Rounded corners for Chart columns
Environment
| Product | Telerik UI for ASP.NET Core Chart |
Description
How can I change Telerik UI for ASP.NET Core Chart columns to appear with rounded corners?
Solution
You can achieve this requirement using the .Visual() property offered by the component. It provides the capability of adding custom content to the chart using the Kendo Drawing Framework.
This allows you to create shapes like rectangles and circles with the option to add desired customizations like color and borders:
Check the full implementation in this live REPL sample:
Chart Example: All Corners Rounded
The result looks like this:
<div class="demo-section wide">
@(Html.Kendo().Chart<Kendo.Mvc.Examples.Models.ElectricityProduction>()
.Name("chart")
.Title("Orders Status")
.Legend(legend => legend
.Position(ChartLegendPosition.Top)
)
.SeriesDefaults(seriesDefaults => seriesDefaults
.Column().Visual("columnVisual")
.Highlight(highlight => highlight.Toggle("toggleHandler"))
)
.Series(series => {
series.Column(new double[] { 440000 })
.Name("Active").Color("#229954");
series.Column(new double[] { 180000 })
.Name("Delayed").Color("#CD5C5C");
series.Column(new double[] { 230000 })
.Name("Delivered").Color("#145a32");
})
.CategoryAxis(axis => axis
.Labels(labels => labels.Rotation(-90))
.MajorGridLines(lines => lines.Visible(false))
)
.ValueAxis(axis => axis.Numeric()
.Labels(labels => labels.Format("{0:N0}"))
.MajorUnit(50000)
.Line(line => line.Visible(false))
)
.Tooltip(tooltip => tooltip
.Visible(true)
.Format("{0:N0}")
)
)
</div>
<script>
function columnVisual(e) {
return createColumn(e.rect, e.options.color);
}
function toggleHandler(e) {
e.preventDefault();
var visual = e.visual;
var opacity = e.show ? 0.8 : 1;
visual.opacity(opacity);
}
function createLegendItem(e) {
var drawing = kendo.drawing;
var geometry = kendo.geometry;
var color = e.options.markers.background;
var labelColor = e.options.labels.color;
var rect = new geometry.Rect([0, 0], [120, 50]);
var layout = new drawing.Layout(rect, {
spacing: 5,
alignItems: "center"
});
var overlay = drawing.Path.fromRect(rect, {
fill: {
color: "#fff",
opacity: 0
},
stroke: {
color: "none"
},
cursor: "pointer"
});
var column = createColumn(new geometry.Rect([0, 0], [15, 10]), color);
var label = new drawing.Text(e.series.name, [0, 0], {
fill: {
color: labelColor
}
})
layout.append(column, label);
layout.reflow();
var group = new drawing.Group().append(layout, overlay);
return group;
}
function createColumn(rect, color) {
// initiate the drawing framework
var drawing = kendo.drawing;
var geometry = kendo.geometry;
var gradient = new drawing.LinearGradient({
stops: [{
offset: 0,
color: color
}, {
offset: 0.5,
color: color,
opacity: 0.9
}, {
offset: 0.5,
color: color,
opacity: 0.9
}, {
offset: 1,
color: color
}]
});
// create a rounded column with fixed radius size
var cornerRadius = 10;
var roundedRect = new geometry.Rect(rect.origin, rect.size, cornerRadius);
var column = new drawing.Rect(roundedRect, {
fill: gradient,
stroke: {
color: "none"
}
});
return column;
}
</script>
It is also possible to have only the top corners rounded:
Chart Example: Top Corners Rounded
Here is the result:
<div class="demo-section wide">
@(Html.Kendo().Chart<Kendo.Mvc.Examples.Models.ElectricityProduction>()
.Name("chart")
.Title("Orders Status")
.SeriesDefaults(seriesDefaults => seriesDefaults
.Column().Visual("columnVisual")
.Highlight(highlight => highlight.Toggle("toggleHandler"))
)
.Series(series => {
series.Column(new double[] { 440000 })
.Name("Active").Color("#229954");
series.Column(new double[] { 180000 })
.Name("Delayed").Color("#CD5C5C");
series.Column(new double[] { 230000 })
.Name("Delivered").Color("#145a32");
})
.CategoryAxis(axis => axis
.Labels(labels => labels.Rotation(-90))
.MajorGridLines(lines => lines.Visible(false))
)
.ValueAxis(axis => axis.Numeric()
.Labels(labels => labels.Format("{0:N0}"))
.MajorUnit(50000)
.Line(line => line.Visible(false))
)
.Tooltip(tooltip => tooltip
.Visible(true)
.Format("{0:N0}")
)
)
</div>
<script>
function columnVisual(e) {
return createColumn(e.rect, e.options.color);
}
function toggleHandler(e) {
e.preventDefault();
var visual = e.visual;
var opacity = e.show ? 0.8 : 1;
visual.opacity(opacity);
}
function createLegendItem(e) {
var drawing = kendo.drawing;
var geometry = kendo.geometry;
var color = e.options.markers.background;
var labelColor = e.options.labels.color;
var rect = new geometry.Rect([0, 0], [120, 50]);
var layout = new drawing.Layout(rect, {
spacing: 5,
alignItems: "center"
});
var overlay = drawing.Path.fromRect(rect, {
fill: {
color: "#fff",
opacity: 0
},
stroke: {
color: "none"
},
cursor: "pointer"
});
var column = createColumn(new geometry.Rect([0, 0], [15, 10]), color);
var label = new drawing.Text(e.series.name, [0, 0], {
fill: {
color: labelColor
}
})
layout.append(column, label);
layout.reflow();
var group = new drawing.Group().append(layout, overlay);
return group;
}
function createColumn(rect, color) {
// initiate the drawing framework
var drawing = kendo.drawing;
var geometry = kendo.geometry;
var gradient = new drawing.LinearGradient({
stops: [{
offset: 0,
color: color
}, {
offset: 0.5,
color: color,
opacity: 0.9
}, {
offset: 0.5,
color: color,
opacity: 0.9
}, {
offset: 1,
color: color
}]
});
// create a rounded column with fixed radius size
var cornerRadius = 10;
var roundedRect = new geometry.Rect(rect.origin, rect.size, cornerRadius);
var column = new drawing.Rect(roundedRect, {
fill: gradient,
stroke: {
color: "none"
}
});
// create another overlapping column for right corners at the bottom
var baseOrigin = [rect.origin.x, rect.origin.y + rect.size.height - cornerRadius];
var baseSize = [rect.size.width, cornerRadius];
var baseRect = new geometry.Rect(baseOrigin, baseSize);
var squareBase = new drawing.Rect(rect, {
fill: gradient,
stroke: {
color: "none"
},
clip: drawing.Path.fromRect(baseRect)
});
var group = new drawing.Group();
group.append(column, squareBase)
return group;
}
</script>