update method

@override void update(double t)

Sets the motion to a specific point in time. The t value that is passed in is a normalized value 0.0 to 1.0 of the duration of the motion. Every motion will always recieve a callback with the end time point (1.0), unless it is cancelled.

Implementation

@override
void update(double t) {
  dynamic newVal;

  if (start is Offset) {
    // Point
    double xStart = (start as Offset).dx;
    double yStart = (start as Offset).dy;
    double xDelta = _delta.dx;
    double yDelta = _delta.dy;
    newVal = Offset(xStart + xDelta * t, yStart + yDelta * t);
  } else if (start is Size) {
    // Size
    double wStart = (start as Size).width;
    double hStart = (start as Size).height;
    double wDelta = _delta.width;
    double hDelta = _delta.height;
    newVal = Size(wStart + wDelta * t, hStart + hDelta * t);
  } else if (start is Rect) {
    // Rect
    double lStart = (start as Rect).left;
    double tStart = (start as Rect).top;
    double rStart = (start as Rect).right;
    double bStart = (start as Rect).bottom;
    double lDelta = _delta.left;
    double tDelta = _delta.top;
    double rDelta = _delta.right;
    double bDelta = _delta.bottom;
    newVal = Rect.fromLTRB(lStart + lDelta * t, tStart + tDelta * t,
        rStart + rDelta * t, bStart + bDelta * t);
  } else if (start is double) {
    // Doubles
    newVal = (start as double) + _delta * t;
  } else if (start is Color) {
    // Colors
    int aNew = ((start as Color).alpha + (_delta.alpha * t).toInt())
        .clamp(0, 255) as int;
    int rNew = ((start as Color).red + (_delta.red * t).toInt()).clamp(0, 255)
        as int;
    int gNew = ((start as Color).green + (_delta.green * t).toInt())
        .clamp(0, 255) as int;
    int bNew = ((start as Color).blue + (_delta.blue * t).toInt())
        .clamp(0, 255) as int;
    newVal = Color.fromARGB(aNew, rNew, gNew, bNew);
  } else {
    // Oopses
    assert(false);
  }

  setter(newVal);
}