ui::DoubleAnimation¶

Header: winui/ui/Animation.hpp.

A from/to/by animation of one property. A missing from starts from the property's current animated value. to wins over by, and with neither the animation goes back to the property's own value. duration is one iteration, a second by default. repeat_count is the number of iterations, infinity repeats forever, and an auto-reversing iteration lasts two durations. On a three-component property (Translation, Scale, CenterPoint), every component runs the same values.

Example:

auto                  stack = std::make_unique<ui::StackControl>(ui::Orientation::Vertical);
ui::RectangleControl* rect  = stack->add(std::make_unique<ui::RectangleControl>());
rect->start_animation(ui::AnimatedProperty::TranslationX,
                      ui::DoubleAnimation{.to           = 200.0f,
                                          .duration     = 500ms,
                                          .easing       = ui::CircleEase{ui::EasingMode::EaseInOut},
                                          .on_completed = [] { /* now at x + 200 */ }});

// A pulsing fade that gives the property back when done.
rect->start_animation(ui::AnimatedProperty::Opacity,
                      ui::DoubleAnimation{.from         = 1.0f,
                                          .to           = 0.2f,
                                          .duration     = 300ms,
                                          .auto_reverse = true,
                                          .repeat_count = 3.0,
                                          .fill         = ui::FillBehavior::Stop});

Field	Type	Default
`from`	`OptionalFloat`		Start value. Unset starts from the property's current animated value.
`to`	`OptionalFloat`		End value; wins over `by`.
`by`	`OptionalFloat`		End value relative to the start, used when `to` is unset.
`duration`	`Duration`	`{1000.0}`	Length of one iteration.
`easing`	`std::optional<EasingFunction>`		Curve over each iteration. Unset is linear.
`begin_time`	`Duration`		Delay before the first iteration.
`auto_reverse`	`bool`	`false`	Plays each iteration forward then backward, doubling its length.
`repeat_count`	`double`	`1.0`	Iterations to run; `std::numeric_limits<double>::infinity()` repeats forever.
`fill`	`FillBehavior`	`FillBehavior::HoldEnd`	What the property shows once the animation finishes.
`on_completed`	`Callback<void()>`		Fires once when the animation finishes (not when it is replaced or stopped).