pySimBlocks.gui.graphics.block_item

class pySimBlocks.gui.graphics.block_item.BlockItem(instance: BlockInstance, pos: QPointF | QPoint, view: DiagramView, layout: dict | None = None)

Bases: QGraphicsRectItem

Render and interact with a block instance on the diagram scene.

view

Diagram view owning this graphics item.

instance

Block instance represented by the item.

orientation

Display orientation of the block.

port_items

Visual port items attached to the block.

WIDTH = 120

HEIGHT = 60

MIN_WIDTH = 40

MIN_HEIGHT = 30

GRID_DX = 5

GRID_DY = 5

SELECTION_HANDLE_SIZE = 8

SELECTION_HANDLE_HIT_SIZE = 16

TYPE_LABEL_MIN_HEIGHT = 45

get_port_item(name: str) → PortItem | None

Return the visual port item matching the given port name.

Parameters:

name – Port name to look up.

Returns:

Matching port item, or None if not found.

refresh_ports()

Synchronize visual ports with the current block instance ports.

toggle_orientation()

Flip the block orientation and relayout its ports.

set_orientation(orientation: str) → None

boundingRect() → QRectF

Return the item bounds including resize-handle hit areas.

Returns:

Bounding rectangle used for painting and interaction.

shape() → QPainterPath

Return the selectable shape including resize handles.

Returns:

Painter path used for hit testing.

paint(painter, option, widget=None)

Paint the block body, label, and resize handles when selected.

Parameters:

• painter – Painter used to render the item.

• option – Style option describing the current paint state.

• widget – Optional target widget.

mousePressEvent(event)

Start resize interaction when a selected handle is pressed.

Parameters:

event – Qt mouse-press event.

mouseMoveEvent(event)

Resize or move the block in response to mouse movement.

Parameters:

event – Qt mouse-move event.

mouseReleaseEvent(event)

End any active resize interaction.

Parameters:

event – Qt mouse-release event.

mouseDoubleClickEvent(event)

Open the block configuration dialog on double click.

Parameters:

event – Qt mouse double-click event.

itemChange(change, value)

Snap movement to the grid and notify the view when position changes.

Parameters:

• change – Item change identifier.

• value – Proposed new value for the change.

Returns:

Adjusted change value when snapping is needed, otherwise the base implementation result.