On hover change SVG from colour to gradient with a transition - html

Question

I have an SVG image which I would like to change from a block colour to a gradient. I have got this working, however I would like to have a transition or animation. Is this possible - if so how would it be achieved?
http://jsfiddle.net/otaxjpa2/
HTML:
<svg width="96px" height="96px" viewBox="0 0 512 512" enable-background="new 0 0 512 512" xml:space="preserve">
<defs>
<linearGradient id="gradient" gradientUnits="userSpaceOnUse" fy="90%" >
<stop offset="0" style="stop-color:#1EBEE0"/>
<stop offset="1" style="stop-color:#952491"/>
<animate attributeName="fy"from="0" to="1" dur="5s" repeatCount="indefinite" />
</linearGradient>
</defs>
<path id="time-3-icon" d="M256,50C142.229,50,50,142.229,50,256c0,113.77,92.229,206,206,206c113.77,0,206-92.23,206-206
C462,142.229,369.77,50,256,50z M256,417c-88.977,0-161-72.008-161-161c0-88.979,72.008-161,161-161c88.977,0,161,72.007,161,161
C417,344.977,344.992,417,256,417z M382.816,265.785c1.711,0.297,2.961,1.781,2.961,3.518v0.093c0,1.72-1.223,3.188-2.914,3.505
c-37.093,6.938-124.97,21.35-134.613,21.35c-13.808,0-25-11.192-25-25c0-9.832,14.79-104.675,21.618-143.081
c0.274-1.542,1.615-2.669,3.181-2.669h0.008c1.709,0,3.164,1.243,3.431,2.932l18.933,119.904L382.816,265.785z"/>
</svg>
CSS:
svg {
fill: blue;
transition: all 0.3s ease;
display: inline-block;
-webkit-transition: fill .4s ease;
-moz-transition: fill .4s ease;
-o-transition: fill .4s ease;
transition: fill .4s ease;
}
svg:hover {
fill: url(#gradient);
}
Any pointers would be much appreciated!

Answer 1

You can avoid using two rects by transitioning the stop-colors instead:
svg {
display: inline-block;
}
stop {
transition: .4s ease;
}
/* Use the colors to transition to */
svg:hover stop:first-child {
stop-color: #1EBEE0;
}
svg:hover stop:last-child {
stop-color: #952491;
}
<svg width="96px" height="96px" viewBox="0 0 512 512" enable-background="new 0 0 512 512" xml:space="preserve">
<defs>
<linearGradient id="gradient" gradientUnits="userSpaceOnUse" fy="90%">
<stop offset="0" stop-color="blue" /> <!-- Colors to transition from -->
<stop offset="1" stop-color="blue" />
</linearGradient>
<mask id="clock-icon-mask" maskUnits="userSpaceOnUse" x="0" y="0" width="512" height="512">
<path d="M256,50C142.229,50,50,142.229,50,256c0,113.77,92.229,206,206,206c113.77,0,206-92.23,206-206C462,142.229,369.77,50,256,50z M256,417c-88.977,0-161-72.008-161-161c0-88.979,72.008-161,161-161c88.977,0,161,72.007,161,161C417,344.977,344.992,417,256,417z M382.816,265.785c1.711,0.297,2.961,1.781,2.961,3.518v0.093c0,1.72-1.223,3.188-2.914,3.505c-37.093,6.938-124.97,21.35-134.613,21.35c-13.808,0-25-11.192-25-25c0-9.832,14.79-104.675,21.618-143.081c0.274-1.542,1.615-2.669,3.181-2.669h0.008c1.709,0,3.164,1.243,3.431,2.932l18.933,119.904L382.816,265.785z"
fill="white" />
</mask>
</defs>
<g mask="url(#clock-icon-mask)">
<rect x="0" y="0" width="512" height="512" fill="url(#gradient)" />
</g>
</svg>
Here's a demo of the technique using a simplified shape (no mask required).

Answer 2

Put the two fill styles on overlapping <rect> objects, and use the clock icon as a mask object applied to both <rect> objects. You can then animate the apparent fill style by animating the opacity of the uppermost <rect>. Remember to apply a white fill to the mask object (white=opaque, black=transparent).
If the following snippet doesn't work, try this jsfiddle link.
#clock-gradient {
opacity: 0.0;
display: inline-block;
-webkit-transition: opacity .4s ease;
-moz-transition: opacity .4s ease;
-o-transition: opacity .4s ease;
transition: opacity .4s ease;
}
#clock-gradient:hover {
opacity: 1.0;
}
<svg width="96px" height="96px" viewBox="0 0 512 512" xmlns:xlink="http://www.w3.org/1999/xlink">
<defs>
<linearGradient id="gradient" gradientUnits="userSpaceOnUse" fy="90%">
<stop offset="0" style="stop-color:#1EBEE0" />
<stop offset="1" style="stop-color:#952491" />
</linearGradient>
<mask id="clock-icon-mask" maskUnits="userSpaceOnUse" x="0" y="0" width="512" height="512">
<path d="M256,50C142.229,50,50,142.229,50,256c0,113.77,92.229,206,206,206c113.77,0,206-92.23,206-206C462,142.229,369.77,50,256,50z M256,417c-88.977,0-161-72.008-161-161c0-88.979,72.008-161,161-161c88.977,0,161,72.007,161,161C417,344.977,344.992,417,256,417z M382.816,265.785c1.711,0.297,2.961,1.781,2.961,3.518v0.093c0,1.72-1.223,3.188-2.914,3.505c-37.093,6.938-124.97,21.35-134.613,21.35c-13.808,0-25-11.192-25-25c0-9.832,14.79-104.675,21.618-143.081c0.274-1.542,1.615-2.669,3.181-2.669h0.008c1.709,0,3.164,1.243,3.431,2.932l18.933,119.904L382.816,265.785z" fill="white" />
</mask>
</defs>
<g mask="url(#clock-icon-mask)">
<rect x="0" y="0" width="512" height="512" fill="blue" />
<rect id="clock-gradient" x="0" y="0" width="512" height="512" fill="url(#gradient)" />
</g>
</svg>