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 width 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                 var char rune
 198                 var canceled bool
 199                 if v.Buf.Settings["autosave"].(bool) {
 200                         char = 'y'
 201                 } else {
 202                         char, canceled = messenger.LetterPrompt("Save changes to "+v.Buf.Name+" before closing? (y,n,esc) ", 'y', 'n')
 203                 }
 204                 if !canceled {
 205                         if char == 'y' {
 206                                 v.Save(true)
 207                                 return true
 208                         } else if char == 'n' {
 209                                 return true
 210                         }
 211                 }
 212         } else {
 213                 return true
 214         }
 215         return false
 216 }
 217
 218 // OpenBuffer opens a new buffer in this view.
 219 // This resets the topline, event handler and cursor.
 220 func (v *View) OpenBuffer(buf *Buffer) {
 221         screen.Clear()
 222         v.CloseBuffer()
 223         v.Buf = buf
 224         v.Cursor = &buf.Cursor
 225         v.Topline = 0
 226         v.leftCol = 0
 227         v.Cursor.ResetSelection()
 228         v.Relocate()
 229         v.Center(false)
 230         v.messages = make(map[string][]GutterMessage)
 231
 232         v.matches = Match(v)
 233
 234         // Set mouseReleased to true because we assume the mouse is not being pressed when
 235         // the editor is opened
 236         v.mouseReleased = true
 237         v.lastClickTime = time.Time{}
 238 }
 239
 240 func (v *View) Open(filename string) {
 241         home, _ := homedir.Dir()
 242         filename = strings.Replace(filename, "~", home, 1)
 243         file, err := ioutil.ReadFile(filename)
 244
 245         var buf *Buffer
 246         if err != nil {
 247                 messenger.Message(err.Error())
 248                 // File does not exist -- create an empty buffer with that name
 249                 buf = NewBuffer([]byte{}, filename)
 250         } else {
 251                 buf = NewBuffer(file, filename)
 252         }
 253         v.OpenBuffer(buf)
 254 }
 255
 256 // CloseBuffer performs any closing functions on the buffer
 257 func (v *View) CloseBuffer() {
 258         if v.Buf != nil {
 259                 v.Buf.Serialize()
 260         }
 261 }
 262
 263 // ReOpen reloads the current buffer
 264 func (v *View) ReOpen() {
 265         if v.CanClose() {
 266                 screen.Clear()
 267                 v.Buf.ReOpen()
 268                 v.Relocate()
 269                 v.matches = Match(v)
 270         }
 271 }
 272
 273 // HSplit opens a horizontal split with the given buffer
 274 func (v *View) HSplit(buf *Buffer) bool {
 275         v.splitNode.HSplit(buf)
 276         tabs[v.TabNum].Resize()
 277         return false
 278 }
 279
 280 // VSplit opens a vertical split with the given buffer
 281 func (v *View) VSplit(buf *Buffer) bool {
 282         v.splitNode.VSplit(buf)
 283         tabs[v.TabNum].Resize()
 284         return false
 285 }
 286
 287 // Relocate moves the view window so that the cursor is in view
 288 // This is useful if the user has scrolled far away, and then starts typing
 289 func (v *View) Relocate() bool {
 290         ret := false
 291         cy := v.Cursor.Y
 292         scrollmargin := int(v.Buf.Settings["scrollmargin"].(float64))
 293         if cy < v.Topline+scrollmargin && cy > scrollmargin-1 {
 294                 v.Topline = cy - scrollmargin
 295                 ret = true
 296         } else if cy < v.Topline {
 297                 v.Topline = cy
 298                 ret = true
 299         }
 300         if cy > v.Topline+v.height-1-scrollmargin && cy < v.Buf.NumLines-scrollmargin {
 301                 v.Topline = cy - v.height + 1 + scrollmargin
 302                 ret = true
 303         } else if cy >= v.Buf.NumLines-scrollmargin && cy > v.height {
 304                 v.Topline = v.Buf.NumLines - v.height
 305                 ret = true
 306         }
 307
 308         cx := v.Cursor.GetVisualX()
 309         if cx < v.leftCol {
 310                 v.leftCol = cx
 311                 ret = true
 312         }
 313         if cx+v.lineNumOffset+1 > v.leftCol+v.width {
 314                 v.leftCol = cx - v.width + v.lineNumOffset + 1
 315                 ret = true
 316         }
 317         return ret
 318 }
 319
 320 // MoveToMouseClick moves the cursor to location x, y assuming x, y were given
 321 // by a mouse click
 322 func (v *View) MoveToMouseClick(x, y int) {
 323         if y-v.Topline > v.height-1 {
 324                 v.ScrollDown(1)
 325                 y = v.height + v.Topline - 1
 326         }
 327         if y >= v.Buf.NumLines {
