[FIX] bus: adapt presence service to work with iframe

Before this PR, the presence service was relying on window events
blur/focus to determine whether or not odoo was focused. The issue is
that in the website backend, an iframe is used. When this iframe is focused,
the window looses the focus and vice versa.

This commit fixes this issue by using `window.parent.hasFocus` method.

task-3003950

closes odoo/odoo#102479

Signed-off-by: Alexandre Kühn (aku) <aku@odoo.com>

addons/bus/static/src/services/presence_service.js

@@ -23,11 +23,10 @@ export const presenceService = {
             lastPresenceTime = new Date().getTime();
             browser.localStorage.setItem(`${LOCAL_STORAGE_PREFIX}.lastPresence`, lastPresenceTime);
         }
-
-        function onFocusChange(isFocused) {
-            isOdooFocused = isFocused;
+        function onFocusChange() {
+            isOdooFocused = parent.document.hasFocus();
             browser.localStorage.setItem(`${LOCAL_STORAGE_PREFIX}.focus`, isOdooFocused);
-            if (isFocused) {
+            if (isOdooFocused) {
                 lastPresenceTime = new Date().getTime();
                 env.bus.trigger('window_focus', isOdooFocused);
             }
@@ -43,9 +42,9 @@ export const presenceService = {
             }
         }
         browser.addEventListener('storage', onStorage);
-        browser.addEventListener('focus', () => onFocusChange(true));
-        browser.addEventListener('blur', () => onFocusChange(false));
-        browser.addEventListener('pagehide', () => onFocusChange(false));
+        browser.addEventListener('focus', () => onFocusChange());
+        browser.addEventListener('blur', () => onFocusChange());
+        browser.addEventListener('pagehide', () => onFocusChange());
         browser.addEventListener('click', onPresence);
         browser.addEventListener('keydown', onPresence);