Layout for floating buttons

examples/floatingControlsContainer/main.go

@@ -0,0 +1,35 @@
+package main
+
+import (
+	"fmt"
+	"image/color"
+
+	"fyne.io/fyne/v2"
+	"fyne.io/fyne/v2/app"
+	"fyne.io/fyne/v2/canvas"
+	"fyne.io/fyne/v2/container"
+	"fyne.io/fyne/v2/widget"
+	"git.martyn.berlin/martyn/fyne-widgets/pkg/layouts"
+)
+
+func main() {
+	a := app.New()
+	w := a.NewWindow("FloatingButtons")
+
+	background := canvas.NewRectangle(color.RGBA{255, 0, 0, 128})
+
+	layout := layouts.NewFloatingControlsLayout()
+	layout.FloatingControlsLocation = layouts.FloatingControlsCenter
+	button := widget.NewButton("X", func() {
+		fmt.Println("button clicked")
+		layout.FloatingControlsLocation = layout.FloatingControlsLocation + 1
+		if layout.FloatingControlsLocation > 4 {
+			layout.FloatingControlsLocation = 0
+		}
+		w.SetContent(w.Content())
+	})
+
+	w.SetContent(container.New(&layout, background, button))
+	w.Resize(fyne.NewSize(100, 100))
+	w.ShowAndRun()
+}

pkg/layouts/floatingControlsContainer.go

@@ -0,0 +1,59 @@
+package layouts
+
+import (
+	"fyne.io/fyne/v2"
+)
+
+type FloatingControlsLocationEnum uint32
+
+const (
+	FloatingControlsTopLeft = iota
+	FloatingControlsTopRight
+	FloatingControlsBottomLeft
+	FloatingControlsBottomRight
+	FloatingControlsCenter
+)
+
+type floatingControlsLayout struct {
+	FloatingControlsLocation FloatingControlsLocationEnum
+}
+
+// NewFloatingControlsLayout creates a new floatingControlsLayout instance
+// This layout contains exactly TWO items, one background item (first) and one
+//  floating container that floats according to FloatingControlsLocation
+func NewFloatingControlsLayout() floatingControlsLayout {
+	return floatingControlsLayout{FloatingControlsTopRight}
+}
+
+func (d *floatingControlsLayout) MinSize(objects []fyne.CanvasObject) fyne.Size {
+	if len(objects) > 1 {
+		return objects[0].MinSize()
+	}
+	return fyne.NewSize(0, 0)
+}
+
+func (d *floatingControlsLayout) Layout(objects []fyne.CanvasObject, containerSize fyne.Size) {
+	if len(objects) == 2 {
+		o := objects[0]
+		size := containerSize
+		o.Resize(size)
+		o.Move(fyne.NewPos(0, 0))
+
+		o = objects[1]
+		size = o.MinSize()
+		o.Resize(size)
+		switch d.FloatingControlsLocation {
+		case FloatingControlsTopLeft:
+			o.Move(fyne.NewPos(0, 0))
+		case FloatingControlsTopRight:
+			o.Move(fyne.NewPos(containerSize.Width-size.Width, 0))
+		case FloatingControlsBottomLeft:
+			o.Move(fyne.NewPos(0, containerSize.Height-size.Height))
+		case FloatingControlsBottomRight:
+			o.Move(fyne.NewPos(containerSize.Width-size.Width, containerSize.Height-size.Height))
+		case FloatingControlsCenter:
+			o.Move(fyne.NewPos((containerSize.Width/2)-(size.Width/2), (containerSize.Height/2)-(size.Height/2)))
+		}
+
+	}
+}