feat: support mark line and mark point render

title.go

@@ -0,0 +1,192 @@
+// 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 (
+	"strconv"
+	"strings"
+
+	"github.com/golang/freetype/truetype"
+)
+
+type TitleOption struct {
+	// The theme of chart
+	Theme ColorPalette
+	// Title text, support \n for new line
+	Text string
+	// Subtitle text, support \n for new line
+	Subtext string
+	// // Title style
+	// Style Style
+	// // Subtitle style
+	// SubtextStyle Style
+	// Distance between title component and the left side of the container.
+	// It can be pixel value: 20, percentage value: 20%,
+	// or position value: right, center.
+	Left string
+	// Distance between title component and the top side of the container.
+	// It can be pixel value: 20.
+	Top string
+	// The font of label
+	Font *truetype.Font
+	// The font size of label
+	FontSize float64
+	// The color of label
+	FontColor Color
+	// The subtext font size of label
+	SubtextFontSize float64
+	// The subtext font color of label
+	SubtextFontColor Color
+}
+
+type titleMeasureOption struct {
+	width  int
+	height int
+	text   string
+	style  Style
+}
+
+func splitTitleText(text string) []string {
+	arr := strings.Split(text, "\n")
+	result := make([]string, 0)
+	for _, v := range arr {
+		v = strings.TrimSpace(v)
+		if v == "" {
+			continue
+		}
+		result = append(result, v)
+	}
+	return result
+}
+
+type titlePainter struct {
+	p   *Painter
+	opt *TitleOption
+}
+
+func NewTitlePainter(p *Painter, opt TitleOption) *titlePainter {
+	return &titlePainter{
+		p:   p,
+		opt: &opt,
+	}
+}
+
+func (t *titlePainter) Render() (Box, error) {
+	opt := t.opt
+	p := t.p
+	theme := opt.Theme
+	measureOptions := make([]titleMeasureOption, 0)
+
+	if opt.Font == nil {
+		opt.Font = theme.GetFont()
+	}
+	if opt.FontColor.IsZero() {
+		opt.FontColor = theme.GetTextColor()
+	}
+	if opt.FontSize == 0 {
+		opt.FontSize = theme.GetFontSize()
+	}
+	if opt.SubtextFontColor.IsZero() {
+		opt.SubtextFontColor = opt.FontColor
+	}
+	if opt.SubtextFontSize == 0 {
+		opt.SubtextFontSize = opt.FontSize
+	}
+
+	titleTextStyle := Style{
+		Font:      opt.Font,
+		FontSize:  opt.FontSize,
+		FontColor: opt.FontColor,
+	}
+	// 主标题
+	for _, v := range splitTitleText(opt.Text) {
+		measureOptions = append(measureOptions, titleMeasureOption{
+			text:  v,
+			style: titleTextStyle,
+		})
+	}
+	subtextStyle := Style{
+		Font:      opt.Font,
+		FontSize:  opt.SubtextFontSize,
+		FontColor: opt.SubtextFontColor,
+	}
+	// 副标题
+	for _, v := range splitTitleText(opt.Subtext) {
+		measureOptions = append(measureOptions, titleMeasureOption{
+			text:  v,
+			style: subtextStyle,
+		})
+	}
+	textMaxWidth := 0
+	textMaxHeight := 0
+	for index, item := range measureOptions {
+		p.OverrideTextStyle(item.style)
+		textBox := p.MeasureText(item.text)
+
+		w := textBox.Width()
+		h := textBox.Height()
+		if w > textMaxWidth {
+			textMaxWidth = w
+		}
+		if h > textMaxHeight {
+			textMaxHeight = h
+		}
+		measureOptions[index].height = h
+		measureOptions[index].width = w
+	}
+	width := textMaxWidth
+
+	titleX := 0
+	switch opt.Left {
+	case PositionRight:
+		titleX = p.Width() - textMaxWidth
+	case PositionCenter:
+		titleX = p.Width()>>1 - (textMaxWidth >> 1)
+	default:
+		if strings.HasSuffix(opt.Left, "%") {
+			value, _ := strconv.Atoi(strings.ReplaceAll(opt.Left, "%", ""))
+			titleX = p.Width() * value / 100
+		} else {
+			value, _ := strconv.Atoi(opt.Left)
+			titleX = value
+		}
+	}
+	titleY := 0
+	// TODO TOP 暂只支持数值
+	if opt.Top != "" {
+		value, _ := strconv.Atoi(opt.Top)
+		titleY += value
+	}
+	for _, item := range measureOptions {
+		p.OverrideTextStyle(item.style)
+		x := titleX + (textMaxWidth-item.width)>>1
+		y := titleY + item.height
+		p.Text(item.text, x, y)
+		titleY += item.height
+	}
+
+	return Box{
+		Bottom: titleY,
+		Right:  titleX + width,
+	}, nil
+}