cmd/micro/view.go

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