cmd/micro/view.go

   1 package main
   2
   3 import (
   4         "io/ioutil"
   5         "strconv"
   6         "strings"
   7         "time"
   8
   9         "github.com/mattn/go-runewidth"
  10         "github.com/mitchellh/go-homedir"
  11         "github.com/zyedidia/tcell"
  12 )
  13
  14 type ViewType int
  15
  16 const (
  17         vtDefault ViewType = iota
  18         vtHelp
  19         vtLog
  20 )
  21
  22 // The View struct stores information about a view into a buffer.
  23 // It stores information about the cursor, and the viewport
  24 // that the user sees the buffer from.
  25 type View struct {
  26         // A pointer to the buffer's cursor for ease of access
  27         Cursor *Cursor
  28
  29         // The topmost line, used for vertical scrolling
  30         Topline int
  31         // The leftmost column, used for horizontal scrolling
  32         leftCol int
  33
  34         // Specifies whether or not this view holds a help buffer
  35         Type ViewType
  36
  37         // Actual width and height
  38         width  int
  39         height int
  40
  41         lockWidth  bool
  42         lockHeight bool
  43
  44         // Where this view is located
  45         x, y int
  46
  47         // How much to offset because of line numbers
  48         lineNumOffset int
  49
  50         // Holds the list of gutter messages
  51         messages map[string][]GutterMessage
  52
  53         // This is the index of this view in the views array
  54         Num int
  55         // What tab is this view stored in
  56         TabNum int
  57
  58         // The buffer
  59         Buf *Buffer
  60         // The statusline
  61         sline Statusline
  62
  63         // Since tcell doesn't differentiate between a mouse release event
  64         // and a mouse move event with no keys pressed, we need to keep
  65         // track of whether or not the mouse was pressed (or not released) last event to determine
  66         // mouse release events
  67         mouseReleased bool
  68
  69         // This stores when the last click was
  70         // This is useful for detecting double and triple clicks
  71         lastClickTime time.Time
  72
  73         // lastCutTime stores when the last ctrl+k was issued.
  74         // It is used for clearing the clipboard to replace it with fresh cut lines.
  75         lastCutTime time.Time
  76
  77         // freshClip returns true if the clipboard has never been pasted.
  78         freshClip bool
  79
  80         // Was the last mouse event actually a double click?
  81         // Useful for detecting triple clicks -- if a double click is detected
  82         // but the last mouse event was actually a double click, it's a triple click
  83         doubleClick bool
  84         // Same here, just to keep track for mouse move events
  85         tripleClick bool
  86
  87         // Syntax highlighting matches
  88         matches SyntaxMatches
  89
  90         splitNode *LeafNode
  91 }
  92
  93 // NewView returns a new fullscreen view
  94 func NewView(buf *Buffer) *View {
  95         screenW, screenH := screen.Size()
  96         return NewViewWidthHeight(buf, screenW, screenH)
  97 }
  98
  99 // NewViewWidthHeight returns a new view with the specified width and height
 100 // Note that w and h are raw column and row values
 101 func NewViewWidthHeight(buf *Buffer, w, h int) *View {
 102         v := new(View)
 103
 104         v.x, v.y = 0, 0
 105
 106         v.width = w
 107         v.height = h
 108
 109         v.ToggleTabbar()
 110
 111         v.OpenBuffer(buf)
 112
 113         v.messages = make(map[string][]GutterMessage)
 114
 115         v.sline = Statusline{
 116                 view: v,
 117         }
 118
 119         if v.Buf.Settings["statusline"].(bool) {
 120                 v.height--
 121         }
 122
 123         for _, pl := range loadedPlugins {
 124                 _, err := Call(pl+".onViewOpen", v)
 125                 if err != nil && !strings.HasPrefix(err.Error(), "function does not exist") {
 126                         TermMessage(err)
 127                         continue
 128                 }
 129         }
 130
 131         return v
 132 }
 133
 134 // ToggleStatusLine creates an extra row for the statusline if necessary
 135 func (v *View) ToggleStatusLine() {
 136         if v.Buf.Settings["statusline"].(bool) {
 137                 v.height--
 138         } else {
 139                 v.height++
 140         }
 141 }
 142
 143 // ToggleTabbar creates an extra row for the tabbar if necessary
 144 func (v *View) ToggleTabbar() {
 145         if len(tabs) > 1 {
 146                 if v.y == 0 {
 147                         // Include one line for the tab bar at the top
 148                         v.height--
 149                         v.y = 1
 150                 }
 151         } else {
 152                 if v.y == 1 {
 153                         v.y = 0
 154                         v.height++
 155                 }
 156         }
 157 }
 158
 159 func (v *View) paste(clip string) {
