Enum ItemSelectionMode 

pub enum ItemSelectionMode {
    IntersectsItemShape,
    ContainsItemShape,
    IntersectsItemBoundingRect,
    ContainsItemBoundingRect,
}

How a region query decides whether an item is picked — Qt’s Qt::ItemSelectionMode, one variant for one.

The …ItemShape modes consult SceneItem::shape, in whichever frame keeps both sides’ bands round — usually the item’s local one, with the region mapped down into it, and scene space when the region’s band cannot make that trip (ItemShape::contained_by_scene_region). The …ItemBoundingRect modes compare the item’s scene AABB, in scene space.

For an item whose transform is identity and whose shape is the default AABB the two families coincide exactly. For an item carrying a rotation or a scale they do not: the scene AABB of a rotated box is the enlarged axis-aligned hull of it, so a bounding-rect query is strictly the looser test. That is a real behaviour difference, not a rounding one — and it is an implication, in both directions. A shape lies inside its own box, so a shape the region meets its box meets too, and a box the region contains drags its shape in with it. Both are pinned by tests/prop_selection_modes.rs, and holding them is what decides how a band may be mapped.

Variants

IntersectsItemShape

Picked when its shape intersects the region. Qt’s default and Teksilo’s: it is the rule that makes a rubber band agree with a click about what an item is.

ContainsItemShape

Picked when its shape lies entirely inside the region — “select what the lasso fully encircles”.

IntersectsItemBoundingRect

Picked when its scene AABB intersects the region. The cheap mode, and the one that reproduces the pre-ItemShape marquee.

ContainsItemBoundingRect

Picked when its scene AABB lies entirely inside the region.

Implementations

impl ItemSelectionMode

pub fn uses_shape(self) -> bool

Whether this mode consults the item’s shape (rather than its AABB).

pub fn requires_containment(self) -> bool

Whether this mode requires full containment (rather than any overlap).

Trait Implementations

impl Clone for ItemSelectionMode

fn clone(&self) -> ItemSelectionMode

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for ItemSelectionMode

impl Debug for ItemSelectionMode

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for ItemSelectionMode

fn default() -> ItemSelectionMode

Returns the “default value” for a type.

impl Eq for ItemSelectionMode

impl PartialEq for ItemSelectionMode

fn eq(&self, other: &ItemSelectionMode) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for ItemSelectionMode