From 47c5859d87fcd3f35a04ee7ead8dbd7dcf1d9530 Mon Sep 17 00:00:00 2001
From: Elias Naur <mail@eliasnaur.com>
Date: Fri, 21 Jun 2019 15:02:37 +0200
Subject: [PATCH] ui/app: make Draw.Config a value, not a pointer

We are going to encourage a model where pointers to a central
(program global) Configs are passed to widgets at setup time, and
not pass Configs at every frame.

That way, the global Gonfig can change, but the pointers won't need
updating.

This change only switches the Draw event's Config pointer to a value
to avoid tempting programs to use the event Config instead of
updating their own central Configs.

Signed-off-by: Elias Naur <mail@eliasnaur.com>
---
 ui/app/app.go        | 2 +-
 ui/app/os_android.go | 2 +-
 ui/app/os_ios.go     | 2 +-
 ui/app/os_js.go      | 2 +-
 ui/app/os_macos.go   | 2 +-
 ui/app/os_wayland.go | 2 +-
 ui/app/os_windows.go | 4 ++--
 7 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/ui/app/app.go b/ui/app/app.go
index 139c992f..454156e9 100644
--- a/ui/app/app.go
+++ b/ui/app/app.go
@@ -15,7 +15,7 @@ type Event interface {
 }
 
 type Draw struct {
-	Config *ui.Config
+	Config ui.Config
 	Size   image.Point
 	// Whether this draw is system generated
 	// and needs a complete frame before
diff --git a/ui/app/os_android.go b/ui/app/os_android.go
index d416ad1b..ab73ce2f 100644
--- a/ui/app/os_android.go
+++ b/ui/app/os_android.go
@@ -275,7 +275,7 @@ func (w *window) draw(sync bool) {
 			X: int(width),
 			Y: int(height),
 		},
-		Config: &ui.Config{
+		Config: ui.Config{
 			PxPerDp: ppdp,
 			PxPerSp: w.fontScale * ppdp,
 			Now:     time.Now(),
diff --git a/ui/app/os_ios.go b/ui/app/os_ios.go
index fabc7911..c410e8a1 100644
--- a/ui/app/os_ios.go
+++ b/ui/app/os_ios.go
@@ -83,7 +83,7 @@ func onDraw(view C.CFTypeRef, dpi, sdpi, width, height C.CGFloat, sync C.int) {
 			X: int(width + .5),
 			Y: int(height + .5),
 		},
-		Config: &ui.Config{
+		Config: ui.Config{
 			PxPerDp: float32(dpi) * inchPrDp,
 			PxPerSp: float32(sdpi) * inchPrDp,
 			Now:     time.Now(),
diff --git a/ui/app/os_js.go b/ui/app/os_js.go
index b27f73e5..29f2b3fb 100644
--- a/ui/app/os_js.go
+++ b/ui/app/os_js.go
@@ -341,7 +341,7 @@ func (w *window) draw(sync bool) {
 			X: width,
 			Y: height,
 		},
-		Config: &cfg,
+		Config: cfg,
 		sync:   sync,
 	})
 }
diff --git a/ui/app/os_macos.go b/ui/app/os_macos.go
index c9d4b398..39f87c53 100644
--- a/ui/app/os_macos.go
+++ b/ui/app/os_macos.go
@@ -149,7 +149,7 @@ func (w *window) draw(sync bool) {
 			X: width,
 			Y: height,
 		},
-		Config: &cfg,
+		Config: cfg,
 		sync:   sync,
 	})
 }
diff --git a/ui/app/os_wayland.go b/ui/app/os_wayland.go
index c2001761..a5438642 100644
--- a/ui/app/os_wayland.go
+++ b/ui/app/os_wayland.go
@@ -1050,7 +1050,7 @@ func (w *window) draw(sync bool) {
 			X: width,
 			Y: height,
 		},
-		Config: &cfg,
+		Config: cfg,
 		sync:   sync,
 	})
 }
diff --git a/ui/app/os_windows.go b/ui/app/os_windows.go
index fdea1d0c..78fab8cb 100644
--- a/ui/app/os_windows.go
+++ b/ui/app/os_windows.go
@@ -487,14 +487,14 @@ func convertKeyCode(code uintptr) (rune, bool) {
 	return r, true
 }
 
-func configForDC(hdc syscall.Handle) *ui.Config {
+func configForDC(hdc syscall.Handle) ui.Config {
 	dpi := getDeviceCaps(hdc, _LOGPIXELSX)
 	ppdp := float32(dpi) * inchPrDp * monitorScale
 	// Force a minimum density to keep text legible and to handle bogus output geometry.
 	if ppdp < minDensity {
 		ppdp = minDensity
 	}
-	return &ui.Config{
+	return ui.Config{
 		PxPerDp: ppdp,
 		PxPerSp: ppdp,
 	}