 160         leadingWS := GetLeadingWhitespace(v.Buf.Line(v.Cursor.Y))
 161
 162         if v.Cursor.HasSelection() {
 163                 v.Cursor.DeleteSelection()
 164                 v.Cursor.ResetSelection()
 165         }
 166         clip = strings.Replace(clip, "\n", "\n"+leadingWS, -1)
 167         v.Buf.Insert(v.Cursor.Loc, clip)
 168         v.Cursor.Loc = v.Cursor.Loc.Move(Count(clip), v.Buf)
 169         v.freshClip = false
 170         messenger.Message("Pasted clipboard")
 171 }
 172
 173 // ScrollUp scrolls the view up n lines (if possible)
 174 func (v *View) ScrollUp(n int) {
 175         // Try to scroll by n but if it would overflow, scroll by 1
 176         if v.Topline-n >= 0 {
 177                 v.Topline -= n
 178         } else if v.Topline > 0 {
 179                 v.Topline--
 180         }
 181 }
 182
 183 // ScrollDown scrolls the view down n lines (if possible)
 184 func (v *View) ScrollDown(n int) {
 185         // Try to scroll by n but if it would overflow, scroll by 1
 186         if v.Topline+n <= v.Buf.NumLines-v.height {
 187                 v.Topline += n
 188         } else if v.Topline < v.Buf.NumLines-v.height {
 189                 v.Topline++
 190         }
 191 }
 192
 193 // CanClose returns whether or not the view can be closed
 194 // If there are unsaved changes, the user will be asked if the view can be closed
 195 // causing them to lose the unsaved changes
 196 func (v *View) CanClose() bool {
 197         if v.Type == vtDefault && v.Buf.IsModified {
 198                 var char rune
 199                 var canceled bool
 200                 if v.Buf.Settings["autosave"].(bool) {
 201                         char = 'y'
 202                 } else {
 203                         char, canceled = messenger.LetterPrompt("Save changes to "+v.Buf.GetName()+" before closing? (y,n,esc) ", 'y', 'n')
 204                 }
 205                 if !canceled {
 206                         if char == 'y' {
 207                                 v.Save(true)
 208                                 return true
 209                         } else if char == 'n' {
 210                                 return true
 211                         }
 212                 }
 213         } else {
 214                 return true
 215         }
 216         return false
 217 }
 218
 219 // OpenBuffer opens a new buffer in this view.
 220 // This resets the topline, event handler and cursor.
 221 func (v *View) OpenBuffer(buf *Buffer) {
 222         screen.Clear()
 223         v.CloseBuffer()
 224         v.Buf = buf
 225         v.Cursor = &buf.Cursor
 226         v.Topline = 0
 227         v.leftCol = 0
 228         v.Cursor.ResetSelection()
 229         v.Relocate()
 230         v.Center(false)
 231         v.messages = make(map[string][]GutterMessage)
 232
 233         v.matches = Match(v)
 234
 235         // Set mouseReleased to true because we assume the mouse is not being pressed when
 236         // the editor is opened
 237         v.mouseReleased = true
 238         v.lastClickTime = time.Time{}
 239 }
 240
 241 // Open opens the given file in the view
 242 func (v *View) Open(filename string) {
 243         home, _ := homedir.Dir()
 244         filename = strings.Replace(filename, "~", home, 1)
 245         file, err := ioutil.ReadFile(filename)
 246
 247         var buf *Buffer
 248         if err != nil {
 249                 messenger.Message(err.Error())
 250                 // File does not exist -- create an empty buffer with that name
 251                 buf = NewBuffer([]byte{}, filename)
 252         } else {
 253                 buf = NewBuffer(file, filename)
 254         }
 255         v.OpenBuffer(buf)
 256 }
 257
 258 // CloseBuffer performs any closing functions on the buffer
 259 func (v *View) CloseBuffer() {
 260         if v.Buf != nil {
 261                 v.Buf.Serialize()
 262         }
 263 }
 264
 265 // ReOpen reloads the current buffer
 266 func (v *View) ReOpen() {
 267         if v.CanClose() {
 268                 screen.Clear()
 269                 v.Buf.ReOpen()
 270                 v.Relocate()
 271                 v.matches = Match(v)
 272         }
 273 }
 274
 275 // HSplit opens a horizontal split with the given buffer
 276 func (v *View) HSplit(buf *Buffer) bool {
 277         v.splitNode.HSplit(buf, v.Buf.Settings["splitRight"].(bool))
 278         return false
 279 }
 280
 281 // VSplit opens a vertical split with the given buffer
 282 func (v *View) VSplit(buf *Buffer) bool {
 283         v.splitNode.VSplit(buf, v.Buf.Settings["splitBottom"].(bool))
 284         return false
 285 }
 286
 287 // GetSoftWrapLocation gets the location of a visual click on the screen and converts it to col,line
 288 func (v *View) GetSoftWrapLocation(vx, vy int) (int, int) {
 289         if !v.Buf.Settings["softwrap"].(bool) {
 290                 vx = v.Cursor.GetCharPosInLine(vy, vx)
 291                 return vx, vy
 292         }
 293
 294         screenX, screenY := 0, v.Topline
 295         for lineN := v.Topline; lineN < v.Bottomline(); lineN++ {
