From 46b3357635f2f5fca2f1338b34cb127ecb0311ec Mon Sep 17 00:00:00 2001
From: Sander Schobers <sander@schobers.eu>
Date: Sat, 12 Dec 2020 14:46:52 +0100
Subject: [PATCH] Added (optional) dropshadow for label.

---
 ui/label.go | 31 +++++++++++++++++++++----------
 1 file changed, 21 insertions(+), 10 deletions(-)

diff --git a/ui/label.go b/ui/label.go
index ee6ccce..66a7df1 100644
--- a/ui/label.go
+++ b/ui/label.go
@@ -1,13 +1,16 @@
 package ui
 
 import (
+	"image/color"
+
 	"opslag.de/schobers/geom"
 )
 
 type Label struct {
 	ControlBase
 
-	Text string
+	Text       string
+	DropShadow color.Color
 
 	desired CachedValue
 }
@@ -37,18 +40,26 @@ func (l *Label) DesiredSize(ctx Context, _ geom.PointF32) geom.PointF32 {
 	return l.desired.GetContext(ctx, l.desiredSize, l.hashDesiredSize).(geom.PointF32)
 }
 
+func (l *Label) getLabelTopLeft(ctx Context) geom.PointF32 {
+	pad := ctx.Style().Dimensions.TextPadding
+	bounds := l.bounds.Inset(pad)
+	switch l.TextAlignment {
+	case AlignRight:
+		return geom.PtF32(bounds.Max.X, bounds.Min.Y)
+	case AlignCenter:
+		return geom.PtF32(.5*(bounds.Min.X+bounds.Max.X), bounds.Min.Y)
+	default:
+		return bounds.Min
+	}
+}
+
 func (l *Label) Render(ctx Context) {
 	l.RenderBackground(ctx)
 	fontColor := l.TextColor(ctx)
 	fontName := l.FontName(ctx)
-	pad := ctx.Style().Dimensions.TextPadding
-	bounds := l.bounds.Inset(pad)
-	switch l.TextAlignment {
-	case AlignLeft:
-		ctx.Fonts().TextAlign(fontName, bounds.Min, fontColor, l.Text, l.TextAlignment)
-	case AlignRight:
-		ctx.Fonts().TextAlign(fontName, geom.PtF32(bounds.Max.X, bounds.Min.Y), fontColor, l.Text, l.TextAlignment)
-	case AlignCenter:
-		ctx.Fonts().TextAlign(fontName, geom.PtF32(.5*(bounds.Min.X+bounds.Max.X), bounds.Min.Y), fontColor, l.Text, l.TextAlignment)
+	topLeft := l.getLabelTopLeft(ctx)
+	if l.DropShadow != nil {
+		ctx.Fonts().TextAlign(fontName, topLeft.Add2D(1, 1), l.DropShadow, l.Text, l.TextAlignment)
 	}
+	ctx.Fonts().TextAlign(fontName, topLeft, fontColor, l.Text, l.TextAlignment)
 }