Add hotkey to open message's image attachments in feh

config/config.go

@@ -56,6 +56,7 @@ var (
 		ShowUpdateNotifications:                true,
 		IndicateChannelAccessRestriction:       false,
 		ShowBottomBar:                          true,
+		ImageViewer:                            "feh",
 	}
 )
 
@@ -133,6 +134,12 @@ type Config struct {
 	// ShowBottomBar decides whether an informational line is shown at the
 	// bottom of cordless or not.
 	ShowBottomBar bool
+
+	// The image viewer to open when the user uses the "view attached images"
+	// shortcut. This program will be passed a list of 1 or more image links
+	// as if it were called from the command line, so the selected program
+	// must be capable of opening image links.
+	ImageViewer string
 }
 
 // Account has a name and a token. The name is just for the users recognition.

shortcuts/shortcuts.go

@@ -31,6 +31,8 @@ var (
 		chatview, tcell.NewEventKey(tcell.KeyRune, 's', tcell.ModNone))
 	DeleteSelectedMessage = addShortcut("toggle_selected_message_spoilers", "Toggle spoilers in selected message",
 		chatview, tcell.NewEventKey(tcell.KeyDelete, 0, tcell.ModNone))
+	ViewSelectedMessageImages = addShortcut("view_selected_message_images", "View selected message's attached images",
+		chatview, tcell.NewEventKey(tcell.KeyRune, 'o', tcell.ModNone))
 
 	ExpandSelectionToLeft = addShortcut("expand_selection_word_to_left", "Expand selection word to left",
 		multilineTextInput, tcell.NewEventKey(tcell.KeyLeft, 0, tcell.ModShift))

ui/window.go

@@ -7,6 +7,7 @@ import (
 	"strings"
 	"time"
 	"unicode"
+	"os/exec"
 
 	"github.com/mattn/go-runewidth"
 	"github.com/mdp/qrterminal/v3"
@@ -385,6 +386,22 @@ func NewWindow(doRestart chan bool, app *tview.Application, session *discordgo.S
 			return nil
 		}
 
+		if shortcuts.ViewSelectedMessageImages.Equals(event) {
+			links := make([]string, 0, len(message.Attachments))
+			for _, file := range message.Attachments {
+				links = append(links, file.URL)
+			}
+			if len(links) > 0 {
+				cmd := exec.Command(config.Current.ImageViewer, links...)
+				err := cmd.Start()
+				if err != nil {
+					window.ShowErrorDialog(err.Error())
+				}
+			}
+
+			return nil
+		}
+
 		return event
 	})
 	window.messageContainer = window.chatView.GetPrimitive()