feat: support line chart draw function

line_chart.go

@@ -0,0 +1,174 @@
+// 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"
+	"github.com/wcharczuk/go-chart/v2/drawing"
+)
+
+type LineChartOption struct {
+	ChartOption
+}
+
+const YAxisWidth = 50
+
+func drawXAxis(d *Draw, opt *XAxisOption, theme *Theme) (int, *Range, error) {
+	dXAxis, err := NewDraw(
+		DrawOption{
+			Parent: d,
+		},
+		PaddingOption(chart.Box{
+			Left: YAxisWidth,
+		}),
+	)
+	if err != nil {
+		return 0, nil, err
+	}
+	data := NewAxisDataListFromStringList(opt.Data)
+	style := AxisStyle{
+		BoundaryGap: opt.BoundaryGap,
+		StrokeColor: theme.GetAxisStrokeColor(),
+		FontColor:   theme.GetAxisStrokeColor(),
+		StrokeWidth: 1,
+	}
+
+	boundary := true
+	max := float64(len(opt.Data))
+	if opt.BoundaryGap != nil && !*opt.BoundaryGap {
+		boundary = false
+		max--
+	}
+
+	dXAxis.Axis(data, style)
+	return d.measureAxis(data, style), &Range{
+		divideCount: len(opt.Data),
+		Min:         0,
+		Max:         max,
+		Size:        dXAxis.Box.Width(),
+		Boundary:    boundary,
+	}, nil
+}
+
+func drawYAxis(d *Draw, opt *ChartOption, theme *Theme, xAxisHeight int) (*Range, error) {
+	yRange := opt.getYRange(0)
+	data := NewAxisDataListFromStringList(yRange.Values())
+	style := AxisStyle{
+		Position:    PositionLeft,
+		BoundaryGap: FalseFlag(),
+		// StrokeColor:    theme.GetAxisStrokeColor(),
+		FontColor:      theme.GetAxisStrokeColor(),
+		StrokeWidth:    1,
+		SplitLineColor: theme.GetAxisSplitLineColor(),
+		SplitLineShow:  true,
+	}
+	width := d.measureAxis(data, style)
+
+	dYAxis, err := NewDraw(
+		DrawOption{
+			Parent: d,
+			Width:  d.Box.Width(),
+			// 减去x轴的高
+			Height: d.Box.Height() - xAxisHeight,
+		},
+		PaddingOption(chart.Box{
+			Left: YAxisWidth - width,
+		}),
+	)
+	if err != nil {
+		return nil, err
+	}
+	dYAxis.Axis(data, style)
+	yRange.Size = dYAxis.Box.Height()
+	return &yRange, nil
+}
+
+func NewLineChart(opt LineChartOption) (*Draw, error) {
+	d, err := NewDraw(
+		DrawOption{
+			Parent: opt.Parent,
+			Width:  opt.getWidth(),
+			Height: opt.getHeight(),
+		},
+		PaddingOption(opt.Padding),
+	)
+	if err != nil {
+		return nil, err
+	}
+
+	theme := Theme{
+		mode: opt.Theme,
+	}
+	// 设置背景色
+	bg := opt.BackgroundColor
+	if bg.IsZero() {
+		bg = theme.GetBackgroundColor()
+	}
+	if opt.Parent == nil {
+		d.setBackground(opt.getWidth(), opt.getHeight(), bg)
+	}
+
+	xAxisHeight, xRange, err := drawXAxis(d, &opt.XAxis, &theme)
+	if err != nil {
+		return nil, err
+	}
+	// 暂时仅支持单一yaxis
+	yRange, err := drawYAxis(d, &opt.ChartOption, &theme, xAxisHeight)
+	if err != nil {
+		return nil, err
+	}
+	sd, err := NewDraw(DrawOption{
+		Parent: d,
+	}, PaddingOption(chart.Box{
+		Left: YAxisWidth,
+	}))
+	if err != nil {
+		return nil, err
+	}
+	for i, series := range opt.SeriesList {
+		points := make([]Point, 0)
+		for j, item := range series.Data {
+			y := yRange.getHeight(item.Value)
+			points = append(points, Point{
+				Y: y,
+				X: xRange.getWidth(float64(j)),
+			})
+			seriesColor := theme.GetSeriesColor(i)
+			dotFillColor := drawing.ColorWhite
+			if theme.IsDark() {
+				dotFillColor = seriesColor
+			}
+			sd.Line(points, LineStyle{
+				StrokeColor:  seriesColor,
+				StrokeWidth:  2,
+				DotColor:     seriesColor,
+				DotWidth:     2,
+				DotFillColor: dotFillColor,
+			})
+		}
+
+	}
+	// fmt.Println(yRange)
+
+	return d, nil
+}