Class: BasicCursor

Constructor

BasicCursor

new BasicCursor()

Class for a basic cursor. This will allow the user to get to all nodes in the AST by hitting next or previous.

Extends: Blockly.Cursor

Property

colour

unknown

The colour of the marker.

Inherited from: Blockly.Marker#colour

Methods

dispose

dispose()

Dispose of this marker.

Inherited from: Blockly.Marker#dispose

draw

package

draw()

Redraw the current marker.

Inherited from: Blockly.Marker#draw

getCurNode

getCurNode() returns Blockly.ASTNode

Gets the current location of the marker.

Inherited from: Blockly.Marker#getCurNode
Returns: The current field, connection, or block the marker is on.

getDrawer

getDrawer() returns Blockly.blockRendering.MarkerSvg

Get the current drawer for the marker.

Inherited from: Blockly.Marker#getDrawer
Returns: The object in charge of drawing the marker.

getNextNode_

protected

getNextNode_(node, isValid) returns Blockly.ASTNode

Uses pre order traversal to navigate the Blockly AST. This will allow a user to easily navigate the entire Blockly AST without having to go in and out levels on the tree.

Parameter
node	Blockly.ASTNode The current position in the AST.
isValid	function(Blockly.ASTNode) A function true/false depending on whether the given node should be traversed. Value must not be null.

Parameter

node

Blockly.ASTNode

The current position in the AST.

isValid

function(Blockly.ASTNode)

A function true/false depending on whether the given node should be traversed.

Value must not be null.

Returns: Blockly.ASTNode The next node in the traversal.

getPreviousNode_

protected

getPreviousNode_(node, isValid) returns Blockly.ASTNode

Reverses the pre order traversal in order to find the previous node. This will allow a user to easily navigate the entire Blockly AST without having to go in and out levels on the tree.

Parameter
node	Blockly.ASTNode The current position in the AST.
isValid	function(Blockly.ASTNode) A function true/false depending on whether the given node should be traversed. Value must not be null.

Parameter

node

Blockly.ASTNode

The current position in the AST.

isValid

function(Blockly.ASTNode)

A function true/false depending on whether the given node should be traversed.

Value must not be null.

Returns: Blockly.ASTNode The previous node in the traversal or null if no previous node exists.

hide

hide()

Hide the marker SVG.

Inherited from: Blockly.Marker#hide

in

protected

in() returns Blockly.ASTNode

For a basic cursor we only have the ability to go next and previous, so in will also allow the user to get to the next node in the pre order traversal.

Inherited from: Blockly.BasicCursor#in
Returns: The next node, or null if the current node is not set or there is no next value.

protected

next() returns Blockly.ASTNode

Find the next node in the pre order traversal.

Inherited from: Blockly.BasicCursor#next
Returns: The next node, or null if the current node is not set or there is no next value.

onBlocklyAction

onBlocklyAction(action) returns boolean

Handles the given action. This is only triggered when keyboard navigation is enabled.

Parameter
action	The action to be handled. Value must not be null.

Parameter

action

The action to be handled.

Value must not be null.

Inherited from: Blockly.Cursor#onBlocklyAction
Implements: Blockly.IBlocklyActionable#onBlocklyAction
Returns: True if the action has been handled, false otherwise.

out

protected

out() returns Blockly.ASTNode

For a basic cursor we only have the ability to go next and previous, so out will allow the user to get to the previous node in the pre order traversal.

Inherited from: Blockly.BasicCursor#out
Returns: The previous node, or null if the current node is not set or there is no previous value.

protected

prev() returns Blockly.ASTNode

Find the previous node in the pre order traversal.

Inherited from: Blockly.BasicCursor#prev
Returns: The previous node, or null if the current node is not set or there is no previous value.

setCurNode

setCurNode(newNode)

Set the location of the marker and call the update method. Setting isStack to true will only work if the newLocation is the top most output or previous connection on a stack.

Parameter
newNode	The new location of the marker.

Inherited from: Blockly.Marker#setCurNode

setDrawer

setDrawer(drawer)

Sets the object in charge of drawing the marker.

Parameter
drawer	The object in charge of drawing the marker.

Inherited from: Blockly.Marker#setDrawer

validNode_

protected

validNode_(node) returns boolean

Decides what nodes to traverse and which ones to skip. Currently, it skips output, stack and workspace nodes.

Parameter
node	Blockly.ASTNode The AST node to check whether it is valid.

Returns: boolean True if the node should be visited, false otherwise.