How to Use the AVLVis System
The AVLVis system provides facilities to insert and delete string-based nodes.
Facilities are also in place to be 'tutored' by the system, or simply receive
feedback information as to what is going on with regard to the current AVL
Tree.
The Function Buttons
The three function buttons all relate to the current AVL Tree (which is
displayed in the AVL tree visualisation canvas).
The Reset Button
This button essentially resets the state of the system to how it was when it
was first loaded. Use this button to clear the current tree and the tutor
probability information (the probability of a question being asked is reduced
if you have successfully answered that question before). This button also
clears the undo information.
The Previous Button
The buttons displays the previous state of the current AVL Tree in its own
window. This is useful when the user wishes to examine the changes that have
occurred to the tree on completion of the last operation. If there the
previous state of the current tree is empty, the operation will not execute.
The Undo Button
This button toggles between the current AVL Tree and its previous state. On a
successful operation, the AVL Tree will revert back to its last state and this
change will be displayed in the AVL Tree visualisation canvas. If the Undo
button is pressed twice without any insert/delete operation in between, the
tree will return to its original state.
Inserting Nodes
To insert a node or nodes, simply select the insert checkbox in the operation
selector, and enter the tokens to represent the node or nodes you wish to
insert into the current AVL Tree in the nodes token field. A token is simply a
string void of white space. If the operation is successful the node
represented by the token is inserted into the tree, and if it fails a message
in the user feedback field will appear explaining why the operation failed. If
the system is currently in tutor or step mode, than a question may be required
to be answered or a click may be needed to progress the tree to its state
reflecting the inserted node.
Deleting Nodes
To delete a node or nodes, simply select the delete checkbox in the operation
selector, and enter the tokens to represent the node or nodes you wish to
delete from the current AVL Tree in the nodes token field. As mentioned in
'Inserting Nodes', a token is simply a string void of white space. If the
operation is successful the node represented by the token is deleted from the
tree, and if it fails a message in the user feedback field will appear
explaining why the operation failed. If the system is currently in tutor or
step mode, than a question may be required to be answered or a click may be
needed to progress the tree to its state reflecting the deleted node.
Tutor Mode
To enter tutor mode, make sure the tutor checkbox is selected in the mode
selector. This will tell the system to go into tutor mode for the next insert
or delete operation. Then, when an insert of delete operation occurs, the
system will decide wether or not to ask the user a question (based on whether
or not the user has previously correctly answered the question to be asked).
If the system decides to ask the user the question, the user feedback image
will change to image below, and either a dialog box will appear with the
current question, or the question will be displayed in the user feedback line
(based on the question being asked). Then after the user has answered the
question, the user feedback image will change to reflect wether or not the
question has been answered correctly and the operation will continue.
NB. Some questions may give the user three chances to answer them, in which
case an [x] will appear in the user feedback line if the user incorrectly
answers the question.
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Step Mode
To enter step mode, make sure the step mode checkbox is selected in the mode
selector. This will tell the system to go into step mode for the next insert
or delete operation. Then, when an insert of delete operation occurs, the
system enters step mode, updates the user feedback image to reflect this, and
provides the user with feedback on the current state of the operation (eg.
swapping node 'x' with node 'y'). The user can continue the system to its next
state by clicking inside the AVL Tree visualisation canvas.
