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Setting the font color
We have learned about the style property and changed the font color in the article. Muffin wants the font color to change to the one that the user selected from the “Font Color” dropdown list. We already worked with dropdown lists in the previous chapter.
The “Font Color” list has 18 values. The user can select one of them by expanding the list and clicking on the desired color:
The selected value is stored in the value property in the dropdown list. To change the color of the text to the one that the user selected, we need to write the selected value to the style property of the article.
The font color should change when the user selects a new value. Therefore, use the onchange event handler. For example:
// Find the dropdown list
let select = document.querySelector('select');
// Add the event handler to the list
select.onchange = function () {
// Change the font color to the selected value
longread.style.color = select.value;
};The “Font Color” list on the news site has the color-setting class. Find it and save it as a variable. Then add the event handler to the list and change the font color in the article to the selected value.
Files
- article.html
- read-mode.js
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<link rel="stylesheet" href="setting.css">
<link rel="stylesheet" href="style.css">
<title>FlashNews!</title>
</head>
<body class="page page-longread light-theme">
<header class="page-header">
<div class="container">
<a class="header-logo" href="index.html">
<img src="img/main-logo.svg" width="67" height="29" alt="FlashNews! portal logo">
</a>
<a href="subscription.html" class="subscription-link">Subscription</a>
<button class="theme-button" type="button">Change the theme</button>
</div>
</header>
<main class="index-main">
<div class="controls">
<div class="container">
<div class="color-filters">
<label>Font color:
<select class="filter color-setting" name="font-color">
<option value="inherit" selected>Default</option>
<option value="black">Black</option>
<option value="white">White</option>
<option value="ghostwhite">Light gray</option>
<option value="pink">Pink</option>
<option value="darkred">Dark red</option>
<option value="darkorange">Orange</option>
<option value="saddlebrown">Brown</option>
<option value="gold">Gold</option>
<option value="greenyellow">Lime green</option>
<option value="forestgreen">Green</option>
<option value="aquamarine">Aquamarine</option>
<option value="lightskyblue">Sky blue</option>
<option value="lightsteelblue">Gray blue</option>
<option value="darkblue">Navy blue</option>
<option value="indigo">Indigo</option>
<option value="mediumpurple">Violet</option>
<option value="purple">Purple</option>
</select>
</label>
<label>Background color:
<select class="filter background-setting" name="background-color">
<option value="inherit" selected>Default</option>
<option value="black">Black</option>
<option value="white">White</option>
<option value="ghostwhite">Light gray</option>
<option value="pink">Pink</option>
<option value="darkred">Dark red</option>
<option value="darkorange">Orange</option>
<option value="saddlebrown">Brown</option>
<option value="gold">Gold</option>
<option value="greenyellow">Lime green</option>
<option value="forestgreen">Green</option>
<option value="aquamarine">Aquamarine</option>
<option value="lightskyblue">Sky blue</option>
<option value="lightsteelblue">Gray blue</option>
<option value="darkblue">Navy blue</option>
<option value="indigo">Indigo</option>
<option value="mediumpurple">Violet</option>
<option value="purple">Purple</option>
</select>
</label>
</div>
<label>Font size (<span class="pixels">14</span>px)
<input class="size-setting" type="range" min="8" max="48" step="1" value="14">
</label>
</div>
</div>
<article class="longread">
<div class="container">
<h1>Why Do We Need Algorithms?</h1>
<p>Many people are afraid of the word "algorithm." It can seem to them that this is something complicated, but in reality it is just a complete set of instructions. It turns out that you use algorithms in your everyday life, such as, for example, when you cook according to a recipe, or you get from point A to point B using your GPS navigation, or you solve a quadratic equation.</p>
<p>When developers talk about algorithms, they are not referring to just any kind of algorithm, but only to what are considered the popular solutions to standard problems. Many algorithms were invented even before there were computers: for example, the radix sorting algorithm was patented in the United States in the nineteenth century to process census data.</p>
<p>Various algorithms can be used effectively to solve the same problem. Imagine that you have a list in which you want to find an element. Let's assume that this is a list of products for sale in an online store, and the user enters a product name in the filter that starts with the letter "E". How can we do that?</p>
