17 // Buffer stores the text for files that are loaded into the text editor
18 // It uses a rope to efficiently store the string and contains some
19 // simple functions for saving and wrapper functions for modifying the rope
21 // The eventhandler for undo/redo
23 // This stores all the text in the buffer as an array of lines
28 // Path to the file on disk
30 // Name of the buffer on the status line
33 // Whether or not the buffer has been modified since it was opened
36 // Stores the last modification time of the file the buffer is pointing to
41 // Syntax highlighting rules
44 // Buffer local settings
45 Settings map[string]interface{}
48 // The SerializedBuffer holds the types that get serialized when a buffer is saved
49 // These are used for the savecursor and saveundo options
50 type SerializedBuffer struct {
51 EventHandler *EventHandler
56 // NewBuffer creates a new buffer from `txt` with path and name `path`
57 func NewBuffer(txt []byte, path string) *Buffer {
58 for _, tab := range tabs {
59 for _, view := range tab.views {
60 if view.Buf.Path == path {
67 b.LineArray = NewLineArray(txt)
69 b.Settings = DefaultLocalSettings()
70 for k, v := range globalSettings {
71 if _, ok := b.Settings[k]; ok {
79 // If the file doesn't have a path to disk then we give it no name
84 // The last time this file was modified
85 b.ModTime, _ = GetModTime(b.Path)
87 b.EventHandler = NewEventHandler(b)
93 if _, err := os.Stat(configDir + "/buffers/"); os.IsNotExist(err) {
94 os.Mkdir(configDir+"/buffers/", os.ModePerm)
97 // Put the cursor at the first spot
100 // If -startpos LINE,COL was passed, use start position LINE,COL
101 if len(*flagStartPos) > 0 {
102 positions := strings.Split(*flagStartPos, ",")
103 if len(positions) == 2 {
104 lineNum, errPos1 := strconv.Atoi(positions[0])
105 colNum, errPos2 := strconv.Atoi(positions[1])
106 if errPos1 == nil && errPos2 == nil {
107 cursorStartX = colNum
108 cursorStartY = lineNum - 1
109 // Check to avoid line overflow
110 if cursorStartY > b.NumLines {
111 cursorStartY = b.NumLines - 1
112 } else if cursorStartY < 0 {
115 // Check to avoid column overflow
116 if cursorStartX > len(b.Line(cursorStartY)) {
117 cursorStartX = len(b.Line(cursorStartY))
118 } else if cursorStartX < 0 {
134 if b.Settings["savecursor"].(bool) || b.Settings["saveundo"].(bool) {
135 // If either savecursor or saveundo is turned on, we need to load the serialized information
136 // from ~/.config/micro/buffers
137 absPath, _ := filepath.Abs(b.Path)
138 file, err := os.Open(configDir + "/buffers/" + EscapePath(absPath))
140 var buffer SerializedBuffer
141 decoder := gob.NewDecoder(file)
142 gob.Register(TextEvent{})
143 err = decoder.Decode(&buffer)
145 TermMessage(err.Error(), "\n", "You may want to remove the files in ~/.config/micro/buffers (these files store the information for the 'saveundo' and 'savecursor' options) if this problem persists.")
