Class: BlockDragStrategy

Defined in: packages/blockly/core/dragging/block_drag_strategy.ts:67

Implements

• IDragStrategy

Properties index

Property	Description
workspace	-
startLoc	-
connectionPreviewer	-
moveMode	The current movement mode.
BLOCK_CONNECTION_OFFSET	-
WORKSPACE_MARGIN	How far in from the edges of the workspace to position newly placed blocks.
block	-

Methods index

Method	Description
isMovable	Returns true if the block is currently movable. False otherwise.
positionNewBlock	Positions a cloned block on its new workspace.
getTargetBlock	Returns the block to use for the current drag operation. This may create and return a newly instantiated block when e.g. dragging from a flyout.
startDrag	Handles any setup for starting the drag, including disconnecting the block from any parent blocks.
cacheAllConnectionPairs	Caches a list of all valid connection pairs between the dragging block and any other blocks on the workspace. This is used to determine the closest valid connection during keyboard-driven moves and to determine the need to disambiguate between multiple compatible connections when announcing moves to assistive technologies.
shouldHealStack	Get whether the drag should act on a single block or a block stack.
shouldDisconnect	Whether or not we should disconnect the block when a drag is started.
drag	Moves the block and updates any connection previews.
getSearchRadius	Get the radius to use when searching for a nearby valid connection.
endDrag	Cleans up any state at the end of the drag. Applies any pending connections.
revertDrag	Moves the block back to where it was at the beginning of the drag, including reconnecting connections.
findTraversalCandidate	Get the nearest valid candidate connection in traversal order.

Constructors

Constructor

new BlockDragStrategy(block): BlockDragStrategy;

Defined in: packages/blockly/core/dragging/block_drag_strategy.ts:118

Parameters

Parameter	Type
block	BlockSvg

Returns

BlockDragStrategy

Properties

workspace

protected workspace: WorkspaceSvg;

Defined in: packages/blockly/core/dragging/block_drag_strategy.ts:68

---

startLoc

protected startLoc: Coordinate | null = null;

Defined in: packages/blockly/core/dragging/block_drag_strategy.ts:79

---

connectionPreviewer

protected connectionPreviewer: 
  | IConnectionPreviewer
  | null = null;

Defined in: packages/blockly/core/dragging/block_drag_strategy.ts:83

---

moveMode

protected moveMode: MoveMode = MoveMode.UNCONSTRAINED;

Defined in: packages/blockly/core/dragging/block_drag_strategy.ts:91

The current movement mode.

---

BLOCK_CONNECTION_OFFSET

protected readonly BLOCK_CONNECTION_OFFSET: 10 = 10;

Defined in: packages/blockly/core/dragging/block_drag_strategy.ts:111

---

WORKSPACE_MARGIN

protected readonly WORKSPACE_MARGIN: 10 = 10;

Defined in: packages/blockly/core/dragging/block_drag_strategy.ts:116

How far in from the edges of the workspace to position newly placed blocks.

---

block

protected block: BlockSvg;

Defined in: packages/blockly/core/dragging/block_drag_strategy.ts:118

Methods

isMovable()

isMovable(): boolean;

Defined in: packages/blockly/core/dragging/block_drag_strategy.ts:123

Returns true if the block is currently movable. False otherwise.

Returns

boolean

Implementation of

IDragStrategy.isMovable

---

positionNewBlock()

protected positionNewBlock(oldBlock, newBlock): void;

Defined in: packages/blockly/core/dragging/block_drag_strategy.ts:140

Positions a cloned block on its new workspace.

Parameters

Parameter	Type	Description
oldBlock	BlockSvg	The flyout block that was cloned.
newBlock	BlockSvg	The new block to position.

Returns

void

---

getTargetBlock()

protected getTargetBlock(): BlockSvg;

Defined in: packages/blockly/core/dragging/block_drag_strategy.ts:243

Returns the block to use for the current drag operation. This may create and return a newly instantiated block when e.g. dragging from a flyout.

Returns

BlockSvg

---

startDrag()

startDrag(e?): IDraggable;

Defined in: packages/blockly/core/dragging/block_drag_strategy.ts:345

Handles any setup for starting the drag, including disconnecting the block from any parent blocks.

Parameters

Parameter	Type
e?	PointerEvent | KeyboardEvent

Returns

IDraggable

Implementation of

IDragStrategy.startDrag

---

cacheAllConnectionPairs()

cacheAllConnectionPairs(): void;

Defined in: packages/blockly/core/dragging/block_drag_strategy.ts:432

Caches a list of all valid connection pairs between the dragging block and any other blocks on the workspace. This is used to determine the closest valid connection during keyboard-driven moves and to determine the need to disambiguate between multiple compatible connections when announcing moves to assistive technologies.

Returns

void

---

shouldHealStack()

protected shouldHealStack(e): boolean;

Defined in: packages/blockly/core/dragging/block_drag_strategy.ts:487

Get whether the drag should act on a single block or a block stack.

Parameters

Parameter	Type	Description
e	PointerEvent | KeyboardEvent | undefined	The instigating pointer or keyboard event, if any.

Returns

boolean

True if just the initial block should be dragged out, false if all following blocks should also be dragged.

---

shouldDisconnect()

protected shouldDisconnect(healStack): boolean;

Defined in: packages/blockly/core/dragging/block_drag_strategy.ts:507

Whether or not we should disconnect the block when a drag is started.

Parameters

Parameter	Type	Description
healStack	boolean	Whether or not to heal the stack after disconnecting.

Returns

boolean

True to disconnect the block, false otherwise.

---

drag()

drag(newLoc, e?): void;

Defined in: packages/blockly/core/dragging/block_drag_strategy.ts:608

Moves the block and updates any connection previews.

Parameters

Parameter	Type
newLoc	Coordinate
e?	PointerEvent | KeyboardEvent

Returns

void

Implementation of

IDragStrategy.drag

---

getSearchRadius()

protected getSearchRadius(): number;

Defined in: packages/blockly/core/dragging/block_drag_strategy.ts:877

Get the radius to use when searching for a nearby valid connection.

Returns

number

---

endDrag()

endDrag(_e, disposition): void;

Defined in: packages/blockly/core/dragging/block_drag_strategy.ts:922

Cleans up any state at the end of the drag. Applies any pending connections.

Parameters

Parameter	Type
_e	PointerEvent | KeyboardEvent | undefined
disposition	DragDisposition

Returns

void

Implementation of

IDragStrategy.endDrag

---

revertDrag()

revertDrag(): void;

Defined in: packages/blockly/core/dragging/block_drag_strategy.ts:1016

Moves the block back to where it was at the beginning of the drag, including reconnecting connections.

Returns

void

Implementation of

IDragStrategy.revertDrag

---

findTraversalCandidate()

findTraversalCandidate(delta): ConnectionCandidate | null;

Defined in: packages/blockly/core/dragging/block_drag_strategy.ts:1071

Get the nearest valid candidate connection in traversal order.

Parameters

Parameter	Type	Description
delta	Coordinate	The distance the block has moved since this drag began.

Returns

ConnectionCandidate | null

A candidate connection and radius, or null if none was found.