Split into category packages; module github.com/ZacharyZhang-NY/MujicaUI

layout/container.go

@@ -0,0 +1,86 @@
+package layout
+
+import (
+	"github.com/egoist/mygo/ui"
+
+	"github.com/ZacharyZhang-NY/MujicaUI/core"
+	"github.com/ZacharyZhang-NY/MujicaUI/theme"
+)
+
+// Space is a spacing step scaled by the window's density. Zero picks the component's default.
+type Space int
+
+const (
+	SpaceDefault Space = iota
+	SpaceNone
+	SpaceXS  // 1 unit, 4 DIPs at default density
+	SpaceS   // 2 units
+	SpaceM   // 3 units
+	SpaceL   // 4 units
+	SpaceXL  // 6 units
+	SpaceXXL // 8 units
+)
+
+// containerSpace returns s in DIPs for density d, using def when s is SpaceDefault.
+func containerSpace(d theme.Density, s, def Space) float32 {
+	if s == SpaceDefault {
+		s = def
+	}
+	var u float32
+	switch s {
+	case SpaceNone:
+	case SpaceXS:
+		u = 1
+	case SpaceS:
+		u = 2
+	case SpaceM:
+		u = 3
+	case SpaceL:
+		u = 4
+	case SpaceXL:
+		u = 6
+	case SpaceXXL:
+		u = 8
+	default:
+		panic("mujica: invalid Space value")
+	}
+	return u * d.Unit()
+}
+
+// ContainerOptions configure a Container.
+type ContainerOptions struct {
+	// Padding defaults to SpaceL.
+	Padding Space
+	// MaxWidth caps the width in DIPs; zero leaves it unbounded.
+	MaxWidth float32
+	// Center places the container in the middle of its parent's width.
+	Center bool
+	// Fill takes the parent's whole content box.
+	Fill bool
+	// Clip cuts content that overflows the padding box.
+	Clip bool
+}
+
+// Container pads its children, caps their width and can center, fill and clip.
+func Container(c *ui.Context, opts ContainerOptions, children func()) *ui.Element {
+	if opts.MaxWidth < 0 {
+		panic("mujica: Container MaxWidth must not be negative")
+	}
+	if children == nil {
+		panic("mujica: Container needs children")
+	}
+	e := ui.Column(c).Padding(containerSpace(core.Density(c), opts.Padding, SpaceL))
+	if opts.MaxWidth > 0 {
+		e.MaxWidth(opts.MaxWidth)
+	}
+	if opts.Fill {
+		e.Fill()
+	}
+	if opts.Center {
+		e.FillWidth().Margin(0, ui.Auto)
+	}
+	if opts.Clip {
+		e.Clip()
+	}
+	return e.Children(children)
+}