author Jan Henning <>
Fri, 11 Jan 2019 19:50:09 +0000
changeset 453553 39207d39e5c2
parent 436316 c6a68b5804d5
child 455929 b0444e0bc801
permissions -rw-r--r--
Bug 1498812 - Part 9: Switch session store/session history to use visual viewport for scroll position tracking. r=mikedeboer,snorp For simplicity's sake, for now we keep storing only one scroll position per history entry (bug 1499210), so if we have to choose between the layout and the visual viewport, the latter is a vastly better choice, as it more accurately represents the scroll position as perceived by the user, especially when the page has been pinch-zoomed. This also means that instead of the normal scroll events, the session store now has to listen for the corresponding events specific to the visual viewport. We also extend the scroll position test to check that the scroll position isn't just properly saved, but also actually properly restored in practice as well. We only add this test now instead of already adding it beforehand like we did with the rest of the test - to avoid having to temporarily extend the checkScroll() helper function to deal with todo()/todo_is etc. - because getting that part of the test to complete without timing out (which would be one of its natural failure modes, because the expected events would be missing) would require faking even more scroll events - because we already have the todo() tests that are telling us the we didn't *store* any scroll position in the first place, so there's no point in trying to actually restore anything For the GeckoView saveAndRestoreState test, we now spin the event loop once before setting the scroll position in order to give APZ opportunity to settle down after the initial page load. Differential Revision:

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* 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 */

 * The interface to nsISHentry. Each document or subframe in
 * Session History will have a nsISHEntry associated with it which will
 * hold all information required to recreate the document from history

#include "nsISupports.idl"

interface nsIMutableArray;
interface nsILayoutHistoryState;
interface nsIContentViewer;
interface nsIURI;
interface nsIInputStream;
interface nsIDocShellTreeItem;
interface nsIStructuredCloneContainer;
interface nsIBFCacheEntry;
interface nsIPrincipal;
interface nsISHistory;

#include "nsRect.h"
class nsDocShellEditorData;
class nsSHEntryShared;
[ref] native nsIntRect(nsIntRect);
[ptr] native nsDocShellEditorDataPtr(nsDocShellEditorData);
[ptr] native nsSHEntryShared(nsSHEntryShared);

[builtinclass, scriptable, uuid(0dad26b8-a259-42c7-93f1-2fa7fc076e45)]
interface nsISHEntry : nsISupports
     * The URI of the current entry.
    [infallible] attribute nsIURI URI;

     * The original URI of the current entry. If an entry is the result of a
     * redirect this attribute holds the original URI.
    [infallible] attribute nsIURI originalURI;

     * URL as stored from nsILoadInfo.resultPrincipalURI.  See nsILoadInfo
     * for more details.
    [infallible] attribute nsIURI resultPrincipalURI;

     *  This flag remembers whether channel has LOAD_REPLACE set.
    [infallible] attribute boolean loadReplace;

     * The title of the current entry.
    // XXX: make it [infallible] when AString supports that (bug 1491187).
    attribute AString title;

     * Was the entry created as a result of a subframe navigation?
     * - Will be 'false' when a frameset page is visited for the first time.
     * - Will be 'true' for all history entries created as a result of a
     *   subframe navigation.
    [infallible] attribute boolean isSubFrame;

    /** Referrer URI */
    [infallible] attribute nsIURI referrerURI;

     * Referrer policy, holding one of the values (REFERRER_POLICY_*) defined
     * in nsIHttpChannel.
    [infallible] attribute unsigned long referrerPolicy;

    /** Content viewer, for fast restoration of presentation */
    [infallible] attribute nsIContentViewer contentViewer;

    /** Whether the content viewer is marked "sticky" */
    [infallible] attribute boolean sticky;

    /** Saved state of the global window object */
    [infallible] attribute nsISupports windowState;

    /** Saved refresh URI list for the content viewer */
    [infallible] attribute nsIMutableArray refreshURIList;

    /** Post Data for the document */
    [infallible] attribute nsIInputStream postData;

    /** LayoutHistoryState for scroll position and form values */
    [infallible] attribute nsILayoutHistoryState layoutHistoryState;

    /** parent of this entry */
    [infallible] attribute nsISHEntry parent;

     * The loadType for this entry. This is typically loadHistory except
     * when reload is pressed, it has the appropriate reload flag
    [infallible] attribute unsigned long loadType;

     * An ID to help identify this entry from others during
     * subframe navigation
    [infallible] attribute unsigned long ID;

