TooltipPlacementDelegate class

Tooltip placement relative to its target.

Currently: side chosen from a snapshot rect on step change + keep-in-screen; recomputing placement on scroll and multi-content collisions are follow-up work.

Why CustomSingleChildLayout: the tooltip size is unknown before layout (text), and the delegate receives it from the framework in getPositionForChild (childSize) — no manual text measuring ("no dry-layout"). The box itself is sized to the screen (default getSize = constraints.biggest), so the tooltip buttons are hit-testable anywhere on screen, and taps past the tooltip fall through (hitTestSelf = false) onto the scrim.

Side selection: try the preferred side; if it does not fit — mirror (bottom↔top, left↔right); still not fitting — the other sides; last resort (tooltip or hole larger than the screen) — a screen corner with a margin.

Inheritance

Constructors

TooltipPlacementDelegate({required Rect screenLocal, required Rect holeLocal, required TooltipPosition position, double gap = 12})

Properties

gap → double
Gap between the tooltip and the hole.
final
hashCode → int
The hash code for this object.
no setterinherited
holeLocal → Rect
The target (scrim hole) rect in the same coordinates: translation & leaderSize.
final
position → TooltipPosition
Preferred side; TooltipPosition.auto — the side with the most free space between the hole and the screen edge.
final
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited
screenLocal → Rect
The screen in the tooltip layer's coordinates (global here — the tooltip lives in the full-screen overlay layer, see overlay_engine.dart).
final

Methods

getConstraintsForChild(BoxConstraints constraints) → BoxConstraints
The tooltip gets loose constraints (up to screen size) and picks its own size; a tight box would stretch it over the whole screen.
override
getPositionForChild(Size size, Size childSize) → Offset
size — the layout box size (= the screen, see class doc); childSize — the tooltip's actual size after layout.
override
getSize(BoxConstraints constraints) → Size
The size of this object given the incoming constraints.
inherited
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
shouldRelayout(covariant TooltipPlacementDelegate oldDelegate) → bool
Called whenever a new instance of the custom layout delegate class is provided to the RenderCustomSingleChildLayoutBox object, or any time that a new CustomSingleChildLayout object is created with a new instance of the custom layout delegate class (which amounts to the same thing, because the latter is implemented in terms of the former).
override
toString() → String
A string representation of this object.
inherited

Operators

operator ==(Object other) → bool
The equality operator.
inherited