simple canvas object wrapper

Making this public would address fyne-io#709.

internal/canvas_object_wrapper.go

@@ -0,0 +1,93 @@
+package internal
+
+import (
+	"fyne.io/fyne/v2"
+	"fyne.io/fyne/v2/canvas"
+)
+
+var _ fyne.CanvasObject = (*SimpleCanvasObjectWrapper)(nil)
+var _ CanvasObjectWrapper = (*SimpleCanvasObjectWrapper)(nil)
+
+// CanvasObjectWrapper defines an interface for objects wrapping a fyne.CanvasObject.
+type CanvasObjectWrapper interface {
+	WrappedObject() fyne.CanvasObject
+}
+
+// SimpleCanvasObjectWrapper is a simple CanvasObjectWrapper which can be easily extended.
+type SimpleCanvasObjectWrapper struct {
+	O fyne.CanvasObject
+
+	pos fyne.Position
+}
+
+// Hide hides the wrapped object.
+//
+// Implements: fyne.CanvasObject
+func (w *SimpleCanvasObjectWrapper) Hide() {
+	w.O.Hide()
+}
+
+// MinSize returns the min size of the wrapped object.
+//
+// Implements: fyne.CanvasObject
+func (w *SimpleCanvasObjectWrapper) MinSize() fyne.Size {
+	return w.O.MinSize()
+}
+
+// Move moves the wrapped object.
+//
+// Implements: fyne.CanvasObject
+func (w *SimpleCanvasObjectWrapper) Move(position fyne.Position) {
+	w.pos = position
+	w.Refresh()
+}
+
+// Position returns the position of the wrapped object.
+//
+// Implements: fyne.CanvasObject
+func (w *SimpleCanvasObjectWrapper) Position() fyne.Position {
+	return w.pos
+}
+
+// Refresh refreshes the wrapped object.
+//
+// Implements: fyne.CanvasObject
+func (w *SimpleCanvasObjectWrapper) Refresh() {
+	w.O.Refresh()
+	canvas.Refresh(w)
+}
+
+// Resize resizes the wrapped object.
+//
+// Implements: fyne.CanvasObject
+func (w *SimpleCanvasObjectWrapper) Resize(size fyne.Size) {
+	w.O.Resize(size)
+}
+
+// Show shows the wrapped object.
+//
+// Implements: fyne.CanvasObject
+func (w *SimpleCanvasObjectWrapper) Show() {
+	w.O.Show()
+}
+
+// Size returns the size of the wrapped object.
+//
+// Implements: fyne.CanvasObject
+func (w *SimpleCanvasObjectWrapper) Size() fyne.Size {
+	return w.O.Size()
+}
+
+// Visible returns whether the wrapped object is visible or not.
+//
+// Implements: fyne.CanvasObject
+func (w *SimpleCanvasObjectWrapper) Visible() bool {
+	return w.O.Visible()
+}
+
+// WrappedObject returns the wrapped object.
+//
+// Implements: CanvasObjectWrapper
+func (w *SimpleCanvasObjectWrapper) WrappedObject() fyne.CanvasObject {
+	return w.O
+}

