added canvas key

ui.go

@@ -1808,6 +1808,9 @@ func main() {
 	)
 
 	right := container.NewMax()
+	legendBar := makeMapLegendBar()
+	rightSplit := container.NewHSplit(right, legendBar)
+	rightSplit.Offset = 0.82
 	var tappableCanvas, tappableHeightmap, tappableBumpmap *tappableImage
 
 	updateRightPanel := func() {
@@ -1862,13 +1865,40 @@ func main() {
 
 	split := container.NewHSplit(
 		left,
-		right,
+		rightSplit,
 	)
 	split.SetOffset(0.3)
 	// Set the window content and start the application
 	w.SetContent(split)
 	w.ShowAndRun()
 }
+func makeMapLegendBar() fyne.CanvasObject {
+	content := container.NewVBox(
+		widget.NewLabelWithStyle("Map Legend", fyne.TextAlignLeading, fyne.TextStyle{Bold: true}),
+		widget.NewSeparator(),
+		makeLegendItem(color.RGBA{R: 34, G: 139, B: 34, A: 255}, "Trees"),
+		makeLegendItem(color.RGBA{R: 128, G: 128, B: 128, A: 255}, "Buildings"),
+		makeLegendItem(color.RGBA{R: 139, G: 69, B: 19, A: 255}, "Roads"),
+		makeLegendItem(color.RGBA{R: 60, G: 42, B: 33, A: 255}, "Bridges"),
+		makeLegendItem(color.RGBA{R: 0, G: 0, B: 0, A: 255}, "Walls"),
+		makeLegendItem(color.RGBA{R: 220, G: 25, B: 25, A: 255}, "Turrets and Gates"),
+		makeLegendItem(color.RGBA{R: 30, G: 90, B: 200, A: 255}, "Water"),
+	)
+	contentWrapper := container.NewPadded(content)
+	contentWrapper.Resize(fyne.NewSize(185, contentWrapper.MinSize().Height))
+	return contentWrapper
+}
+
+func makeLegendItem(swatch color.Color, label string) fyne.CanvasObject {
+	rect := canvas.NewRectangle(swatch)
+	rect.SetMinSize(fyne.NewSize(18, 18))
+	outline := canvas.NewRectangle(color.Transparent)
+	outline.StrokeColor = color.RGBA{R: 50, G: 50, B: 50, A: 255}
+	outline.StrokeWidth = 1
+	outline.SetMinSize(fyne.NewSize(18, 18))
+	return container.NewHBox(container.NewStack(rect, outline), widget.NewLabel(label))
+}
+
 func encodeImageToWriter(w io.Writer, img image.Image, format string) error {
 	switch format {
 	case "PNG":