percentOffScreen method
The percentage of the shape that is off screen.
- 0.0 means the shape is completely on screen.
- 0.5 means the shape is halfway off screen.
- 1.0 means the shape is completely off screen.
shapeDimension
is the width or height of the shape depending on the
ScrollDirection. Width in the case of horizontal (left/right) scrolling
and height in the case of vertical (up/down) scrolling.
screenDimension
is the width or height of the screen depending on the
ScrollDirection. Width in the case of horizontal (left/right) scrolling
and height in the case of vertical (up/down) scrolling.
Implementation
double percentOffScreen(
double x,
double shapeDimension,
double screenDimension,
) {
late final double amountOffScreen;
if (x < 0) {
amountOffScreen = x;
} else if (x > screenDimension - shapeDimension) {
amountOffScreen = x - (screenDimension - shapeDimension);
} else {
amountOffScreen = 0.0;
}
return (amountOffScreen / shapeDimension).abs();
}