feat: support label for line chart, #23

series_label.go

@@ -0,0 +1,56 @@
+// MIT License
+
+// Copyright (c) 2022 Tree Xie
+
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+package charts
+
+import "github.com/wcharczuk/go-chart/v2"
+
+type LabelValue struct {
+	Text  string
+	Style Style
+	X     int
+	Y     int
+}
+
+type SeriesLabelPainter struct {
+	p      *Painter
+	values []LabelValue
+}
+
+func NewSeriesLabelPainter(p *Painter) *SeriesLabelPainter {
+	return &SeriesLabelPainter{
+		p:      p,
+		values: make([]LabelValue, 0),
+	}
+}
+
+func (o *SeriesLabelPainter) Add(value LabelValue) {
+	o.values = append(o.values, value)
+}
+
+func (o *SeriesLabelPainter) Render() (Box, error) {
+	for _, item := range o.values {
+		o.p.OverrideTextStyle(item.Style)
+		o.p.Text(item.Text, item.X, item.Y)
+	}
+	return chart.BoxZero, nil
+}