msgview: add copy-link command

Add a command to copy links to the system clipboard. This can be useful
for instance when the URL should be handled in some other way than
opened (e. g. resent via some other communication channel or saved to a
file). It also improves security for situations where it's not desirable
for the URL to be visible on the process command line, such as when it
contains sensitive information such as an access token.

Adapted from open-link.

Changelog-added: If supported by the terminal, links from a message
 can now be copied to the system clipboard with the :copy-link command
 of the message viewer.
Signed-off-by: Karel Balej <[email protected]>
Acked-by: Robin Jarry <[email protected]>

commands/msgview/copy-link.go

@@ -0,0 +1,53 @@
+package msgview
+
+import (
+	"net/url"
+
+	"git.sr.ht/~rjarry/aerc/app"
+	"git.sr.ht/~rjarry/aerc/commands"
+	"git.sr.ht/~rjarry/aerc/lib/ui"
+)
+
+type CopyLink struct {
+	Url *url.URL `opt:"url" action:"ParseUrl" complete:"CompleteUrl"`
+}
+
+func init() {
+	commands.Register(CopyLink{})
+}
+
+func (CopyLink) Description() string {
+	return "Copy the specified URL to the system clipboard."
+}
+
+func (CopyLink) Context() commands.CommandContext {
+	return commands.MESSAGE_VIEWER
+}
+
+func (CopyLink) Aliases() []string {
+	return []string{"copy-link"}
+}
+
+func (*CopyLink) CompleteUrl(arg string) []string {
+	mv := app.SelectedTabContent().(*app.MessageViewer)
+	if mv != nil {
+		if p := mv.SelectedMessagePart(); p != nil {
+			return commands.FilterList(p.Links, arg, nil)
+		}
+	}
+	return nil
+}
+
+func (o *CopyLink) ParseUrl(arg string) error {
+	u, err := url.Parse(arg)
+	if err != nil {
+		return err
+	}
+	o.Url = u
+	return nil
+}
+
+func (o CopyLink) Execute(args []string) error {
+	ui.PushClipboard(o.Url.String())
+	return nil
+}

config/binds.conf

@@ -105,6 +105,7 @@ S = :save<space>
 D = :delete<Enter>
 A = :archive flat<Enter>
 
+<C-y> = :copy-link <space>
 <C-l> = :open-link <space>
 
 f = :forward<Enter>

doc/aerc.1.scd

@@ -815,6 +815,10 @@ message list, the message in the message viewer, etc).
 	  not encountered in the arguments, the temporary filename will be
 	  appended to the end of the command.
 
+*:copy-link* _<url>_
+	Copy the specified URL to the system clipboard. This uses the OSC52
+	escape sequence which must be supported by the terminal.
+
 *:open-link* _<url>_ [_<args...>_]
 	Open the specified URL with an external program. The opening logic is
 	the same than for *:open* but the opener program will be looked up

lib/ui/ui.go

@@ -142,6 +142,10 @@ func QueueRefresh() {
 	}
 }
 
+func PushClipboard(text string) {
+	state.vx.ClipboardPush(text)
+}
+
 func Render() {
 	if atomic.SwapUint32(&state.dirty, 0) != 0 {
 		state.vx.Window().Clear()