Files
gio-patched/widget/material/label.go
T
Egon Elbre 21ef492cc9 all: use color.NRGBA in public API
color.RGBA has two problems with regards to using it.

First the color values need to be premultiplied, whereas most APIs
have non-premultiplied values. This is mainly to preserve color components
with low alpha values.

Second there are two ways to premultiply with sRGB. One is to premultiply
after sRGB conversion, the other is before. This makes using the API more
confusing.

Using color.NRGBA in sRGB makes it align with CSS.e

Signed-off-by: Egon Elbre <egonelbre@gmail.com>
2020-11-19 11:30:11 +01:00

80 lines
1.8 KiB
Go

// SPDX-License-Identifier: Unlicense OR MIT
package material
import (
"image/color"
"gioui.org/layout"
"gioui.org/op/paint"
"gioui.org/text"
"gioui.org/unit"
"gioui.org/widget"
)
type LabelStyle struct {
// Face defines the text style.
Font text.Font
// Color is the text color.
Color color.NRGBA
// Alignment specify the text alignment.
Alignment text.Alignment
// MaxLines limits the number of lines. Zero means no limit.
MaxLines int
Text string
TextSize unit.Value
shaper text.Shaper
}
func H1(th *Theme, txt string) LabelStyle {
return Label(th, th.TextSize.Scale(96.0/16.0), txt)
}
func H2(th *Theme, txt string) LabelStyle {
return Label(th, th.TextSize.Scale(60.0/16.0), txt)
}
func H3(th *Theme, txt string) LabelStyle {
return Label(th, th.TextSize.Scale(48.0/16.0), txt)
}
func H4(th *Theme, txt string) LabelStyle {
return Label(th, th.TextSize.Scale(34.0/16.0), txt)
}
func H5(th *Theme, txt string) LabelStyle {
return Label(th, th.TextSize.Scale(24.0/16.0), txt)
}
func H6(th *Theme, txt string) LabelStyle {
return Label(th, th.TextSize.Scale(20.0/16.0), txt)
}
func Body1(th *Theme, txt string) LabelStyle {
return Label(th, th.TextSize, txt)
}
func Body2(th *Theme, txt string) LabelStyle {
return Label(th, th.TextSize.Scale(14.0/16.0), txt)
}
func Caption(th *Theme, txt string) LabelStyle {
return Label(th, th.TextSize.Scale(12.0/16.0), txt)
}
func Label(th *Theme, size unit.Value, txt string) LabelStyle {
return LabelStyle{
Text: txt,
Color: th.Color.Text,
TextSize: size,
shaper: th.Shaper,
}
}
func (l LabelStyle) Layout(gtx layout.Context) layout.Dimensions {
paint.ColorOp{Color: l.Color}.Add(gtx.Ops)
tl := widget.Label{Alignment: l.Alignment, MaxLines: l.MaxLines}
return tl.Layout(gtx, l.shaper, l.Font, l.TextSize, l.Text)
}