michael@0: /* Any copyright is dedicated to the Public Domain.
michael@0:    http://creativecommons.org/publicdomain/zero/1.0/ */
michael@0: 
michael@0: XPCOMUtils.defineLazyGetter(this, "docShell", () => {
michael@0:   return window.QueryInterface(Ci.nsIInterfaceRequestor)
michael@0:                .getInterface(Ci.nsIWebNavigation)
michael@0:                .QueryInterface(Ci.nsIDocShell);
michael@0: });
michael@0: 
michael@0: const EXPECTED_REFLOWS = [
michael@0:   // tabbrowser.adjustTabstrip() call after tabopen animation has finished
michael@0:   "adjustTabstrip@chrome://browser/content/tabbrowser.xml|" +
michael@0:     "_handleNewTab@chrome://browser/content/tabbrowser.xml|" +
michael@0:     "onxbltransitionend@chrome://browser/content/tabbrowser.xml|",
michael@0: 
michael@0:   // switching focus in updateCurrentBrowser() causes reflows
michael@0:   "updateCurrentBrowser@chrome://browser/content/tabbrowser.xml|" +
michael@0:     "onselect@chrome://browser/content/browser.xul|",
michael@0: 
michael@0:   // switching focus in openLinkIn() causes reflows
michael@0:   "openLinkIn@chrome://browser/content/utilityOverlay.js|" +
michael@0:     "openUILinkIn@chrome://browser/content/utilityOverlay.js|" +
michael@0:     "BrowserOpenTab@chrome://browser/content/browser.js|",
michael@0: 
michael@0:   // accessing element.scrollPosition in _fillTrailingGap() flushes layout
michael@0:   "get_scrollPosition@chrome://global/content/bindings/scrollbox.xml|" +
michael@0:     "_fillTrailingGap@chrome://browser/content/tabbrowser.xml|" +
michael@0:     "_handleNewTab@chrome://browser/content/tabbrowser.xml|" +
michael@0:     "onxbltransitionend@chrome://browser/content/tabbrowser.xml|",
michael@0: 
michael@0:   // The TabView iframe causes reflows in the parent document.
michael@0:   "iQClass_height@chrome://browser/content/tabview.js|" +
michael@0:     "GroupItem_getContentBounds@chrome://browser/content/tabview.js|" +
michael@0:     "GroupItem_shouldStack@chrome://browser/content/tabview.js|" +
michael@0:     "GroupItem_arrange@chrome://browser/content/tabview.js|" +
michael@0:     "GroupItem_add@chrome://browser/content/tabview.js|" +
michael@0:     "GroupItems_newTab@chrome://browser/content/tabview.js|" +
michael@0:     "TabItem__reconnect@chrome://browser/content/tabview.js|" +
michael@0:     "TabItem@chrome://browser/content/tabview.js|" +
michael@0:     "TabItems_link@chrome://browser/content/tabview.js|" +
michael@0:     "TabItems_init/this._eventListeners.open@chrome://browser/content/tabview.js|",
michael@0: 
michael@0:   // SessionStore.getWindowDimensions()
michael@0:   "ssi_getWindowDimension@resource:///modules/sessionstore/SessionStore.jsm|" +
michael@0:     "ssi_updateWindowFeatures/<@resource:///modules/sessionstore/SessionStore.jsm|" +
michael@0:     "ssi_updateWindowFeatures@resource:///modules/sessionstore/SessionStore.jsm|" +
michael@0:     "ssi_collectWindowData@resource:///modules/sessionstore/SessionStore.jsm|",
michael@0: 
michael@0:   // tabPreviews.capture()
michael@0:   "tabPreviews_capture@chrome://browser/content/browser.js|" +
michael@0:     "tabPreviews_handleEvent/<@chrome://browser/content/browser.js|",
michael@0: 
michael@0:   // tabPreviews.capture()
michael@0:   "tabPreviews_capture@chrome://browser/content/browser.js|" +
michael@0:     "@chrome://browser/content/browser.js|"
michael@0: ];
michael@0: 
michael@0: const PREF_PRELOAD = "browser.newtab.preload";
michael@0: const PREF_NEWTAB_DIRECTORYSOURCE = "browser.newtabpage.directorySource";
michael@0: 
michael@0: /*
michael@0:  * This test ensures that there are no unexpected
michael@0:  * uninterruptible reflows when opening new tabs.
michael@0:  */
michael@0: function test() {
michael@0:   waitForExplicitFinish();
michael@0: 
michael@0:   Services.prefs.setBoolPref(PREF_PRELOAD, false);
michael@0:   Services.prefs.setCharPref(PREF_NEWTAB_DIRECTORYSOURCE, "data:application/json,{}");
michael@0:   registerCleanupFunction(() => {
michael@0:     Services.prefs.clearUserPref(PREF_PRELOAD);
michael@0:     Services.prefs.clearUserPref(PREF_NEWTAB_DIRECTORYSOURCE);
michael@0:   });
michael@0: 
michael@0:   // Add a reflow observer and open a new tab.
michael@0:   docShell.addWeakReflowObserver(observer);
michael@0:   BrowserOpenTab();
michael@0: 
michael@0:   // Wait until the tabopen animation has finished.
michael@0:   waitForTransitionEnd(function () {
michael@0:     // Remove reflow observer and clean up.
michael@0:     docShell.removeWeakReflowObserver(observer);
michael@0:     gBrowser.removeCurrentTab();
michael@0: 
michael@0:     finish();
michael@0:   });
michael@0: }
michael@0: 
michael@0: let observer = {
michael@0:   reflow: function (start, end) {
michael@0:     // Gather information about the current code path.
michael@0:     let path = (new Error().stack).split("\n").slice(1).map(line => {
michael@0:       return line.replace(/:\d+:\d+$/, "");
michael@0:     }).join("|");
michael@0:     let pathWithLineNumbers = (new Error().stack).split("\n").slice(1).join("|");
michael@0: 
michael@0:     // Stack trace is empty. Reflow was triggered by native code.
michael@0:     if (path === "") {
michael@0:       return;
michael@0:     }
michael@0: 
michael@0:     // Check if this is an expected reflow.
michael@0:     for (let stack of EXPECTED_REFLOWS) {
michael@0:       if (path.startsWith(stack)) {
michael@0:         ok(true, "expected uninterruptible reflow '" + stack + "'");
michael@0:         return;
michael@0:       }
michael@0:     }
michael@0: 
michael@0:     ok(false, "unexpected uninterruptible reflow '" + pathWithLineNumbers + "'");
michael@0:   },
michael@0: 
michael@0:   reflowInterruptible: function (start, end) {
michael@0:     // We're not interested in interruptible reflows.
michael@0:   },
michael@0: 
michael@0:   QueryInterface: XPCOMUtils.generateQI([Ci.nsIReflowObserver,
michael@0:                                          Ci.nsISupportsWeakReference])
michael@0: };
michael@0: 
michael@0: function waitForTransitionEnd(callback) {
michael@0:   let tab = gBrowser.selectedTab;
michael@0:   tab.addEventListener("transitionend", function onEnd(event) {
michael@0:     if (event.propertyName === "max-width") {
michael@0:       tab.removeEventListener("transitionend", onEnd);
michael@0:       executeSoon(callback);
michael@0:     }
michael@0:   });
michael@0: }