more nsBrowserInstance lovin' - move the show/hide button junk into JavaScript using the now-working pref-change-observer system. bug 46200.

a=ben, r=jag

xpfe/browser/resources/content/navigator.js

@@ -371,9 +371,43 @@ function UpdateBackForwardButtons()
   forwardBroadcaster.setAttribute("disabled", !webNavigation.canGoForward);
 }
 
+
+function nsButtonPrefListener()
+{
+  try {
+    pref.addObserver(this.domain, this);
+  } catch(ex) {
+    dump("Failed to observe prefs: " + ex + "\n");
+  }
+}
+
+// implements nsIObserver
+nsButtonPrefListener.prototype =
+{
+  domain: "browser.toolbars.showbutton",
+  Observe: function(subject, topic, prefName)
+  {
+    // verify that we're changing a button pref
+    if (topic != "nsPref:changed") return;
+    if (prefName.substr(0, this.domain.length) != this.domain) return;
+    
+    var buttonName = prefName.substr(this.domain.length+1);
+    var buttonId = buttonName + "-button";
+    var button = document.getElementById(buttonId);
+    
+    var show = pref.GetBoolPref(prefName);
+    if (show)
+      button.removeAttribute("hidden");
+    else
+      button.setAttribute("hidden", "true");
+  }
+}
+
 function Startup()
 {
   window.XULBrowserWindow = new nsXULBrowserWindow();
+  window.buttonPrefListener = new nsButtonPrefListener();
+
 
   var webNavigation;
   try {
@@ -490,6 +524,11 @@ function Shutdown()
   } catch (ex) {
   }
 
+  // unregister us as a pref listener
+  pref.removeObserver(window.buttonPrefListener.domain,
+                      window.buttonPrefListener);
+  window.offlineObserver.unload();
+  
   // Close the app core.
   if (appCore)
     appCore.close();
@@ -1020,18 +1059,20 @@ var consoleListener = {
 function initConsoleListener()
 {
   /**
-   * XXX - console launch hookup requires some work that I'm not sure how to
-   *       do.
+   * XXX - console launch hookup requires some work that I'm not sure
+   * how to do.
    *
-   *       1) ideally, the notification would disappear when the document that had the
-   *          error was flushed. how do I know when this happens? All the nsIScriptError
-   *          object I get tells me is the URL. Where is it located in the content area?
-   *       2) the notification service should not display chrome script errors.
-   *          web developers and users are not interested in the failings of our shitty,
-   *          exception unsafe js. One could argue that this should also extend to
-   *          the console by default (although toggle-able via setting for chrome authors)
-   *          At any rate, no status indication should be given for chrome script
-   *          errors.
+   *       1) ideally, the notification would disappear when the
+   *       document that had the error was flushed. how do I know when
+   *       this happens? All the nsIScriptError object I get tells me
+   *       is the URL. Where is it located in the content area?
+   *       2) the notification service should not display chrome
+   *       script errors.  web developers and users are not interested
+   *       in the failings of our shitty, exception unsafe js. One
+   *       could argue that this should also extend to the console by
+   *       default (although toggle-able via setting for chrome
+   *       authors) At any rate, no status indication should be given
+   *       for chrome script errors.
    *
    *       As a result I am commenting out this for the moment.
    *

xpfe/browser/src/nsBrowserInstance.cpp

@@ -421,10 +421,7 @@ void TimesUp(nsITimer *aTimer, void *aClosure)
 
 #endif //ENABLE_PAGE_CYCLER
 
-PRUint32 nsBrowserInstance::gRefCnt = 0;
 PRBool nsBrowserInstance::sCmdLineURLUsed = PR_FALSE;
-int PR_CALLBACK ButtonShowHideCallback(const char* aPref, void* aClosure);
-static const char kShowToolbarElts[] = "browser.toolbars.showbutton";
 
 //*****************************************************************************
 //***    nsBrowserInstance: Object Management
@@ -437,29 +434,11 @@ nsBrowserInstance::nsBrowserInstance() : mIsClosed(PR_FALSE)
   mDOMWindow            = nsnull;
   mContentAreaDocShellWeak  = nsnull;
   NS_INIT_REFCNT();
-  gRefCnt++;
-  if (gRefCnt == 1) {
-    nsresult rv;
-    // Add callback listeners for toolbar buttons showing/hiding.
-    NS_WITH_SERVICE(nsIPref, prefs, NS_PREF_CONTRACTID, &rv);
-    if (NS_SUCCEEDED(rv)) {
-      prefs->RegisterCallback(kShowToolbarElts, ButtonShowHideCallback, nsnull);
-    }    
-  }
 }
 
 nsBrowserInstance::~nsBrowserInstance()
 {
   Close();
-  gRefCnt--;
-  if (gRefCnt == 0) {
-    // Remove callback listeners for toolbar buttons showing/hiding.
-    nsresult rv;
-    NS_WITH_SERVICE(nsIPref, prefs, NS_PREF_CONTRACTID, &rv);
-    if (NS_SUCCEEDED(rv)) {
-      prefs->UnregisterCallback(kShowToolbarElts, ButtonShowHideCallback, nsnull);
-    }    
-  }
 }
 
 void
@@ -1810,82 +1789,6 @@ static nsModuleComponentInfo components[] = {
 
 NS_IMPL_NSGETMODULE("nsBrowserModule", components)
 