 296                 line := v.Buf.Line(lineN)
 297
 298                 colN := 0
 299                 for _, ch := range line {
 300                         if screenX >= v.width-v.lineNumOffset {
 301                                 screenX = 0
 302                                 screenY++
 303                         }
 304
 305                         if screenX == vx && screenY == vy {
 306                                 return colN, lineN
 307                         }
 308
 309                         if ch == '\t' {
 310                                 screenX += int(v.Buf.Settings["tabsize"].(float64)) - 1
 311                         }
 312
 313                         screenX++
 314                         colN++
 315                 }
 316                 if screenY == vy {
 317                         return colN, lineN
 318                 }
 319                 screenX = 0
 320                 screenY++
 321         }
 322
 323         return 0, 0
 324 }
 325
 326 func (v *View) Bottomline() int {
 327         if !v.Buf.Settings["softwrap"].(bool) {
 328                 return v.Topline + v.height
 329         }
 330
 331         screenX, screenY := 0, 0
 332         numLines := 0
 333         for lineN := v.Topline; lineN < v.Topline+v.height; lineN++ {
 334                 line := v.Buf.Line(lineN)
 335
 336                 colN := 0
 337                 for _, ch := range line {
 338                         if screenX >= v.width-v.lineNumOffset {
 339                                 screenX = 0
 340                                 screenY++
 341                         }
 342
 343                         if ch == '\t' {
 344                                 screenX += int(v.Buf.Settings["tabsize"].(float64)) - 1
 345                         }
 346
 347                         screenX++
 348                         colN++
 349                 }
 350                 screenX = 0
 351                 screenY++
 352                 numLines++
 353
 354                 if screenY >= v.height {
 355                         break
 356                 }
 357         }
 358         return numLines + v.Topline
 359 }
 360
 361 // Relocate moves the view window so that the cursor is in view
 362 // This is useful if the user has scrolled far away, and then starts typing
 363 func (v *View) Relocate() bool {
 364         height := v.Bottomline() - v.Topline
 365         ret := false
 366         cy := v.Cursor.Y
 367         scrollmargin := int(v.Buf.Settings["scrollmargin"].(float64))
 368         if cy < v.Topline+scrollmargin && cy > scrollmargin-1 {
 369                 v.Topline = cy - scrollmargin
 370                 ret = true
 371         } else if cy < v.Topline {
 372                 v.Topline = cy
 373                 ret = true
 374         }
 375         if cy > v.Topline+height-1-scrollmargin && cy < v.Buf.NumLines-scrollmargin {
 376                 v.Topline = cy - height + 1 + scrollmargin
 377                 ret = true
 378         } else if cy >= v.Buf.NumLines-scrollmargin && cy > height {
 379                 v.Topline = v.Buf.NumLines - height
 380                 ret = true
 381         }
 382
 383         if !v.Buf.Settings["softwrap"].(bool) {
 384                 cx := v.Cursor.GetVisualX()
 385                 if cx < v.leftCol {
 386                         v.leftCol = cx
 387                         ret = true
 388                 }
 389                 if cx+v.lineNumOffset+1 > v.leftCol+v.width {
 390                         v.leftCol = cx - v.width + v.lineNumOffset + 1
 391                         ret = true
 392                 }
 393         }
 394         return ret
 395 }
 396
 397 // MoveToMouseClick moves the cursor to location x, y assuming x, y were given
 398 // by a mouse click
 399 func (v *View) MoveToMouseClick(x, y int) {
 400         if y-v.Topline > v.height-1 {
 401                 v.ScrollDown(1)
 402                 y = v.height + v.Topline - 1
 403         }
 404         if y >= v.Buf.NumLines {
 405                 y = v.Buf.NumLines - 1
 406         }
 407         if y < 0 {
 408                 y = 0
 409         }
 410         if x < 0 {
 411                 x = 0
 412         }
 413
 414         x, y = v.GetSoftWrapLocation(x, y)
 415         // x = v.Cursor.GetCharPosInLine(y, x)
 416         if x > Count(v.Buf.Line(y)) {
 417                 x = Count(v.Buf.Line(y))
 418         }
 419         v.Cursor.X = x
 420         v.Cursor.Y = y
 421         v.Cursor.LastVisualX = v.Cursor.GetVisualX()
 422 }
 423
 424 // HandleEvent handles an event passed by the main loop
 425 func (v *View) HandleEvent(event tcell.Event) {
 426         // This bool determines whether the view is relocated at the end of the function
 427         // By default it's true because most events should cause a relocate
 428         relocate := true
 429
 430         v.Buf.CheckModTime()
 431
 432         switch e := event.(type) {
 433         case *tcell.EventResize:
 434                 // Window resized
 435                 tabs[v.TabNum].Resize()
