Move to float32 coordinates (#1661)

* Move geometry from int to float32.

* remove deprecated Size.Union

* Move mouse events to Delta from (int, int)

* Add Vector2 for interoperability between Size, Position and Delta.

Fixes #835

CHANGELOG.md

@@ -10,9 +10,19 @@ More detailed release notes can be found on the [releases page](https://github.c
 These changes likely break some apps, please read the 
 [upgrading doc](https://developer.fyne.io/api/v2.0/upgrading) for more info
 
+* Coordinate system to float32
+  * Size and Position units were changed from int to float32
+  * `Text.TextSize` moved to float32 and `fyne.MeasureText` now takes a float32 size parameter
+  * Removed `Size.Union`
+  * Added fyne.Delta for difference based X, Y representation
+  * DraggedEvent.DraggedX and DraggedX (int, int) to DraggedEvent.Dragged (Delta)
+  * ScrollEvent.DeltaX and DeltaY (int, int) moved to ScrollEvent.Scrolled (Delta)
+
+* Theme API update
+  * `fyne.Theme` moved to `fyne.LegacyTheme` and can be load to a new theme using `theme.FromLegacy`
+  * A new, more flexible, Theme interface has been created that we encourage developers to use
+
 * The second parameter of `theme.NewThemedResource` was removed, it was previously ignored
-* `fyne.Theme` moved to `fyne.LegacyTheme` and can be load to a new theme using `theme.FromLegacy`
-* A new, more flexible, Theme interface has been created that we encourage developers to use
 * The desktop.Cursor definition was renamed desktop.StandardCursor to make way for custom cursors
 
 * Dialogs no longer show when created, unless using the ShowXxx convenience methods
@@ -21,9 +31,13 @@ These changes likely break some apps, please read the
 ### Added
 
 * Add MouseButtonTertiary for middle mouse button events on desktop
+* Add fyne.Vector for simple x/y coordinates
 
 ### Changed
 
+* Coordinate system is now float32 - see breaking changes above
+* ScrollEvent and DragEvent moved to Delta from (int, int)
+
 * Change bundled resources to use more efficient string storage
 * Desktop left and right mouse buttons renamed to MouseButtonPrimary and MouseButtonSecondary
 * Many optimisations and widget performance enhancements

canvas/animation.go

@@ -49,7 +49,7 @@ func NewPositionAnimation(start, stop fyne.Position, d time.Duration, fn func(fy
 	return &fyne.Animation{
 		Duration: d,
 		Tick: func(done float32) {
-			fn(fyne.NewPos(scaleInt(start.X, xDelta, done), scaleInt(start.Y, yDelta, done)))
+			fn(fyne.NewPos(scaleVal(start.X, xDelta, done), scaleVal(start.Y, yDelta, done)))
 		}}
 }
 
@@ -63,14 +63,14 @@ func NewSizeAnimation(start, stop fyne.Size, d time.Duration, fn func(fyne.Size)
 	return &fyne.Animation{
 		Duration: d,
 		Tick: func(done float32) {
-			fn(fyne.NewSize(scaleInt(start.Width, widthDelta, done), scaleInt(start.Height, heightDelta, done)))
+			fn(fyne.NewSize(scaleVal(start.Width, widthDelta, done), scaleVal(start.Height, heightDelta, done)))
 		}}
 }
 
 func scaleChannel(start int, diff, done float32) uint8 {
 	return uint8(start + int(diff*done))
 }
 
-func scaleInt(start int, delta, done float32) int {
-	return start + int(delta*done)
+func scaleVal(start float32, delta, done float32) float32 {
+	return start + delta*done
 }

canvas/base_internal_test.go

@@ -21,17 +21,17 @@ func TestBase_Move(t *testing.T) {
 	base.Move(fyne.NewPos(10, 10))
 	pos := base.Position()
 
-	assert.Equal(t, 10, pos.X)
-	assert.Equal(t, 10, pos.Y)
+	assert.Equal(t, float32(10), pos.X)
+	assert.Equal(t, float32(10), pos.Y)
 }
 
 func TestBase_Resize(t *testing.T) {
 	base := &baseObject{}
 	base.Resize(fyne.NewSize(10, 10))
 	size := base.Size()
 
