getDirectionalIncrement static method
- ScrollableState state,
- ScrollIntent intent
Find out how much of an increment to move by, taking the different directions into account.
Implementation
static double getDirectionalIncrement(ScrollableState state, ScrollIntent intent) {
final double increment = _calculateScrollIncrement(state, type: intent.type);
switch (intent.direction) {
case AxisDirection.down:
switch (state.axisDirection) {
case AxisDirection.up:
return -increment;
case AxisDirection.down:
return increment;
case AxisDirection.right:
case AxisDirection.left:
return 0.0;
}
case AxisDirection.up:
switch (state.axisDirection) {
case AxisDirection.up:
return increment;
case AxisDirection.down:
return -increment;
case AxisDirection.right:
case AxisDirection.left:
return 0.0;
}
case AxisDirection.left:
switch (state.axisDirection) {
case AxisDirection.right:
return -increment;
case AxisDirection.left:
return increment;
case AxisDirection.up:
case AxisDirection.down:
return 0.0;
}
case AxisDirection.right:
switch (state.axisDirection) {
case AxisDirection.right:
return increment;
case AxisDirection.left:
return -increment;
case AxisDirection.up:
case AxisDirection.down:
return 0.0;
}
}
}