 436         case *tcell.EventKey:
 437                 // Check first if input is a key binding, if it is we 'eat' the input and don't insert a rune
 438                 isBinding := false
 439                 if e.Key() != tcell.KeyRune || e.Modifiers() != 0 {
 440                         for key, actions := range bindings {
 441                                 if e.Key() == key.keyCode {
 442                                         if e.Key() == tcell.KeyRune {
 443                                                 if e.Rune() != key.r {
 444                                                         continue
 445                                                 }
 446                                         }
 447                                         if e.Modifiers() == key.modifiers {
 448                                                 relocate = false
 449                                                 isBinding = true
 450                                                 for _, action := range actions {
 451                                                         relocate = action(v, true) || relocate
 452                                                         funcName := FuncName(action)
 453                                                         if funcName != "main.(*View).ToggleMacro" && funcName != "main.(*View).PlayMacro" {
 454                                                                 if recordingMacro {
 455                                                                         curMacro = append(curMacro, action)
 456                                                                 }
 457                                                         }
 458                                                 }
 459                                                 break
 460                                         }
 461                                 }
 462                         }
 463                 }
 464                 if !isBinding && e.Key() == tcell.KeyRune {
 465                         // Insert a character
 466                         if v.Cursor.HasSelection() {
 467                                 v.Cursor.DeleteSelection()
 468                                 v.Cursor.ResetSelection()
 469                         }
 470                         v.Buf.Insert(v.Cursor.Loc, string(e.Rune()))
 471                         v.Cursor.Right()
 472
 473                         for _, pl := range loadedPlugins {
 474                                 _, err := Call(pl+".onRune", string(e.Rune()), v)
 475                                 if err != nil && !strings.HasPrefix(err.Error(), "function does not exist") {
 476                                         TermMessage(err)
 477                                 }
 478                         }
 479
 480                         if recordingMacro {
 481                                 curMacro = append(curMacro, e.Rune())
 482                         }
 483                 }
 484         case *tcell.EventPaste:
 485                 if !PreActionCall("Paste", v) {
 486                         break
 487                 }
 488
 489                 v.paste(e.Text())
 490
 491                 PostActionCall("Paste", v)
 492         case *tcell.EventMouse:
 493                 x, y := e.Position()
 494                 x -= v.lineNumOffset - v.leftCol + v.x
 495                 y += v.Topline - v.y
 496                 // Don't relocate for mouse events
 497                 relocate = false
 498
 499                 button := e.Buttons()
 500
 501                 switch button {
 502                 case tcell.Button1:
 503                         // Left click
 504                         if v.mouseReleased {
 505                                 v.MoveToMouseClick(x, y)
 506                                 if time.Since(v.lastClickTime)/time.Millisecond < doubleClickThreshold {
 507                                         if v.doubleClick {
 508                                                 // Triple click
 509                                                 v.lastClickTime = time.Now()
 510
 511                                                 v.tripleClick = true
 512                                                 v.doubleClick = false
 513
 514                                                 v.Cursor.SelectLine()
 515                                         } else {
 516                                                 // Double click
 517                                                 v.lastClickTime = time.Now()
 518
 519                                                 v.doubleClick = true
 520                                                 v.tripleClick = false
 521
 522                                                 v.Cursor.SelectWord()
 523                                         }
 524                                 } else {
 525                                         v.doubleClick = false
 526                                         v.tripleClick = false
 527                                         v.lastClickTime = time.Now()