-	assert.Equal(t, 10, size.Width)
-	assert.Equal(t, 10, size.Height)
+	assert.Equal(t, float32(10), size.Width)
+	assert.Equal(t, float32(10), size.Height)
 }
 
 func TestBase_HideShow(t *testing.T) {

canvas/circle_test.go

@@ -26,8 +26,8 @@ func TestCircle_FillColor(t *testing.T) {
 }
 
 func TestCircle_Resize(t *testing.T) {
-	targetWidth := 50
-	targetHeight := 50
+	targetWidth := float32(50)
+	targetHeight := float32(50)
 	circle := canvas.NewCircle(color.White)
 	start := circle.Size()
 	assert.True(t, start.Height == 0)

canvas/line.go

@@ -24,8 +24,8 @@ type Line struct {
 
 // Size returns the current size of bounding box for this line object
 func (l *Line) Size() fyne.Size {
-	return fyne.NewSize(int(math.Abs(float64(l.Position2.X)-float64(l.Position1.X))),
-		int(math.Abs(float64(l.Position2.Y)-float64(l.Position1.Y))))
+	return fyne.NewSize(float32(math.Abs(float64(l.Position2.X)-float64(l.Position1.X))),
+		float32(math.Abs(float64(l.Position2.Y)-float64(l.Position1.Y))))
 }
 
 // Resize sets a new bottom-right position for the line object and it will then be refreshed.

canvas/line_test.go

@@ -24,8 +24,8 @@ func TestLine_Resize(t *testing.T) {
 	line.Resize(fyne.NewSize(10, 0))
 	size := line.Size()
 
-	assert.Equal(t, size.Width, 10)
-	assert.Equal(t, size.Height, 0)
+	assert.Equal(t, float32(10), size.Width)
+	assert.Equal(t, float32(0), size.Height)
 }
 
 func TestLine_StrokeColor(t *testing.T) {

canvas/text.go

@@ -18,7 +18,7 @@ type Text struct {
 
 	Color     color.Color    // The main text draw color
 	Text      string         // The string content of this Text
-	TextSize  int            // Size of the text - if the Canvas scale is 1.0 this will be equivalent to point size
+	TextSize  float32        // Size of the text - if the Canvas scale is 1.0 this will be equivalent to point size
 	TextStyle fyne.TextStyle // The style of the text content
 }
 

canvas/text_test.go

@@ -51,7 +51,7 @@ func TestText_Layout(t *testing.T) {
 		"short_leading_large": {
 			text:  "abc",
 			align: fyne.TextAlignLeading,
-			size:  fyne.NewSize(500, 100),
+			size:  fyne.NewSize(500, 101),
 		},
 		"long_leading_small": {
 			text:  "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ",
@@ -61,7 +61,7 @@ func TestText_Layout(t *testing.T) {
 		"long_leading_large": {
 			text:  "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ",
 			align: fyne.TextAlignLeading,
-			size:  fyne.NewSize(500, 100),
+			size:  fyne.NewSize(500, 101),
 		},
 		"short_center_small": {
 			text:  "abc",
@@ -71,7 +71,7 @@ func TestText_Layout(t *testing.T) {
 		"short_center_large": {
 			text:  "abc",
 			align: fyne.TextAlignCenter,
-			size:  fyne.NewSize(500, 100),
+			size:  fyne.NewSize(500, 101),
 		},
 		"long_center_small": {
 			text:  "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ",
@@ -81,7 +81,7 @@ func TestText_Layout(t *testing.T) {
 		"long_center_large": {
 			text:  "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ",
 			align: fyne.TextAlignCenter,
-			size:  fyne.NewSize(500, 100),
+			size:  fyne.NewSize(500, 101),
 		},
 		"short_trailing_small": {
 			text:  "abc",
@@ -91,7 +91,7 @@ func TestText_Layout(t *testing.T) {
 		"short_trailing_large": {
 			text:  "abc",
 			align: fyne.TextAlignTrailing,
-			size:  fyne.NewSize(500, 100),
+			size:  fyne.NewSize(500, 101),
 		},
 		"long_trailing_small": {
 			text:  "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ",
@@ -101,7 +101,7 @@ func TestText_Layout(t *testing.T) {
 		"long_trailing_large": {
 			text:  "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ",
 			align: fyne.TextAlignTrailing,
-			size:  fyne.NewSize(500, 100),
+			size:  fyne.NewSize(500, 101),
 		},
 	} {
 		t.Run(name, func(t *testing.T) {

cmd/fyne_demo/tutorials/animation.go

@@ -34,7 +34,7 @@ func makeAnimationCanvas() fyne.CanvasObject {
 	a2 = canvas.NewPositionAnimation(fyne.NewPos(0, 0), fyne.NewPos(350, 80), time.Second*3, func(p fyne.Position) {
 		i.Move(p)
 
-		width := int(10 + (float64(p.X) / 7))
+		width := 10 + (p.X / 7)
 		i.Resize(fyne.NewSize(width, width))
 	})
 	a2.Repeat = true
@@ -78,7 +78,7 @@ func makeAnimationCurves() fyne.CanvasObject {
 	return fyne.NewContainerWithoutLayout(label1, label2, label3, label4, box1, box2, box3, box4, start)
 }
 
