tsai
/
Avalonia
mirror of https://github.com/AvaloniaUI/Avalonia.git
1
0
Fork 0
Code Issues Projects Releases Wiki Activity
Browse Source

Improve scroll snapping with mouse wheel (#14562) 

* improve scroll snapping

* remove debug code, ensure snappoints are in range
pull/16303/head
Emmanuel Hansen 2 years ago
committed by GitHub
parent
4dbb165a7b
commit
e1203becc6
No known key found for this signature in database GPG Key ID: B5690EEEBB952194
1 changed files with 40 additions and 43 deletions
Whitespace
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
Split View
Diff Options
Show Stats Download Patch File Download Diff File
  1. 83
      src/Avalonia.Controls/Presenters/ScrollContentPresenter.cs

83
src/Avalonia.Controls/Presenters/ScrollContentPresenter.cs
View File

@ -634,8 +634,6 @@ namespace Avalonia.Controls.Presenters
offset = new Vector(offset.X + xDistance, offset.Y + yDistance);
System.Diagnostics.Debug.WriteLine($"{offset}");
_scrollGestureSnapPoints.Add(e.Id, SnapOffset(offset));
double GetDistance(double speed)
@ -692,7 +690,7 @@ namespace Avalonia.Controls.Presenters
x = Math.Min(x, Extent.Width - Viewport.Width);
}
Vector newOffset = SnapOffset(new Vector(x, y));
Vector newOffset = SnapOffset(new Vector(x, y), delta, true);
bool offsetChanged = newOffset != Offset;
SetCurrentValue(OffsetProperty, newOffset);
@ -930,67 +928,64 @@ namespace Avalonia.Controls.Presenters
}
}
private Vector SnapOffset(Vector offset)
private Vector SnapOffset(Vector offset, Vector direction = default, bool snapToNext = false)
{
var scrollable = GetScrollSnapPointsInfo(Content);
if(scrollable is null)
if (scrollable is null || (VerticalSnapPointsType == SnapPointsType.None && HorizontalSnapPointsType == SnapPointsType.None))
return offset;
var diff = GetAlignedDiff();
var diff = GetAlignmentDiff();
if (VerticalSnapPointsType != SnapPointsType.None)
if (VerticalSnapPointsType != SnapPointsType.None && (_areVerticalSnapPointsRegular || _verticalSnapPoints?.Count > 0) && (!snapToNext || snapToNext && direction.Y != 0))
{
offset = new Vector(offset.X, offset.Y + diff.Y);
double nearestSnapPoint = offset.Y;
var estimatedOffset = new Vector(offset.X, offset.Y + diff.Y);
double previousSnapPoint = 0, nextSnapPoint = 0, midPoint = 0;
if (_areVerticalSnapPointsRegular)
{
var minSnapPoint = (int)(offset.Y / _verticalSnapPoint) * _verticalSnapPoint + _verticalSnapPointOffset;
var maxSnapPoint = minSnapPoint + _verticalSnapPoint;
var midPoint = (minSnapPoint + maxSnapPoint) / 2;
nearestSnapPoint = offset.Y < midPoint ? minSnapPoint : maxSnapPoint;
previousSnapPoint = (int)(estimatedOffset.Y / _verticalSnapPoint) * _verticalSnapPoint + _verticalSnapPointOffset;
nextSnapPoint = previousSnapPoint + _verticalSnapPoint;
midPoint = (previousSnapPoint + nextSnapPoint) / 2;
}
else if (_verticalSnapPoints != null && _verticalSnapPoints.Count > 0)
else if (_verticalSnapPoints?.Count > 0)
{
var higherSnapPoint = FindNearestSnapPoint(_verticalSnapPoints, offset.Y, out var lowerSnapPoint);
var midPoint = (lowerSnapPoint + higherSnapPoint) / 2;
nearestSnapPoint = offset.Y < midPoint ? lowerSnapPoint : higherSnapPoint;
(previousSnapPoint, nextSnapPoint) = FindNearestSnapPoint(_verticalSnapPoints, estimatedOffset.Y);
midPoint = (previousSnapPoint + nextSnapPoint) / 2;
