feat: support line chart render function

xaxis.go

@@ -0,0 +1,88 @@
+// 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 XAxisOption struct {
+	// The font of x axis
+	Font *truetype.Font
+	// The boundary gap on both sides of a coordinate axis.
+	// Nil or *true means the center part of two axis ticks
+	BoundaryGap *bool
+	// The data value of x axis
+	Data []string
+	// The theme of chart
+	Theme ColorPalette
+	// The font size of x axis label
+	FontSize float64
+	// Hidden x axis
+	Hidden bool
+	// Number of segments that the axis is split into. Note that this number serves only as a recommendation.
+	SplitNumber int
+	// The position of axis, it can be 'top' or 'bottom'
+	Position string
+	// The line color of axis
+	StrokeColor Color
+	// The color of label
+	FontColor Color
+}
+
+const defaultXAxisHeight = 30
+
+func NewXAxisOption(data []string, boundaryGap ...*bool) XAxisOption {
+	opt := XAxisOption{
+		Data: data,
+	}
+	if len(boundaryGap) != 0 {
+		opt.BoundaryGap = boundaryGap[0]
+	}
+	return opt
+}
+
+func (opt *XAxisOption) ToAxisPainterOption() AxisPainterOption {
+	position := PositionBottom
+	if opt.Position == PositionTop {
+		position = PositionTop
+	}
+	return AxisPainterOption{
+		Theme:       opt.Theme,
+		Data:        opt.Data,
+		BoundaryGap: opt.BoundaryGap,
+		Position:    position,
+		SplitNumber: opt.SplitNumber,
+		StrokeColor: opt.StrokeColor,
+		FontSize:    opt.FontSize,
+		Font:        opt.Font,
+		FontColor:   opt.FontColor,
+	}
+}
+
+func NewBottomXAxis(p *Painter, opt XAxisOption) *axisPainter {
+	p = p.Child(PainterPaddingOption(Box{
+		Top: p.Height() - defaultXAxisHeight,
+	}))
+	return NewAxisPainter(p, opt.ToAxisPainterOption())
+}