-func makeAnimationCurveItem(label string, curve fyne.AnimationCurve, yOff int) (
+func makeAnimationCurveItem(label string, curve fyne.AnimationCurve, yOff float32) (
 	text *widget.Label, box fyne.CanvasObject, anim *fyne.Animation) {
 	text = widget.NewLabel(label)
 	text.Alignment = fyne.TextAlignCenter

cmd/fyne_demo/tutorials/theme.go

@@ -42,7 +42,7 @@ func (customTheme) Icon(n fyne.ThemeIconName) fyne.Resource {
 	return theme.DefaultTheme().Icon(n)
 }
 
-func (customTheme) Size(s fyne.ThemeSizeName) int {
+func (customTheme) Size(s fyne.ThemeSizeName) float32 {
 	switch s {
 	case theme.SizeNamePadding:
 		return 10

cmd/fyne_settings/settings/scale.go

@@ -24,7 +24,7 @@ var scales = []*scaleItems{
 
 func (s *Settings) appliedScale(value float32) {
 	for _, scale := range scales {
-		scale.preview.TextSize = int(float32(theme.TextSize()) * scale.scale / value)
+		scale.preview.TextSize = theme.TextSize() * scale.scale / value
 	}
 }
 
@@ -72,7 +72,7 @@ func (s *Settings) makeScalePreviews(value float32) []fyne.CanvasObject {
 	for i, scale := range scales {
 		text := canvas.NewText("A", theme.TextColor())
 		text.Alignment = fyne.TextAlignCenter
-		text.TextSize = int(float32(theme.TextSize()) * scale.scale / value)
+		text.TextSize = theme.TextSize() * scale.scale / value
 
 		scale.preview = text
 		previews[i] = text

cmd/fyne_settings/settings/scale_test.go

@@ -40,5 +40,5 @@ func TestMakeScalePreviews(t *testing.T) {
 	assert.Equal(t, theme.TextSize(), previews[2].(*canvas.Text).TextSize)
 
 	s.appliedScale(1.5)
-	assert.Equal(t, int(float32(theme.TextSize())/1.5), previews[2].(*canvas.Text).TextSize)
+	assert.Equal(t, theme.TextSize()/1.5, previews[2].(*canvas.Text).TextSize)
 }

container.go

@@ -73,7 +73,7 @@ func (c *Container) MinSize() Size {
 
 	minSize := NewSize(1, 1)
 	for _, child := range c.Objects {
-		minSize = minSize.Union(child.MinSize())
+		minSize = minSize.Max(child.MinSize())
 	}
 
 	return minSize

dialog/base.go

@@ -105,7 +105,7 @@ func (d *dialog) Layout(obj []fyne.CanvasObject, size fyne.Size) {
 	d.bg.Move(fyne.NewPos(0, 0))
 	d.bg.Resize(size)
 
-	btnMin := obj[3].MinSize().Union(obj[3].Size())
+	btnMin := obj[3].MinSize().Max(obj[3].Size())
 
 	// icon
 	iconHeight := padHeight*2 + d.label.MinSize().Height*2 - theme.Padding()
@@ -125,7 +125,7 @@ func (d *dialog) Layout(obj []fyne.CanvasObject, size fyne.Size) {
 
 func (d *dialog) MinSize(obj []fyne.CanvasObject) fyne.Size {
 	contentMin := obj[2].MinSize()
-	btnMin := obj[3].MinSize().Union(obj[3].Size())
+	btnMin := obj[3].MinSize().Max(obj[3].Size())
 
 	width := fyne.Max(fyne.Max(contentMin.Width, btnMin.Width), obj[4].MinSize().Width) + padWidth
 	height := contentMin.Height + btnMin.Height + d.label.MinSize().Height + theme.Padding() + padHeight*2

dialog/color_wheel.go

@@ -131,20 +131,20 @@ func (a *colorWheel) colorAt(x, y, w, h int) color.Color {
 
 func (a *colorWheel) locationForPosition(pos fyne.Position) (x, y int) {
 	can := fyne.CurrentApp().Driver().CanvasForObject(a)
-	x, y = pos.X, pos.Y
+	x, y = int(pos.X), int(pos.Y)
 	if can != nil {
 		x, y = can.PixelCoordinateForPosition(pos)
 	}
 	return
 }
 