<p>If the list is sorted alphabetically, then a binary search is the most suitable: you look in the middle of the list and find a product there whose name begins with "K", for example. The list is sorted, so you know for sure that the product you need is on the left side of the list, because "E" occurs before "K" in the alphabet. Now take the left side of the list and perform another binary search on it.</p>
<p>If the list is not sorted, then a brute force search is better. According to this method, you go through the list from the beginning to the end until you find the element that you are interested in. In the worst case scenario, you will have to look through all of the elements, but then at least you will have advanced knowledge of the amount of time that is required to find the desired item.</p>
<p>You need to select the appropriate algorithm for the problem at hand. Gain an understanding of the data that you are working with, and build on that.</p>
</div>
</article>
</main>
<footer class="page-footer">
<div class="container">
<p>© FlashNews!</p>
<a class="footer-logo">
<img src="img/white-logo.svg" alt="FlashNews! portal logo">
</a>
</div>
</footer>
<script src="themes.js"></script>
<script src="read-mode.js"></script>
</body>
</html>
/* Longread styles */
.controls {
padding: 16px 0 6px;
overflow-x: hidden;
}
.controls label {
font-size: 14px;
line-height: 24px;
margin-bottom: 14px;
}
.color-filters {
display: flex;
margin-right: -20px;
}
.color-filters label {
display: flex;
flex-direction: column;
flex-grow: 1;
margin-right: 20px;
}
.color-filters .filter {
margin-top: 4px;
}
.controls .filter {
margin-left: 0;
}
.longread {
min-height: calc(100vh - 237px);
padding-bottom: 1em;
font-size: 14px;
}
.longread h1 {
margin: 1em 0 0.6em;
line-height: 1.2;
}
.longread p {
margin: 0 0 0.8em;
line-height: 1.6;
}
/* Cross-browser range input without JavaScript */
.size-setting {
-webkit-appearance: none;
-moz-appearance: none;
appearance: none;
display: block;
width: 100%;
height: 10px;
margin-top: 8px;
padding: 2px 0;
border-radius: 5px;
outline-offset: 0;
}
.size-setting::-webkit-slider-thumb {
box-sizing: border-box;
-webkit-appearance: none;
width: 20px;
height: 20px;
border-radius: 50%;
}
.size-setting::-moz-range-thumb {
box-sizing: border-box;
-moz-appearance: none;
width: 20px;
height: 20px;
border-radius: 50%;
}
.size-setting::-ms-thumb {
box-sizing: border-box;
width: 20px;
height: 20px;
border-radius: 50%;
}
/* Color themes */
.page-longread.light-theme {
background-color: #ffffff;
color: #333333;
}
.light-theme .controls {
background-color: #eae9f2;
}
.light-theme .size-setting {
background-color: #ffffff;
box-shadow: inset 0 0 0 1px #b6aaff;
outline-color: #b6aaff;
}
.light-theme .size-setting::-webkit-slider-thumb {
background-color: #ffffff;
border: 5px solid #6653d9;
}
.light-theme .size-setting::-moz-range-thumb {
background-color: #ffffff;
border: 5px solid #6653d9;
}
.light-theme .size-setting::-ms-thumb {
background-color: #ffffff;
border: 5px solid #6653d9;
}
.light-theme .size-setting::-webkit-slider-thumb:active {
background-color: #6653d9;
}
.light-theme .size-setting::-moz-range-thumb:active {
background-color: #6653d9;
}
.light-theme .size-setting::-ms-thumb:active {
background-color: #6653d9;
}
.page-longread.dark-theme {
background-color: #0a0910;
color: #f2f2f2;
}
.dark-theme .controls {
background-color: #17161a;
}
.dark-theme .size-setting {
background-color: #0a0910;
box-shadow: inset 0 0 0 1px #473c8d;
outline-color: #6653d9;
}
.dark-theme .size-setting::-webkit-slider-thumb {
background-color: #0a0910;
border: 5px solid #9484f2;
}
.dark-theme .size-setting::-moz-range-thumb {
background-color: #0a0910;
border: 5px solid #9484f2;
}
.dark-theme .size-setting::-ms-thumb {
background-color: #0a0910;
border: 5px solid #9484f2;
}
.dark-theme .size-setting::-webkit-slider-thumb:active {
background-color: #9484f2;
}
.dark-theme .size-setting::-moz-range-thumb:active {
background-color: #9484f2;
}
.dark-theme .size-setting::-ms-thumb:active {
background-color: #9484f2;
}
let longread = document.querySelector('.longread');
// Declare a variable here
longread.style.color = 'purple';
let page = document.querySelector('.page');
let themeButton = document.querySelector('.theme-button');
themeButton.onclick = function () {
page.classList.toggle('light-theme');
page.classList.toggle('dark-theme');
};
- article.html
- style.css
- read-mode.js
- themes.js
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<!DOCTYPE html>
<html lang="en">
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let longread = document.querySelector('.longread');
// Declare a variable here
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Thanks! We’ll fix everything at once!
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Console
- On line 2, declare a variable
colorSettingand assign an element with thecolor-settingclass to it. - Below, add the
onchangeevent handler to thecolorSettingelement. - Place the
longread.style.color = 'purple';instruction inside the handler. - Inside the handler, change
'purple'to the selected value from the drop-down list:colorSetting.value. - In the mini-browser, select the value “Orange” from the “Font Color” dropdown list. Please note that the font color in the article is now orange.
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