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DeTransDraw: Decentralized Transactional collaborative Drawing

DeTransDraw is a decentralized collaborative vector-based graphical editor with a shared drawing area. It provides synchronous collaboration between users with graphical support for notifications about other users' activities. Conflict resolution is achieved with a decentralized transactional service with storage replication, and self-management replication for fault-tolerance. The transactional service also allows the application to prevent performance degradation due to network latency, which is an important feature for synchronous collaboration.

Screenshots

DeTransDraw offers a simple user interface to create a ring of P2PS nodes. The first screenshot is the manager window for the node 21797. Two buttons named Save: and Save allow the user to save the ticket, while Load: and Join help to connect to some already saved tickets. When the ring is ready, the editor window may be opened thanks to Open editor button.

The drawing area is divided in three parts : the toolbar, the drawing part and the status bar. Button SEL stands for the selection of an object or multiple object with Shift key pressed. The buttons rect and oval allows the user to draw rectangles and ovals. The two colored buttons represent the color of the object and its border. The status bar notifies the user of the action he is currently doing.

If the user is in selection mode, he is able to select either rectangles or ovals. A selected object appears with nine dots at each coins and center of coins.

As it appears in the following screenshots, the dots may be filled in black or red. The colour depends on the status of the lock for the object. Here, the user on the left try to select the cyan rectangle which is already selected by the user of the right window. When an object is selected, the node try to lock it. While trying to get the lock, the dots are in red meaning that the lock may not be accepted. The user on the left will see the object unselected and back to the original position as soon as the lock is refused. The user on the right has got the lock and the dots are black.

How to install and run DeTransDraw

Requirements : Mozart 1.4.0

Installation : Download DeTransDraw binaries and extract it.

Run in real mode : Each user should execute DT.exe to get the manager window. If there are more than ten users, one of the user may save a ticket and send it to other users which will load it. A ring of nodes without drawing features may be created with the Bootstrap binary with option dss.

Run in simulation mode : First create the ring with Bootstrap binary with option sim. Each user can join the ring loading a ticket of this ring or connect with this command :
./DT.exe sim URL
Where URL is the location of a ticket of this ring.