-func (a *colorWheel) selection(width, height int) (int, int) {
+func (a *colorWheel) selection(width, height float32) (float32, float32) {
 	w, h := float64(width), float64(height)
 	radius := float64(a.Saturation) / 100.0 * math.Min(w, h) / 2.0
 	degrees := float64(a.Hue)
 	radians := degrees * math.Pi / 180.0
 	c := cmplx.Rect(radius, radians)
-	return int(real(c) + w/2.0), int(imag(c) + h/2.0)
+	return float32(real(c) + w/2.0), float32(imag(c) + h/2.0)
 }
 
 func (a *colorWheel) trigger(pos fyne.Position) {

dialog/confirm_test.go

@@ -72,9 +72,9 @@ func TestConfirmDialog_Resize(t *testing.T) {
 	//Test resize - normal size scenario
 	size := fyne.NewSize(300, 180) //normal size to fit (600,400)
 	theDialog.Resize(size)
-	expectedWidth := 300
+	expectedWidth := float32(300)
 	assert.Equal(t, expectedWidth, theDialog.win.Content.Size().Width+theme.Padding()*2)
-	expectedHeight := 180
+	expectedHeight := float32(180)
 	assert.Equal(t, expectedHeight, theDialog.win.Content.Size().Height+theme.Padding()*2)
 	//Test resize - normal size scenario again
 	size = fyne.NewSize(310, 280) //normal size to fit (600,400)

dialog/file.go

@@ -165,7 +165,7 @@ func (f *fileDialog) makeUI() fyne.CanvasObject {
 		fileIconSize+theme.Padding()+fileTextSize)),
 	)
 	f.fileScroll = widget.NewScrollContainer(f.files)
-	verticalExtra := int(float64(fileIconSize) * 0.25)
+	verticalExtra := float32(float64(fileIconSize) * 0.25)
 	f.fileScroll.SetMinSize(fyne.NewSize(fileIconCellWidth*2+theme.Padding(),
 		(fileIconSize+fileTextSize)+theme.Padding()*2+verticalExtra))
 

dialog/file_test.go

@@ -128,9 +128,9 @@ func TestFileDialogResize(t *testing.T) {
 	//Test resize - normal size scenario
 	size := fyne.NewSize(200, 180) //normal size to fit (600,400)
 	file.Resize(size)
-	expectedWidth := 200
+	expectedWidth := float32(200)
 	assert.Equal(t, expectedWidth, file.dialog.win.Content.Size().Width+theme.Padding()*2)
-	expectedHeight := 180
+	expectedHeight := float32(180)
 	assert.Equal(t, expectedHeight, file.dialog.win.Content.Size().Height+theme.Padding()*2)
 	//Test resize - normal size scenario again
 	size = fyne.NewSize(300, 280) //normal size to fit (600,400)

dialog/information_test.go

@@ -33,9 +33,9 @@ func TestDialog_Resize(t *testing.T) {
 	//Test resize - normal size scenario
 	size := fyne.NewSize(300, 180) //normal size to fit (600,400)
 	theDialog.Resize(size)
-	expectedWidth := 300
+	expectedWidth := float32(300)
 	assert.Equal(t, expectedWidth, theDialog.win.Content.Size().Width+theme.Padding()*2)
-	expectedHeight := 180
+	expectedHeight := float32(180)
 	assert.Equal(t, expectedHeight, theDialog.win.Content.Size().Height+theme.Padding()*2)
 	//Test resize - normal size scenario again
 	size = fyne.NewSize(310, 280) //normal size to fit (600,400)

dialog/progressinfinite_test.go

@@ -32,9 +32,9 @@ func TestProgressInfiniteDialog_Resize(t *testing.T) {
 	//Test resize - normal size scenario
 	size := fyne.NewSize(300, 180) //normal size to fit (600,400)
 	theDialog.Resize(size)
-	expectedWidth := 300
+	expectedWidth := float32(300)
 	assert.Equal(t, expectedWidth, theDialog.win.Content.Size().Width+theme.Padding()*2)
-	expectedHeight := 180
+	expectedHeight := float32(180)
 	assert.Equal(t, expectedHeight, theDialog.win.Content.Size().Height+theme.Padding()*2)
 	//Test resize - normal size scenario again
 	size = fyne.NewSize(310, 280) //normal size to fit (600,400)

driver.go

@@ -10,7 +10,7 @@ type Driver interface {
 
 	// RenderedTextSize returns the size required to render the given string of specified
 	// font size and style.
-	RenderedTextSize(string, int, TextStyle) Size
+	RenderedTextSize(string, float32, TextStyle) Size
 
 	// FileReaderForURI opens a file reader for the given resource indicator.
 	// This may refer to a filesystem (typical on desktop) or data from another application.

event.go

@@ -16,12 +16,12 @@ type PointEvent struct {
 // The DeltaX and DeltaY represent how large the scroll was in two dimensions.
 type ScrollEvent struct {
 	PointEvent
-	DeltaX, DeltaY int
+	Scrolled Delta
 }
 
 // DragEvent defines the parameters of a pointer or other drag event.
 // The DraggedX and DraggedY fields show how far the item was dragged since the last event.
 type DragEvent struct {
 	PointEvent
-	DraggedX, DraggedY int
+	Dragged Delta
 }