Bug 489127 - nodesFromRect required for better usability on mobile devices (part 4) [r=roc]

content/base/public/nsIDocument.h

@@ -115,8 +115,8 @@ class Link;
 } // namespace mozilla
 
 #define NS_IDOCUMENT_IID      \
-{ 0x5a428059, 0x4f29, 0x4d7c, \
- { 0x93, 0xae, 0x7c, 0x68, 0xd6, 0x5a, 0x86, 0x45 } }
+{ 0x3e162645, 0x4827, 0x4600, \
+ { 0x9c, 0xaa, 0xe8, 0xdd, 0xcb, 0x05, 0xfd, 0x85 } }
 
 // Flag for AddStyleSheet().
 #define NS_STYLESHEET_FROM_CATALOG                (1 << 0)
@@ -990,6 +990,13 @@ public:
                                           PRBool aFlushLayout,
                                           nsIDOMElement** aReturn) = 0;
 
+  virtual nsresult NodesFromRectHelper(float aX, float aY,
+                                       float aTopSize, float aRightSize,
+                                       float aBottomSize, float aLeftSize,
+                                       PRBool aIgnoreRootScrollFrame,
+                                       PRBool aFlushLayout,
+                                       nsIDOMNodeList** aReturn) = 0;
+
   /**
    * See FlushSkinBindings on nsBindingManager
    */

content/base/src/nsDocument.cpp

@@ -2690,6 +2690,94 @@ nsDocument::ElementFromPointHelper(float aX, float aY,
   return NS_OK;
 }
 
+nsresult
+nsDocument::NodesFromRectHelper(float aX, float aY,
+                                float aTopSize, float aRightSize,
+                                float aBottomSize, float aLeftSize,
+                                PRBool aIgnoreRootScrollFrame,
+                                PRBool aFlushLayout,
+                                nsIDOMNodeList** aReturn)
+{
+  NS_ENSURE_ARG_POINTER(aReturn);
+  
+  nsBaseContentList* elements = new nsBaseContentList();
+  NS_ADDREF(elements);
+  *aReturn = elements;
+
+  // Following the same behavior of elementFromPoint,
+  // we don't return anything if either coord is negative
+  if (!aIgnoreRootScrollFrame && (aX < 0 || aY < 0))
+    return NS_OK;
+
+  nscoord x = nsPresContext::CSSPixelsToAppUnits(aX - aLeftSize);
+  nscoord y = nsPresContext::CSSPixelsToAppUnits(aY - aTopSize);
+  nscoord w = nsPresContext::CSSPixelsToAppUnits(aLeftSize + aRightSize) + 1;
+  nscoord h = nsPresContext::CSSPixelsToAppUnits(aTopSize + aBottomSize) + 1;
+
+  nsRect rect(x, y, w, h);
+
+  // Make sure the layout information we get is up-to-date, and
+  // ensure we get a root frame (for everything but XUL)
+  if (aFlushLayout) {
+    FlushPendingNotifications(Flush_Layout);
+  }
+
+  nsIPresShell *ps = GetPrimaryShell();
+  NS_ENSURE_STATE(ps);
+  nsIFrame *rootFrame = ps->GetRootFrame();
+
+  // XUL docs, unlike HTML, have no frame tree until everything's done loading
+  if (!rootFrame)
+    return NS_OK; // return nothing to premature XUL callers as a reminder to wait
+
+  nsTArray<nsIFrame*> outFrames;
+  nsLayoutUtils::GetFramesForArea(rootFrame, rect, outFrames,
+                                  PR_TRUE, aIgnoreRootScrollFrame);
+
+  PRInt32 length = outFrames.Length();
+  if (!length)
+    return NS_OK;
+
+  // Used to filter out repeated elements in sequence.
+  nsIContent* lastAdded = nsnull;
+
+  for (PRInt32 i = 0; i < length; i++) {
+
+    nsIContent* ptContent = outFrames.ElementAt(i)->GetContent();
+    NS_ENSURE_STATE(ptContent);
+
+    // If the content is in a subdocument, try to get the element from |this| doc
+    nsIDocument *currentDoc = ptContent->GetCurrentDoc();
+    if (currentDoc && (currentDoc != this)) {
+      // XXX felipe: I can't get this type right without the intermediate vars
+      nsCOMPtr<nsIDOMElement> x = CheckAncestryAndGetFrame(currentDoc);
+      nsCOMPtr<nsIContent> elementDoc = do_QueryInterface(x);
+      if (elementDoc != lastAdded) {
+        elements->AppendElement(elementDoc);
+        lastAdded = elementDoc;
+      }
+      continue;
+    }
+
+    // If we have an anonymous element (such as an internal div from a textbox),
+    // or a node that isn't an element or a text node,
+    // replace it with the first non-anonymous parent node.
+    while (ptContent &&
+           (!(ptContent->IsNodeOfType(nsINode::eELEMENT) ||
+              ptContent->IsNodeOfType(nsINode::eTEXT)) ||
+            ptContent->IsInAnonymousSubtree())) {
+      // XXXldb: Faster to jump to GetBindingParent if non-null?
+      ptContent = ptContent->GetParent();
+    }
+   
+    if (ptContent && ptContent != lastAdded) {
+      elements->AppendElement(ptContent);
+      lastAdded = ptContent;
+    }
+  }
+  return NS_OK;
+}
+
 NS_IMETHODIMP
 nsDocument::GetElementsByClassName(const nsAString& aClasses,
                                    nsIDOMNodeList** aReturn)

