nsIWindowWatcher is the keeper of Gecko/DOM Windows. It maintains
a list of open top-level windows, and allows some operations on them.
Usage notes:
This component has an |activeWindow| property. Clients may expect
this property to be always current, so to properly integrate this component
the application will need to keep it current by setting the property
as the active window changes.
This component should not keep a (XPCOM) reference to any windows;
the implementation will claim no ownership. Windows must notify
this component when they are created or destroyed, so only a weak
reference is kept. Note that there is no interface for such notifications
(not a public one, anyway). This is taken care of both in Mozilla and
by common embedding code. Embedding clients need do nothing special
about that requirement.
This component must be initialized at application startup by calling
setWindowCreator.
Create a new window. It will automatically be added to our list
(via addWindow()).
@note This method may examine the JS context stack for purposes of
determining the security context to use for the search for a given
window named aName.
@note This method should try to set the default charset for the new
window to the default charset of aParent. This is not guaranteed,
however.
@note This method may dispatch a “toplevel-window-ready” notification
via nsIObserverService if the window did not already exist.
| aParent | parent window, if any. Null if no parent. If it is impossible to get to an nsIWebBrowserChrome from aParent, this method will effectively act as if aParent were null. |
| aURL | url to which to open the new window. Must already be escaped, if applicable. can be null. |
| aName | window name from JS window.open. can be null. If a window with this name already exists, the openWindow call may just load aUrl in it (if aUrl is not null) and return it. |
| aFeatures | window features from JS window.open. can be null. |
| aArguments | extra argument(s) to the new window, to be attached as the |arguments| property. An nsISupportsArray will be unwound into multiple arguments (but not recursively!). can be null. |
| the new window |
Clients of this service can register themselves to be notified
when a window is opened or closed (added to or removed from this
service). This method adds an aObserver to the list of objects
to be notified.
aObserver::Observe interprets its parameters so:
aSubject the window being opened or closed, sent as an nsISupports
which can be QIed to an nsIDOMWindow.
aTopic a wstring, either “domwindowopened” or “domwindowclosed”.
someData not used.
| aObserver | the object to be notified when windows are opened or closed. Its Observe method will be called with the following parameters: |
Clients of this service can register themselves to be notified
when a window is opened or closed (added to or removed from this
service). This method removes an aObserver from the list of objects
to be notified.
| aObserver | the observer to be removed. |
Get an iterator for currently open windows in the order they were opened,
guaranteeing that each will be visited exactly once.
| an enumerator which will itself return nsISupports objects which can be QIed to an nsIDOMWindow |
Return a newly created nsIPrompt implementation.
| aParent | the parent window used for posing alerts. can be null. |
| a new nsIPrompt object |
Return a newly created nsIAuthPrompt implementation.
| aParent | the parent window used for posing alerts. can be null. |
| a new nsIAuthPrompt object |
Set the window creator callback. It must be filled in by the app.
openWindow will use it to create new windows.
| creator | the callback. if null, the callback will be cleared and window creation capabilities lost. |
Returns true if a window creator callback has been set, false otherwise.
Retrieve the chrome window mapped to the given DOM window. Window
Watcher keeps a list of all top-level DOM windows currently open,
along with their corresponding chrome interfaces. Since DOM Windows
lack a (public) means of retrieving their corresponding chrome,
this method will do that.
| aWindow | the DOM window whose chrome window the caller needs |
| the corresponding chrome window |
Retrieve an existing window (or frame).
Note: This method will search all open windows for any window or
frame with the given window name. Make sure you understand the
security implications of this before using this method!
| aTargetName | the window name |
| aCurrentWindow | a starting point in the window hierarchy to begin the search. If null, each toplevel window will be searched. |
The Watcher serves as a global storage facility for the current active
(frontmost non-floating-palette-type) window, storing and returning
it on demand. Users must keep this attribute current, including after
the topmost window is closed. This attribute obviously can return null
if no windows are open, but should otherwise always return a valid
window.