-// =================================================================================
-// Toolbar button pref callback
-// =================================================================================
-
-int PR_CALLBACK ButtonShowHideCallback(const char* aPref, void* aClosure)
-{
-  nsresult rv;
-  NS_WITH_SERVICE(nsIPref, prefs, NS_PREF_CONTRACTID, &rv);
-  if (NS_FAILED(rv))
-    return 0;
-
-  // There is an intelligent mapping from
-  // the name of the pref to the id of the element in the XUL.
-  //
-  // browser.toolbars.showbutton.XXX maps to
-  // an element with an ID of XXX-button.  If the ID is of the
-  // correct form, then this code will scale tolerably
-  // as new buttons are added, and I won't need to have special
-  // "My Netscape" and "Net2Phone" cases in the Netscape tree (which
-  // would be non-ideal to say the least).
-  //
-  // hyatt
-
-  nsAutoString pref; pref.AssignWithConversion(aPref);
-  PRInt32 index = pref.RFindChar('.');
-  if (index == -1)
-    return 0;
-
-  nsAutoString element;
-  pref.Right(element, pref.Length()-index-1);
-  element += NS_LITERAL_STRING("-button");
-
-  PRBool show = PR_TRUE;
-  prefs->GetBoolPref(aPref, &show);
-
-  // Get the window mediator and loop over all navigator windows.
-  NS_WITH_SERVICE(nsIWindowMediator, windowMediator, kWindowMediatorCID, &rv);
-  if (NS_SUCCEEDED(rv)) {
-    nsCOMPtr<nsISimpleEnumerator> windowEnumerator;
-
-    if (NS_SUCCEEDED(windowMediator->GetEnumerator(NS_LITERAL_STRING("navigator:browser").get(), 
-                                                   getter_AddRefs(windowEnumerator)))) {
-      // Get each dom window
-      PRBool more;
-      windowEnumerator->HasMoreElements(&more);
-      while (more) {
-        nsCOMPtr<nsISupports> protoWindow;
-        windowEnumerator->GetNext(getter_AddRefs(protoWindow));
-        if (protoWindow) {
-          nsCOMPtr<nsIDOMWindowInternal> domWindow = do_QueryInterface(protoWindow);
-          if (domWindow) {
-            nsCOMPtr<nsIDOMDocument> doc;
-            domWindow->GetDocument(getter_AddRefs(doc));
-            
-            nsCOMPtr<nsIDOMElement> elt;
-            doc->GetElementById(element, getter_AddRefs(elt));
-            if (elt) {
-              if (show)
-                elt->SetAttribute(NS_LITERAL_STRING("hidden"), NS_LITERAL_STRING("false"));
-              else elt->SetAttribute(NS_LITERAL_STRING("hidden"), NS_LITERAL_STRING("true"));
-
-              // Modality issues with the (sigh) modal prefs dialog necessitate a synchronous
-              // reflow.  Otherwise the reflow seems to get "lost".
-              // Do that here by flushing all pending reflows.
-              nsCOMPtr<nsIDocument> document(do_QueryInterface(doc));
-              document->FlushPendingNotifications();
-            }
-          }
-        }
-        windowEnumerator->HasMoreElements(&more);
-      }
-    }
-  }
-
-  return 0;
-}
 
 NS_IMETHODIMP
 nsBrowserInstance::GetPostData( nsIInputStream **aResult ) {

xpfe/browser/src/nsBrowserInstance.h

@@ -30,8 +30,6 @@
 #include "nsIBrowserInstance.h"
 #include "nsIURIContentListener.h"
 
- 
-
 #include "nsIAppShellComponentImpl.h"
 
 #include "nscore.h"
@@ -83,8 +81,6 @@ class nsBrowserInstance : public nsIBrowserInstance,
     // WebProgress listener
     NS_DECL_NSIWEBPROGRESSLISTENER
 
-    static PRUint32 gRefCnt;
-
   protected:
 
     nsresult GetContentAreaDocShell(nsIDocShell** outDocShell);