private void PaintSurface(object sender, SKPaintSurfaceEventArgs e)
{
float width = e.Info.Width;
float height = e.Info.Height;
float scale = height / (float)GraphHeight;
List <IGraphItem> graphItems = new List <IGraphItem>();
if (ViewModel.BackgroundColor.HasValue)
{
graphItems.Add(new GraphClear {
Color = ViewModel.BackgroundColor.Value
});
}
if (ViewModel.Title != null && !string.IsNullOrWhiteSpace(ViewModel.Title.Text))
{
int xPos = 0;
switch (ViewModel.Title.TextAlignment)
{
case TextAlignment.Start:
xPos = 40;
break;
case TextAlignment.Center:
xPos = Convert.ToInt32(width / 2);
break;
case TextAlignment.End:
xPos = Convert.ToInt32(width - 40);
break;
}
graphItems.Add(new GraphText
{
Alignment = ViewModel.Title.TextAlignment,
Color = ViewModel.Title.Color,
PointSize = ViewModel.Title.PointSize * scale,
Text = ViewModel.Title.Text, // "Do you support or oppose 'defund the police'?",
XPos = xPos,
YPos = 45,
Bold = ViewModel.Title.Bold
});
}
if (ViewModel.SubTitle != null && !string.IsNullOrWhiteSpace(ViewModel.SubTitle.Text))
{
int xPos = 0;
switch (ViewModel.Title.TextAlignment)
{
case TextAlignment.Start:
xPos = 40;
break;
case TextAlignment.Center:
xPos = Convert.ToInt32(width / 2);
break;
case TextAlignment.End:
xPos = Convert.ToInt32(width - 40);
break;
}
graphItems.Add(new GraphText
{
Alignment = ViewModel.SubTitle.TextAlignment,
Color = ViewModel.SubTitle.Color,
PointSize = ViewModel.SubTitle.PointSize * scale,
Text = ViewModel.SubTitle.Text,
XPos = xPos,
YPos = 85,
Bold = ViewModel.SubTitle.Bold
});
}
if (ViewModel.LeftFooter != null && !string.IsNullOrWhiteSpace(ViewModel.LeftFooter.Text))
{
graphItems.Add(new GraphText
{
Alignment = ViewModel.LeftFooter.TextAlignment,
Color = ViewModel.LeftFooter.Color,
PointSize = ViewModel.LeftFooter.PointSize * scale,
Text = ViewModel.LeftFooter.Text,
XPos = 40,
YPos = Convert.ToInt32(height * 0.9),
Bold = ViewModel.LeftFooter.Bold
});
}
if (ViewModel.RightFooter != null && !string.IsNullOrWhiteSpace(ViewModel.RightFooter.Text))
{
graphItems.Add(new GraphText
{
Alignment = ViewModel.RightFooter.TextAlignment,
Color = ViewModel.RightFooter.Color,
PointSize = ViewModel.RightFooter.PointSize * scale,
Text = ViewModel.RightFooter.Text,
XPos = Convert.ToInt32(width * 0.9),
YPos = Convert.ToInt32(height * 0.9),
Bold = ViewModel.RightFooter.Bold
});
}
graphItems.Add(new GraphLine
{
Color = SKColors.Black,
StrokeWidth = 2,
XPosStart = 40,
YPosStart = 140,
XPosEnd = Convert.ToInt32(width * 0.9),
YPosEnd = 140
});
int index = 0;
int max = 0;
foreach (var dataPoint in ViewModel.DataPoints)
{
index++;
if (dataPoint.Value > max)
{
max = dataPoint.Value;
}
graphItems.Add(new GraphText
{
Alignment = TextAlignment.End,
Color = dataPoint.TextColor,
PointSize = dataPoint.PointSize * scale,
Text = dataPoint.Label,
XPos = 145,
YPos = Convert.ToInt32(height * (0.25 + 0.2 * index)),
Bold = dataPoint.Bold
});
}
int lineMax = (Convert.ToInt32((max + 10) / 10) * 10);
int lines = lineMax / 10;
float lineWidth = Convert.ToInt32(width * 0.9) - 180 + 1;
float lineSpacing = lineWidth / lines;
