Simplify icat code and write to STDOUT rather than the terminal device

The terminal device is now used only for detection.

tools/cmd/icat/detect.go

@@ -0,0 +1,121 @@
+// License: GPLv3 Copyright: 2023, Kovid Goyal, <kovid at kovidgoyal.net>
+
+package icat
+
+import (
+	"errors"
+	"fmt"
+	"os"
+	"time"
+
+	"kitty/tools/tui/graphics"
+	"kitty/tools/tui/loop"
+	"kitty/tools/utils"
+	"kitty/tools/utils/shm"
+)
+
+var _ = fmt.Print
+
+func DetectSupport(timeout time.Duration) (memory, files, direct bool, err error) {
+	var direct_query_id, file_query_id, memory_query_id uint32
+	lp, e := loop.New(loop.NoAlternateScreen, loop.NoRestoreColors, loop.NoMouseTracking)
+	if e != nil {
+		err = e
+		return
+	}
+	print_error := func(format string, args ...any) {
+		lp.Println(fmt.Sprintf(format, args...))
+	}
+
+	lp.OnInitialize = func() (string, error) {
+		var iid uint32
+		lp.AddTimer(timeout, false, func(loop.IdType) error {
+			return fmt.Errorf("Timed out waiting for a response form the terminal: %w", os.ErrDeadlineExceeded)
+		})
+
+		g := func(t graphics.GRT_t, payload string) uint32 {
+			iid += 1
+			g1 := &graphics.GraphicsCommand{}
+			g1.SetTransmission(t).SetAction(graphics.GRT_action_query).SetImageId(iid).SetDataWidth(1).SetDataHeight(1).SetFormat(
+				graphics.GRT_format_rgb).SetDataSize(uint64(len(payload)))
+			g1.WriteWithPayloadToLoop(lp, utils.UnsafeStringToBytes(payload))
+			return iid
+		}
+
+		direct_query_id = g(graphics.GRT_transmission_direct, "123")
+		tf, err := graphics.CreateTempInRAM()
+		if err == nil {
+			file_query_id = g(graphics.GRT_transmission_tempfile, tf.Name())
+			temp_files_to_delete = append(temp_files_to_delete, tf.Name())
+			tf.Write([]byte{1, 2, 3})
+			tf.Close()
+		} else {
+			print_error("Failed to create temporary file for data transfer, file based transfer is disabled. Error: %v", err)
+		}
+		sf, err := shm.CreateTemp("icat-", 3)
+		if err == nil {
+			memory_query_id = g(graphics.GRT_transmission_sharedmem, sf.Name())
+			shm_files_to_delete = append(shm_files_to_delete, sf)
+			copy(sf.Slice(), []byte{1, 2, 3})
+			sf.Close()
+		} else {
+			var ens *shm.ErrNotSupported
+			if !errors.As(err, &ens) {
+				print_error("Failed to create SHM for data transfer, memory based transfer is disabled. Error: %v", err)
+			}
+		}
+		lp.QueueWriteString("\x1b[c")
+
+		return "", nil
+	}
+
+	lp.OnEscapeCode = func(etype loop.EscapeCodeType, payload []byte) (err error) {
+		switch etype {
+		case loop.CSI:
+			if len(payload) > 3 && payload[0] == '?' && payload[len(payload)-1] == 'c' {
+				lp.Quit(0)
+				return nil
+			}
+		case loop.APC:
+			g := graphics.GraphicsCommandFromAPC(payload)
+			if g != nil {
+				if g.ResponseMessage() == "OK" {
+					switch g.ImageId() {
+					case direct_query_id:
+						direct = true
+					case file_query_id:
+						files = true
+					case memory_query_id:
+						memory = true
+					}
+				}
+				return
+			}
+		}
+		return
+	}
+
+	lp.OnKeyEvent = func(event *loop.KeyEvent) error {
+		if event.MatchesPressOrRepeat("ctrl+c") {
+			event.Handled = true
+			print_error("Waiting for response from terminal, aborting now could lead to corruption")
+		}
+		if event.MatchesPressOrRepeat("ctrl+z") {
+			event.Handled = true
+		}
+		return nil
+	}
+
+	err = lp.Run()
+	if err != nil {
+		return
+	}
+	ds := lp.DeathSignalName()
+	if ds != "" {
+		fmt.Println("Killed by signal: ", ds)
+		lp.KillIfSignalled()
+		return
+	}
+
+	return
+}