content/base/src/nsDocument.h

@@ -878,6 +878,13 @@ public:
                                                       PRBool aFlushLayout,
                                                       nsIDOMElement** aReturn);
 
+  virtual NS_HIDDEN_(nsresult) NodesFromRectHelper(float aX, float aY,
+                                                   float aTopSize, float aRightSize,
+                                                   float aBottomSize, float aLeftSize,
+                                                   PRBool aIgnoreRootScrollFrame,
+                                                   PRBool aFlushLayout,
+                                                   nsIDOMNodeList** aReturn);
+
   virtual NS_HIDDEN_(void) FlushSkinBindings();
 
   virtual NS_HIDDEN_(nsresult) InitializeFrameLoader(nsFrameLoader* aLoader);

dom/base/nsDOMWindowUtils.cpp

@@ -621,6 +621,21 @@ nsDOMWindowUtils::ElementFromPoint(float aX, float aY,
                                      aReturn);
 }
 
+NS_IMETHODIMP
+nsDOMWindowUtils::NodesFromRect(float aX, float aY,
+                                float aTopSize, float aRightSize,
+                                float aBottomSize, float aLeftSize,
+                                PRBool aIgnoreRootScrollFrame,
+                                PRBool aFlushLayout,
+                                nsIDOMNodeList** aReturn)
+{
+  nsCOMPtr<nsIDocument> doc(do_QueryInterface(mWindow->GetExtantDocument()));
+  NS_ENSURE_STATE(doc);
+
+  return doc->NodesFromRectHelper(aX, aY, aTopSize, aRightSize, aBottomSize, aLeftSize, 
+                                  aIgnoreRootScrollFrame, aFlushLayout, aReturn);
+}
+
 static already_AddRefed<gfxImageSurface>
 CanvasToImageSurface(nsIDOMHTMLCanvasElement *canvas)
 {

dom/interfaces/base/nsIDOMWindowUtils.idl

@@ -46,13 +46,14 @@
  */
 
 interface nsIDOMNode;
+interface nsIDOMNodeList;
 interface nsIDOMElement;
 interface nsIDOMHTMLCanvasElement;
 interface nsIDOMEvent;
 interface nsITransferable;
 interface nsIQueryContentEventResult;
 
-[scriptable, uuid(25ada920-d727-45b6-ac70-847a3aa9c7cf)]
+[scriptable, uuid(22a62b54-bcf5-422a-a329-fed4de5e78b2)]
 interface nsIDOMWindowUtils : nsISupports {
 
   /**
@@ -303,6 +304,29 @@ interface nsIDOMWindowUtils : nsISupports {
                                  in boolean aIgnoreRootScrollFrame,
                                  in boolean aFlushLayout);
 
+  /**
+   * Retrieve all nodes that intersect a rect in the window's document.
+   *
+   * @param aX x reference for the rectangle in CSS pixels
+   * @param aY y reference for the rectangle in CSS pixels
+   * @param aTopSize How much to expand up the rectangle
+   * @param aRightSize How much to expand right the rectangle
+   * @param aBottomSize How much to expand down the rectangle
+   * @param aLeftSize How much to expand left the rectangle
+   * @param aIgnoreRootScrollFrame whether or not to ignore the root scroll
+   *        frame when retrieving the element. If false, this method returns
+   *        null for coordinates outside of the viewport.
+   * @param aFlushLayout flushes layout if true. Otherwise, no flush occurs.
+   */
+  nsIDOMNodeList nodesFromRect(in float aX,
+                               in float aY,
+                               in float aTopSize, 
+                               in float aRightSize,
+                               in float aBottomSize,
+                               in float aLeftSize,
+                               in boolean aIgnoreRootScrollFrame,
+                               in boolean aFlushLayout);
+
   /**
    * Compare the two canvases, returning the number of differing pixels and
    * the maximum difference in a channel.  This will throw an error if