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