147 if b.Settings["savecursor"].(bool) {
148 b.Cursor = buffer.Cursor
153 if b.Settings["saveundo"].(bool) {
154 // We should only use last time's eventhandler if the file wasn't by someone else in the meantime
155 if b.ModTime == buffer.ModTime {
156 b.EventHandler = buffer.EventHandler
157 b.EventHandler.buf = b
167 // UpdateRules updates the syntax rules and filetype for this buffer
168 // This is called when the colorscheme changes
169 func (b *Buffer) UpdateRules() {
170 b.rules = GetRules(b)
173 // FindFileType identifies this buffer's filetype based on the extension or header
174 func (b *Buffer) FindFileType() {
175 b.Settings["filetype"] = FindFileType(b)
178 // FileType returns the buffer's filetype
179 func (b *Buffer) FileType() string {
180 return b.Settings["filetype"].(string)
183 // CheckModTime makes sure that the file this buffer points to hasn't been updated
184 // by an external program since it was last read
185 // If it has, we ask the user if they would like to reload the file
186 func (b *Buffer) CheckModTime() {
187 modTime, ok := GetModTime(b.Path)
189 if modTime != b.ModTime {
190 choice, canceled := messenger.YesNoPrompt("The file has changed since it was last read. Reload file? (y,n)")
193 if !choice || canceled {
194 // Don't load new changes -- do nothing
195 b.ModTime, _ = GetModTime(b.Path)
204 // ReOpen reloads the current buffer from disk
205 func (b *Buffer) ReOpen() {
206 data, err := ioutil.ReadFile(b.Path)
210 messenger.Error(err.Error())
213 b.EventHandler.ApplyDiff(txt)
215 b.ModTime, _ = GetModTime(b.Path)
221 // Update fetches the string from the rope and updates the `text` and `lines` in the buffer
222 func (b *Buffer) Update() {
223 b.NumLines = len(b.lines)
226 // Save saves the buffer to its default path
227 func (b *Buffer) Save() error {
228 return b.SaveAs(b.Path)
231 // SaveWithSudo saves the buffer to the default path with sudo
232 func (b *Buffer) SaveWithSudo() error {
233 return b.SaveAsWithSudo(b.Path)
236 // Serialize serializes the buffer to configDir/buffers
237 func (b *Buffer) Serialize() error {
238 if b.Settings["savecursor"].(bool) || b.Settings["saveundo"].(bool) {
239 absPath, _ := filepath.Abs(b.Path)
240 file, err := os.Create(configDir + "/buffers/" + EscapePath(absPath))
242 enc := gob.NewEncoder(file)
243 gob.Register(TextEvent{})
244 err = enc.Encode(SerializedBuffer{
256 // SaveAs saves the buffer to a specified path (filename), creating the file if it does not exist
257 func (b *Buffer) SaveAs(filename string) error {
262 data := []byte(b.String())
263 err := ioutil.WriteFile(filename, data, 0644)
266 b.ModTime, _ = GetModTime(filename)
272 // SaveAsWithSudo is the same as SaveAs except it uses a neat trick
273 // with tee to use sudo so the user doesn't have to reopen micro with sudo
274 func (b *Buffer) SaveAsWithSudo(filename string) error {
280 // The user may have already used sudo in which case we won't need the password
281 // It's a bit nicer for them if they don't have to enter the password every time
282 _, err := RunShellCommand("sudo -v")
283 needPassword := err != nil
285 // If we need the password, we have to close the screen and ask using the shell
287 // Shut down the screen because we're going to interact directly with the shell
292 // Set up everything for the command
293 cmd := exec.Command("sudo", "tee", filename)
294 cmd.Stdin = bytes.NewBufferString(b.String())
296 // This is a trap for Ctrl-C so that it doesn't kill micro
297 // Instead we trap Ctrl-C to kill the program we're running
298 c := make(chan os.Signal, 1)
299 signal.Notify(c, os.Interrupt)
310 // If we needed the password, we closed the screen, so we have to initialize it again
312 // Start the screen back up
317 b.ModTime, _ = GetModTime(filename)
323 func (b *Buffer) insert(pos Loc, value []byte) {
325 b.LineArray.insert(pos, value)
328 func (b *Buffer) remove(start, end Loc) string {
330 sub := b.LineArray.remove(start, end)
335 // Start returns the location of the first character in the buffer
336 func (b *Buffer) Start() Loc {
340 // End returns the location of the last character in the buffer
341 func (b *Buffer) End() Loc {
342 return Loc{utf8.RuneCount(b.lines[b.NumLines-1]), b.NumLines - 1}
345 // Line returns a single line
346 func (b *Buffer) Line(n int) string {
347 return string(b.lines[n])
350 // Lines returns an array of strings containing the lines from start to end
351 func (b *Buffer) Lines(start, end int) []string {
352 lines := b.lines[start:end]
354 for _, line := range lines {
355 slice = append(slice, string(line))
360 // Len gives the length of the buffer
361 func (b *Buffer) Len() int {
362 return Count(b.String())