Add basic dropdown functionality

src/buffer.go

@@ -68,6 +68,7 @@ func CreateFileBuffer(filename string) (*Buffer, error) {
 	}
 
 	Buffers[buffer.Id] = &buffer
+	LastBufferId++
 
 	return &buffer, nil
 }
@@ -82,6 +83,7 @@ func CreateBuffer(bufferName string) *Buffer {
 	}
 
 	Buffers[buffer.Id] = &buffer
+	LastBufferId++
 
 	return &buffer
 }

src/dropdown.go

@@ -0,0 +1,72 @@
+package main
+
+import (
+	"github.com/gdamore/tcell"
+)
+
+type Dropdown struct {
+	Active     bool
+	Selected   int
+	Options    []string
+	PosX, PosY int
+	Width      int
+	Action     func(int)
+}
+
+var dropdowns = make([]*Dropdown, 0)
+
+func CreateDropdownMenu(options []string, posX, posY, dropdownWidth int, action func(int)) *Dropdown {
+	if len(options) == 0 {
+		return nil
+	}
+
+	width := 0
+
+	if dropdownWidth <= 0 {
+		for _, option := range options {
+			if len(option) > width {
+				width = len(option)
+			}
+		}
+	}
+
+	d := &Dropdown{
+		Active:   false,
+		Selected: 0,
+		Options:  options,
+		PosX:     posX,
+		PosY:     posY,
+		Width:    width,
+		Action:   action,
+	}
+
+	dropdowns = append(dropdowns, d)
+
+	return d
+}
+
+func GetActiveDropdown() *Dropdown {
+	for _, dropdown := range dropdowns {
+		if dropdown.Active {
+			return dropdown
+		}
+	}
+	return nil
+}
+
+func drawDropdowns(window *Window) {
+	dropdownStyle := tcell.StyleDefault.Foreground(tcell.ColorBlack).Background(tcell.ColorWhite)
+	for _, d := range dropdowns {
+		drawBox(window.screen, d.PosX, d.PosY, d.PosX+d.Width+1, d.PosY+len(d.Options)+1, dropdownStyle)
+		line := d.PosY
+		for i, option := range d.Options {
+			if d.Selected == i {
+				drawText(window.screen, d.PosX+1, d.PosY+line, d.PosX+d.Width+1, d.PosY+line, dropdownStyle.Background(tcell.Color250), option)
+			} else {
+				drawText(window.screen, d.PosX+1, d.PosY+line, d.PosX+d.Width+1, d.PosY+line, dropdownStyle, option)
+			}
+
+			line++
+		}
+	}
+}

src/main.go

@@ -20,7 +20,7 @@ func main() {
 				PrintMessage(window, "Could not open file: "+file)
 				continue
 			}
-			Buffers[b.Id] = b
+
 			if initialBuffer == nil {
 				initialBuffer = b
 			}
@@ -28,7 +28,6 @@ func main() {
 	}
 
 	if initialBuffer != nil {
-		delete(Buffers, window.textArea.CurrentBuffer.Id)
 		window.textArea.CurrentBuffer = initialBuffer
 	}
 

src/top_menu.go

@@ -1,11 +1,18 @@
 package main
 
 import (
+	"fmt"
 	"github.com/gdamore/tcell"
+	"maps"
+	"slices"
+	"strconv"
+	"strings"
 )
 
 type TopMenuButton struct {
-	Name string
+	Name   string
+	Key    rune
+	Action func(w *Window)
 }
 
