github.com/jancarloviray/community@v0.41.1-0.20170124221257-33a66c87cf2f/app/public/codemirror/addon/display/placeholder.js (about)

     1  // CodeMirror, copyright (c) by Marijn Haverbeke and others
     2  // Distributed under an MIT license: http://codemirror.net/LICENSE
     3  
     4  (function(mod) {
     5    if (typeof exports == "object" && typeof module == "object") // CommonJS
     6      mod(require("../../lib/codemirror"));
     7    else if (typeof define == "function" && define.amd) // AMD
     8      define(["../../lib/codemirror"], mod);
     9    else // Plain browser env
    10      mod(CodeMirror);
    11  })(function(CodeMirror) {
    12    CodeMirror.defineOption("placeholder", "", function(cm, val, old) {
    13      var prev = old && old != CodeMirror.Init;
    14      if (val && !prev) {
    15        cm.on("blur", onBlur);
    16        cm.on("change", onChange);
    17        onChange(cm);
    18      } else if (!val && prev) {
    19        cm.off("blur", onBlur);
    20        cm.off("change", onChange);
    21        clearPlaceholder(cm);
    22        var wrapper = cm.getWrapperElement();
    23        wrapper.className = wrapper.className.replace(" CodeMirror-empty", "");
    24      }
    25  
    26      if (val && !cm.hasFocus()) onBlur(cm);
    27    });
    28  
    29    function clearPlaceholder(cm) {
    30      if (cm.state.placeholder) {
    31        cm.state.placeholder.parentNode.removeChild(cm.state.placeholder);
    32        cm.state.placeholder = null;
    33      }
    34    }
    35    function setPlaceholder(cm) {
    36      clearPlaceholder(cm);
    37      var elt = cm.state.placeholder = document.createElement("pre");
    38      elt.style.cssText = "height: 0; overflow: visible";
    39      elt.className = "CodeMirror-placeholder";
    40      var placeHolder = cm.getOption("placeholder")
    41      if (typeof placeHolder == "string") placeHolder = document.createTextNode(placeHolder)
    42      elt.appendChild(placeHolder)
    43      cm.display.lineSpace.insertBefore(elt, cm.display.lineSpace.firstChild);
    44    }
    45  
    46    function onBlur(cm) {
    47      if (isEmpty(cm)) setPlaceholder(cm);
    48    }
    49    function onChange(cm) {
    50      var wrapper = cm.getWrapperElement(), empty = isEmpty(cm);
    51      wrapper.className = wrapper.className.replace(" CodeMirror-empty", "") + (empty ? " CodeMirror-empty" : "");
    52  
    53      if (empty) setPlaceholder(cm);
    54      else clearPlaceholder(cm);
    55    }
    56  
    57    function isEmpty(cm) {
    58      return (cm.lineCount() === 1) && (cm.getLine(0) === "");
    59    }
    60  });