}
var nearestSnapPoint = snapToNext ? (direction.Y > 0 ? previousSnapPoint : nextSnapPoint ) :
estimatedOffset.Y < midPoint ? previousSnapPoint : nextSnapPoint;
offset = new Vector(offset.X, nearestSnapPoint - diff.Y);
}
if (HorizontalSnapPointsType != SnapPointsType.None)
if (HorizontalSnapPointsType != SnapPointsType.None && (_areHorizontalSnapPointsRegular || _horizontalSnapPoints?.Count > 0) && (!snapToNext || snapToNext && direction.X != 0))
{
offset = new Vector(offset.X + diff.X, offset.Y);
double nearestSnapPoint = offset.X;
var estimatedOffset = new Vector(offset.X + diff.X, offset.Y);
double previousSnapPoint = 0, nextSnapPoint = 0, midPoint = 0;
if (_areHorizontalSnapPointsRegular)
{
var minSnapPoint = (int)(offset.X / _horizontalSnapPoint) * _horizontalSnapPoint + _horizontalSnapPointOffset;
var maxSnapPoint = minSnapPoint + _horizontalSnapPoint;
var midPoint = (minSnapPoint + maxSnapPoint) / 2;
nearestSnapPoint = offset.X < midPoint ? minSnapPoint : maxSnapPoint;
previousSnapPoint = (int)(estimatedOffset.X / _horizontalSnapPoint) * _horizontalSnapPoint + _horizontalSnapPointOffset;
nextSnapPoint = previousSnapPoint + _horizontalSnapPoint;
midPoint = (previousSnapPoint + nextSnapPoint) / 2;
}
else if (_horizontalSnapPoints != null && _horizontalSnapPoints.Count > 0)
else if (_horizontalSnapPoints?.Count > 0)
{
var higherSnapPoint = FindNearestSnapPoint(_horizontalSnapPoints, offset.X, out var lowerSnapPoint);
var midPoint = (lowerSnapPoint + higherSnapPoint) / 2;
nearestSnapPoint = offset.X < midPoint ? lowerSnapPoint : higherSnapPoint;
(previousSnapPoint, nextSnapPoint) = FindNearestSnapPoint(_horizontalSnapPoints, estimatedOffset.X);
midPoint = (previousSnapPoint + nextSnapPoint) / 2;
}
offset = new Vector(nearestSnapPoint - diff.X, offset.Y);
var nearestSnapPoint = snapToNext ? (direction.X > 0 ? previousSnapPoint : nextSnapPoint) :
estimatedOffset.X < midPoint ? previousSnapPoint : nextSnapPoint;
offset = new Vector(nearestSnapPoint - diff.X, offset.Y);
}
Vector GetAlignedDiff()
Vector GetAlignmentDiff()
{
var vector = offset;
var vector = default(Vector);
switch (VerticalSnapPointsAlignment)
{
@ -1010,31 +1005,33 @@ namespace Avalonia.Controls.Presenters
case SnapPointsAlignment.Far:
vector += new Vector(Viewport.Width, 0);
break;
}
}
return vector - offset;
return vector;
}
return offset;
}
private static double FindNearestSnapPoint(IReadOnlyList<double> snapPoints, double value, out double lowerSnapPoint)
private static (double previous, double next) FindNearestSnapPoint(IReadOnlyList<double> snapPoints, double value)
{
var point = snapPoints.BinarySearch(value, Comparer<double>.Default);
double previousSnapPoint, nextSnapPoint;
if (point < 0)
{
point = ~point;
lowerSnapPoint = snapPoints[Math.Max(0, point - 1)];
previousSnapPoint = snapPoints[Math.Max(0, point - 1)];
nextSnapPoint = point >= snapPoints.Count ? snapPoints.Last() : snapPoints[Math.Max(0, point)];
}
else
{
lowerSnapPoint = snapPoints[point];
point += 1;
previousSnapPoint = nextSnapPoint = snapPoints[Math.Max(0, point)];
}
return snapPoints[Math.Min(point, snapPoints.Count - 1)];
return (previousSnapPoint, nextSnapPoint);
}
private IScrollSnapPointsInfo? GetScrollSnapPointsInfo(object? content)

Write Preview
Loading…
Cancel
Save