 var TopMenuButtons = make([]TopMenuButton, 0)
@@ -14,12 +21,80 @@ func initTopMenu() {
 	// Buttons
 	fileButton := TopMenuButton{
 		Name: "File",
+		Key:  'f',
+		Action: func(window *Window) {
+			dropdowns = make([]*Dropdown, 0)
+			d := CreateDropdownMenu([]string{"New", "Save", "Open", "Close", "Quit"}, 0, 1, 0, func(i int) {
+				switch i {
+				case 0:
+					number := 1
+					for _, buffer := range Buffers {
+						if strings.HasPrefix(buffer.Name, "New File ") {
+							number++
+						}
+					}
+					buffer := CreateBuffer(fmt.Sprintf("New File %d", number))
+					window.textArea.CurrentBuffer = buffer
+					window.SetCursorPos(0)
+				case 1:
+				case 2:
+				case 3:
+					delete(Buffers, window.textArea.CurrentBuffer.Id)
+					buffersSlice := slices.Collect(maps.Values(Buffers))
+					if len(buffersSlice) == 0 {
+						window.Close()
+						return
+					}
+					window.textArea.CurrentBuffer = buffersSlice[0]
+					window.SetCursorPos(0)
+				case 4:
+					window.Close()
+				}
+				dropdowns = make([]*Dropdown, 0)
+				window.textArea.Typing = true
+			})
+			d.Active = true
+			window.textArea.Typing = false
+		},
 	}
 	EditButton := TopMenuButton{
 		Name: "Edit",
+		Key:  'e',
 	}
 	Buffers := TopMenuButton{
 		Name: "Buffers",
+		Key:  'b',
+		Action: func(window *Window) {
+			dropdowns = make([]*Dropdown, 0)
+			buffersSlice := make([]string, 0)
+			for _, buffer := range Buffers {
+				if window.textArea.CurrentBuffer == buffer {
+					buffersSlice = append(buffersSlice, fmt.Sprintf("[%d] * %s", buffer.Id, buffer.Name))
+				} else {
+					buffersSlice = append(buffersSlice, fmt.Sprintf("[%d] %s", buffer.Id, buffer.Name))
+				}
+			}
+
+			slices.Sort(buffersSlice)
+
+			d := CreateDropdownMenu(buffersSlice, 0, 1, 0, func(i int) {
+				start := strings.Index(buffersSlice[i], "[")
+				end := strings.Index(buffersSlice[i], "]")
+
+				id, err := strconv.Atoi(buffersSlice[i][start+1 : end])
+				if err != nil {
+					PrintMessage(window, fmt.Sprintf("Cannot convert buffer id '%s' to int", buffersSlice[i][start:end]))
+					return
+				}
+
+				window.textArea.CurrentBuffer = Buffers[id]
+				window.SetCursorPos(0)
+				dropdowns = make([]*Dropdown, 0)
+				window.textArea.Typing = true
+			})
+			d.Active = true
+			window.textArea.Typing = false
+		},
 	}
 
 	// Append buttons

src/utils.go

@@ -17,3 +17,39 @@ func drawText(s tcell.Screen, x1, y1, x2, y2 int, style tcell.Style, text string
 		}
 	}
 }
+
+func drawBox(s tcell.Screen, x1, y1, x2, y2 int, style tcell.Style) {
+	if y2 < y1 {
+		y1, y2 = y2, y1
+	}
+	if x2 < x1 {
+		x1, x2 = x2, x1
+	}
+
+	// Fill background
+	for row := y1; row <= y2; row++ {
+		for col := x1; col <= x2; col++ {
+			s.SetContent(col, row, ' ', nil, style)
+		}
+	}
+
+	// Draw borders
+	for col := x1; col <= x2; col++ {
+		s.SetContent(col, y1, tcell.RuneHLine, nil, style)
+		s.SetContent(col, y2, tcell.RuneHLine, nil, style)
+	}
+	for row := y1 + 1; row < y2; row++ {
+		s.SetContent(x1, row, tcell.RuneVLine, nil, style)
+		s.SetContent(x2, row, tcell.RuneVLine, nil, style)
+	}
+
+	// Only draw corners if necessary
+	if y1 != y2 && x1 != x2 {
+		s.SetContent(x1, y1, tcell.RuneULCorner, nil, style)
+		s.SetContent(x2, y1, tcell.RuneURCorner, nil, style)
+		s.SetContent(x1, y2, tcell.RuneLLCorner, nil, style)
+		s.SetContent(x2, y2, tcell.RuneLRCorner, nil, style)
+	}
+
+	drawText(s, x1+1, y1+1, x2-1, y2-1, style, " ")
+}

