键入时的Google Material Design不断增长的文本区域

Question

I'm trying to implement Google Material Design Guidelines in my forms and it's working great, until I bumped into the textarea. What I want is this: When you focus on the textarea there is only one line, but when you reach the end of the line (while typing) it automatically adds another line and continues typing there.

I have found this on codepen, but this uses an inputfield, not a textarea. This just scrolls horizontally... Demo

  <input type="text" required>

Anyone who has this code and is willing to share? Thanks

Answer 1

You are creating all the Material Design CSS & Jquery by yourself?

Otherwise, I found Material Design textarea like you mentioned in here:

Source: https://materializecss.com/text-inputs.html#textarea

Check out their Textarea part.

Answer 2

Actually, to obtain this level of control, and work around the fact that a textarea, on most web browsers, can be resized by hand, you'll want to use a div with the contenteditable attribute .

See the HTML doctor entry on contenteditable for more.

Further, to calculate font sizes and overflow, you might want to use the canvas measureText method , for example using canvas as an offscreen substitute (where you input exactly the same text that is typed inside your contenteditable element).

Finally, while the css lineHeight attribute can somewhat facilitate those calculations, there are a few javascript libraries out there that are dedicated to the purpose. I found Font.js , haven't tested it at the time of this writing.

Answer 3

You can use <div contentEditable> instead of textarea and that will make a trick. Also you might not use additional libraries (Material-ui, jQuery, etc.).With your code it will look like this:

 .inputBlock { position: relative; margin-top: 20px; font-family: 'Roboto'; display: block; width: 300px; background: #FFF; } .input { font-size: 15px; padding: 0 0 6px; display: block; width: 100%; height: auto; border: none; box-sizing: border-box; resize: none } .input:focus { outline: none; } /* LABEL */ label { color: #777; font-size: 15px; font-weight: normal; position: absolute; pointer-events: none; top: 0; transition: 0.2s ease all; -moz-transition: 0.2s ease all; -webkit-transition: 0.2s ease all; } /* active state */ .input:focus~label, .input:not(:empty)~label { top: -15px; font-size: 11px; color: #00968a; } /* BOTTOM BARS */ .bar { position: relative; display: block; width: 100%; } .bar:before, .bar:after { content: ''; height: 2px; width: 0; bottom: 1px; position: absolute; background: #00968a; transition: 0.2s ease all; -moz-transition: 0.2s ease all; -webkit-transition: 0.2s ease all; } .bar:before { left: 50%; } .bar:after { right: 50%; } /* active state */ .input:focus~.bar:before, .input:focus~.bar:after { width: 50%; } /* HIGHLIGHTER */ .highlight { position: absolute; height: 73%; width: 100%; top: 25%; left: 0; pointer-events: none; opacity: 0.5; border-bottom: 1px solid #777; } /* active state */ .input:focus~.highlight { -webkit-animation: inputHighlighter 0.3s ease; -moz-animation: inputHighlighter 0.3s ease; animation: inputHighlighter 0.3s ease; border: none; } /* ANIMATIONS */ @-webkit-keyframes inputHighlighter { from { background: #5264AE; } to { width: 0; background: transparent; } } @-moz-keyframes inputHighlighter { from { background: #5264AE; } to { width: 0; background: transparent; } } @keyframes inputHighlighter { from { background: #5264AE; } to { width: 0; background: transparent; } } [class='input textarea'] height: auto !important color: #000000 !important font-size: 15px !important div color: #000000 !important font-size: 15px !important~.highlight height: 77% !important 

 <div class="inputBlock"> <div contentEditable class="input" required></div> <span class="highlight"></span> <span class="bar"></span> <label>Name</label> </div>