private void SnapToClosestBar(double position, GroupChartItem selectedItem)
{
var selectedValues = new SelectedChartValueItemArgs
{
ChartValueItems = new List <ChartValueItemParam>(),
TouchedPoint = TouchedPoint
};
foreach (var chartEntry in ChartEntries.Where(x => x.IsVisible))
{
var chartEntryItem = chartEntry.Items.FirstOrDefault(i => i.Tag.ToString() == selectedItem.Tag.ToString());
if (chartEntryItem == null)
{
continue;
}
selectedValues.ChartValueItems.Add(new ChartValueItemParam(chartEntryItem, null, chartEntry));
}
// Invoke command with selected items
SelectedValuesCommand?.Execute(selectedValues);
Device.BeginInvokeOnMainThread(async() =>
{
isSnapping = true;
ScrollComponent.Scrolled -= ScrollComponent_Scrolled;
SelectedLabel = selectedItem.Label;
lastScrollPosition = position;
await ScrollComponent.ScrollToAsync(lastScrollPosition, 0, false);
ShowSwipeNotifications(lastScrollPosition);
ScrollComponent.Scrolled += ScrollComponent_Scrolled;
isSnapping = false;
});
}
private void DrawSlider(SKCanvas canvas, SKRect frame, SKRect chart)
{
if (!IsSliderVisible)
{
return;
}
if (!IsInitialized)
{
FindClosestItem(TouchedPoint.X);
}
float x = chart.GetInsideXValue(TouchedPoint.X);
using (var paint = new SKPaint
{
Style = SKPaintStyle.Stroke,
StrokeCap = UseItemWidthSlider ? SKStrokeCap.Butt : SKStrokeCap.Round,
Color = this.SliderColor.ToSKColor().AsTransparency(),
StrokeWidth = UseItemWidthSlider ? frame.GetItemWidth(MaxItems) : this.SliderWidth
})
{
// Straight slider line
canvas.DrawLine(x, chart.Top, x, DisplayHorizontalValuesBySlider && !UseItemWidthSlider ? frame.Bottom + HorizontalTextSize : chart.Bottom, paint);
DrawSliderHint(canvas, x);
}
// Get items on x axis
var valueItems = ChartEntries.GetChartValueItemFromX(x, frame, frame.GetItemWidth(MaxItems));
// Send selected items with command
SelectedValuesCommand?.Execute(new SelectedChartValueItemArgs
{
ChartValueItems = valueItems,
TouchedPoint = new SKPoint(x, TouchedPoint.Y)
});
}
private void LineChart_PaintSurface(object sender, SKPaintSurfaceEventArgs e)
{
if (ChartEntries?.Any() != true)
{
return;
}
var info = e.Info;
var canvas = e.Surface.Canvas;
canvas.Clear();
var frame = CreateFrame(info);
var chart = CreateChart(frame);
if (!IsInitialized)
{
// Makes slider first init in middle of frame
TouchedPoint = new SKPoint(frame.MidX, 0);
}
DrawVerticalLabels(canvas, frame, chart);
if (ChartEntries.Any(x => x.IsVisible))
{
CalculateChartValuesXPoints(chart);
DrawBackground(canvas, frame);
DrawInnerFrame(canvas, frame);
if (!string.IsNullOrEmpty(SelectedTag) && !isTouching)
{
var selectedTagPosition = ChartValueItemsXPoints.FirstOrDefault(x => x.Item1.ToString() == SelectedTag)?.Item2 ?? 0f;
TouchedPoint = new SKPoint(selectedTagPosition, 0f);
}
DrawSlider(canvas, frame, chart);
foreach (var entry in ChartEntries.Where(x => x.IsVisible).OrderByDescending(x => x.Items.Count()))
{
DrawLines(entry, canvas, CalculatePoints(entry.Items, frame, chart));
}
DrawHorizontalLabels(canvas, frame, chart);
// Get items on x axis