 328                 y = v.Buf.NumLines - 1
 329         }
 330         if y < 0 {
 331                 y = 0
 332         }
 333         if x < 0 {
 334                 x = 0
 335         }
 336
 337         x = v.Cursor.GetCharPosInLine(y, x)
 338         if x > Count(v.Buf.Line(y)) {
 339                 x = Count(v.Buf.Line(y))
 340         }
 341         v.Cursor.X = x
 342         v.Cursor.Y = y
 343         v.Cursor.LastVisualX = v.Cursor.GetVisualX()
 344 }
 345
 346 // HandleEvent handles an event passed by the main loop
 347 func (v *View) HandleEvent(event tcell.Event) {
 348         // This bool determines whether the view is relocated at the end of the function
 349         // By default it's true because most events should cause a relocate
 350         relocate := true
 351
 352         v.Buf.CheckModTime()
 353
 354         switch e := event.(type) {
 355         case *tcell.EventResize:
 356                 // Window resized
 357                 tabs[v.TabNum].Resize()
 358         case *tcell.EventKey:
 359                 // Check first if input is a key binding, if it is we 'eat' the input and don't insert a rune
 360                 isBinding := false
 361                 if e.Key() != tcell.KeyRune || e.Modifiers() != 0 {
 362                         for key, actions := range bindings {
 363                                 if e.Key() == key.keyCode {
 364                                         if e.Key() == tcell.KeyRune {
 365                                                 if e.Rune() != key.r {
 366                                                         continue
 367                                                 }
 368                                         }
 369                                         if e.Modifiers() == key.modifiers {
 370                                                 relocate = false
 371                                                 isBinding = true
 372                                                 for _, action := range actions {
 373                                                         relocate = action(v, true) || relocate
 374                                                         funcName := FuncName(action)
 375                                                         if funcName != "main.(*View).ToggleMacro" && funcName != "main.(*View).PlayMacro" {
 376                                                                 if recordingMacro {
 377                                                                         curMacro = append(curMacro, action)
 378                                                                 }
 379                                                         }
 380                                                 }
 381                                                 break
 382                                         }
 383                                 }
 384                         }
 385                 }
 386                 if !isBinding && e.Key() == tcell.KeyRune {
 387                         // Insert a character
 388                         if v.Cursor.HasSelection() {
 389                                 v.Cursor.DeleteSelection()
 390                                 v.Cursor.ResetSelection()
 391                         }
 392                         v.Buf.Insert(v.Cursor.Loc, string(e.Rune()))
 393                         v.Cursor.Right()
 394
 395                         for _, pl := range loadedPlugins {
 396                                 _, err := Call(pl+".onRune", string(e.Rune()), v)
 397                                 if err != nil && !strings.HasPrefix(err.Error(), "function does not exist") {
 398                                         TermMessage(err)
 399                                 }
 400                         }
 401
 402                         if recordingMacro {
 403                                 curMacro = append(curMacro, e.Rune())
 404                         }
 405                 }
 406         case *tcell.EventPaste:
 407                 if !PreActionCall("Paste", v) {
 408                         break
 409                 }
 410
 411                 leadingWS := GetLeadingWhitespace(v.Buf.Line(v.Cursor.Y))
 412
 413                 if v.Cursor.HasSelection() {
 414                         v.Cursor.DeleteSelection()
 415                         v.Cursor.ResetSelection()
 416                 }
 417                 clip := e.Text()
 418                 clip = strings.Replace(clip, "\n", "\n"+leadingWS, -1)
 419                 v.Buf.Insert(v.Cursor.Loc, clip)
 420                 v.Cursor.Loc = v.Cursor.Loc.Move(Count(clip), v.Buf)
 421                 v.freshClip = false
 422                 messenger.Message("Pasted clipboard")
 423
 424                 PostActionCall("Paste", v)