src/window.go

@@ -3,6 +3,8 @@ package main
 import (
 	"github.com/gdamore/tcell"
 	"log"
+	"maps"
+	"slices"
 )
 
 type Window struct {
@@ -16,6 +18,7 @@ type Window struct {
 
 type TextArea struct {
 	CursorPos     int
+	Typing        bool
 	CurrentBuffer *Buffer
 }
 
@@ -26,6 +29,7 @@ func CreateWindow() (*Window, error) {
 
 		textArea: TextArea{
 			CursorPos:     0,
+			Typing:        true,
 			CurrentBuffer: nil,
 		},
 
@@ -33,7 +37,7 @@ func CreateWindow() (*Window, error) {
 	}
 
 	// Create empty buffer if nil
-	window.textArea.CurrentBuffer = CreateBuffer("New File")
+	window.textArea.CurrentBuffer = CreateBuffer("New File 1")
 
 	// Create tcell screen
 	screen, err := tcell.NewScreen()
@@ -109,8 +113,15 @@ func (window *Window) Draw() {
 	// Draw message bar
 	drawMessageBar(window)
 
+	// Draw dropdowns
+	drawDropdowns(window)
+
 	// Draw cursor
-	window.screen.ShowCursor(window.GetAbsoluteCursorPos())
+	if window.textArea.Typing {
+		window.screen.ShowCursor(window.GetAbsoluteCursorPos())
+	} else {
+		window.screen.HideCursor()
+	}
 
 	// Update screen
 	window.screen.Show()
@@ -123,46 +134,93 @@ func (window *Window) Draw() {
 	case *tcell.EventResize:
 		window.screen.Sync()
 	case *tcell.EventKey:
-		// Navigation Keys
-		if ev.Key() == tcell.KeyRight {
+		window.input(ev)
+	}
+}
+
+func (window *Window) input(ev *tcell.EventKey) {
+	if ev.Key() == tcell.KeyRight { // Navigation Keys
+		if window.textArea.Typing {
 			window.SetCursorPos(window.textArea.CursorPos + 1)
-		} else if ev.Key() == tcell.KeyLeft {
+		}
+	} else if ev.Key() == tcell.KeyLeft {
+		if window.textArea.Typing {
 			window.SetCursorPos(window.textArea.CursorPos - 1)
-		} else if ev.Key() == tcell.KeyUp {
+		}
+	} else if ev.Key() == tcell.KeyUp {
+		if window.textArea.Typing {
 			x, y := window.GetCursorPos2D()
 			window.SetCursorPos2D(x, y-1)
-		} else if ev.Key() == tcell.KeyDown {
+		} else if GetActiveDropdown() != nil {
+			dropdown := GetActiveDropdown()
+			dropdown.Selected--
+			if dropdown.Selected < 0 {
+				dropdown.Selected = 0
+			}
+		}
+	} else if ev.Key() == tcell.KeyDown {
+		if window.textArea.Typing {
 			x, y := window.GetCursorPos2D()
 			window.SetCursorPos2D(x, y+1)
+		} else if GetActiveDropdown() != nil {
+			dropdown := GetActiveDropdown()
+			dropdown.Selected++
+			if dropdown.Selected >= len(dropdown.Options) {
+				dropdown.Selected = len(dropdown.Options) - 1
+			}
 		}
-
-		// Exit key
-		if ev.Key() == tcell.KeyCtrlC {
+	} else if ev.Key() == tcell.KeyEscape {
+		dropdowns = make([]*Dropdown, 0)
+		window.textArea.Typing = true
+	} else if ev.Key() == tcell.KeyCtrlC { // Close buffer key
+		delete(Buffers, window.textArea.CurrentBuffer.Id)
+		buffersSlice := slices.Collect(maps.Values(Buffers))
+		if len(buffersSlice) == 0 {
 			window.Close()
+			return
+		}
+		window.textArea.CurrentBuffer = buffersSlice[0]
+		window.SetCursorPos(0)
+		dropdowns = make([]*Dropdown, 0)
+		window.textArea.Typing = true
+	} else if ev.Key() == tcell.KeyCtrlQ { // Exit key
+		window.Close()
+	} else if ev.Modifiers()&tcell.ModAlt != 0 { // Menu Bar
+		for _, button := range TopMenuButtons {
+			if ev.Rune() == button.Key {
+				button.Action(window)
+				break
+			}
+		}
+	} else if ev.Key() == tcell.KeyBackspace2 { // Typing
+		str := window.textArea.CurrentBuffer.Contents
+		index := window.textArea.CursorPos
+
+		if index != 0 {
+			str = str[:index-1] + str[index:]
+			window.textArea.CursorPos--
+			window.textArea.CurrentBuffer.Contents = str
+		}
+	} else if ev.Key() == tcell.KeyTab {
+		if GetActiveDropdown() != nil {
+			return
 		}
 