    /** The cache key for the entry */
    [infallible] attribute unsigned long cacheKey;

    /** Should the layoutHistoryState be saved? */
    [infallible] attribute boolean saveLayoutStateFlag;

    /** Has the page already expired in cache? */
    [infallible] attribute boolean expirationStatus;

     * attribute to indicate the content-type of the document that this
     * is a session history entry for
    // XXX: make it [infallible] when ACString supports that (bug 1491187).
    attribute ACString contentType;

     * If we created this SHEntry via history.pushState or modified it via
     * history.replaceState, and if we changed the SHEntry's URI via the
     * push/replaceState call, and if the SHEntry's new URI differs from its
     * old URI by more than just the hash, then we set this field to true.
     * Additionally, if this SHEntry was created by calling pushState from a
     * SHEntry whose URI was modified, this SHEntry's URIWasModified field is
     * true.
    [infallible] attribute boolean URIWasModified;

     * Get the principal, if any, that was associated with the channel
     * that the document that was loaded to create this history entry
     * came from.
    [infallible] attribute nsIPrincipal triggeringPrincipal;

     * Get the principal, if any, that is used when the inherit flag
     * is set.
    [infallible] attribute nsIPrincipal principalToInherit;

     * Get/set data associated with this history state via a pushState() call,
     * serialized using structured clone.
    [infallible] attribute nsIStructuredCloneContainer stateData;

     * The history ID of the docshell.
    // Would be [infallible], but we don't support that property for nsIDPtr.
    attribute nsIDPtr docshellID;

    [infallible] readonly attribute nsIBFCacheEntry BFCacheEntry;

     * True if this SHEntry corresponds to a document created by a srcdoc
     * iframe. Set when a value is assigned to srcdocData.
    [infallible] readonly attribute boolean isSrcdocEntry;

     * Contents of the srcdoc attribute in a srcdoc iframe to be loaded instead
     * of the URI.  Similar to a Data URI, this information is needed to
     * recreate the document at a later stage.
     * Setting this sets isSrcdocEntry to true
    // XXX: make it [infallible] when AString supports that (bug 1491187).
    attribute AString srcdocData;

     * When isSrcdocEntry is true, this contains the baseURI of the srcdoc
     * document for use in situations where it cannot otherwise be determined,
     * for example with view-source.
    [infallible] attribute nsIURI baseURI;

     * Sets/gets the current scroll restoration state,
     * if true == "manual", false == "auto".
    [infallible] attribute boolean scrollRestorationIsManual;

     * Flag to indicate that the history entry was originally loaded in the
     * current process. This flag does not survive a browser process switch.
    [infallible] readonly attribute boolean loadedInThisProcess;

     * The session history it belongs to. It's usually only set on root entries.
     * SHEntry is strictly bound to the SHistory it belongs to; it should not be
     * changed once set to a non-null value.
    [noscript, infallible] attribute nsISHistory SHistory;

     * A number that is assigned by the sHistory when the entry is activated
    [noscript, infallible] attribute unsigned long lastTouched;

     * The current number of nsISHEntries which are immediate children of this
     * SHEntry.
    [infallible] readonly attribute long childCount;

     * When an entry is serving is within nsISHistory's array of entries, this
     * property specifies if it should persist. If not it will be replaced by
     * new additions to the list.
    [infallible] attribute boolean persist;

     * Set/Get the visual viewport scroll position if session history is
     * changed through anchor navigation or pushState.
    void setScrollPosition(in long x, in long y);
    void getScrollPosition(out long x, out long y);

     * Saved position and dimensions of the content viewer; we must adjust the
     * root view's widget accordingly if this has changed when the presentation
     * is restored.
    [noscript, notxpcom] void getViewerBounds(in nsIntRect bounds);
    [noscript, notxpcom] void setViewerBounds([const] in nsIntRect bounds);

     * Saved child docshells corresponding to contentViewer.  The child shells
     * are restored as children of the parent docshell, in this order, when the
     * parent docshell restores a saved presentation.

