feat: support line chart render function

yaxis.go

@@ -0,0 +1,66 @@
+// 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/golang/freetype/truetype"
+
+type YAxisOption struct {
+	// The font of y axis
+	Font *truetype.Font
+	// The data value of x axis
+	Data []string
+	// The theme of chart
+	Theme ColorPalette
+	// The font size of x axis label
+	FontSize float64
+	// The position of axis, it can be 'left' or 'right'
+	Position string
+	// The color of label
+	FontColor Color
+}
+
+func (opt *YAxisOption) ToAxisPainterOption() AxisPainterOption {
+	position := PositionLeft
+	if opt.Position == PositionRight {
+		position = PositionRight
+	}
+	return AxisPainterOption{
+		Theme:          opt.Theme,
+		Data:           opt.Data,
+		Position:       position,
+		FontSize:       opt.FontSize,
+		StrokeWidth:    -1,
+		Font:           opt.Font,
+		FontColor:      opt.FontColor,
+		BoundaryGap:    FalseFlag(),
+		SplitLineShow:  true,
+		SplitLineColor: opt.Theme.GetAxisSplitLineColor(),
+	}
+}
+
+func NewLeftYAxis(p *Painter, opt YAxisOption) *axisPainter {
+	p = p.Child(PainterPaddingOption(Box{
+		Bottom: defaultXAxisHeight,
+	}))
+	return NewAxisPainter(p, opt.ToAxisPainterOption())
+}