 528
 529                                         v.Cursor.OrigSelection[0] = v.Cursor.Loc
 530                                         v.Cursor.CurSelection[0] = v.Cursor.Loc
 531                                         v.Cursor.CurSelection[1] = v.Cursor.Loc
 532                                 }
 533                                 v.mouseReleased = false
 534                         } else if !v.mouseReleased {
 535                                 v.MoveToMouseClick(x, y)
 536                                 if v.tripleClick {
 537                                         v.Cursor.AddLineToSelection()
 538                                 } else if v.doubleClick {
 539                                         v.Cursor.AddWordToSelection()
 540                                 } else {
 541                                         v.Cursor.SetSelectionEnd(v.Cursor.Loc)
 542                                 }
 543                         }
 544                 case tcell.Button2:
 545                         // Middle mouse button was clicked,
 546                         // We should paste primary
 547                         v.PastePrimary(true)
 548                 case tcell.ButtonNone:
 549                         // Mouse event with no click
 550                         if !v.mouseReleased {
 551                                 // Mouse was just released
 552
 553                                 // Relocating here isn't really necessary because the cursor will
 554                                 // be in the right place from the last mouse event
 555                                 // However, if we are running in a terminal that doesn't support mouse motion
 556                                 // events, this still allows the user to make selections, except only after they
 557                                 // release the mouse
 558
 559                                 if !v.doubleClick && !v.tripleClick {
 560                                         v.MoveToMouseClick(x, y)
 561                                         v.Cursor.SetSelectionEnd(v.Cursor.Loc)
 562                                 }
 563                                 v.mouseReleased = true
 564                         }
 565                 case tcell.WheelUp:
 566                         // Scroll up
 567                         scrollspeed := int(v.Buf.Settings["scrollspeed"].(float64))
 568                         v.ScrollUp(scrollspeed)
 569                 case tcell.WheelDown:
 570                         // Scroll down
 571                         scrollspeed := int(v.Buf.Settings["scrollspeed"].(float64))
 572                         v.ScrollDown(scrollspeed)
 573                 }
 574         }
 575
 576         if relocate {
 577                 v.Relocate()
 578         }
 579 }
 580
 581 // GutterMessage creates a message in this view's gutter
 582 func (v *View) GutterMessage(section string, lineN int, msg string, kind int) {
 583         lineN--
 584         gutterMsg := GutterMessage{
 585                 lineNum: lineN,
 586                 msg:     msg,
 587                 kind:    kind,
 588         }
 589         for _, v := range v.messages {
 590                 for _, gmsg := range v {
 591                         if gmsg.lineNum == lineN {
 592                                 return
 593                         }
 594                 }
 595         }
 596         messages := v.messages[section]
 597         v.messages[section] = append(messages, gutterMsg)
 598 }
 599
 600 // ClearGutterMessages clears all gutter messages from a given section
 601 func (v *View) ClearGutterMessages(section string) {
 602         v.messages[section] = []GutterMessage{}
 603 }
 604
 605 // ClearAllGutterMessages clears all the gutter messages
 606 func (v *View) ClearAllGutterMessages() {
 607         for k := range v.messages {
 608                 v.messages[k] = []GutterMessage{}
 609         }
 610 }
 611
 612 // Opens the given help page in a new horizontal split
 613 func (v *View) openHelp(helpPage string) {
 614         if data, err := FindRuntimeFile(RTHelp, helpPage).Data(); err != nil {
 615                 TermMessage("Unable to load help text", helpPage, "\n", err)
 616         } else {
 617                 helpBuffer := NewBuffer(data, helpPage+".md")
 618                 helpBuffer.name = "Help"
 619
 620                 if v.Type == vtHelp {
 621                         v.OpenBuffer(helpBuffer)
 622                 } else {
 623                         v.HSplit(helpBuffer)
 624                         CurView().Type = vtHelp
 625                 }
 626         }
 627 }
 628
 629 func (v *View) drawCell(x, y int, ch rune, combc []rune, style tcell.Style) {
 630         if x >= v.x && x < v.x+v.width && y >= v.y && y < v.y+v.height {
 631                 screen.SetContent(x, y, ch, combc, style)
 632         }
 633 }
 634
 635 // DisplayView renders the view to the screen
 636 func (v *View) DisplayView() {
 637         if v.Type == vtLog {
 638                 // Log views should always follow the cursor...
