Function indentLine

external/.scrollLibs.js:11050–11129

(cm, n, how, aggressive)

  // lines are not indented, and places where the mode returns Pass
  // are left alone.
  function indentLine(cm, n, how, aggressive) {
    var doc = cm.doc,
      state
    if (how == null) {
      how = "add"
    }
    if (how == "smart") {
      // Fall back to "prev" when the mode doesn't have an indentation
      // method.
      if (!doc.mode.indent) {
        how = "prev"
      } else {
        state = getContextBefore(cm, n).state
      }
    }

    var tabSize = cm.options.tabSize
    var line = getLine(doc, n),
      curSpace = countColumn(line.text, null, tabSize)
    if (line.stateAfter) {
      line.stateAfter = null
    }
    var curSpaceString = line.text.match(/^\s*/)[0],
      indentation
    if (!aggressive && !/\S/.test(line.text)) {
      indentation = 0
      how = "not"
    } else if (how == "smart") {
      indentation = doc.mode.indent(state, line.text.slice(curSpaceString.length), line.text)
      if (indentation == Pass || indentation > 150) {
        if (!aggressive) {
          return
        }
        how = "prev"
      }
    }
    if (how == "prev") {
      if (n > doc.first) {
        indentation = countColumn(getLine(doc, n - 1).text, null, tabSize)
      } else {
        indentation = 0
      }
    } else if (how == "add") {
      indentation = curSpace + cm.options.indentUnit
    } else if (how == "subtract") {
      indentation = curSpace - cm.options.indentUnit
    } else if (typeof how == "number") {
      indentation = curSpace + how
    }
    indentation = Math.max(0, indentation)

    var indentString = "",
      pos = 0
    if (cm.options.indentWithTabs) {
      for (var i = Math.floor(indentation / tabSize); i; --i) {
        pos += tabSize
        indentString += "\t"
      }