 425         case *tcell.EventMouse:
 426                 x, y := e.Position()
 427                 x -= v.lineNumOffset - v.leftCol + v.x
 428                 y += v.Topline - v.y
 429                 // Don't relocate for mouse events
 430                 relocate = false
 431
 432                 button := e.Buttons()
 433
 434                 switch button {
 435                 case tcell.Button1:
 436                         // Left click
 437                         if v.mouseReleased {
 438                                 v.MoveToMouseClick(x, y)
 439                                 if time.Since(v.lastClickTime)/time.Millisecond < doubleClickThreshold {
 440                                         if v.doubleClick {
 441                                                 // Triple click
 442                                                 v.lastClickTime = time.Now()
 443
 444                                                 v.tripleClick = true
 445                                                 v.doubleClick = false
 446
 447                                                 v.Cursor.SelectLine()
 448                                         } else {
 449                                                 // Double click
 450                                                 v.lastClickTime = time.Now()
 451
 452                                                 v.doubleClick = true
 453                                                 v.tripleClick = false
 454
 455                                                 v.Cursor.SelectWord()
 456                                         }
 457                                 } else {
 458                                         v.doubleClick = false
 459                                         v.tripleClick = false
 460                                         v.lastClickTime = time.Now()
 461
 462                                         v.Cursor.OrigSelection[0] = v.Cursor.Loc
 463                                         v.Cursor.CurSelection[0] = v.Cursor.Loc
 464                                         v.Cursor.CurSelection[1] = v.Cursor.Loc
 465                                 }
 466                                 v.mouseReleased = false
 467                         } else if !v.mouseReleased {
 468                                 v.MoveToMouseClick(x, y)
 469                                 if v.tripleClick {
 470                                         v.Cursor.AddLineToSelection()
 471                                 } else if v.doubleClick {
 472                                         v.Cursor.AddWordToSelection()
 473                                 } else {
 474                                         v.Cursor.SetSelectionEnd(v.Cursor.Loc)
 475                                 }
 476                         }
 477                 case tcell.Button2:
 478                         // Middle mouse button was clicked,
 479                         // We should paste primary
 480                         v.PastePrimary(true)
 481                 case tcell.ButtonNone:
 482                         // Mouse event with no click
 483                         if !v.mouseReleased {
 484                                 // Mouse was just released
 485
 486                                 // Relocating here isn't really necessary because the cursor will
 487                                 // be in the right place from the last mouse event
 488                                 // However, if we are running in a terminal that doesn't support mouse motion
 489                                 // events, this still allows the user to make selections, except only after they
 490                                 // release the mouse
 491
 492                                 if !v.doubleClick && !v.tripleClick {
 493                                         v.MoveToMouseClick(x, y)
 494                                         v.Cursor.SetSelectionEnd(v.Cursor.Loc)
 495                                 }
 496                                 v.mouseReleased = true
 497                         }
 498                 case tcell.WheelUp:
 499                         // Scroll up
 500                         scrollspeed := int(v.Buf.Settings["scrollspeed"].(float64))
 501                         v.ScrollUp(scrollspeed)
 502                 case tcell.WheelDown:
 503                         // Scroll down
 504                         scrollspeed := int(v.Buf.Settings["scrollspeed"].(float64))
 505                         v.ScrollDown(scrollspeed)
 506                 }
 507         }
 508
 509         if relocate {
 510                 v.Relocate()
 511         }
 512 }
 513
 514 // GutterMessage creates a message in this view's gutter
 515 func (v *View) GutterMessage(section string, lineN int, msg string, kind int) {
 516         lineN--