    /** Append a child shell to the end of our list. */
    [noscript, notxpcom] void addChildShell(in nsIDocShellTreeItem shell);

     * Get the child shell at |index|; returns null if |index| is out of bounds.
    [noscript] nsIDocShellTreeItem childShellAt(in long index);

     * Clear the child shell list.
    [noscript, notxpcom] void clearChildShells();

     * Ensure that the cached presentation members are self-consistent.
     * If either |contentViewer| or |windowState| are null, then all of the
     * following members are cleared/reset:
     *  contentViewer, sticky, windowState, viewerBounds, childShells,
     *  refreshURIList.
    [noscript, notxpcom] void syncPresentationState();

     * Initialises `layoutHistoryState` if it doesn't already exist
     * and returns a reference to it.
    nsILayoutHistoryState initLayoutHistoryState();

    /** Additional ways to create an entry */
    [noscript] void create(in nsIURI URI, in AString title,
                           in nsIInputStream inputStream,
                           in nsILayoutHistoryState layoutHistoryState,
                           in unsigned long cacheKey, in ACString contentType,
                           in nsIPrincipal triggeringPrincipal,
                           in nsIPrincipal principalToInherit,
                           in nsIDRef docshellID,
                           in boolean dynamicCreation);

    nsISHEntry clone();

    /** Return any content viewer present in or below this node in the
        nsSHEntry tree.  This will differ from contentViewer in the case
        where a child nsSHEntry has the content viewer for this tree. */
    [noscript] nsIContentViewer getAnyContentViewer(out nsISHEntry ownerEntry);

     * Gets the owning pointer to the editor data assosicated with
     * this shistory entry. This forgets its pointer, so free it when
     * you're done.
    [noscript, notxpcom] nsDocShellEditorDataPtr forgetEditorData();

     * Sets the owning pointer to the editor data assosicated with
     * this shistory entry. Unless forgetEditorData() is called, this
     * shentry will destroy the editor data when it's destroyed.
    [noscript, notxpcom] void setEditorData(in nsDocShellEditorDataPtr aData);

    /** Returns true if this shistory entry is storing a detached editor. */
    [noscript, notxpcom] boolean hasDetachedEditor();

     * Returns true if the related docshell was added because of
     * dynamic addition of an iframe/frame.
    [noscript, notxpcom] boolean isDynamicallyAdded();

     * Returns true if any of the child entries returns true
     * when isDynamicallyAdded is called on it.
    boolean hasDynamicallyAddedChild();

     * Helper method for accessing `docshellID` from C++
    [noscript, notxpcom] nsID DocshellID();

     * Does this SHEntry point to the given BFCache entry? If so, evicting
     * the BFCache entry will evict the SHEntry, since the two entries
     * correspond to the same document.
    [noscript, notxpcom] boolean hasBFCacheEntry(in nsIBFCacheEntry aEntry);

     * Adopt aEntry's BFCacheEntry, so now both this and aEntry point to
     * aEntry's BFCacheEntry.
    void adoptBFCacheEntry(in nsISHEntry aEntry);

     * Create a new BFCache entry and drop our reference to our old one. This
     * call unlinks this SHEntry from any other SHEntries for its document.
    void abandonBFCacheEntry();

     * Does this SHEntry correspond to the same document as aEntry? This is
     * true iff the two SHEntries have the same BFCacheEntry. So in particular,
     * sharesDocumentWith(aEntry) is guaranteed to return true if it's
     * preceded by a call to adoptBFCacheEntry(aEntry).
    boolean sharesDocumentWith(in nsISHEntry aEntry);

     * Sets an SHEntry to reflect that it is a history type load. As
     * nsIDocShellLoadInfo and its LoadType enum were removed, this is the
     * equivalent to doing
     * shEntry.loadType = 4;
     * in js, but easier to maintain and less opaque.
    void setLoadTypeAsHistory();

     * Some state, particularly that related to the back/forward cache, is
     * shared between SHEntries which correspond to the same document.  This
     * method gets a pointer to that shared state.
     * This shared state is the SHEntry's BFCacheEntry.  So
     * hasBFCacheEntry(getSharedState()) is guaranteed to return true.
    [noscript, notxpcom] nsSHEntryShared getSharedState();

     * Add a new child SHEntry. If offset is -1 adds to the end of the list.
    void AddChild(in nsISHEntry aChild, in long aOffset);

     * Remove a child SHEntry.
    [noscript] void RemoveChild(in nsISHEntry aChild);

     * Get child at an index.
    nsISHEntry GetChildAt(in long aIndex);

     * Replaces a child which is for the same docshell as aNewChild
     * with aNewChild.
     * @throw if nothing was replaced.
    [noscript] void ReplaceChild(in nsISHEntry aNewChild);

%{ C++
// {BFD1A791-AD9F-11d3-BDC7-0050040A9B44}
#define NS_SHENTRY_CID \
{0xbfd1a791, 0xad9f, 0x11d3, {0xbd, 0xc7, 0x0, 0x50, 0x4, 0xa, 0x9b, 0x44}}