zntg/ui/label.go
Sander Schobers 75fce53716 Added Paragraph control.
Extended DesiredSize method with extra arguments that tells the control how much space is available for the parent control (note: this might not be the actual given size when Arrange is called on the control).
2020-05-16 15:37:53 +02:00

55 lines
1.3 KiB
Go

package ui
import (
"opslag.de/schobers/geom"
)
type Label struct {
ControlBase
Text string
desired CachedValue
}
func BuildLabel(text string, fn func(*Label)) *Label {
var l = &Label{Text: text}
if fn != nil {
fn(l)
}
return l
}
func (l *Label) hashDesiredSize(ctx Context) string {
return l.FontName(ctx) + l.Text
}
func (l *Label) desiredSize(ctx Context) interface{} {
fontName := l.FontName(ctx)
font := ctx.Fonts().Font(fontName)
width := font.WidthOf(l.Text)
height := font.Height()
pad := ctx.Style().Dimensions.TextPadding
return geom.PtF32(width+pad*2, height+pad*2)
}
func (l *Label) DesiredSize(ctx Context, _ geom.PointF32) geom.PointF32 {
return l.desired.GetContext(ctx, l.desiredSize, l.hashDesiredSize).(geom.PointF32)
}
func (l *Label) Render(ctx Context) {
l.RenderBackground(ctx)
fontColor := l.TextColor(ctx)
fontName := l.FontName(ctx)
pad := ctx.Style().Dimensions.TextPadding
bounds := l.bounds.Inset(pad)
switch l.TextAlignment {
case AlignLeft:
ctx.Fonts().TextAlign(fontName, bounds.Min, fontColor, l.Text, l.TextAlignment)
case AlignRight:
ctx.Fonts().TextAlign(fontName, geom.PtF32(bounds.Max.X, bounds.Min.Y), fontColor, l.Text, l.TextAlignment)
case AlignCenter:
ctx.Fonts().TextAlign(fontName, geom.PtF32(.5*(bounds.Min.X+bounds.Max.X), bounds.Min.Y), fontColor, l.Text, l.TextAlignment)
}
}