Please see my code below. I need to highlight those area that selected in the dropdown option.
<select name="hightlight" multiple>
<option value="20">20</option>
<option value="21">21</option>
<option value="22">22</option>
<option value="23">23</option>
<option value="24">24</option>
<option value="25">25</option>
<option value="26">26</option>
<option value="27">27</option>
<option value="28">28</option>
<option value="29">29</option>
<option value="30">30</option>
</select>
<div class="inner-profile-map1">
<img src="images/plot_map.png" alt="" usemap="#Map">
</div>
<map name="Map">
<area class="area1 thumbLink area_21" shape="poly" coords="115,315,64,270,103,229,151,273">
<area class="area2 thumbLink area_22" shape="poly" coords="155,269,106,225,142,185,191,230">
<area class="area3 thumbLink area_21" shape="poly" coords="147,182,182,144,231,187,194,227">
<area class="area4 thumbLink area_23" shape="poly" coords="185,140,241,77,267,137,274,145,236,183" >
<area class="area5 thumbLink area_20" shape="poly" coords="278,143,270,134,246,75,253,66,315,62,319,131,302,131">
<area class="area6 thumbLink area_20" shape="poly" coords="325,129,320,63,368,60,370,126">
<area class="area7 thumbLink area_20" shape="poly" coords="375,127,374,60,445,56,422,131,406,127">
<area class="area8 thumbLink area_22" shape="poly" coords="446,149,497,95,537,131,487,186">
<area class="area9 thumbLink area_23" shape="poly" coords="490,189,540,134,579,168,527,225">
<area class="area10 thumbLink area_23" shape="poly" coords="531,227,582,172,620,207,569,263">
<area class="area11 thumbLink area_28" shape="poly" coords="573,266,624,210,663,246,611,300">
<area class="area12 thumbLink area_29" shape="poly" coords="616,304,666,249,704,284,653,338">
<area class="area13 thumbLink area_29" shape="poly" coords="657,343,709,288,747,323,697,378">
<area class="area14 thumbLink area_27" shape="poly" coords="702,382,752,327,790,361,740,417">
<area class="area15 thumbLink area_27" shape="poly" coords="743,420,794,365,831,400,782,456">
<area class="area16 thumbLink area_23" shape="poly" coords="787,460,838,404,876,442,829,498">
<area class="area17 thumbLink area_23" shape="poly" coords="766,480,807,518,768,564,727,525">
<area class="area18 thumbLink area_20" shape="poly" coords="724,441,763,476,723,520,684,486">
<area class="area19 thumbLink area_20" shape="poly" coords="680,402,719,438,680,481,642,445">
<area class="area20 thumbLink area_20" shape="poly" coords="638,363,677,397,637,441,600,406">
<area class="area21 thumbLink area_25" shape="poly" coords="594,323,635,360,595,403,557,367">
<area class="area22 thumbLink area_25" shape="poly" coords="219,256,256,217,299,255,263,296">
<area class="area23 thumbLink area_24" shape="poly" coords="183,299,217,260,258,300,224,335">
<area class="area24 thumbLink area_26" shape="poly" coords="143,340,180,302,221,341,186,379">
</map>
</div>
When i change dropdown i need to highlight those area that match area class. i have tried to do for CSS and JQuery but both are not work. Please let me know how i do this.
