: this function shouldn't need to exist, had the platform provided a
    * suitable API for determining the offset between the iframe's content and
    * its bounding client rect. Bug 626359 should provide us with such an API.
    *
    * @param aIframe
    *        The iframe.
    * @returns array [offsetTop, offsetLeft]
    *          offsetTop is the distance from the top of the iframe and the
    *            top of the content document.
    *          offsetLeft is the distance from the left of the iframe and the
    *            left of the content document.
    */
   getIframeContentOffset: function LH_getIframeContentOffset(aIframe) {
     let style = aIframe.contentWindow.getComputedStyle(aIframe, null);
     // In some cases, the computed style is null
     if (!style) {
       return [0, 0];
     }
     let paddingTop = parseInt(style.getPropertyValue("padding-top"));
     let paddingLeft = parseInt(style.getPropertyValue("padding-left"));
     let borderTop = parseInt(style.getPropertyValue("border-top-width"));
     let borderLeft = parseInt(style.getPropertyValue("border-left-width"));
     return [borderTop + paddingTop, borderLeft + paddingLeft];
   },
   /**
    * Find an element from the given coordinates. This method descends through
    * frames to find the element the user clicked inside frames.
    *
    * @param DOMDocument aDocument the document to look into.
    * @param integer aX
    * @param integer aY
    * @returns Node|null the element node found at the given coordinates.
    */
   getElementFromPoint: function LH_elementFromPoint(aDocument, aX, aY) {
     let node = aDocument.elementFromPoint(aX, aY);
     if (node && node.contentDocument) {
       if (node instanceof Ci.nsIDOMHTMLIFrameElement) {
         let rect = node.getBoundingClientRect();
         // Gap between the iframe and its content window.
         let [offsetTop, offsetLeft] = this.getIframeContentOffset(node);
         aX -= rect.left + offsetLeft;
         aY -= rect.top + offsetTop;
         if (aX < 0 || aY < 0) {
           // Didn't reach the content document, still over the iframe.
           return node;
         }
       }
       if (node instanceof Ci.nsIDOMHTMLIFrameElement ||
           node instanceof Ci.nsIDOMHTMLFrameElement) {
         let subnode = this.getElementFromPoint(node.contentDocument, aX, aY);
         if (subnode) {
           node = subnode;
         }
       }
     }
     return node;
   },
   /**
    * Scroll the document so that the element "elem" appears in the viewport.
    *
    * @param Element elem the element that needs to appear in the viewport.
    * @param bool centered true if you want it centered, false if you want it to
    * appear on the top of the viewport. It is true by default, and that is
    * usually what you want.
    */
   scrollIntoViewIfNeeded: function(elem, centered) {
     // We want to default to centering the element in the page,
     // so as to keep the context of the element.
     centered = centered === undefined? true: !!centered;
     let win = elem.ownerDocument.defaultView;
     let clientRect = elem.getBoundingClientRect();
     // The following are always from the {top, bottom, left, right}
     // of the viewport, to the {top, …} of the box.
     // Think of them as geometrical vectors, it helps.
     // The origin is at the top left.
     let topToBottom = clientRect.bottom;
     let bottomToTop = clientRect.top - win.innerHeight;
     let leftToRight = clientRect.right;
     let rightToLeft = clientRect.left - win.innerWidth;
     let xAllowed = true;  // We allow one translation on the x axis,
     let yAllowed = true;  // and one on the y axis.
     // Whatever `centered` is, the behavior is the same if the box is
     // (even partially) visible.
     if ((topToBottom > 0 || !centered) && topToBottom <= elem.offsetHeight) {
       win.scrollBy(0, topToBottom - elem.offsetHeight);
       yAllowed = false;
     } else
     if ((bottomToTop < 0 || !centered) && bottomToTop >= -elem.offsetHeight) {
       win.scrollBy(0, bottomToTop + elem.offsetHeight);
       yAllowed = false;
     }
     if ((leftToRight > 0 || !centered) && leftToRight <= elem.offsetWidth) {
       if (xAllowed) {
         win.scrollBy(leftToRight - elem.offsetWidth, 0);
         xAllowed = false;
       }
     } else
     if ((rightToLeft < 0 || !centered) && rightToLeft >= -elem.offsetWidth) {
       if (xAllowed) {
         win.scrollBy(rightToLeft + elem.offsetWidth, 0);
         xAllowed = false;
       }
     }
     // If we want it centered, and the box is completely hidden,
     // then we center it explicitly.