 517         gutterMsg := GutterMessage{
 518                 lineNum: lineN,
 519                 msg:     msg,
 520                 kind:    kind,
 521         }
 522         for _, v := range v.messages {
 523                 for _, gmsg := range v {
 524                         if gmsg.lineNum == lineN {
 525                                 return
 526                         }
 527                 }
 528         }
 529         messages := v.messages[section]
 530         v.messages[section] = append(messages, gutterMsg)
 531 }
 532
 533 // ClearGutterMessages clears all gutter messages from a given section
 534 func (v *View) ClearGutterMessages(section string) {
 535         v.messages[section] = []GutterMessage{}
 536 }
 537
 538 // ClearAllGutterMessages clears all the gutter messages
 539 func (v *View) ClearAllGutterMessages() {
 540         for k := range v.messages {
 541                 v.messages[k] = []GutterMessage{}
 542         }
 543 }
 544
 545 // Opens the given help page in a new horizontal split
 546 func (v *View) openHelp(helpPage string) {
 547         if data, err := FindRuntimeFile(RTHelp, helpPage).Data(); err != nil {
 548                 TermMessage("Unable to load help text", helpPage, "\n", err)
 549         } else {
 550                 helpBuffer := NewBuffer(data, helpPage+".md")
 551                 helpBuffer.Name = "Help"
 552
 553                 if v.Type == vtHelp {
 554                         v.OpenBuffer(helpBuffer)
 555                 } else {
 556                         v.HSplit(helpBuffer)
 557                         CurView().Type = vtHelp
 558                 }
 559         }
 560 }
 561
 562 func (v *View) drawCell(x, y int, ch rune, combc []rune, style tcell.Style) {
 563         if x >= v.x && x < v.x+v.width && y >= v.y && y < v.y+v.height {
 564                 screen.SetContent(x, y, ch, combc, style)
 565         }
 566 }
 567
 568 // DisplayView renders the view to the screen
 569 func (v *View) DisplayView() {
 570         if v.Type == vtLog {
 571                 // Log views should always follow the cursor...
 572                 v.Relocate()
 573         }
 574
 575         if v.Buf.Settings["syntax"].(bool) {
 576                 v.matches = Match(v)
 577         }
 578
 579         // The charNum we are currently displaying
 580         // starts at the start of the viewport
 581         charNum := Loc{0, v.Topline}
 582
 583         // Convert the length of buffer to a string, and get the length of the string
 584         // We are going to have to offset by that amount
 585         maxLineLength := len(strconv.Itoa(v.Buf.NumLines))
 586
 587         if v.Buf.Settings["ruler"] == true {
 588                 // + 1 for the little space after the line number
 589                 v.lineNumOffset = maxLineLength + 1
 590         } else {
 591                 v.lineNumOffset = 0
 592         }
 593
 594         // We need to add to the line offset if there are gutter messages
 595         var hasGutterMessages bool
 596         for _, v := range v.messages {
 597                 if len(v) > 0 {
 598                         hasGutterMessages = true
 599                 }
 600         }
 601         if hasGutterMessages {
 602                 v.lineNumOffset += 2
 603         }
 604
 605         if v.x != 0 {
 606                 // One space for the extra split divider
 607                 v.lineNumOffset++
 608         }
 609
 610         // These represent the current screen coordinates
 611         screenX, screenY := 0, 0
 612
 613         highlightStyle := defStyle
 614
 615         // ViewLine is the current line from the top of the viewport
 616         for viewLine := 0; viewLine < v.height; viewLine++ {
 617                 screenY = v.y + viewLine
 618                 screenX = v.x
 619
 620                 // This is the current line number of the buffer that we are drawing
 621                 curLineN := viewLine + v.Topline
 622
 623                 if v.x != 0 {
 624                         // Draw the split divider
 625                         v.drawCell(screenX, screenY, '|', nil, defStyle.Reverse(true))
 626                         screenX++
 627                 }
 628
 629                 // If the buffer is smaller than the view height we have to clear all this space
 630                 if curLineN >= v.Buf.NumLines {
 631                         for i := screenX; i < v.x+v.width; i++ {
 632                                 v.drawCell(i, screenY, ' ', nil, defStyle)
 633                         }
 634
 635                         continue
 636                 }
 637                 line := v.Buf.Line(curLineN)
 638
 639                 // If there are gutter messages we need to display the '>>' symbol here
 640                 if hasGutterMessages {
