How to add line breaks within tooltip in angular material design

How to add line break in tooltip I have implemented the Tooltip but i am not able to add multi line or line breaks in tooltip.Below is my code

http://codepen.io/apps4any/pen/RWQLyr

Html

<div ng-controller="AppCtrl" ng-cloak="" class="tooltipdemoBasicUsage" ng-app="MyApp">
  <md-content layout-padding="">
    <md-button class="md-fab md-fab-top-right right" aria-label="Photos">
      <md-icon md-svg-src="img/icons/ic_photo_24px.svg" style="width: 24px; height: 24px;"></md-icon>
      <md-tooltip>
        List1<br>
        List2<br>
        List3<br>
        List4
      </md-tooltip>
    </md-button>
    <div style="margin-top: 150px;">
    </div>
  </md-content>
</div>

CSS:

.tooltipdemoBasicUsage md-toolbar .md-toolbar-tools .md-button, .tooltipdemoBasicUsage md-toolbar .md-toolbar-tools .md-button:hover {
  box-shadow: none;
  border: none;
  transform: none;
  -webkit-transform: none; }
.tooltipdemoBasicUsage .left {
  top: 70px !important;
  left: 56px !important; }
.tooltipdemoBasicUsage .right {
  top: 70px !important;
  right: 56px !important; }

JS

angular.module('MyApp')
.controller('AppCtrl', function($scope) {
  $scope.demo = {};
});

Adding this CSS seems to work in your case (with the <br>s):

md-tooltip .md-content {
    height: auto;
}

I'm not sure why Angular-Material hard-coded the height to 22px. You'll need to check whether this change breaks other tooltips.

Or you can apply it specifically to this use case only by giving it a class, e.g. tt-multiline, so you can target it in CSS:

md-tooltip.tt-multiline .md-content {
    height: auto;
}

Edit: Starting from Angular-Material 1.1, some class names have changed to start with a underscore.

In this case use

md-tooltip ._md-content {
    height: auto;
}

and for specific class

md-tooltip.tt-multiline ._md-content {
    height: auto;
}

Since angular-material version >1.1.2 you can simply override .md-tooltip class:
(JsFiddle)

.md-tooltip {
    height: auto;
}

HTML

<md-tooltip class="tooltip-multiline">
    I'm a multiline <br/> tooltip
</md-tooltip>

CSS

.tooltip-multiline {
  height: auto;
}

both cases tested in angular-material 1.1.2, 1.1.3 and 1.1.4 versions

Set the max-with's below to what ever you need. Now it will do automatic line breaks or put a <br/> into it.

md-tooltip .md-content {
    height: auto !important;
    max-width: 200px !important;
    font-size: 13px !important;
}

md-tooltip {
    height: auto !important;
    max-width: 200px !important;
    font-size: 13px !important;
    overflow: visible !important;
    white-space: normal !important;
}

md-tooltip ._md-content {
    height: auto !important;
    max-width: 200px !important;
    font-size: 13px !important;
}

You can view the styling for md-tooltip (v0.11.4) here: https://cdnjs.cloudflare.com/ajax/libs/angular-material/0.11.4/angular-material.css

My own overwrites to the material design styling to allow nice looking multi-line tooltips:

md-tooltip {
  font-family: Roboto, 'Helvetica Neue', sans-serif;
  .md-background {
    border-radius: inherit;
  }
  .md-content {
    height: auto;
    width: 400px;
    max-width: 400px;
    padding: 8px;
    white-space: initial;
  }
}
@media screen and (min-width: 600px) {
  md-tooltip .md-content {
    font-size: 14px;
    height: auto;
    width: 300px;
    padding: 8px;
    max-width: 300px;
  }
}

Or you can use white-space: pre-line; in the custom class of your md tooltip. :)