icat kitten: Add a command line argument to override terminal window size detection

Fixes #7165

I had five minutes, so why not.

docs/changelog.rst

@@ -70,6 +70,8 @@ Detailed list of changes
 - hints kitten: The option to set the text color for hints now allows arbitrary
   colors (:pull:`7150`)
 
+- icat kitten: Add a command line argument to override terminal window size detection (:iss:`7165`)
+
 
 0.32.2 [2024-02-12]
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

kittens/icat/main.go

@@ -146,6 +146,7 @@ func main(cmd *cli.Command, o *Options, args []string) (rc int, err error) {
 	if err != nil {
 		return 1, err
 	}
+	if opts.UseWindowSize == "" {
 		if tty.IsTerminal(os.Stdout.Fd()) {
 			screen_size, err = tty.GetSize(int(os.Stdout.Fd()))
 		} else {
@@ -158,6 +159,33 @@ func main(cmd *cli.Command, o *Options, args []string) (rc int, err error) {
 		if err != nil {
 			return 1, fmt.Errorf("Failed to query terminal using TIOCGWINSZ with error: %w", err)
 		}
+	} else {
+		parts := strings.SplitN(opts.UseWindowSize, ",", 4)
+		if len(parts) != 4 {
+			return 1, fmt.Errorf("Invalid size specification: " + opts.UseWindowSize)
+		}
+		screen_size = &unix.Winsize{}
+		t := 0
+		if t, err = strconv.Atoi(parts[0]); err != nil || t < 1 {
+			return 1, fmt.Errorf("Invalid size specification: %s with error: %w", opts.UseWindowSize, err)
+		}
+		screen_size.Col = uint16(t)
+		if t, err = strconv.Atoi(parts[1]); err != nil || t < 1 {
+			return 1, fmt.Errorf("Invalid size specification: %s with error: %w", opts.UseWindowSize, err)
+		}
+		screen_size.Row = uint16(t)
+		if t, err = strconv.Atoi(parts[2]); err != nil || t < 1 {
+			return 1, fmt.Errorf("Invalid size specification: %s with error: %w", opts.UseWindowSize, err)
+		}
+		screen_size.Xpixel = uint16(t)
+		if t, err = strconv.Atoi(parts[3]); err != nil || t < 1 {
+			return 1, fmt.Errorf("Invalid size specification: %s with error: %w", opts.UseWindowSize, err)
+		}
+		screen_size.Ypixel = uint16(t)
+		if screen_size.Xpixel == 0 || screen_size.Ypixel == 0 {
+			return 1, fmt.Errorf("zero is not allowed for screen pixel size")
+		}
+	}
 
 	if opts.PrintWindowSize {
 		fmt.Printf("%dx%d", screen_size.Xpixel, screen_size.Ypixel)

kittens/icat/main.py

@@ -72,6 +72,11 @@ The amount of time (in seconds) to wait for a response from the terminal, when
 detecting image display support.
 
 
+--use-window-size
+Instead of querying the terminal for the window size, use the specified size, which must
+be of the format: width_in_cells,height_in_cells,width_in_pixels,height_in_pixels
+
+
 --print-window-size
 type=bool-set
 Print out the window size as <:italic:`width`>x<:italic:`height`> (in pixels) and quit. This is a