Add background_color attribute to text display elements

Signed-off-by: Knut Ahlers <knut@ahlers.me>

cmd/streamdeck/config.go

@@ -20,6 +20,7 @@ func init() {
 type attributeCollection struct {
 	AttachStderr    bool              `json:"attach_stderr,omitempty" yaml:"attach_stderr,omitempty"`
 	AttachStdout    bool              `json:"attach_stdout,omitempty" yaml:"attach_stdout,omitempty"`
+	BackgroundColor []int             `json:"background_color,omitempty" yaml:"background_color,omitempty"`
 	Border          *int              `json:"border,omitempty" yaml:"border,omitempty"`
 	Caption         string            `json:"caption,omitempty" yaml:"caption,omitempty"`
 	ChangeVolume    *float64          `json:"change_volume,omitempty" yaml:"change_volume,omitempty"`
@@ -49,6 +50,10 @@ type attributeCollection struct {
 	Wait            bool              `json:"wait,omitempty" yaml:"wait,omitempty"`
 }
 
+func (a attributeCollection) BackgroundToColor() color.RGBA {
+	return a.rgbaToColor(a.BackgroundColor)
+}
+
 func (a attributeCollection) Clone() attributeCollection {
 	var (
 		buf = new(bytes.Buffer)
@@ -62,10 +67,14 @@ func (a attributeCollection) Clone() attributeCollection {
 }
 
 func (a attributeCollection) RGBAToColor() color.RGBA {
-	if len(a.RGBA) != 4 {
+	return a.rgbaToColor(a.RGBA)
+}
+
+func (a attributeCollection) rgbaToColor(src []int) color.RGBA {
+	if len(src) != 4 {
 		return color.RGBA{}
 	}
-	return color.RGBA{uint8(a.RGBA[0]), uint8(a.RGBA[1]), uint8(a.RGBA[2]), uint8(a.RGBA[3])}
+	return color.RGBA{uint8(src[0]), uint8(src[1]), uint8(src[2]), uint8(src[3])}
 }
 
 type config struct {

cmd/streamdeck/display_text.go

@@ -2,11 +2,12 @@ package main
 
 import (
 	"context"
-	"github.com/pkg/errors"
 	"image/color"
 	_ "image/jpeg"
 	_ "image/png"
 	"strings"
+
+	"github.com/pkg/errors"
 )
 
 func init() {
@@ -24,6 +25,19 @@ func (d displayElementText) Display(ctx context.Context, idx int, attributes att
 	)
 
 	// Initialize background
+	if attributes.BackgroundColor != nil {
+		if len(attributes.BackgroundColor) != 4 {
+			return errors.New("Background color definition needs 4 hex values")
+		}
+
+		if err := ctx.Err(); err != nil {
+			// Page context was cancelled, do not draw
+			return err
+		}
+
+		imgRenderer.DrawBackgroundColor(attributes.BackgroundToColor())
+	}
+
 	if attributes.Image != "" {
 		if err = imgRenderer.DrawBackgroundFromFile(attributes.Image); err != nil {
 			return errors.Wrap(err, "Unable to draw background from disk")

cmd/streamdeck/helper_displayText.go

@@ -42,6 +42,18 @@ func (t *textOnImageRenderer) DrawBackground(bgi image.Image) {
 	draw.Draw(t.img, t.img.Bounds(), bgi, image.ZP, draw.Src)
 }
 
+func (t *textOnImageRenderer) DrawBackgroundColor(col color.RGBA) {
+	img := image.NewRGBA(image.Rect(0, 0, sd.IconSize(), sd.IconSize()))
+
+	for x := 0; x < sd.IconSize(); x++ {
+		for y := 0; y < sd.IconSize(); y++ {
+			img.Set(x, y, col)
+		}
+	}
+
+	t.DrawBackground(img)
+}
+
 func (t *textOnImageRenderer) DrawBackgroundFromFile(filename string) error {
 	bgi, err := t.getImageFromDisk(filename)
 	if err != nil {
@@ -70,7 +82,7 @@ func (t *textOnImageRenderer) DrawBigText(text string, fontSizeHint float64, bor
 }
 
 func (t *textOnImageRenderer) DrawCaptionText(text string) error {
-	var fontFile = userConfig.CaptionFont
+	fontFile := userConfig.CaptionFont
 	if fontFile == "" {
 		fontFile = userConfig.RenderFont
 	}
@@ -91,7 +103,7 @@ func (t *textOnImageRenderer) DrawCaptionText(text string) error {
 		}
 	}
 
-	var anchor = textDrawAnchorBottom
+	anchor := textDrawAnchorBottom
 	if userConfig.CaptionPosition == "top" {
 		anchor = textDrawAnchorTop
 	}