 639                 v.Relocate()
 640         }
 641
 642         if v.Buf.Settings["syntax"].(bool) {
 643                 v.matches = Match(v)
 644         }
 645
 646         // The charNum we are currently displaying
 647         // starts at the start of the viewport
 648         charNum := Loc{0, v.Topline}
 649
 650         // Convert the length of buffer to a string, and get the length of the string
 651         // We are going to have to offset by that amount
 652         maxLineLength := len(strconv.Itoa(v.Buf.NumLines))
 653
 654         if v.Buf.Settings["ruler"] == true {
 655                 // + 1 for the little space after the line number
 656                 v.lineNumOffset = maxLineLength + 1
 657         } else {
 658                 v.lineNumOffset = 0
 659         }
 660
 661         // We need to add to the line offset if there are gutter messages
 662         var hasGutterMessages bool
 663         for _, v := range v.messages {
 664                 if len(v) > 0 {
 665                         hasGutterMessages = true
 666                 }
 667         }
 668         if hasGutterMessages {
 669                 v.lineNumOffset += 2
 670         }
 671
 672         if v.x != 0 {
 673                 // One space for the extra split divider
 674                 v.lineNumOffset++
 675         }
 676
 677         // These represent the current screen coordinates
 678         screenX, screenY := v.x, v.y-1
 679
 680         highlightStyle := defStyle
 681         curLineN := 0
 682
 683         // ViewLine is the current line from the top of the viewport
 684         for viewLine := 0; viewLine < v.height; viewLine++ {
 685                 screenY++
 686                 screenX = v.x
 687
 688                 // This is the current line number of the buffer that we are drawing
 689                 curLineN = viewLine + v.Topline
 690
 691                 if screenY-v.y >= v.height {
 692                         break
 693                 }
 694
 695                 if v.x != 0 {
 696                         // Draw the split divider
 697                         v.drawCell(screenX, screenY, '|', nil, defStyle.Reverse(true))
 698                         screenX++
 699                 }
 700
 701                 // If the buffer is smaller than the view height we have to clear all this space
 702                 if curLineN >= v.Buf.NumLines {
 703                         for i := screenX; i < v.x+v.width; i++ {
 704                                 v.drawCell(i, screenY, ' ', nil, defStyle)
 705                         }
 706
 707                         continue
 708                 }
 709                 line := v.Buf.Line(curLineN)
 710
 711                 // If there are gutter messages we need to display the '>>' symbol here
 712                 if hasGutterMessages {
 713                         // msgOnLine stores whether or not there is a gutter message on this line in particular
 714                         msgOnLine := false
 715                         for k := range v.messages {
 716                                 for _, msg := range v.messages[k] {
 717                                         if msg.lineNum == curLineN {
 718                                                 msgOnLine = true
 719                                                 gutterStyle := defStyle
 720                                                 switch msg.kind {
 721                                                 case GutterInfo:
 722                                                         if style, ok := colorscheme["gutter-info"]; ok {
 723                                                                 gutterStyle = style
 724                                                         }
 725                                                 case GutterWarning:
 726                                                         if style, ok := colorscheme["gutter-warning"]; ok {
 727                                                                 gutterStyle = style
 728                                                         }
 729                                                 case GutterError:
 730                                                         if style, ok := colorscheme["gutter-error"]; ok {
 731                                                                 gutterStyle = style
 732                                                         }
 733                                                 }
 734                                                 v.drawCell(screenX, screenY, '>', nil, gutterStyle)
 735                                                 screenX++
 736                                                 v.drawCell(screenX, screenY, '>', nil, gutterStyle)
 737                                                 screenX++
 738                                                 if v.Cursor.Y == curLineN && !messenger.hasPrompt {
 739                                                         messenger.Message(msg.msg)
 740                                                         messenger.gutterMessage = true
 741                                                 }
 742                                         }
 743                                 }
 744                         }
 745                         // If there is no message on this line we just display an empty offset
 746                         if !msgOnLine {
 747                                 v.drawCell(screenX, screenY, ' ', nil, defStyle)
 748                                 screenX++
 749                                 v.drawCell(screenX, screenY, ' ', nil, defStyle)
 750                                 screenX++
 751                                 if v.Cursor.Y == curLineN && messenger.gutterMessage {
 752                                         messenger.Reset()
 753                                         messenger.gutterMessage = false
 754                                 }
 755                         }
 756                 }
 757
 758                 lineNumStyle := defStyle
 759                 if v.Buf.Settings["ruler"] == true {
