Ejemplo n.º 1
0
// draw draws the axis along the left side of a draw.Canvas.
func (a *verticalAxis) draw(c draw.Canvas) {
	x := c.Min.X
	if a.Label.Text != "" {
		x += a.Label.Height(a.Label.Text)
		c.Push()
		c.Rotate(math.Pi / 2)
		c.FillText(a.Label.TextStyle, c.Center().Y, -x, -0.5, 0, a.Label.Text)
		c.Pop()
		x += -a.Label.Font.Extents().Descent
	}
	marks := a.Tick.Marker.Ticks(a.Min, a.Max)
	if w := tickLabelWidth(a.Tick.Label, marks); len(marks) > 0 && w > 0 {
		x += w
	}
	major := false
	for _, t := range marks {
		y := c.Y(a.Norm(t.Value))
		if !c.ContainsY(y) || t.IsMinor() {
			continue
		}
		c.FillText(a.Tick.Label, x, y, -1, -0.5, t.Label)
		major = true
	}
	if major {
		x += a.Tick.Label.Width(" ")
	}
	if a.drawTicks() && len(marks) > 0 {
		len := a.Tick.Length
		for _, t := range marks {
			y := c.Y(a.Norm(t.Value))
			if !c.ContainsY(y) {
				continue
			}
			start := t.lengthOffset(len)
			c.StrokeLine2(a.Tick.LineStyle, x+start, y, x+len, y)
		}
		x += len
	}
	c.StrokeLine2(a.LineStyle, x, c.Min.Y, x, c.Max.Y)
}