func drawParagraph(ctx *nanovgo.Context, x, y, width, height, mx, my float32) {
text := "This is longer chunk of text.\n \n Would have used lorem ipsum but she was busy jumping over the lazy dog with the fox and all the men who came to the aid of the party."
ctx.Save()
defer ctx.Restore()
ctx.SetFontSize(18.0)
ctx.SetFontFace("sans")
ctx.SetTextAlign(nanovgo.AlignLeft | nanovgo.AlignTop)
_, _, lineh := ctx.TextMetrics()
// The text break API can be used to fill a large buffer of rows,
// or to iterate over the text just few lines (or just one) at a time.
// The "next" variable of the last returned item tells where to continue.
runes := []rune(text)
var gx, gy float32
var gutter int
lnum := 0
for _, row := range ctx.TextBreakLinesRune(runes, width) {
hit := mx > x && mx < (x+width) && my >= y && my < (y+lineh)
ctx.BeginPath()
var alpha uint8
if hit {
alpha = 64
} else {
alpha = 16
}
ctx.SetFillColor(nanovgo.RGBA(255, 255, 255, alpha))
ctx.Rect(x, y, row.Width, lineh)
ctx.Fill()
ctx.SetFillColor(nanovgo.RGBA(255, 255, 255, 255))
ctx.TextRune(x, y, runes[row.StartIndex:row.EndIndex])
if hit {
var caretX float32
if mx < x+row.Width/2 {
caretX = x
} else {
caretX = x + row.Width
}
px := x
lineRune := runes[row.StartIndex:row.EndIndex]
glyphs := ctx.TextGlyphPositionsRune(x, y, lineRune)
for j, glyph := range glyphs {
x0 := glyph.X
var x1 float32
if j+1 < len(glyphs) {
x1 = glyphs[j+1].X
} else {
x1 = x + row.Width
}
gx = x0*0.3 + x1*0.7
if mx >= px && mx < gx {
caretX = glyph.X
}
px = gx
}
ctx.BeginPath()
ctx.SetFillColor(nanovgo.RGBA(255, 192, 0, 255))
ctx.Rect(caretX, y, 1, lineh)
ctx.Fill()
gutter = lnum + 1
gx = x - 10
gy = y + lineh/2
}
lnum++
y += lineh
}
if gutter > 0 {
txt := strconv.Itoa(gutter)
ctx.SetFontSize(13.0)
ctx.SetTextAlign(nanovgo.AlignRight | nanovgo.AlignMiddle)
_, bounds := ctx.TextBounds(gx, gy, txt)
ctx.BeginPath()
ctx.SetFillColor(nanovgo.RGBA(255, 192, 0, 255))
ctx.RoundedRect(
float32(int(bounds[0]-4)),
float32(int(bounds[1]-2)),
float32(int(bounds[2]-bounds[0])+8),
float32(int(bounds[3]-bounds[1])+4),
float32(int(bounds[3]-bounds[1])+4)/2.0-1.0)
ctx.Fill()
ctx.SetFillColor(nanovgo.RGBA(32, 32, 32, 255))
ctx.Text(gx, gy, txt)
}
y += 20.0
ctx.SetFontSize(13.0)
ctx.SetTextAlign(nanovgo.AlignLeft | nanovgo.AlignTop)
ctx.SetTextLineHeight(1.2)
bounds := ctx.TextBoxBounds(x, y, 150, "Hover your mouse over the text to see calculated caret position.")
// Fade the tooltip out when close to it.
gx = absF((mx - (bounds[0]+bounds[2])*0.5) / (bounds[0] - bounds[2]))
gy = absF((my - (bounds[1]+bounds[3])*0.5) / (bounds[1] - bounds[3]))
a := maxF(gx, gy) - 0.5
a = clampF(a, 0, 1)
ctx.SetGlobalAlpha(a)
ctx.BeginPath()
ctx.SetFillColor(nanovgo.RGBA(220, 220, 220, 255))
ctx.RoundedRect(bounds[0]-2, bounds[1]-2, float32(int(bounds[2]-bounds[0])+4), float32(int(bounds[3]-bounds[1])+4), 3)
px := float32(int((bounds[2] + bounds[0]) / 2))
ctx.MoveTo(px, bounds[1]-10)
ctx.LineTo(px+7, bounds[1]+1)
ctx.LineTo(px-7, bounds[1]+1)
ctx.Fill()
ctx.SetFillColor(nanovgo.RGBA(0, 0, 0, 220))
ctx.TextBox(x, y, 150, "Hover your mouse over the text to see calculated caret position.")
}