 641                         // msgOnLine stores whether or not there is a gutter message on this line in particular
 642                         msgOnLine := false
 643                         for k := range v.messages {
 644                                 for _, msg := range v.messages[k] {
 645                                         if msg.lineNum == curLineN {
 646                                                 msgOnLine = true
 647                                                 gutterStyle := defStyle
 648                                                 switch msg.kind {
 649                                                 case GutterInfo:
 650                                                         if style, ok := colorscheme["gutter-info"]; ok {
 651                                                                 gutterStyle = style
 652                                                         }
 653                                                 case GutterWarning:
 654                                                         if style, ok := colorscheme["gutter-warning"]; ok {
 655                                                                 gutterStyle = style
 656                                                         }
 657                                                 case GutterError:
 658                                                         if style, ok := colorscheme["gutter-error"]; ok {
 659                                                                 gutterStyle = style
 660                                                         }
 661                                                 }
 662                                                 v.drawCell(screenX, screenY, '>', nil, gutterStyle)
 663                                                 screenX++
 664                                                 v.drawCell(screenX, screenY, '>', nil, gutterStyle)
 665                                                 screenX++
 666                                                 if v.Cursor.Y == curLineN && !messenger.hasPrompt {
 667                                                         messenger.Message(msg.msg)
 668                                                         messenger.gutterMessage = true
 669                                                 }
 670                                         }
 671                                 }
 672                         }
 673                         // If there is no message on this line we just display an empty offset
 674                         if !msgOnLine {
 675                                 v.drawCell(screenX, screenY, ' ', nil, defStyle)
 676                                 screenX++
 677                                 v.drawCell(screenX, screenY, ' ', nil, defStyle)
 678                                 screenX++
 679                                 if v.Cursor.Y == curLineN && messenger.gutterMessage {
 680                                         messenger.Reset()
 681                                         messenger.gutterMessage = false
 682                                 }
 683                         }
 684                 }
 685
 686                 if v.Buf.Settings["ruler"] == true {
 687                         // Write the line number
 688                         lineNumStyle := defStyle
 689                         if style, ok := colorscheme["line-number"]; ok {
 690                                 lineNumStyle = style
 691                         }
 692                         if style, ok := colorscheme["current-line-number"]; ok {
 693                                 if curLineN == v.Cursor.Y && tabs[curTab].curView == v.Num && !v.Cursor.HasSelection() {
 694                                         lineNumStyle = style
 695                                 }
 696                         }
 697
 698                         lineNum := strconv.Itoa(curLineN + 1)
 699
 700                         // Write the spaces before the line number if necessary
 701                         for i := 0; i < maxLineLength-len(lineNum); i++ {
 702                                 v.drawCell(screenX, screenY, ' ', nil, lineNumStyle)
 703                                 screenX++
 704                         }
 705                         // Write the actual line number
 706                         for _, ch := range lineNum {
 707                                 v.drawCell(screenX, screenY, ch, nil, lineNumStyle)
 708                                 screenX++
 709                         }
 710
 711                         // Write the extra space
 712                         v.drawCell(screenX, screenY, ' ', nil, lineNumStyle)
 713                         screenX++
 714                 }
 715
 716                 // Now we actually draw the line
 717                 colN := 0
 718                 strWidth := 0