var valueItems = ChartEntries.GetChartValueItemFromX(chart.GetInsideXValue(TouchedPoint.X), frame, frame.GetItemWidth(MaxItems));
// Send selected items with command
SelectedValuesCommand?.Execute(new SelectedChartValueItemArgs
{
ChartValueItems = valueItems,
TouchedPoint = new SKPoint(chart.GetInsideXValue(TouchedPoint.X), TouchedPoint.Y)
});
DrawHorizontalLabel(valueItems?.FirstOrDefault()?.ChartValueItem, canvas, frame, chart);
DrawFrame(canvas, frame);
DrawSliderPoints(valueItems, canvas, chart);
}
else
{
DrawInnerFrame(canvas, frame);
DrawFrame(canvas, frame);
}
IsInitialized = true;
}
private void DrawBars(SKCanvas canvas, SKRect frame, SKRect chart)
{
// Selected bar width
var selectedValueItems = ChartEntries.GetChartValueItemFromX(chart.GetInsideXValue(TouchedPoint.X), chart, chart.GetItemWidth(MaxItems));
var selectedTags = selectedValueItems?.Select(x => x.ChartValueItem.Tag);
// Invoke command with selected items
SelectedValuesCommand?.Execute(new SelectedChartValueItemArgs
{
ChartValueItems = selectedValueItems,
TouchedPoint = new SKPoint(chart.GetInsideXValue(TouchedPoint.X), TouchedPoint.Y)
});
using (var paint = new SKPaint
{
IsAntialias = true,
Style = SKPaintStyle.StrokeAndFill,
StrokeCap = SKStrokeCap.Butt,
})
{
var groupedItems = ChartEntries.Where(x => x.IsVisible).SelectMany(x => x.Items).GroupBy(x => x.Tag.ToString()).OrderBy(x => x.Key);
// Calc max items in one group
var maxItemsInGroups = groupedItems.Max(x => x.Count());
// Calc how many groups there is
var groupCount = groupedItems.Count();
// Calc how many bars there will be
var totalBars = groupCount * maxItemsInGroups;
var internalGroupMargin = maxItemsInGroups == 1 ? BarMargin : GroupMargin;
var internalBarMargin = maxItemsInGroups == 1 ? 0 : BarMargin;
var internalBarWidth = MinimumBarWidth;
float itemWidth;
if (AllowScroll)
{
// Calc total item width
itemWidth = internalBarWidth * maxItemsInGroups + ((maxItemsInGroups - 1) * barMargin);
}
else
{
itemWidth = chart.Width / groupCount;
itemWidth -= internalGroupMargin;
internalBarWidth = (itemWidth / maxItemsInGroups) - ((maxItemsInGroups - 1) * barMargin);
}
int groupIndex = 0;
float scrollLeftPadding = 0;
float left = 0;
float groupLeft = 0;
float right = 0;
groupCenters = new List <GroupChartItem>();
foreach (var groupedItem in groupedItems)
{
int itemIndex = 0;
groupLeft = left;
if (!AllowScroll && IsSliderVisible && selectedTags?.Contains(groupedItem.Key) == true)
{
var item = groupedItem.OrderByDescending(x => x.Value).First();
paint.Color = SliderColor.ToSKColor();
paint.PathEffect = SKPathEffect.CreateCorner(SliderCornerRadius);
var bounds = new SKRect(
item.Point.X - (itemWidth * .5f) - (groupMargin * .5f),
item.Point.Y - (itemWidth * .5f),
item.Point.X + (itemWidth * .5f) + (groupMargin * .5f),
chart.Bottom + HorizontalTextSize);
paint.StrokeWidth = 0;
canvas.DrawRect(bounds, paint);
}
foreach (var item in groupedItem)
{
var parent = ChartEntries.FirstOrDefault(x => x.Items.Contains(item));
SKRect bounds = new SKRect();
if (AllowScroll)
{
if (left == 0)
{
left = itemWidth.FromDpiAdjusted();
groupLeft = left;
