From 324ba258ebf23facf34adaeb1a7065841181b809 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Pawe=C5=82=20Gronowski?= <pawel.gronowski@docker.com>
Date: Mon, 19 Aug 2024 12:11:52 +0200
Subject: [PATCH] list/tree: Hide `Used` column if no truthy value
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Don't show the `Used` column in the image tree view when no image is
actually used and the column would be empty.

Signed-off-by: Paweł Gronowski <pawel.gronowski@docker.com>
---
 cli/command/image/tree.go | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/cli/command/image/tree.go b/cli/command/image/tree.go
index a8ecd4fc9e8b..15ea137f3335 100644
--- a/cli/command/image/tree.go
+++ b/cli/command/image/tree.go
@@ -3,6 +3,7 @@ package image
 import (
 	"context"
 	"fmt"
+	"slices"
 	"sort"
 	"strings"
 	"unicode/utf8"
@@ -25,6 +26,9 @@ type treeOptions struct {
 type treeView struct {
 	images []topImage
 
+	// showUsed indicates whether the "Used" column should be shown.
+	showUsed bool
+
 	// imageSpacing indicates whether there should be extra spacing between images.
 	imageSpacing bool
 }
@@ -71,6 +75,9 @@ func runTree(ctx context.Context, dockerCLI command.Cli, opts treeOptions) error
 			if sub.Details.Used {
 				// Mark top-level parent image as used if any of its subimages are used.
 				details.Used = true
+
+				// Show the Used column only if there will be at least one non-zero value.
+				view.showUsed = true
 			}
 
 			totalContent += im.Size.Content
@@ -192,6 +199,12 @@ func printImageTree(dockerCLI command.Cli, view treeView) error {
 		},
 	}
 
+	if !view.showUsed {
+		columns = slices.DeleteFunc(columns, func(c imgColumn) bool {
+			return c.Title == "Used"
+		})
+	}
+
 	nameWidth := int(width)
 	for idx, h := range columns {
 		if h.Width == 0 {