 760                         // Write the line number
 761                         if style, ok := colorscheme["line-number"]; ok {
 762                                 lineNumStyle = style
 763                         }
 764                         if style, ok := colorscheme["current-line-number"]; ok {
 765                                 if curLineN == v.Cursor.Y && tabs[curTab].curView == v.Num && !v.Cursor.HasSelection() {
 766                                         lineNumStyle = style
 767                                 }
 768                         }
 769
 770                         lineNum := strconv.Itoa(curLineN + 1)
 771
 772                         // Write the spaces before the line number if necessary
 773                         for i := 0; i < maxLineLength-len(lineNum); i++ {
 774                                 v.drawCell(screenX, screenY, ' ', nil, lineNumStyle)
 775                                 screenX++
 776                         }
 777                         // Write the actual line number
 778                         for _, ch := range lineNum {
 779                                 v.drawCell(screenX, screenY, ch, nil, lineNumStyle)
 780                                 screenX++
 781                         }
 782
 783                         // Write the extra space
 784                         v.drawCell(screenX, screenY, ' ', nil, lineNumStyle)
 785                         screenX++
 786                 }
 787
 788                 // Now we actually draw the line
 789                 colN := 0
 790                 strWidth := 0
 791                 tabSize := int(v.Buf.Settings["tabsize"].(float64))
 792                 for _, ch := range line {
 793                         if v.Buf.Settings["softwrap"].(bool) {
 794                                 if screenX-v.x >= v.width {
 795                                         screenY++
 796                                         for i := 0; i < v.lineNumOffset; i++ {
 797                                                 screen.SetContent(v.x+i, screenY, ' ', nil, lineNumStyle)
 798                                         }
 799                                         screenX = v.x + v.lineNumOffset
 800                                 }
 801                         }
 802
 803                         if tabs[curTab].curView == v.Num && !v.Cursor.HasSelection() && v.Cursor.Y == curLineN && colN == v.Cursor.X {
 804                                 v.DisplayCursor(screenX-v.leftCol, screenY)
 805                         }
 806
 807                         lineStyle := defStyle
 808
 809                         if v.Buf.Settings["syntax"].(bool) {
 810                                 // Syntax highlighting is enabled
 811                                 highlightStyle = v.matches[viewLine][colN]
 812                         }
 813
 814                         if v.Cursor.HasSelection() &&
 815                                 (charNum.GreaterEqual(v.Cursor.CurSelection[0]) && charNum.LessThan(v.Cursor.CurSelection[1]) ||
 816                                         charNum.LessThan(v.Cursor.CurSelection[0]) && charNum.GreaterEqual(v.Cursor.CurSelection[1])) {
 817                                 // The current character is selected
 818                                 lineStyle = defStyle.Reverse(true)
 819
 820                                 if style, ok := colorscheme["selection"]; ok {
 821                                         lineStyle = style
 822                                 }
 823                         } else {
 824                                 lineStyle = highlightStyle
 825                         }
 826
 827                         // We need to display the background of the linestyle with the correct color if cursorline is enabled
 828                         // and this is the current view and there is no selection on this line and the cursor is on this line
 829                         if v.Buf.Settings["cursorline"].(bool) && tabs[curTab].curView == v.Num && !v.Cursor.HasSelection() && v.Cursor.Y == curLineN {
 830                                 if style, ok := colorscheme["cursor-line"]; ok {
 831                                         fg, _, _ := style.Decompose()
 832                                         lineStyle = lineStyle.Background(fg)
 833                                 }
 834                         }
 835
 836                         if ch == '\t' {
 837                                 // If the character we are displaying is a tab, we need to do a bunch of special things
 838
 839                                 // First the user may have configured an `indent-char` to be displayed to show that this
 840                                 // is a tab character
 841                                 lineIndentStyle := defStyle
 842                                 if style, ok := colorscheme["indent-char"]; ok && v.Buf.Settings["indentchar"].(string) != " " {
 843                                         lineIndentStyle = style
 844                                 }
 845                                 if v.Cursor.HasSelection() &&
 846                                         (charNum.GreaterEqual(v.Cursor.CurSelection[0]) && charNum.LessThan(v.Cursor.CurSelection[1]) ||
 847                                                 charNum.LessThan(v.Cursor.CurSelection[0]) && charNum.GreaterEqual(v.Cursor.CurSelection[1])) {
 848
 849                                         lineIndentStyle = defStyle.Reverse(true)
 850
 851                                         if style, ok := colorscheme["selection"]; ok {
 852                                                 lineIndentStyle = style
 853                                         }
 854                                 }
 855                                 if v.Buf.Settings["cursorline"].(bool) && tabs[curTab].curView == v.Num && !v.Cursor.HasSelection() && v.Cursor.Y == curLineN {
 856                                         if style, ok := colorscheme["cursor-line"]; ok {
 857                                                 fg, _, _ := style.Decompose()