     if (centered) {
       if (yAllowed && (topToBottom <= 0 || bottomToTop >= 0)) {
         win.scroll(win.scrollX,
                    win.scrollY + clientRect.top
                    - (win.innerHeight - elem.offsetHeight) / 2);
       }
       if (xAllowed && (leftToRight <= 0 || rightToLeft <= 0)) {
         win.scroll(win.scrollX + clientRect.left
                    - (win.innerWidth - elem.offsetWidth) / 2,
                    win.scrollY);
       }
     }
     if (!this.isTopLevelWindow(win)) {
       // We are inside an iframe.
       let frameElement = this.getFrameElement(win);
       this.scrollIntoViewIfNeeded(frameElement, centered);
     }
   },
   /**
    * Check if a node and its document are still alive
    * and attached to the window.
    *
    * @param aNode
    */
   isNodeConnected: function LH_isNodeConnected(aNode)
   {
     try {
       let connected = (aNode.ownerDocument && aNode.ownerDocument.defaultView &&
                       !(aNode.compareDocumentPosition(aNode.ownerDocument.documentElement) &
                       aNode.DOCUMENT_POSITION_DISCONNECTED));
       return connected;
     } catch (e) {
       // "can't access dead object" error
       return false;
     }
   },
   /**
    * like win.parent === win, but goes through mozbrowsers and mozapps iframes.
    */
   isTopLevelWindow: function LH_isTopLevelWindow(win) {
     let docShell = win.QueryInterface(Ci.nsIInterfaceRequestor)
                    .getInterface(Ci.nsIWebNavigation)
                    .QueryInterface(Ci.nsIDocShell);
     return docShell === this._topDocShell;
   },
   /**
    * Check a window is part of the top level window.
    */
   isIncludedInTopLevelWindow: function LH_isIncludedInTopLevelWindow(win) {
     if (this.isTopLevelWindow(win)) {
       return true;
     }
     let parent = this.getParentWindow(win);
     if (!parent || parent === win) {
       return false;
     }
     return this.isIncludedInTopLevelWindow(parent);
   },
   /**
    * like win.parent, but goes through mozbrowsers and mozapps iframes.
    */
   getParentWindow: function LH_getParentWindow(win) {
     if (this.isTopLevelWindow(win)) {
       return null;
     }
     let docShell = win.QueryInterface(Ci.nsIInterfaceRequestor)
                    .getInterface(Ci.nsIWebNavigation)
                    .QueryInterface(Ci.nsIDocShell);
     if (docShell.isBrowserOrApp) {
       let parentDocShell = docShell.getSameTypeParentIgnoreBrowserAndAppBoundaries();
       return parentDocShell ? parentDocShell.contentViewer.DOMDocument.defaultView : null;
     } else {
       return win.parent;
     }
   },
   /**
    * like win.frameElement, but goes through mozbrowsers and mozapps iframes.
    *
    * @param DOMWindow win The window to get the frame for
    * @return DOMElement The element in which the window is embedded.
    */
   getFrameElement: function LH_getFrameElement(win) {
     if (this.isTopLevelWindow(win)) {
       return null;
     }
     let winUtils = win.
       QueryInterface(Components.interfaces.nsIInterfaceRequestor).
       getInterface(Components.interfaces.nsIDOMWindowUtils);
     return winUtils.containerElement;
   },
   /**
    * Get the x and y offsets for a node taking iframes into account.
    *
    * @param {DOMNode} node
    *        The node for which we are to get the offset
    */
   _getNodeOffsets: function(node) {
     let xOffset = 0;
     let yOffset = 0;
     let frameWin = node.ownerDocument.defaultView;
     let scale = this.calculateScale(node);
     while (true) {
       // Are we in the top-level window?
       if (this.isTopLevelWindow(frameWin)) {
         break;
       }
       let frameElement = this.getFrameElement(frameWin);
       if (!frameElement) {
         break;
       }
       // We are in an iframe.
