Implement copy and pasting

src/buffer.go

@@ -72,10 +72,17 @@ func (buffer *Buffer) GetSelectedText() string {
 	start := buffer.Selection.selectionStart
 	end := buffer.Selection.selectionEnd
 
+	if start >= len(buffer.Contents) {
+		start = len(buffer.Contents) - 1
+	}
+	if end >= len(buffer.Contents) {
+		end = len(buffer.Contents) - 1
+	}
+
 	if start <= end {
-		return buffer.Contents[buffer.Selection.selectionStart : buffer.Selection.selectionEnd+1]
+		return buffer.Contents[start : end+1]
 	} else {
-		return buffer.Contents[buffer.Selection.selectionEnd : buffer.Selection.selectionStart+1]
+		return buffer.Contents[end : start+1]
 	}
 }
 

src/window.go

@@ -3,8 +3,8 @@ package main
 import (
 	"github.com/gdamore/tcell"
 	"log"
-	"maps"
 	"slices"
+	"strings"
 )
 
 type CursorMode uint8
@@ -21,6 +21,8 @@ type Window struct {
 	ShowLineIndex bool
 	CursorMode    CursorMode
 
+	Clipboard string
+
 	CurrentBuffer *Buffer
 
 	screen tcell.Screen
@@ -317,16 +319,32 @@ func (window *Window) input(ev *tcell.EventKey) {
 			ClearDropdowns()
 			window.CursorMode = CursorModeBuffer
 		}
-	} else if ev.Key() == tcell.KeyCtrlC { // Close buffer key
-		delete(Buffers, window.CurrentBuffer.Id)
-		buffersSlice := slices.Collect(maps.Values(Buffers))
-		if len(buffersSlice) == 0 {
-			window.Close()
-			return
+	} else if ev.Key() == tcell.KeyCtrlC { // Copy to clipboard key
+		if window.CursorMode == CursorModeBuffer {
+			if window.CurrentBuffer.Selection == nil {
+				// Copy line
+				_, line := window.GetCursorPos2D()
+				window.Clipboard = strings.SplitAfter(window.CurrentBuffer.Contents, "\n")[line]
+				PrintMessage(window, "Copied line to clipboard.")
+			} else {
+				// Copy selection
+				window.Clipboard = window.CurrentBuffer.GetSelectedText()
+				PrintMessage(window, "Copied selection to clipboard.")
+			}
+		}
+	} else if ev.Key() == tcell.KeyCtrlV { // Paste from clipboard
+		if window.CursorMode == CursorModeBuffer {
+			str := window.CurrentBuffer.Contents
+			index := window.CurrentBuffer.CursorPos
+
+			if index == len(str) {
+				str += window.Clipboard
+			} else {
+				str = str[:index] + window.Clipboard + str[index:]
+			}
+			window.CurrentBuffer.CursorPos += len(window.Clipboard)
+			window.CurrentBuffer.Contents = str
 		}
-		window.CurrentBuffer = buffersSlice[0]
-		ClearDropdowns()
-		window.CursorMode = CursorModeBuffer
 	} else if ev.Key() == tcell.KeyCtrlQ { // Exit key
 		window.Close()
 	} else if ev.Modifiers()&tcell.ModAlt != 0 { // Menu Bar