window.addEventListener('load', function() {
/* GET FIRST IMAGE TAG AND ADD SOME CSS TO IT */
var img = document.querySelector('img');
img.style.position = 'absolute';
img.style.display = 'block';
img.style.border = '1px solid red';
/* CANVAS ELEMENT CREATION, AND SOME CSS */
var canvas = document.createElement('canvas');
canvas.style.border = '1px solid blue';
canvas.style.position = 'absolute';
canvas.style.pointerEvents = 'none';
canvas.width = img.clientWidth;
canvas.height = img.clientHeight;
/* INSERTES 'canvas' TO '.inner-profile-map1' */
var wrap = document.querySelector('.inner-profile-map1');
wrap.appendChild(canvas);
/* GETS THE CANVAS CONTEXT */
var ctx = canvas.getContext('2d');
var select = document.body.querySelector('select');
/* ADDS BACKGROUND COLOR TO EACH OPTION */
select.querySelectorAll('option').forEach(function(option) {
option.style.backgroundColor = option.getAttribute('data-color');
});
/* LISTENS FOR SELECT CHANGE */
select.addEventListener('change', function(event) {
/* CLEARS WHOLE CANVAS */
ctx.clearRect(0, 0, canvas.width, canvas.height);
/* GET ALL SELECTED OPTIONS */
var options = this.querySelectorAll('option:checked');
/* FOR EACH OPTION GET COORDINATES, DATA-COLOR AND DRAW COORDINATES */
options.forEach(function(option) {
/* FINDS ALL AREAS ASSOCIATED WITH OPTION */
var areas = document.body.querySelectorAll(`.area_${option.value}`);
var color = option.getAttribute('data-color') || 'rgba(255, 255, 255, 0.5)';
/* DRAW EACH AREA COORDINATES */
areas.forEach(function(area) {
var coords = area.getAttribute('coords').split(',');
/* DRAW THE AREA COORDINATES */
ctx.beginPath();
ctx.moveTo(coords[0], coords[1]);
for (var n=2; n<coords.length; n+=2) {
ctx.lineTo(coords[n], coords[n+1]);
}
ctx.lineTo(coords[0], coords[1]);
ctx.fillStyle = color;
ctx.stroke();
ctx.fill();
});
});
});
});<select name="hightlight" multiple>
<option value="20" data-color="rgba(255, 0, 0, 0.5)">20</option>
<option value="21" data-color="rgba(255, 0, 255, 0.5)">21</option>
<option value="22" data-color="rgba(0, 255, 0, 0.5)">22</option>
<option value="23">23</option>
<option value="24">24</option>
<option value="25">25</option>
<option value="26">26</option>
<option value="27">27</option>
<option value="28">28</option>
<option value="29">29</option>
<option value="30">30</option>
</select>
<div class="inner-profile-map1">
<img src="https://i.sstatic.net/J3uwz.jpg" alt="" usemap="#Map">
</div>
<map name="Map">
<area class="area1 thumbLink area_21" shape="poly" coords="115,315,64,270,103,229,151,273">
<area class="area2 thumbLink area_22" shape="poly" coords="155,269,106,225,142,185,191,230">
<area class="area3 thumbLink area_21" shape="poly" coords="147,182,182,144,231,187,194,227">
<area class="area4 thumbLink area_23" shape="poly" coords="185,140,241,77,267,137,274,145,236,183" >
<area class="area5 thumbLink area_20" shape="poly" coords="278,143,270,134,246,75,253,66,315,62,319,131,302,131">
<area class="area6 thumbLink area_20" shape="poly" coords="325,129,320,63,368,60,370,126">
<area class="area7 thumbLink area_20" shape="poly" coords="375,127,374,60,445,56,422,131,406,127">
<area class="area8 thumbLink area_22" shape="poly" coords="446,149,497,95,537,131,487,186">
<area class="area9 thumbLink area_23" shape="poly" coords="490,189,540,134,579,168,527,225">
<area class="area10 thumbLink area_23" shape="poly" coords="531,227,582,172,620,207,569,263">
<area class="area11 thumbLink area_28" shape="poly" coords="573,266,624,210,663,246,611,300">
<area class="area12 thumbLink area_29" shape="poly" coords="616,304,666,249,704,284,653,338">
<area class="area13 thumbLink area_29" shape="poly" coords="657,343,709,288,747,323,697,378">
<area class="area14 thumbLink area_27" shape="poly" coords="702,382,752,327,790,361,740,417">
<area class="area15 thumbLink area_27" shape="poly" coords="743,420,794,365,831,400,782,456">
<area class="area16 thumbLink area_23" shape="poly" coords="787,460,838,404,876,442,829,498">
<area class="area17 thumbLink area_23" shape="poly" coords="766,480,807,518,768,564,727,525">
<area class="area18 thumbLink area_20" shape="poly" coords="724,441,763,476,723,520,684,486">
<area class="area19 thumbLink area_20" shape="poly" coords="680,402,719,438,680,481,642,445">
<area class="area20 thumbLink area_20" shape="poly" coords="638,363,677,397,637,441,600,406">
<area class="area21 thumbLink area_25" shape="poly" coords="594,323,635,360,595,403,557,367">
<area class="area22 thumbLink area_25" shape="poly" coords="219,256,256,217,299,255,263,296">
<area class="area23 thumbLink area_24" shape="poly" coords="183,299,217,260,258,300,224,335">
<area class="area24 thumbLink area_26" shape="poly" coords="143,340,180,302,221,341,186,379">
</map>
</div>