theme/material: add the material theme

Signed-off-by: Elias Naur <mail@eliasnaur.com>

widget/material/label.go

@@ -0,0 +1,80 @@
+// 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 Label struct {
+	// Face defines the text style.
+	Font text.Font
+	// Color is the text color.
+	Color color.RGBA
+	// Alignment specify the text alignment.
+	Alignment text.Alignment
+	// MaxLines limits the number of lines. Zero means no limit.
+	MaxLines int
+	Text     string
+
+	shaper *text.Shaper
+}
+
+func (t *Theme) H1(txt string) Label {
+	return t.Label(t.TextSize.Scale(96.0/16.0), txt)
+}
+
+func (t *Theme) H2(txt string) Label {
+	return t.Label(t.TextSize.Scale(60.0/16.0), txt)
+}
+
+func (t *Theme) H3(txt string) Label {
+	return t.Label(t.TextSize.Scale(48.0/16.0), txt)
+}
+
+func (t *Theme) H4(txt string) Label {
+	return t.Label(t.TextSize.Scale(34.0/16.0), txt)
+}
+
+func (t *Theme) H5(txt string) Label {
+	return t.Label(t.TextSize.Scale(24.0/16.0), txt)
+}
+
+func (t *Theme) H6(txt string) Label {
+	return t.Label(t.TextSize.Scale(20.0/16.0), txt)
+}
+
+func (t *Theme) Body1(txt string) Label {
+	return t.Label(t.TextSize, txt)
+}
+
+func (t *Theme) Body2(txt string) Label {
+	return t.Label(t.TextSize.Scale(14.0/16.0), txt)
+}
+
+func (t *Theme) Caption(txt string) Label {
+	return t.Label(t.TextSize.Scale(12.0/16.0), txt)
+}
+
+func (t *Theme) Label(size unit.Value, txt string) Label {
+	return Label{
+		Text:  txt,
+		Color: t.Color.Text,
+		Font: text.Font{
+			Size: size,
+		},
+		shaper: t.Shaper,
+	}
+}
+
+func (l Label) Layout(gtx *layout.Context) {
+	paint.ColorOp{Color: l.Color}.Add(gtx.Ops)
+	tl := widget.Label{Alignment: l.Alignment, MaxLines: l.MaxLines}
+	tl.Layout(gtx, l.shaper, l.Font, l.Text)
+}