From 99be31bc2676c1a548e01142d2bc3516e35655df Mon Sep 17 00:00:00 2001
From: Elias Naur <mail@eliasnaur.com>
Date: Tue, 9 Jul 2019 11:28:41 +0200
Subject: [PATCH] ui/layout: convert Sized and Insets to use ui.Value

Layout objects are usually ephemereal, but when saved and re-used
between frames their measurements are not updated with varying pixel
density and font scaling.

Go back to storing unconverted ui.Values instead of raw pixels,
and convert them at each use.

Signed-off-by: Elias Naur <mail@eliasnaur.com>
---
 ui/layout/layout.go | 41 ++++++++++++++++++++++-------------------
 1 file changed, 22 insertions(+), 19 deletions(-)

diff --git a/ui/layout/layout.go b/ui/layout/layout.go
index cfa6743f..c436cb63 100644
--- a/ui/layout/layout.go
+++ b/ui/layout/layout.go
@@ -68,25 +68,29 @@ func ExactConstraints(size image.Point) Constraints {
 }
 
 type Insets struct {
-	Top, Right, Bottom, Left float32
+	Top, Right, Bottom, Left ui.Value
 
-	ops   *ui.Ops
-	begun bool
-	cs    Constraints
+	top, right, bottom, left int
+	ops                      *ui.Ops
+	begun                    bool
+	cs                       Constraints
 }
 
-func (in *Insets) Begin(ops *ui.Ops, cs Constraints) Constraints {
+func (in *Insets) Begin(c *ui.Config, ops *ui.Ops, cs Constraints) Constraints {
 	if in.begun {
 		panic("must End before Begin")
 	}
+	in.top = int(math.Round(float64(c.Val(in.Top))))
+	in.right= int(math.Round(float64(c.Val(in.Right))))
+	in.bottom = int(math.Round(float64(c.Val(in.Bottom))))
+	in.left = int(math.Round(float64(c.Val(in.Left))))
 	in.begun = true
 	in.ops = ops
 	in.cs = cs
 	mcs := cs
-	t, r, b, l := int(math.Round(float64(in.Top))), int(math.Round(float64(in.Right))), int(math.Round(float64(in.Bottom))), int(math.Round(float64(in.Left)))
 	if mcs.Width.Max != ui.Inf {
-		mcs.Width.Min -= l + r
-		mcs.Width.Max -= l + r
+		mcs.Width.Min -= in.left + in.right
+		mcs.Width.Max -= in.left + in.right
 		if mcs.Width.Min < 0 {
 			mcs.Width.Min = 0
 		}
@@ -95,8 +99,8 @@ func (in *Insets) Begin(ops *ui.Ops, cs Constraints) Constraints {
 		}
 	}
 	if mcs.Height.Max != ui.Inf {
-		mcs.Height.Min -= t + b
-		mcs.Height.Max -= t + b
+		mcs.Height.Min -= in.top + in.bottom
+		mcs.Height.Max -= in.top + in.bottom
 		if mcs.Height.Min < 0 {
 			mcs.Height.Min = 0
 		}
@@ -105,7 +109,7 @@ func (in *Insets) Begin(ops *ui.Ops, cs Constraints) Constraints {
 		}
 	}
 	ui.PushOp{}.Add(ops)
-	ui.TransformOp{Transform: ui.Offset(toPointF(image.Point{X: l, Y: t}))}.Add(ops)
+	ui.TransformOp{Transform: ui.Offset(toPointF(image.Point{X: in.left, Y: in.top}))}.Add(ops)
 	return mcs
 }
 
@@ -116,14 +120,13 @@ func (in *Insets) End(dims Dimens) Dimens {
 	in.begun = false
 	ops := in.ops
 	ui.PopOp{}.Add(ops)
-	t, r, b, l := int(math.Round(float64(in.Top))), int(math.Round(float64(in.Right))), int(math.Round(float64(in.Bottom))), int(math.Round(float64(in.Left)))
 	return Dimens{
-		Size:     in.cs.Constrain(dims.Size.Add(image.Point{X: r + l, Y: t + b})),
-		Baseline: dims.Baseline + t,
+		Size:     in.cs.Constrain(dims.Size.Add(image.Point{X: in.right + in.left, Y: in.top + in.bottom})),
+		Baseline: dims.Baseline + in.top,
 	}
 }
 
-func EqualInsets(v float32) Insets {
+func EqualInsets(v ui.Value) Insets {
 	return Insets{Top: v, Right: v, Bottom: v, Left: v}
 }
 
@@ -132,11 +135,11 @@ func isInf(v ui.Value) bool {
 }
 
 type Sized struct {
-	Width, Height float32
+	Width, Height ui.Value
 }
 
-func (s Sized) Constrain(cs Constraints) Constraints {
-	if h := int(s.Height + 0.5); h != 0 {
+func (s Sized) Constrain(c *ui.Config, cs Constraints) Constraints {
+	if h := int(c.Val(s.Height) + 0.5); h != 0 {
 		if cs.Height.Min < h {
 			cs.Height.Min = h
 		}
@@ -144,7 +147,7 @@ func (s Sized) Constrain(cs Constraints) Constraints {
 			cs.Height.Max = h
 		}
 	}
-	if w := int(s.Width + .5); w != 0 {
+	if w := int(c.Val(s.Width) + .5); w != 0 {
 		if cs.Width.Min < w {
 			cs.Width.Min = w
 		}