 858                                                 lineIndentStyle = lineIndentStyle.Background(fg)
 859                                         }
 860                                 }
 861                                 // Here we get the indent char
 862                                 indentChar := []rune(v.Buf.Settings["indentchar"].(string))
 863                                 if screenX-v.x-v.leftCol >= v.lineNumOffset {
 864                                         v.drawCell(screenX-v.leftCol, screenY, indentChar[0], nil, lineIndentStyle)
 865                                 }
 866                                 // Now the tab has to be displayed as a bunch of spaces
 867                                 visLoc := strWidth
 868                                 remainder := tabSize - (visLoc % tabSize)
 869                                 for i := 0; i < remainder-1; i++ {
 870                                         screenX++
 871                                         if screenX-v.x-v.leftCol >= v.lineNumOffset {
 872                                                 v.drawCell(screenX-v.leftCol, screenY, ' ', nil, lineStyle)
 873                                         }
 874                                 }
 875                         } else if runewidth.RuneWidth(ch) > 1 {
 876                                 if screenX-v.x-v.leftCol >= v.lineNumOffset {
 877                                         v.drawCell(screenX, screenY, ch, nil, lineStyle)
 878                                 }
 879                                 for i := 0; i < runewidth.RuneWidth(ch)-1; i++ {
 880                                         screenX++
 881                                         if screenX-v.x-v.leftCol >= v.lineNumOffset {
 882                                                 v.drawCell(screenX-v.leftCol, screenY, '<', nil, lineStyle)
 883                                         }
 884                                 }
 885                         } else {
 886                                 if screenX-v.x-v.leftCol >= v.lineNumOffset {
 887                                         v.drawCell(screenX-v.leftCol, screenY, ch, nil, lineStyle)
 888                                 }
 889                         }
 890                         charNum = charNum.Move(1, v.Buf)
 891                         screenX++
 892                         colN++
 893                         strWidth += StringWidth(string(ch), tabSize)
 894                 }
 895                 // Here we are at a newline
 896
 897                 if tabs[curTab].curView == v.Num && !v.Cursor.HasSelection() && v.Cursor.Y == curLineN && colN == v.Cursor.X {
 898                         v.DisplayCursor(screenX-v.leftCol, screenY)
 899                 }
 900
 901                 // The newline may be selected, in which case we should draw the selection style
 902                 // with a space to represent it
 903                 if v.Cursor.HasSelection() &&
 904                         (charNum.GreaterEqual(v.Cursor.CurSelection[0]) && charNum.LessThan(v.Cursor.CurSelection[1]) ||
 905                                 charNum.LessThan(v.Cursor.CurSelection[0]) && charNum.GreaterEqual(v.Cursor.CurSelection[1])) {
 906
 907                         selectStyle := defStyle.Reverse(true)
 908
 909                         if style, ok := colorscheme["selection"]; ok {
 910                                 selectStyle = style
 911                         }
 912                         v.drawCell(screenX, screenY, ' ', nil, selectStyle)
 913                         screenX++
 914                 }
 915
 916                 charNum = charNum.Move(1, v.Buf)
 917
 918                 for i := 0; i < v.width; i++ {
 919                         lineStyle := defStyle
 920                         if v.Buf.Settings["cursorline"].(bool) && tabs[curTab].curView == v.Num && !v.Cursor.HasSelection() && v.Cursor.Y == curLineN {
 921                                 if style, ok := colorscheme["cursor-line"]; ok {
 922                                         fg, _, _ := style.Decompose()
 923                                         lineStyle = lineStyle.Background(fg)
 924                                 }
 925                         }
 926                         if screenX-v.x-v.leftCol+i >= v.lineNumOffset {
 927                                 colorcolumn := int(v.Buf.Settings["colorcolumn"].(float64))
 928                                 if colorcolumn != 0 && screenX-v.lineNumOffset+i == colorcolumn-1 {
 929                                         if style, ok := colorscheme["color-column"]; ok {
 930                                                 fg, _, _ := style.Decompose()
 931                                                 lineStyle = lineStyle.Background(fg)
 932                                         }
 933                                 }
 934                                 v.drawCell(screenX-v.leftCol+i, screenY, ' ', nil, lineStyle)
 935                         }
 936                 }
 937         }
 938 }
 939
 940 // DisplayCursor draws the current buffer's cursor to the screen
 941 func (v *View) DisplayCursor(x, y int) {
 942         // screen.ShowCursor(v.x+v.Cursor.GetVisualX()+v.lineNumOffset-v.leftCol, y)
 943         screen.ShowCursor(x, y)
 944 }
 945
 946 // Display renders the view, the cursor, and statusline
 947 func (v *View) Display() {
 948         v.DisplayView()
 949         // Don't draw the cursor if it is out of the viewport or if it has a selection
 950         if (v.Cursor.Y-v.Topline < 0 || v.Cursor.Y-v.Topline > v.height-1) || v.Cursor.HasSelection() {
 951                 screen.HideCursor()
 952         }
 953         _, screenH := screen.Size()
 954         if v.Buf.Settings["statusline"].(bool) {
 955                 v.sline.Display()
 956         } else if (v.y + v.height) != screenH-1 {
 957                 for x := 0; x < v.width; x++ {
 958                         screen.SetContent(v.x+x, v.y+v.height, '-', nil, defStyle.Reverse(true))
 959                 }
 960         }
 961 }