-		// Typing
-		if ev.Key() == tcell.KeyBackspace2 {
-			str := window.textArea.CurrentBuffer.Contents
-			index := window.textArea.CursorPos
+		str := window.textArea.CurrentBuffer.Contents
+		index := window.textArea.CursorPos
 
-			if index != 0 {
-				str = str[:index-1] + str[index:]
-				window.textArea.CursorPos--
-				window.textArea.CurrentBuffer.Contents = str
-			}
-		} else if ev.Key() == tcell.KeyTab {
-			str := window.textArea.CurrentBuffer.Contents
-			index := window.textArea.CursorPos
-
-			if index == len(str) {
-				str += "\t"
-			} else {
-				str = str[:index] + "\t" + str[index:]
-			}
-			window.textArea.CursorPos++
-			window.textArea.CurrentBuffer.Contents = str
-		} else if ev.Key() == tcell.KeyEnter {
+		if index == len(str) {
+			str += "\t"
+		} else {
+			str = str[:index] + "\t" + str[index:]
+		}
+		window.textArea.CursorPos++
+		window.textArea.CurrentBuffer.Contents = str
+	} else if ev.Key() == tcell.KeyEnter {
+		if GetActiveDropdown() != nil {
+			d := GetActiveDropdown()
+			d.Action(d.Selected)
+		} else {
 			str := window.textArea.CurrentBuffer.Contents
 			index := window.textArea.CursorPos
 
@@ -173,18 +231,22 @@ func (window *Window) Draw() {
 			}
 			window.textArea.CursorPos++
 			window.textArea.CurrentBuffer.Contents = str
-		} else if ev.Key() == tcell.KeyRune {
-			str := window.textArea.CurrentBuffer.Contents
-			index := window.textArea.CursorPos
-
-			if index == len(str) {
-				str += string(ev.Rune())
-			} else {
-				str = str[:index] + string(ev.Rune()) + str[index:]
-			}
-			window.textArea.CursorPos++
-			window.textArea.CurrentBuffer.Contents = str
 		}
+	} else if ev.Key() == tcell.KeyRune {
+		if GetActiveDropdown() != nil {
+			return
+		}
+
+		str := window.textArea.CurrentBuffer.Contents
+		index := window.textArea.CursorPos
+
+		if index == len(str) {
+			str += string(ev.Rune())
+		} else {
+			str = str[:index] + string(ev.Rune()) + str[index:]
+		}
+		window.textArea.CursorPos++
+		window.textArea.CurrentBuffer.Contents = str
 	}
 }