AddLines(graphItems, 180, 140, Convert.ToInt32(height * 0.8), lineMax, lineSpacing, (float)scale);
index = 0;
foreach (var dataPoint in ViewModel.DataPoints)
{
index++;
graphItems.Add(new GraphLine
{
Color = dataPoint.Color,
StrokeWidth = 40 * scale,
XPosStart = 180,
YPosStart = Convert.ToInt32(height * (0.25 + 0.2 * index)),
XPosEnd = lineWidth * dataPoint.Value / lineMax + 180,
YPosEnd = Convert.ToInt32(height * (0.25 + 0.2 * index)),
});
graphItems.Add(new GraphText
{
Alignment = TextAlignment.Start,
Color = dataPoint.Color,
PointSize = 20 * scale,
Text = dataPoint.Value.ToString() + "%",
XPos = lineWidth * dataPoint.Value / lineMax + 190,
YPos = Convert.ToInt32(height * (0.25 + 0.2 * index)),
Bold = true
});
}
graphEngine.Draw(e.Surface, graphItems);
}
protected virtual void PaintGraph(SKPaintSurfaceEventArgs e)
{
#region Define/Initialize Variables
float canvasWidth = e.Info.Width;
float canvasHeight = e.Info.Height;
float scale = canvasHeight / (float)GraphHeight;
float padding = ViewModel.Padding * scale;
List <IGraphItem> graphItems = new List <IGraphItem>();
float yPos, xPos, xLabelWidth;
float footerHeight;
float xLabelYPos;
double minimum;
List <IDataPoint> dataPoints;
List <decimal> vValues;
decimal vValue;
List <string> YLabels = new List <string>();
float labelWidth, graphHeight, ySectionHeight, lineYPos, pointWidth;
int horizontalRow = 0;
double minimumGraphValue, maximumGraphValue;
float zeroYPos = -1;
#endregion
ValidateData();
SetBackgroundColor(graphItems);
yPos = SetTitle(canvasWidth, scale, graphItems, padding);
footerHeight = SetFooter(canvasHeight, canvasWidth, scale, graphItems, padding);
YAxisRangeAndSections(out minimum, out dataPoints, out vValues, out vValue, out minimumGraphValue, out maximumGraphValue);
DefineYAxisLabelText(vValues, YLabels);
graphHeight = CalculateGraphHeight(canvasHeight, yPos, padding, footerHeight, scale, out xLabelYPos);
DefineGraphAndGroupWidths(canvasWidth, graphHeight, scale, padding, yPos, dataPoints, YLabels, out labelWidth, out ySectionHeight, out lineYPos, out pointWidth, out xPos, out xLabelWidth);
DrawLeftLabel(graphItems, graphHeight, scale, yPos);
DrawShadedSections(graphItems, graphHeight, xPos, yPos, padding, labelWidth);
DrawVerticalShading(padding, graphItems, yPos, YLabels, labelWidth, ySectionHeight, xPos);
DrawHorizontalLinesAndShading(xPos, xLabelWidth, canvasWidth, padding, graphItems, YLabels, labelWidth, ySectionHeight, ref lineYPos, ref horizontalRow, vValues, ref zeroYPos);
DrawYAxisLabels(scale, padding, graphItems, yPos, YLabels, labelWidth, ySectionHeight, xLabelWidth);
DrawVerticalLines(padding, xPos, graphItems, yPos, YLabels, labelWidth, ySectionHeight);
// Heart of the graph - define lines from one data point to the next.
GraphData(padding, graphItems, xPos, yPos, minimum, dataPoints, labelWidth, graphHeight, pointWidth, minimumGraphValue, maximumGraphValue, vValues, ySectionHeight, zeroYPos, scale);
DrawXAxisLabels(xLabelYPos, scale, padding, graphItems, labelWidth, xPos);
graphEngine.Draw(e.Surface, graphItems);
}
