Firefox's behavior around window.open features

Basic behavior

Current behavior

• Each feature corresponds to visibility of each UI part, or position/size
  toolbar
  Show/hide the toolbar buttons except the location bar.
  location
  Show/hide the location bar.
  personalbar
  Show/hide the bookmarks toolbar.
  menubar
  Show/hide the menu bar, if the menu bar is shown inside the window.
  resizable
  Enable/disable window resize.
  left, screenX
  Controls the X-coord of the top left corner of the window.
  top, screenY
  Controls the Y-coord of the top left corner of the window.
  width, innerWidth
  Controls the width of the window.
  outerWidth
  Controls the outer width of the window.
  height, innerHeight
  Controls the height of the window.
  outerHeight
  Controls the outer height of the window.
• Each feature can be turned on/off separately
• User has control over which feature to allow/deny from web content.
• With empty feature, new tab is opened
  • Depends on browser.link.open_newwindow pref and browser.link.open_newwindow.restriction pref.

Proposed behavior

To align with Chrome, Safari, and new Edge, make each boolean feature just a condition for where to open the link, from:

• Open a new tab (or new window, or load in current tab, depending on browser.link.open_newwindow pref)
• Open a new resizable popup (only with titlebar, location, status, and buttons)

This change affects web content only. Any window.open call from chrome code still has ability to separately control visibility of each UI part.

Related prefs

browser.link.open_newwindow (int)

Current behavior

Control where to open a link.

Used in nsWindowWatcher::GetWindowOpenLocation

Proposed behavior

If the target browsing context isn't opened in popup (IsPopup returns false), open it in the specified place.

browser.link.open_newwindow.restriction (int)

Current behavior

Restrict where the new window can be opened

Used in nsWindowWatcher::GetWindowOpenLocation

Proposed behavior

Keep the same behavior.

browser.link.open_newwindow.disabled_in_fullscreen (bool)

Used in nsWindowWatcher::GetWindowOpenLocation

Current behavior

1. If the current window is in fullscreen, then:
   1. If browser.link.open_newwindow is 2 (new window), then:
      1. Override the pref value with 1 (current tab)
   1. Override browser.link.open_newwindow.restriction value with 0 (No restrictions)

Proposed behavior

Keep the same behavior.

dom.disable_window_open_feature.* (bool)

Current behavior

Allow/disallow each feature.

Used in nsWindowWatcher::CalculateChromeFlagsHelper

Introduced by Bug 107949

• Web content can try to controll each feature
• User can allow/disallow each feature
• If all feature are allowed, web content can open a non-resizable window only with title bar
• If all features are disallowed, web content can open only a new tab or normal new window

Proposed behavior

They are ignored.