layout: simplified Axis methods

Removed the Main and Cross Axis methods in favor of Convert.

Signed-off-by: pierre <pierre.curto@gmail.com>

layout/flex.go

@@ -3,6 +3,8 @@
 package layout
 
 import (
+	"image"
+
 	"gioui.org/op"
 )
 
@@ -96,7 +98,7 @@ func (f Flex) Layout(gtx Context, children ...FlexChild) Dimensions {
 		cgtx.Constraints = f.Axis.constraints(0, remaining, crossMin, crossMax)
 		dims := child.widget(cgtx)
 		c := macro.Stop()
-		sz := f.Axis.Main(dims.Size)
+		sz := f.Axis.Convert(dims.Size).X
 		size += sz
 		remaining -= sz
 		if remaining < 0 {
@@ -131,7 +133,7 @@ func (f Flex) Layout(gtx Context, children ...FlexChild) Dimensions {
 		cgtx.Constraints = f.Axis.constraints(flexSize, flexSize, crossMin, crossMax)
 		dims := child.widget(cgtx)
 		c := macro.Stop()
-		sz := f.Axis.Main(dims.Size)
+		sz := f.Axis.Convert(dims.Size).X
 		size += sz
 		remaining -= sz
 		if remaining < 0 {
@@ -143,7 +145,7 @@ func (f Flex) Layout(gtx Context, children ...FlexChild) Dimensions {
 	var maxCross int
 	var maxBaseline int
 	for _, child := range children {
-		if c := f.Axis.Cross(child.dims.Size); c > maxCross {
+		if c := f.Axis.Convert(child.dims.Size).Y; c > maxCross {
 			maxCross = c
 		}
 		if b := child.dims.Size.Y - child.dims.Baseline; b > maxBaseline {
@@ -173,19 +175,20 @@ func (f Flex) Layout(gtx Context, children ...FlexChild) Dimensions {
 		var cross int
 		switch f.Alignment {
 		case End:
-			cross = maxCross - f.Axis.Cross(dims.Size)
+			cross = maxCross - f.Axis.Convert(dims.Size).Y
 		case Middle:
-			cross = (maxCross - f.Axis.Cross(dims.Size)) / 2
+			cross = (maxCross - f.Axis.Convert(dims.Size).Y) / 2
 		case Baseline:
 			if f.Axis == Horizontal {
 				cross = maxBaseline - b
 			}
 		}
 		stack := op.Save(gtx.Ops)
-		op.Offset(FPt(f.Axis.point(mainSize, cross))).Add(gtx.Ops)
+		pt := f.Axis.Convert(image.Pt(mainSize, cross))
+		op.Offset(FPt(pt)).Add(gtx.Ops)
 		child.call.Add(gtx.Ops)
 		stack.Load()
-		mainSize += f.Axis.Main(dims.Size)
+		mainSize += f.Axis.Convert(dims.Size).X
 		if i < len(children)-1 {
 			switch f.Spacing {
 			case SpaceEvenly:
@@ -213,7 +216,7 @@ func (f Flex) Layout(gtx Context, children ...FlexChild) Dimensions {
 			mainSize += space / (len(children) * 2)
 		}
 	}
-	sz := f.Axis.point(mainSize, maxCross)
+	sz := f.Axis.Convert(image.Pt(mainSize, maxCross))
 	return Dimensions{Size: sz, Baseline: sz.Y - maxBaseline}
 }
 

layout/layout.go

@@ -225,31 +225,14 @@ func (a Alignment) String() string {
 	}
 }
 
-// Main returns the main axis of p.
-// I.e. if a is Horizontal, then the returned value is p.X.
-func (a Axis) Main(p image.Point) int {
+// Convert a point in (x, y) coordinates to (main, cross) coordinates,
+// or vice versa. Specifically, Convert((x, y)) returns (x, y) unchanged
+// for the horizontal axis, or (y, x) for the vertical axis.
+func (a Axis) Convert(pt image.Point) image.Point {
 	if a == Horizontal {
-		return p.X
+		return pt
 	}
-	return p.Y
-}
-
-// Cross returns the cross axis of p.
-// I.e. if a is Horizontal, then the returned value is p.Y.
-func (a Axis) Cross(p image.Point) int {
-	if a == Horizontal {
-		return p.Y
-	}
-	return p.X
-}
-
-// point returns the point having its values set based on the axis.
-// I.e. if a is Horizontal, then the returned value is image.Point{X: main, Y: cross}.
-func (a Axis) point(main, cross int) image.Point {
-	if a == Horizontal {
-		return image.Pt(main, cross)
-	}
-	return image.Pt(cross, main)
+	return image.Pt(pt.Y, pt.X)
 }
 
