1. A method to enable users of mobile devices to collaborate in a session over a canvas, wherein a mobile device client includes a graphical user interface (GUI) viewport, and wherein viewports on individual mobile devices are capable of displaying different portions of the canvas concurrently, the method comprising:
establishing and maintaining a whiteboard for the session;
receiving a request for a change to the whiteboard from a mobile device client and, in response, updating the whiteboard to reflect the change and notifying one or more other mobile device clients of the change;
receiving a synchronization request that is one of: a first type, and a second type, the first type being a synchronization request received from a given mobile device client and indicating that one or more other mobile device clients should synchronize their viewports to the viewport of the given mobile device client, and the second type being a synchronization request received from a first mobile device client and indicating that the first mobile device client desires to synchronize its viewport to that of a second mobile device client; and
enforcing the synchronization request to synchronize viewports across the session.
2. The method as described in claim 1 wherein the given mobile device client is associated with a moderator of the session, and the first type of synchronization request synchronizes the viewports of the other mobile device clients to the moderator’s viewport.
3. The method as described in claim 1 wherein the first mobile device client is associated with a participant of the session, and the second type of synchronization request synchronizes the viewport of the first mobile device client to the viewport of the second mobile device client.
4. The method as described in claim 1 further including providing a notification to the first mobile device client of an activity of a user of a second mobile device client, the notification indicating a relative position on the canvas of the activity of the user of the second mobile device with respect to a viewport of the first mobile device client.
5. The method as described in claim 4 further including receiving the synchronization request of the second type in response to a selection by a user of the first mobile device client, the selection having been made upon the user of the first mobile device client receiving the notification.
6. The method as described in claim 4 wherein the notification has a visual cue uniquely associated with the user of the second mobile device client.
7. The method as described in claim 4 wherein the notification is adapted to be acted upon to generate the synchronization request for a configurable time period.
8. The method as described in claim 1 wherein, relative to a viewport, the canvas is infinite.
9. The method as described in claim 1 wherein the mobile devices are networked together and the requests are communicated via a real-time communication protocol.
10. The method as described in claim 9 wherein the real-time communication protocol is XMPP.
11. A server apparatus, comprising:
at least one processor;
computer memory holding computer program instructions operative to enable users of mobile devices to collaborate in a session over a canvas, wherein a mobile device client includes a graphical user interface (GUI) viewport, the computer program instructions operative to:
establish and maintain a whiteboard for the session;
receive a request for a change to the whiteboard from a mobile device client and, in response, update the whiteboard to reflect the change and notify one or more other mobile device clients of the change;
receive a synchronization request that is one of: a first type, and a second type, the first type being a synchronization request received from a given mobile device client and indicating that one or more other mobile device clients should synchronize their viewports to the viewport of the given mobile device client, and the second type being a synchronization request received from a first mobile device client and indicating that the first mobile device client desires to synchronize its viewport to that of a second mobile device client; and
enforce the synchronization request to synchronize viewports across the session.
12. The server apparatus as described in claim 11 wherein the computer program instructions are further operative to provide a notification to a first mobile device client of an activity of a user of a second mobile device client, the notification indicating a relative position on the canvas of the activity of the user of the second mobile device with respect to a viewport of the first mobile device client.
13. The server apparatus as described in claim 12 wherein the computer program instructions are further operative to receive a one-time synchronization request of the second type in response to a selection by a user of the first mobile device client, the selection having been made upon the user of the first mobile device client receiving the notification.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A fluorescent material comprising a europium-diketone chelate compound represented by the following formula (3) or (4):
wherein X+ is a heterocyclic cationic polymer, a cationic oligomer or a cationic heteroaromatic compound, R1 is an alkyl group or an alkoxy group, Z is a hydrogen atom or a substituent of an aliphatic or alicyclic compound and R is selected from the group consisting of
\u2003for the europium-diketone chelate compound of formula (3) and R is selected from the group consisting of
\u2003for the europium-diketone chelate compound of formula (4).