placeholder.js (2139B)
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 cm.on("swapDoc", onChange); 18 onChange(cm); 19 } else if (!val && prev) { 20 cm.off("blur", onBlur); 21 cm.off("change", onChange); 22 cm.off("swapDoc", onChange); 23 clearPlaceholder(cm); 24 var wrapper = cm.getWrapperElement(); 25 wrapper.className = wrapper.className.replace(" CodeMirror-empty", ""); 26 } 27 28 if (val && !cm.hasFocus()) onBlur(cm); 29 }); 30 31 function clearPlaceholder(cm) { 32 if (cm.state.placeholder) { 33 cm.state.placeholder.parentNode.removeChild(cm.state.placeholder); 34 cm.state.placeholder = null; 35 } 36 } 37 function setPlaceholder(cm) { 38 clearPlaceholder(cm); 39 var elt = cm.state.placeholder = document.createElement("pre"); 40 elt.style.cssText = "height: 0; overflow: visible"; 41 elt.className = "CodeMirror-placeholder"; 42 var placeHolder = cm.getOption("placeholder") 43 if (typeof placeHolder == "string") placeHolder = document.createTextNode(placeHolder) 44 elt.appendChild(placeHolder) 45 cm.display.lineSpace.insertBefore(elt, cm.display.lineSpace.firstChild); 46 } 47 48 function onBlur(cm) { 49 if (isEmpty(cm)) setPlaceholder(cm); 50 } 51 function onChange(cm) { 52 var wrapper = cm.getWrapperElement(), empty = isEmpty(cm); 53 wrapper.className = wrapper.className.replace(" CodeMirror-empty", "") + (empty ? " CodeMirror-empty" : ""); 54 55 if (empty) setPlaceholder(cm); 56 else clearPlaceholder(cm); 57 } 58 59 function isEmpty(cm) { 60 return (cm.lineCount() === 1) && (cm.getLine(0) === ""); 61 } 62 });