       // We take into account the parent iframe position and its
       // offset (borders and padding).
       let frameRect = frameElement.getBoundingClientRect();
       let [offsetTop, offsetLeft] =
         this.getIframeContentOffset(frameElement);
       xOffset += frameRect.left + offsetLeft;
       yOffset += frameRect.top + offsetTop;
       frameWin = this.getParentWindow(frameWin);
     }
     return [xOffset * scale, yOffset * scale];
   },
   /********************************************************************
    * GetBoxQuads POLYFILL START TODO: Remove this when bug 917755 is fixed.
    ********************************************************************/
   _getBoxQuadsFromRect: function(rect, node) {
     let scale = this.calculateScale(node);
     let [xOffset, yOffset] = this._getNodeOffsets(node);
     let out = {
       p1: {
         x: rect.left * scale + xOffset,
         y: rect.top * scale + yOffset
       },
       p2: {
         x: (rect.left + rect.width) * scale + xOffset,
         y: rect.top * scale + yOffset
       },
       p3: {
         x: (rect.left + rect.width) * scale + xOffset,
         y: (rect.top + rect.height) * scale + yOffset
       },
       p4: {
         x: rect.left * scale + xOffset,
         y: (rect.top + rect.height) * scale + yOffset
       }
     };
     out.bounds = {
       bottom: out.p4.y,
       height: out.p4.y - out.p1.y,
       left: out.p1.x,
       right: out.p2.x,
       top: out.p1.y,
       width: out.p2.x - out.p1.x,
       x: out.p1.x,
       y: out.p1.y
     };
     return out;
   },
   _parseNb: function(distance) {
     let nb = parseFloat(distance, 10);
     return isNaN(nb) ? 0 : nb;
   },
   getAdjustedQuadsPolyfill: function(node, region) {
     // Get the border-box rect
     // Note that this is relative to the node's viewport, so before we can use
     // it, will need to go back up the frames like getRect
     let borderRect = node.getBoundingClientRect();
     // If the boxType is border, no need to go any further, we're done
     if (region === "border") {
       return this._getBoxQuadsFromRect(borderRect, node);
     }
     // Else, need to get margin/padding/border distances
     let style = node.ownerDocument.defaultView.getComputedStyle(node);
     let camel = s => s.substring(0, 1).toUpperCase() + s.substring(1);
     let distances = {border:{}, padding:{}, margin: {}};
     for (let side of ["top", "right", "bottom", "left"]) {
       distances.border[side] = this._parseNb(style["border" + camel(side) + "Width"]);
       distances.padding[side] = this._parseNb(style["padding" + camel(side)]);
       distances.margin[side] = this._parseNb(style["margin" + camel(side)]);
     }
     // From the border-box rect, calculate the content-box, padding-box and
     // margin-box rects
     function offsetRect(rect, offsetType, dir=1) {
       return {
         top: rect.top + (dir * distances[offsetType].top),
         left: rect.left + (dir * distances[offsetType].left),
         width: rect.width - (dir * (distances[offsetType].left + distances[offsetType].right)),
         height: rect.height - (dir * (distances[offsetType].top + distances[offsetType].bottom))
       };
     }
     if (region === "margin") {
       return this._getBoxQuadsFromRect(offsetRect(borderRect, "margin", -1), node);
     } else if (region === "padding") {
       return this._getBoxQuadsFromRect(offsetRect(borderRect, "border"), node);
     } else if (region === "content") {
       let paddingRect = offsetRect(borderRect, "border");
       return this._getBoxQuadsFromRect(offsetRect(paddingRect, "padding"), node);
     }
   },
   /********************************************************************
    * GetBoxQuads POLYFILL END
    ********************************************************************/
 };

The Tor Browser / annotate

toolkit/devtools/LayoutHelpers.jsm@8bccb770b82d (annotated)

toolkit/devtools/LayoutHelpers.jsm