 719                 tabSize := int(v.Buf.Settings["tabsize"].(float64))
 720                 for _, ch := range line {
 721                         lineStyle := defStyle
 722
 723                         if v.Buf.Settings["syntax"].(bool) {
 724                                 // Syntax highlighting is enabled
 725                                 highlightStyle = v.matches[viewLine][colN]
 726                         }
 727
 728                         if v.Cursor.HasSelection() &&
 729                                 (charNum.GreaterEqual(v.Cursor.CurSelection[0]) && charNum.LessThan(v.Cursor.CurSelection[1]) ||
 730                                         charNum.LessThan(v.Cursor.CurSelection[0]) && charNum.GreaterEqual(v.Cursor.CurSelection[1])) {
 731                                 // The current character is selected
 732                                 lineStyle = defStyle.Reverse(true)
 733
 734                                 if style, ok := colorscheme["selection"]; ok {
 735                                         lineStyle = style
 736                                 }
 737                         } else {
 738                                 lineStyle = highlightStyle
 739                         }
 740
 741                         // We need to display the background of the linestyle with the correct color if cursorline is enabled
 742                         // and this is the current view and there is no selection on this line and the cursor is on this line
 743                         if v.Buf.Settings["cursorline"].(bool) && tabs[curTab].curView == v.Num && !v.Cursor.HasSelection() && v.Cursor.Y == curLineN {
 744                                 if style, ok := colorscheme["cursor-line"]; ok {
 745                                         fg, _, _ := style.Decompose()
 746                                         lineStyle = lineStyle.Background(fg)
 747                                 }
 748                         }
 749
 750                         if ch == '\t' {
 751                                 // If the character we are displaying is a tab, we need to do a bunch of special things
 752
 753                                 // First the user may have configured an `indent-char` to be displayed to show that this
 754                                 // is a tab character
 755                                 lineIndentStyle := defStyle
 756                                 if style, ok := colorscheme["indent-char"]; ok && v.Buf.Settings["indentchar"].(string) != " " {
 757                                         lineIndentStyle = style
 758                                 }
 759                                 if v.Cursor.HasSelection() &&
 760                                         (charNum.GreaterEqual(v.Cursor.CurSelection[0]) && charNum.LessThan(v.Cursor.CurSelection[1]) ||
 761                                                 charNum.LessThan(v.Cursor.CurSelection[0]) && charNum.GreaterEqual(v.Cursor.CurSelection[1])) {
 762
 763                                         lineIndentStyle = defStyle.Reverse(true)
 764
 765                                         if style, ok := colorscheme["selection"]; ok {
 766                                                 lineIndentStyle = style
 767                                         }
 768                                 }
 769                                 if v.Buf.Settings["cursorline"].(bool) && tabs[curTab].curView == v.Num && !v.Cursor.HasSelection() && v.Cursor.Y == curLineN {
 770                                         if style, ok := colorscheme["cursor-line"]; ok {
 771                                                 fg, _, _ := style.Decompose()
 772                                                 lineIndentStyle = lineIndentStyle.Background(fg)
 773                                         }
 774                                 }
 775                                 // Here we get the indent char
 776                                 indentChar := []rune(v.Buf.Settings["indentchar"].(string))
 777                                 if screenX-v.x-v.leftCol >= v.lineNumOffset {
 778                                         v.drawCell(screenX-v.leftCol, screenY, indentChar[0], nil, lineIndentStyle)
 779                                 }
 780                                 // Now the tab has to be displayed as a bunch of spaces
 781                                 visLoc := strWidth
 782                                 remainder := tabSize - (visLoc % tabSize)
 783                                 for i := 0; i < remainder-1; i++ {
 784                                         screenX++
 785                                         if screenX-v.x-v.leftCol >= v.lineNumOffset {
 786                                                 v.drawCell(screenX-v.leftCol, screenY, ' ', nil, lineStyle)
