Client-Server

Module Description

Base classes (independent of any GUI toolkit) to write Cadabra clients and servers.

All clients use two threads. One is the main thread and runs most of the logic in the DocumentThread object. The other one is a thread which communicates with the server process; code for this thread is in the ComputeThread object. One typically subclasses the former into a full-fledged object driving the graphical user interface.

All functionality that deals with GUI updates is isolated in GUIBase. A client should derive from this abstract base class and implement the methods there. Clients should also derive from DocumentThread, but there are no abstract virtual members to implemented from this base class.

All actual updates to the document stored in the DocumentThread::dtree member are made on the GUI thread as well. The compute thread merely puts requests to change the document onto a stack, and then requests that the GUI updates the document.

In order to enable undo/redo, all updates to DocumentThread::dtree are made by putting objects derived from ActionBase onto the action stack. See DocumentThread::queue_action for details. These ActionBase objects (among which ActionAddCell, ActionRemoveCell, ActionInsertText, etc) get executed on the GUI thread, and contain the actual logic to perform updates to the document and related GUI elements.

Classes
class	cadabra::ActionBase
class	cadabra::ActionAddCell
class	cadabra::ActionPositionCursor
class	cadabra::ActionSetRunStatus
class	cadabra::ActionRemoveCell
class	cadabra::ActionSplitCell
class	cadabra::ActionInsertText
class	cadabra::ActionCompleteText
class	cadabra::ActionEraseText
class	cadabra::CadabraJupyter
class	cadabra::ComputeThread
class	cadabra::DocumentThread
class	cadabra::GUIBase
class	Server