transitionProgressMin property
Progress 0..1 derived from the four rect/crop animation
controllers, gated by openingOrDismissing || changingMode so
release/settle don't move it. Three aggregations exposed —
consumer picks based on desired fade timing:
- transitionProgressMin: slowest controller.
- transitionProgressMean: average across all four.
- transitionProgressMax: fastest controller.
Implementation
final ValueListenable<double> transitionProgressMin;