init

pub fn init(self: *AnimateWidget, src: std.builtin.SourceLocation, init_opts: InitOptions, opts: Options) void {
    const defaults = Options{ .name = "Animate" };
    self.* = .{ .wd = WidgetData.init(src, .{}, defaults.override(opts)), .init_opts = init_opts };

    if (self.init_opts.kind != .none) {
        if (dvui.firstFrame(self.data().id)) {
            // start begin animation
            self.start();
        }

        if (dvui.animationGet(self.data().id, "_end")) |a| {
            self.val = a.value();
        } else if (dvui.animationGet(self.data().id, "_start")) |a| {
            self.val = a.value();
        }
    }

    if (self.val) |v| {
        switch (self.init_opts.kind) {
            .none => {},
            .alpha => {
                self.prev_alpha = dvui.alpha(v);
            },
            .vertical => {
                if (dvui.minSizeGet(self.data().id)) |ms| {
                    if (self.data().rect.h > ms.h + 0.001) {
                        // we are bigger than our min size (maybe expanded) - account for floating point
                        const h = self.data().rect.h;
                        self.data().rect.h *= @max(v, 0);
                        self.data().rect.y += self.data().options.gravityGet().y * (h - self.data().rect.h);
                    }
                }
            },
            .horizontal => {
                if (dvui.minSizeGet(self.data().id)) |ms| {
                    if (self.data().rect.w > ms.w + 0.001) {
                        // we are bigger than our min size (maybe expanded) - account for floating point
                        const w = self.data().rect.w;
                        self.data().rect.w *= @max(v, 0);
                        self.data().rect.x += self.data().options.gravityGet().x * (w - self.data().rect.w);
                    }
                }
            },
        }
    }

    dvui.parentSet(self.widget());
    self.data().register();
    self.data().borderAndBackground(.{});
}