MultitouchDragStrategy enum

Only the latest active pointer is tracked by the recognizer.

If the tracked pointer is released, the first accepted of the remaining active pointers will continue to be tracked.

This is the behavior typically seen on Android.

All active pointers will be tracked, and the result is computed from the boundary pointers.

The scrolling offset is determined by the maximum deltas of both directions.

If the user is dragging with 3 pointers at the same time, each having [+10, +20, +33] pixels of offset, the recognizer will report a delta of 33 pixels.

If the user is dragging with 5 pointers at the same time, each having [+10, +20, +33, -1, -12] pixels of offset, the recognizer will report a delta of (+33) + (-12) = 21 pixels.

The panning PanGestureRecognizer offset is the average of all pointers.

If the user is dragging with 3 pointers at the same time, each having [+10, +50, -30] pixels of offset in one direction (horizontal or vertical), the recognizer will report a delta of (10 + 50 -30) / 3 = 10 pixels in this direction.

This is the behavior typically seen on iOS.

All active pointers will be tracked together. The scrolling offset is the sum of the offsets of all active pointers.

When a Scrollable drives scrolling by this drag strategy, the scrolling speed will double or triple, depending on how many fingers are dragging at the same time.

If the user is dragging with 3 pointers at the same time, each having [+10, +20, +33] pixels of offset, the recognizer will report a delta of 10 + 20 + 33 = 63 pixels.

If the user is dragging with 5 pointers at the same time, each having [+10, +20, +33, -1, -12] pixels of offset, the recognizer will report a delta of 10 + 20 + 33 - 1 - 12 = 50 pixels.