firefox startScroll and sendAsyncMessage

Question

In recent version of Firefox 31+ the startScroll(e) function was changed and should be called with startScroll(scrolldir, screenX, screenY)

Diff of the change: https://hg.mozilla.org/integration/mozilla-inbound/diff/cc298e4b0f47/toolkit/content/widgets/browser.xml

Before the change I could initiate startScroll manually from my classic bootstrap.js extension with:

aWindow.gBrowser.selectedBrowser.startScroll(e);

I've received a tip on mozilla IRC channel to use sendAsyncMessage "Autoscroll:Start" so I tried various combinations of

aWindow.gBrowser.selectedBrowser.startScroll("NSEW", e.screenX, e.screenY);
aWindow.gBrowser.selectedBrowser.messageManager.sendAsyncMessage("Autoscroll:Start", {scrolldir:"NSEW", screenX:e.screenX, screenY:e.screenY});

but nothing works.

Bare minimum boostrap.js extension of my problem can be seen on http://pastebin.com/azv1jePt

Does anybody have any idea how to manually start autoscroll in the newer version of Firefox directly from bootstrap.js extension, without using any chrome scripts?

Thanks
Senicar

Interesting find though: http://mxr.mozilla.org/mozilla-release/source/toolkit/content/widgets/browser.xml#948 — Noitidart, Sep 19 '14 at 14:21
@Noitidart thanks for looking into it, I guess I'll have to try my luck again on mozilla irc channels, because I can't figure it out too. — senicar, Sep 19 '14 at 19:15
@senicar did you figure this one out? another person on irc was having similar issue — Noitidart, Nov 16 '14 at 03:32
@Noitidart sadly not yet, been pretty busy lately with work and haven't been able to muster up enough time to dive into the source. — senicar, Nov 19 '14 at 08:39
Thanks for the update please share when you figure it out I am also very interested in this. — Noitidart, Nov 19 '14 at 08:53

score 0 · Answer 1 · answered Nov 18 '15 at 19:12

What worked for me was to simulate a middle button mousedown event from a frame script (no need to call startScroll nor sendAsyncMessage):

content.document.documentElement.dispatchEvent(new content.MouseEvent("mousedown", {
    view: content,
    bubbles: true,
    cancelable: true,
    button: 1,
    screenX: /* anEvent.screenX */,
    screenY: /* anEvent.screenY */
}));

Hope this helps

firefox startScroll and sendAsyncMessage

1 Answers1