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