internal/canvas_object_wrapper_test.go

@@ -0,0 +1,139 @@
+package internal_test
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+
+	"fyne.io/fyne/v2"
+	"fyne.io/fyne/v2/internal"
+)
+
+var _ fyne.CanvasObject = (*simpleCanvasObject)(nil)
+
+func TestSimpleCanvasObjectWrapper_Hide(t *testing.T) {
+	o := &simpleCanvasObject{}
+	w := &internal.SimpleCanvasObjectWrapper{O: o}
+
+	assert.True(t, o.Visible())
+	w.Hide()
+	assert.False(t, o.Visible())
+}
+
+func TestSimpleCanvasObjectWrapper_MinSize(t *testing.T) {
+	o := &simpleCanvasObject{minSize: fyne.NewSize(12, 34)}
+	w := &internal.SimpleCanvasObjectWrapper{O: o}
+	assert.Equal(t, fyne.NewSize(12, 34), w.MinSize())
+	o = &simpleCanvasObject{minSize: fyne.NewSize(13, 42)}
+	w = &internal.SimpleCanvasObjectWrapper{O: o}
+	assert.Equal(t, fyne.NewSize(13, 42), w.MinSize())
+}
+
+func TestSimpleCanvasObjectWrapper_MoveAndPosition(t *testing.T) {
+	o := &simpleCanvasObject{}
+	w := &internal.SimpleCanvasObjectWrapper{O: o}
+
+	assert.Equal(t, fyne.NewPos(0, 0), w.Position())
+	assert.Equal(t, fyne.NewPos(0, 0), o.Position())
+	w.Move(fyne.NewPos(17, 389))
+	assert.Equal(t, fyne.NewPos(17, 389), w.Position())
+	assert.Equal(t, fyne.NewPos(0, 0), o.Position())
+}
+
+func TestSimpleCanvasObjectWrapper_Refresh(t *testing.T) {
+	o := &simpleCanvasObject{}
+	w := &internal.SimpleCanvasObjectWrapper{O: o}
+
+	assert.Equal(t, 0, o.refreshCount)
+	w.Refresh()
+	assert.Equal(t, 1, o.refreshCount)
+	w.Refresh()
+	w.Refresh()
+	assert.Equal(t, 3, o.refreshCount)
+}
+
+func TestSimpleCanvasObjectWrapper_Resize(t *testing.T) {
+	o := &simpleCanvasObject{}
+	w := &internal.SimpleCanvasObjectWrapper{O: o}
+
+	assert.Equal(t, fyne.NewSize(0, 0), o.Size())
+	w.Resize(fyne.NewSize(17, 389))
+	assert.Equal(t, fyne.NewSize(17, 389), o.Size())
+}
+
+func TestSimpleCanvasObjectWrapper_Show(t *testing.T) {
+	o := &simpleCanvasObject{hidden: true}
+	w := &internal.SimpleCanvasObjectWrapper{O: o}
+
+	assert.False(t, o.Visible())
+	w.Show()
+	assert.True(t, o.Visible())
+}
+
+func TestSimpleCanvasObjectWrapper_Size(t *testing.T) {
+	o := &simpleCanvasObject{size: fyne.NewSize(12, 34)}
+	w := &internal.SimpleCanvasObjectWrapper{O: o}
+	assert.Equal(t, fyne.NewSize(12, 34), w.Size())
+	o = &simpleCanvasObject{size: fyne.NewSize(13, 42)}
+	w = &internal.SimpleCanvasObjectWrapper{O: o}
+	assert.Equal(t, fyne.NewSize(13, 42), w.Size())
+}
+
+func TestSimpleCanvasObjectWrapper_Visible(t *testing.T) {
+	o := &simpleCanvasObject{hidden: true}
+	w := &internal.SimpleCanvasObjectWrapper{O: o}
+	assert.False(t, w.Visible())
+	o = &simpleCanvasObject{hidden: false}
+	w = &internal.SimpleCanvasObjectWrapper{O: o}
+	assert.True(t, w.Visible())
+}
+
+func TestSimpleCanvasObjectWrapper_WrappedObject(t *testing.T) {
+	o := &simpleCanvasObject{}
+	w := &internal.SimpleCanvasObjectWrapper{O: o}
+	assert.Same(t, o, w.WrappedObject())
+}
+
+type simpleCanvasObject struct {
+	hidden       bool
+	minSize      fyne.Size
+	pos          fyne.Position
+	refreshCount int
+	size         fyne.Size
+}
+
+func (o *simpleCanvasObject) MinSize() fyne.Size {
+	return o.minSize
+}
+
+func (o *simpleCanvasObject) Move(position fyne.Position) {
+	o.pos = position
+}
+
+func (o *simpleCanvasObject) Position() fyne.Position {
+	return o.pos
+}
+
+func (o *simpleCanvasObject) Resize(size fyne.Size) {
+	o.size = size
+}
+
+func (o *simpleCanvasObject) Size() fyne.Size {
+	return o.size
+}
+
+func (o *simpleCanvasObject) Hide() {
+	o.hidden = true
+}
+
+func (o *simpleCanvasObject) Visible() bool {
+	return !o.hidden
+}
+
+func (o *simpleCanvasObject) Show() {
+	o.hidden = false
+}
+
+func (o *simpleCanvasObject) Refresh() {
+	o.refreshCount++
+}