492312 - DocumentLoaded() called multiple times loading one page

Status: RESOLVED FIXED

(Core Graveyard :: Embedding: APIs, defect)

Description

[hui xue]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US) AppleWebKit/525.19 (KHTML, like Gecko) Chrome/1.0.154.59 Safari/525.19
Build Identifier: change set 117:0567bf985e06, Thu Mar 26 00:48:30 2009 -0500

I am trying to figure out how to know one page is "totally" 
loaded. I tried the DocumentLoaded() function, but it is called 
multiple times when loading one page. My guess: it is called whenever 
one iframe is finished loading. 

SYMPTOM:    Try this web site:   www.sina.com.cn   and  DocumentLoaded 
()  will be called multiple times. 

QUESTION: how to know one page is "totally" loaded? 

DETAILS ABOUT WHAT I DID: 
I am using the "mozembed" from this page: https://wiki.mozilla.org/Embedding/NewApi#Getting_the_code 

in /mozembed/gtk/tests/test.cpp, 

I added 
    g_signal_connect(view,"document_loaded",G_CALLBACK 
(my_loaded),view); 
to "add_page()" function: 
================================================== 
GtkWidget * 
add_page(GtkNotebook *notebook) 
{ 
    GtkWidget *view = moz_web_view_new(); 
    GtkWidget *box = gtk_hbox_new(FALSE, 5); 
    GtkWidget *tab_label = gtk_label_new("Loading..."); 
    GtkWidget *close_button = gtk_button_new(); 
    gtk_button_set_relief(GTK_BUTTON(close_button), GTK_RELIEF_NONE); 
    GtkWidget *close = gtk_image_new_from_stock(GTK_STOCK_CLOSE, 
                                                GTK_ICON_SIZE_MENU); 
    gtk_container_add(GTK_CONTAINER(close_button), close); 
    gtk_box_pack_start(GTK_BOX(box), tab_label, TRUE, TRUE, 0); 
    gtk_box_pack_end(GTK_BOX(box), close_button, FALSE, FALSE, 0); 
    gtk_widget_show_all(box); 
    gtk_widget_show(view); 
    g_signal_connect(view, "title-changed", G_CALLBACK(title_cb), 
tab_label); 
    g_signal_connect(view, "location-changed", G_CALLBACK 
(location_cb), NULL); 
    g_signal_connect(view, "status-changed", G_CALLBACK(status_cb), 
NULL); 
    g_signal_connect(close_button, "clicked", G_CALLBACK(close_cb), 
view); 
////////////////Hui 
    g_signal_connect(view,"document_loaded",G_CALLBACK 
(my_loaded),view); 
////////////////Hui 
    moz_web_view_load_uri(MOZ_WEB_VIEW(view), "http:// 
www.google.com"); 
    int page = gtk_notebook_append_page(notebook, view, box); 
    gtk_notebook_set_current_page(GTK_NOTEBOOK(notebook), page); 
    return view; 
} 

=================================================== 
where "my_loaded" is the function I am calling whenever after 
DocumentLoaded() is called. 

In this way, I detected DocumentLoaded() called multiple times when I 
am loading  www.sina.com.cn   by simply printing out something in 
"my_loaded()", actually it is called seven times, corresponding to 
seven iframes in that web page. 
Your help is deeply appreciated. 

Reproducible: Always

Steps to Reproduce:
1. add     g_signal_connect(view,"document_loaded",G_CALLBACK 
(my_loaded),view); 
into "add_page(GtkNotebook*)" function, I have described how to do this in "details". (or you can simply print something out in DocumentLoaded() function in Moz-web-view.cpp)

2. load   www.sina.com.cn
3. watch how many times DocumentLoaded() get called.
Actual Results:  
about 15 times.(guess it is called for each iframe)

Expected Results:  
should be only 1 time.

Struggling to know WHEN the page is totally loaded AND rendered. Seems to be a hard question to answer.

In MS Trident, the same problem could be bypassed by figuring out who is calling the callback, if the top level window, should be really finished, otherwise should not be finished yet.

Comment 1

[Boris Zbarsky [:bzbarsky]]

mfinkle, looks like this code has been around since rev 6524d040e08f in incubator-central.  The code for DocumentLoaded is fundamentally broken; as hui xue guesses it will call the callback for every single subframe, possibly multiple times for a given subframe during a single toplevel document load.  And it doesn't give the callee the information needed to tell _what_ has loaded.

Basically, this callback is completely useless as it stands.

Comment 2

[hui xue]

Thanks Boris, you are fast on this!

Comment 3

[Christopher Blizzard (:blizzard)]

Is there a standards issue here or just embedding?

Comment 4

[Boris Zbarsky [:bzbarsky]]

This is a pure "our embedding api is not usable" issue.

Comment 5

[Boris Zbarsky [:bzbarsky]]

Attachment: This should fix it

I have no idea how to compile and test this, sadly... the incubator repo seems to have nothing like makefiles and such in it.

Comment 6

[Mark Finkle (:mfinkle) (use needinfo?)]

Tested via projects. Before/after tests show this does fix the problem:
http://hg.mozilla.org/incubator/embedding/rev/c335c76103d5

Comment 7

[Mark Finkle (:mfinkle) (use needinfo?)]

Comment on attachment 381458 [details] [diff] [review]
This should fix it

forgot to actually flip this