Add support for copy-paste via OSC 52

Ref #1754

internal/clipboard/clipboard.go

@@ -0,0 +1,151 @@
+package clipboard
+
+import (
+	"errors"
+
+	"github.com/zyedidia/clipboard"
+)
+
+type Method int
+
+const (
+	// External relies on external tools for accessing the clipboard
+	// These include xclip, xsel, wl-clipboard for linux, pbcopy/pbpaste on Mac,
+	// and Syscalls on Windows.
+	External Method = iota
+	// Terminal uses the terminal to manage the clipboard via OSC 52. Many
+	// terminals do not support OSC 52, in which case this method won't work.
+	Terminal
+	// Internal just manages the clipboard with an internal buffer and doesn't
+	// attempt to interface with the system clipboard
+	Internal
+)
+
+// CurrentMethod is the method used to store clipboard information
+var CurrentMethod Method = Internal
+
+// A Register is a buffer used to store text. The system clipboard has the 'clipboard'
+// and 'primary' (linux-only) registers, but other registers may be used internal to micro.
+type Register int
+
+const (
+	// ClipboardReg is the main system clipboard
+	ClipboardReg Register = -1
+	// PrimaryReg is the system primary clipboard (linux only)
+	PrimaryReg = -2
+)
+
+// Initialize attempts to initialize the clipboard using the given method
+func Initialize(m Method) error {
+	var err error
+	switch m {
+	case External:
+		err = clipboard.Initialize()
+	}
+	return err
+}
+
+// SetMethod changes the clipboard access method
+func SetMethod(m string) Method {
+	switch m {
+	case "internal":
+		CurrentMethod = Internal
+	case "external":
+		CurrentMethod = External
+	case "terminal":
+		CurrentMethod = Terminal
+	}
+	return CurrentMethod
+}
+
+// Read reads from a clipboard register
+func Read(r Register) (string, error) {
+	return read(r, CurrentMethod)
+}
+
+// Write writes text to a clipboard register
+func Write(text string, r Register) error {
+	return write(text, r, CurrentMethod)
+}
+
+// ReadMulti reads text from a clipboard register for a certain multi-cursor
+func ReadMulti(r Register, num int) (string, error) {
+	s := multi.getText(r, num)
+	return s, nil
+}
+
+// WriteMulti writes text to a clipboard register for a certain multi-cursor
+func WriteMulti(text string, r Register, num int) error {
+	return writeMulti(text, r, num, CurrentMethod)
+}
+
+// ValidMulti checks if the internal multi-clipboard is valid and up-to-date
+// with the system clipboard
+func ValidMulti(r Register, ncursors int) bool {
+	clip, err := Read(r)
+	if err != nil {
+		return false
+	}
+	return multi.isValid(r, ncursors, clip)
+}
+
+func writeMulti(text string, r Register, num int, m Method) error {
+	multi.writeText(text, r, num)
+	return write(multi.getAllText(r), r, m)
+}
+
+func read(r Register, m Method) (string, error) {
+	switch m {
+	case External:
+		switch r {
+		case ClipboardReg:
+			return clipboard.ReadAll("clipboard")
+		case PrimaryReg:
+			return clipboard.ReadAll("primary")
+		default:
+			return internal.read(r), nil
+		}
+	case Internal:
+		return internal.read(r), nil
+	case Terminal:
+		switch r {
+		case ClipboardReg:
+			// terminal paste works by sending an esc sequence to the
+			// terminal to trigger a paste event
+			err := terminal.read("clipboard")
+			return "", err
+		case PrimaryReg:
+			err := terminal.read("primary")
+			return "", err
+		default:
+			return internal.read(r), nil
+		}
+	}
+	return "", errors.New("Invalid clipboard method")
+}
+
+func write(text string, r Register, m Method) error {
+	switch m {
+	case External:
+		switch r {
+		case ClipboardReg:
+			return clipboard.WriteAll(text, "clipboard")
+		case PrimaryReg:
+			return clipboard.WriteAll(text, "primary")
+		default:
+			internal.write(text, r)
+		}
+	case Internal:
+		internal.write(text, r)
+	case Terminal:
+		switch r {
+		case ClipboardReg:
+			return terminal.write(text, "c")
+		case PrimaryReg:
+			return terminal.write(text, "p")
+		default:
+			internal.write(text, r)
+		}
+	}
+	return nil
+}