 787                                         }
 788                                 }
 789                         } else if runewidth.RuneWidth(ch) > 1 {
 790                                 if screenX-v.x-v.leftCol >= v.lineNumOffset {
 791                                         v.drawCell(screenX, screenY, ch, nil, lineStyle)
 792                                 }
 793                                 for i := 0; i < runewidth.RuneWidth(ch)-1; i++ {
 794                                         screenX++
 795                                         if screenX-v.x-v.leftCol >= v.lineNumOffset {
 796                                                 v.drawCell(screenX-v.leftCol, screenY, '<', nil, lineStyle)
 797                                         }
 798                                 }
 799                         } else {
 800                                 if screenX-v.x-v.leftCol >= v.lineNumOffset {
 801                                         v.drawCell(screenX-v.leftCol, screenY, ch, nil, lineStyle)
 802                                 }
 803                         }
 804                         charNum = charNum.Move(1, v.Buf)
 805                         screenX++
 806                         colN++
 807                         strWidth += StringWidth(string(ch), tabSize)
 808                 }
 809                 // Here we are at a newline
 810
 811                 // The newline may be selected, in which case we should draw the selection style
 812                 // with a space to represent it
 813                 if v.Cursor.HasSelection() &&
 814                         (charNum.GreaterEqual(v.Cursor.CurSelection[0]) && charNum.LessThan(v.Cursor.CurSelection[1]) ||
 815                                 charNum.LessThan(v.Cursor.CurSelection[0]) && charNum.GreaterEqual(v.Cursor.CurSelection[1])) {
 816
 817                         selectStyle := defStyle.Reverse(true)
 818
 819                         if style, ok := colorscheme["selection"]; ok {
 820                                 selectStyle = style
 821                         }
 822                         v.drawCell(screenX, screenY, ' ', nil, selectStyle)
 823                         screenX++
 824                 }
 825
 826                 charNum = charNum.Move(1, v.Buf)
 827
 828                 for i := 0; i < v.width; i++ {
 829                         lineStyle := defStyle
 830                         if v.Buf.Settings["cursorline"].(bool) && tabs[curTab].curView == v.Num && !v.Cursor.HasSelection() && v.Cursor.Y == curLineN {
 831                                 if style, ok := colorscheme["cursor-line"]; ok {
 832                                         fg, _, _ := style.Decompose()
 833                                         lineStyle = lineStyle.Background(fg)
 834                                 }
 835                         }
 836                         if screenX-v.x-v.leftCol+i >= v.lineNumOffset {
 837                                 colorcolumn := int(v.Buf.Settings["colorcolumn"].(float64))
 838                                 if colorcolumn != 0 && screenX-v.lineNumOffset+i == colorcolumn-1 {
 839                                         if style, ok := colorscheme["color-column"]; ok {
 840                                                 fg, _, _ := style.Decompose()
 841                                                 lineStyle = lineStyle.Background(fg)
 842                                         }
 843                                 }
 844                                 v.drawCell(screenX-v.leftCol+i, screenY, ' ', nil, lineStyle)
 845                         }
 846                 }
 847         }
 848 }
 849
 850 // DisplayCursor draws the current buffer's cursor to the screen
 851 func (v *View) DisplayCursor() {
 852         // Don't draw the cursor if it is out of the viewport or if it has a selection
 853         if (v.Cursor.Y-v.Topline < 0 || v.Cursor.Y-v.Topline > v.height-1) || v.Cursor.HasSelection() {
 854                 screen.HideCursor()
 855         } else {
 856                 screen.ShowCursor(v.x+v.Cursor.GetVisualX()+v.lineNumOffset-v.leftCol, v.Cursor.Y-v.Topline+v.y)
 857         }
 858 }
 859
 860 // Display renders the view, the cursor, and statusline
 861 func (v *View) Display() {
 862         v.DisplayView()
 863         if v.Num == tabs[curTab].curView {
 864                 v.DisplayCursor()
 865         }
 866         _, screenH := screen.Size()
 867         if v.Buf.Settings["statusline"].(bool) {
 868                 v.sline.Display()
 869         } else if (v.y + v.height) != screenH-1 {
 870                 for x := 0; x < v.width; x++ {
 871                         screen.SetContent(v.x+x, v.y+v.height, '-', nil, defStyle.Reverse(true))
 872                 }
 873         }
 874 }