More actions

The animation is often used when we show additional actions inside a menu or popover.

Layout

You can use a SVG element to create the plus icon inside the button. Another approach seen in the demo above uses two different elements representing the :before and :after selectors of the button.

To archive that, we use the relative position of the button:

.btn {
    position: relative;
}

The vertical line represents the :before selector which is positioned absolutely:

.btn::before {
    background: #4b5563;

    /* Absolute position */
    content: '';
    position: absolute;
    bottom: 0.25rem;
    top: 0.25rem;

    /* Size */
    width: 1px;
}

The vertical line is displayed at the center of the button exactly via two CSS declarations:

.btn::before {
    left: 50%;
    transform: translate(-50%, 0);
}

In the same way, the :after selector can be used to represent the horizontal line:

.btn::after {
    background: #4b5563;

    /* Absolute position */
    content: '';
    position: absolute;
    left: 0.25rem;
    right: 0.25rem;

    /* Display at the center horizontally */
    top: 50%;
    transform: translate(0, -50%);

    /* Size */
    height: 1px;
}

To display the popover or menu right under the button, you can organize the layout as follows:

<div class="container">
    <!-- The button -->
    <button class="btn"></button>

    <!-- The additional contents -->
    <div class="popover">...</div>
</div>

The popover should be positioned absolutely to its container:

.container {
    position: relative;
}

.popover {
    position: absolute;
    left: 0;
    top: 100%;
    margin-top: 0.5rem;
}

You can take a look at the popover arrow pattern if you want to include an arrow at the top left corner of the popover

Animation

When users click the button, it will be rotated by 45 degrees. The target variant has the following styles:

.btn--rotate {
    transform: rotate(45deg);
}

To animate the button, we can add a transition for the transform property:

.btn {
    transform-origin: center center;
    transition: transform 100ms;
}

Clicking the button needs to toggle the btn--rotate class, assuming that the buttonEle variable represents the button element:

buttonEle.addEventListener('click', () => {
    buttonEle.classList.toggle('btn--rotate');
});