From b5f67c65b0dcc88697b66e1a2b1fea1b70d07f36 Mon Sep 17 00:00:00 2001
From: Sasha Koshka <sashakoshka@tebibyte.media>
Date: Fri, 25 Aug 2023 02:51:07 -0400
Subject: [PATCH] Cleaned up code relating to transparency

---
 box.go          | 32 ++++++++++++--------------------
 containerbox.go | 24 +++++++-----------------
 textbox.go      |  5 +++++
 util.go         |  7 +++++++
 4 files changed, 31 insertions(+), 37 deletions(-)

diff --git a/box.go b/box.go
index 634f3c2..776a159 100644
--- a/box.go
+++ b/box.go
@@ -25,8 +25,6 @@ type box struct {
 	border  []tomo.Border
 	color   color.Color
 	texture *xcanvas.Texture
-	
-	fillTransparent bool
 
 	dndData   data.Data
 	dndAccept []data.Mime
@@ -56,7 +54,7 @@ type box struct {
 func (backend *Backend) newBox (outer anyBox) *box {
 	box := &box {
 		backend: backend,
-		color:   color.White,
+		color:   color.Transparent,
 		outer:   outer,
 		drawer:  outer,
 	}
@@ -118,19 +116,16 @@ func (this *box) SetColor (c color.Color) {
 	if c == nil { c = color.Transparent }
 	if this.color == c { return }
 	this.color = c
-	this.determineFillTransparency()
 	this.invalidateDraw()
 }
 
 func (this *box) SetTexture (texture canvas.Texture) {
 	this.texture = xcanvas.AssertTexture(texture)
-	this.determineFillTransparency()
 	this.invalidateDraw()
 }
 
 func (this *box) SetBorder (border ...tomo.Border) {
 	this.border = border
-	this.determineFillTransparency()
 	this.invalidateLayout()
 	this.invalidateMinimum()
 }
@@ -283,12 +278,12 @@ func (this *box) Draw (can canvas.Canvas) {
 	if can == nil { return }
 	pen := can.Pen()
 	pen.Fill(this.color)
-	if this.texture == nil || !this.texture.Opaque() {
-		pen.Rectangle(this.bounds)
-	}
-	if this.texture != nil {
-		// TODO drawR texture
+	pen.Texture(this.texture)
+	
+	if this.transparent() && this.parent != nil {
+		this.parent.drawBackgroundPart(can)
 	}
+	pen.Rectangle(can.Bounds())
 }
 
 func (this *box) drawBorders (can canvas.Canvas) {
@@ -298,8 +293,7 @@ func (this *box) drawBorders (can canvas.Canvas) {
 
 	rectangle := func (x0, y0, x1, y1 int, c color.Color) {
 		area := image.Rect(x0, y0, x1, y1)
-		_, _, _, a := c.RGBA()
-		if a != 0xFFFF && this.parent != nil {
+		if transparent(c) && this.parent != nil {
 			this.parent.drawBackgroundPart(can.Clip(area))
 		}
 		pen.Fill(c)
@@ -428,13 +422,6 @@ func (this *box) boxUnder (point image.Point) anyBox {
 	}
 }
 
-func (this *box) determineFillTransparency () {
-	_, _, _, a := this.color.RGBA()
-	this.fillTransparent =
-		a != 0xFFFF &&
-		!(this.texture != nil && this.texture.Opaque())
-}
-
 func (this *box) propagate (callback func (anyBox) bool) bool {
 	return callback(this.outer)
 }
@@ -442,3 +429,8 @@ func (this *box) propagate (callback func (anyBox) bool) bool {
 func (this *box) propagateAlt (callback func (anyBox) bool) bool {
 	return callback(this.outer)
 }
+
+func (this *box) transparent () bool {
+	return transparent(this.color) &&
+		(this.texture == nil || !this.texture.Opaque())
+}
diff --git a/containerbox.go b/containerbox.go
index 5d8937f..70670c3 100644
--- a/containerbox.go
+++ b/containerbox.go
@@ -134,40 +134,30 @@ func (this *containerBox) Draw (can canvas.Canvas) {
 	if can == nil { return }
 	pen := can.Pen()
 	pen.Fill(this.color)
+	pen.Texture(this.texture)
 
 	rocks := make([]image.Rectangle, len(this.children))
 	for index, box := range this.children {
 		rocks[index] = box.Bounds()
 	}
 	for _, tile := range canvas.Shatter(this.bounds, rocks...) {
-		if this.fillTransparent && this.parent != nil {
+		if this.transparent() && this.parent != nil {
 			this.parent.drawBackgroundPart(can.Clip(tile))
 		}
-		if this.texture == nil || !this.texture.Opaque() {
-			pen.Rectangle(tile)
-		}
-		if this.texture != nil {
-			// TODO draw texture
-		}
+		pen.Rectangle(tile)
 	}
 }
 
 func (this *containerBox) drawBackgroundPart (can canvas.Canvas) {
 	if can == nil { return }
-
-	if this.fillTransparent && this.parent != nil {
-		this.parent.drawBackgroundPart(can)
-	}
-	
 	pen := can.Pen()
 	pen.Fill(this.color)
+	pen.Texture(this.texture)
 	
-	if this.texture == nil || !this.texture.Opaque() {
-		pen.Rectangle(can.Bounds())
-	}
-	if this.texture != nil {
-		// TODO draw texture
+	if this.transparent() && this.parent != nil {
+		this.parent.drawBackgroundPart(can)
 	}
+	pen.Rectangle(can.Bounds())
 }
 
 func (this *containerBox) flushActionQueue () {
diff --git a/textbox.go b/textbox.go
index b98a1c4..7d36dd7 100644
--- a/textbox.go
+++ b/textbox.go
@@ -146,6 +146,11 @@ func (this *textBox) Draw (can canvas.Canvas) {
 	this.drawBorders(can)
 	pen := can.Pen()
 	pen.Fill(this.color)
+	pen.Texture(this.texture)
+	
+	if this.transparent() && this.parent != nil {
+		this.parent.drawBackgroundPart(can)
+	}
 	pen.Rectangle(can.Bounds())
 
 	if this.selectable && this.Focused() {
diff --git a/util.go b/util.go
index 86e1143..9294ce5 100644
--- a/util.go
+++ b/util.go
@@ -1,5 +1,7 @@
 package x
 
+import "image/color"
+
 func indexOf[T comparable] (haystack []T, needle T) int {
 	for index, test := range haystack {
 		if test == needle {
@@ -18,3 +20,8 @@ func insert[T any] (slice []T, index int, element T) []T {
 	slice[index] = element
 	return slice
 }
+
+func transparent (c color.Color) bool {
+	_, _, _, a := c.RGBA()
+	return a != 0xFFFF
+}