scrollLeftPadding = left;
}
else if (itemIndex != 0)
{
left += internalBarMargin;
}
right = left + internalBarWidth;
bounds = new SKRect(
left,
item.Point.Y,
right,
chart.Bottom);
left = right;
}
else
{
left = (item.Point.X - (itemWidth * .5f)) + (internalBarWidth * itemIndex) + (internalBarMargin * itemIndex);
right = left + internalBarWidth;
bounds = new SKRect(
left,
item.Point.Y,
right,
chart.Bottom);
}
paint.StrokeWidth = 0;
if (parent.UseDashedEffect)
{
paint.Color = parent.Color.ToSKColor().AsTransparency();
paint.PathEffect = SKPathEffect.CreateCorner(BarCornerRadius);
canvas.DrawRect(bounds, paint);
paint.Color = parent.Color.ToSKColor();
paint.PathEffect = SKPathEffect.CreateDash(new float[] { StrokeDashFirst, StrokeDashSecond }, StrokeDashPhase);
paint.StrokeWidth = bounds.Width;
canvas.DrawLine(bounds.MidX, bounds.Bottom, bounds.MidX, bounds.Top, paint);
}
else
{
paint.Color = parent.Color.ToSKColor();
paint.PathEffect = SKPathEffect.CreateCorner(BarCornerRadius);
canvas.DrawRect(bounds, paint);
}
itemIndex++;
}
left += internalGroupMargin;
groupIndex++;
var groupCenterPosition = groupLeft + (itemWidth / 2);
groupCenters.Add(new GroupChartItem
{
Label = groupedItem.FirstOrDefault().Label,
Position = groupCenterPosition.FromDpiAdjusted(),
Tag = groupedItem.Key
});
}
if (AllowScroll)
{
var requestedWidth = right.FromDpiAdjusted() + frame.Left.FromDpiAdjusted();
if (requestedWidth != this.WidthRequest)
{
this.WidthRequest = requestedWidth;
}
else
{
SetStartPosition(groupCenters);
IsInitialized = true;
}
if (ScrollComponent != null)
{
var deviceWidth = Xamarin.Essentials.DeviceDisplay.MainDisplayInfo.Width;
var halfDeviceWidth = ((float)(deviceWidth / 2)).FromDpiAdjusted();
var frameLeftVal = frame.Left.FromDpiAdjusted();
var rectRightMarginVal = ChartRectMargin.Right.FromDpiAdjusted();
var leftPadding = halfDeviceWidth - frameLeftVal - scrollLeftPadding.FromDpiAdjusted();
var rightPadding = halfDeviceWidth - frameLeftVal - rectRightMarginVal - itemWidth.FromDpiAdjusted();
ScrollComponent.Padding = new Thickness(leftPadding, 0, rightPadding, 0);
ScrollComponent.Margin = new Thickness(frame.Left.FromDpiAdjusted(), 0, ChartRectMargin.Right.FromDpiAdjusted(), 0);
if (Selector != null)
{
Selector.WidthRequest = itemWidth.FromDpiAdjusted();
Selector.Margin = new Thickness(halfDeviceWidth, 0, 0, this.Height - frame.Bottom.FromDpiAdjusted());
}
if (!isScrollEventActive)
{
ScrollComponent.Scrolled += ScrollComponent_Scrolled;
isScrollEventActive = true;
}
}
if (SwipeNotificationLeft != null)
{
SwipeNotificationLeft.Margin = new Thickness(frame.Left.FromDpiAdjusted(), 0, 0, this.Height - frame.Bottom.FromDpiAdjusted());
SwipeNotificationLeft.WidthRequest = ScrollComponent.Padding.Left;
}
if (SwipeNotificationRight != null)
{
SwipeNotificationRight.Margin = new Thickness(0, 0, ChartRectMargin.Right.FromDpiAdjusted(), this.Height - frame.Bottom.FromDpiAdjusted());
SwipeNotificationRight.WidthRequest = ScrollComponent.Padding.Left;
}
}
}
DrawHorizontalLabel(selectedValueItems?.FirstOrDefault()?.ChartValueItem, canvas, frame, chart);
}