 // mainConstraint returns the min and max main constraints for axis a.

layout/list.go

@@ -178,7 +178,7 @@ func (l *List) nextDir() iterationDir {
 // End the current child by specifying its dimensions.
 func (l *List) end(dims Dimensions, call op.CallOp) {
 	child := scrollChild{dims.Size, call}
-	mainSize := l.Axis.Main(child.size)
+	mainSize := l.Axis.Convert(child.size).X
 	l.maxSize += mainSize
 	switch l.dir {
 	case iterateForward:
@@ -205,7 +205,7 @@ func (l *List) layout(ops *op.Ops, macro op.MacroOp) Dimensions {
 	// Skip invisible children
 	for len(children) > 0 {
 		sz := children[0].size
-		mainSize := l.Axis.Main(sz)
+		mainSize := l.Axis.Convert(sz).X
 		if l.Position.Offset <= mainSize {
 			break
 		}
@@ -216,11 +216,11 @@ func (l *List) layout(ops *op.Ops, macro op.MacroOp) Dimensions {
 	size := -l.Position.Offset
 	var maxCross int
 	for i, child := range children {
-		sz := child.size
-		if c := l.Axis.Cross(sz); c > maxCross {
+		sz := l.Axis.Convert(child.size)
+		if c := sz.Y; c > maxCross {
 			maxCross = c
 		}
-		size += l.Axis.Main(sz)
+		size += sz.X
 		if size >= mainMax {
 			children = children[:i+1]
 			break
@@ -232,15 +232,15 @@ func (l *List) layout(ops *op.Ops, macro op.MacroOp) Dimensions {
 		pos += space
 	}
 	for _, child := range children {
-		sz := child.size
+		sz := l.Axis.Convert(child.size)
 		var cross int
 		switch l.Alignment {
 		case End:
-			cross = maxCross - l.Axis.Cross(sz)
+			cross = maxCross - sz.Y
 		case Middle:
-			cross = (maxCross - l.Axis.Cross(sz)) / 2
+			cross = (maxCross - sz.Y) / 2
 		}
-		childSize := l.Axis.Main(sz)
+		childSize := sz.X
 		max := childSize + pos
 		if max > mainMax {
 			max = mainMax
@@ -250,12 +250,13 @@ func (l *List) layout(ops *op.Ops, macro op.MacroOp) Dimensions {
 			min = 0
 		}
 		r := image.Rectangle{
-			Min: l.Axis.point(min, -inf),
-			Max: l.Axis.point(max, inf),
+			Min: l.Axis.Convert(image.Pt(min, -inf)),
+			Max: l.Axis.Convert(image.Pt(max, inf)),
 		}
 		stack := op.Save(ops)
 		clip.Rect(r).Add(ops)
-		op.Offset(FPt(l.Axis.point(pos, cross))).Add(ops)
+		pt := l.Axis.Convert(image.Pt(pos, cross))
+		op.Offset(FPt(pt)).Add(ops)
 		child.call.Add(ops)
 		stack.Load()
 		pos += childSize
@@ -272,7 +273,7 @@ func (l *List) layout(ops *op.Ops, macro op.MacroOp) Dimensions {
 	if pos > mainMax {
 		pos = mainMax
 	}
-	dims := l.Axis.point(pos, maxCross)
+	dims := l.Axis.Convert(image.Pt(pos, maxCross))
 	call := macro.Stop()
 	defer op.Save(ops).Load()
 	pointer.Rect(image.Rectangle{Max: dims}).Add(ops)