w3c · scottaohara · Sep 5, 2024 · Sep 5, 2024 · Sep 6, 2024 · Sep 6, 2024
diff --git a/techniques/general/g20x.html b/techniques/general/g20x.html
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+<!DOCTYPE html>
+<html lang="en" xml:lang="en" xmlns="http://www.w3.org/1999/xhtml">
+  <head>
+    <title>Accounting for meaningful text indentation and Reflow</title>
+    <link rel="stylesheet" href="../../css/sources.css" class="remove"/>
+  </head>
+  <body>
+    <h1>Accounting for meaningful text indentation and Reflow</h1>
+    <section class="meta"><p class="id">ID: G206</p><p class="technology">Technology: general</p><p class="type">Type: Technique</p></section>
+    <section id="applicability">
+      <h2>When to Use</h2>
+      <p>All technologies that support style switching</p>
+    </section>
+
+    <section id="description">
+      <h2>Description</h2>
+      <p>There are instances where indentation of text is considered important to the understandability of the text content. If the indentations were to be removed, then meaning or functionality could suffer. For instance, the nesting of unordered list hierarchies would become more difficult to notice if indentation were removed. Additionally, maintaining indentations can be important to help understand code patterns, if not even necessary for the code to function.</p>
+      <p>Maintaining indentation is important for these instances of text, and would be considered essential for two-dimensional scrolling if the text were enlarged and could not be fully presented within the available viewport. However, there are still styling modifications that could be made to help ensure the indentation was maintained, but as much text was made visible within the viewport as possible.</p>
+      </div>
+   </section>
+
+    <section id="examples">
+      <h2>Examples</h2>
+      <section class="example">
+        <p>A website conveys information in a nested list format. The understandability of the list hierarchy is supported by the indentation of the list content. While it is important for the individual list item text to reflow, the list hierarchy would suffer if flattened so that all content would fit within a 320 CSS pixel wide container.</p>  
+        <p>The following example list contains additional nested lists to provide more context for each of the parent list item's text. To maintain the visual hierarchy, the indentation of the lists is maintained, but reduced once an author defined CSS breakpoint is met. The container of the text content of each list item is given a maximum width of 320 CSS pixels so that even though the list will require bi-dimensional scrolling to view all nested lists, each list item in each nested list level will be able to be read witout the need to scroll in two directions.</p>
+<pre>
+&lt;div class=example>
+	&lt;ul>
+		&lt;li>
+			&lt;p>Make a list using one of the HTML list elements, or even an ARIA <code>role=list</code> container.&lt;/p>
+			&lt;ul>
+				&lt;li>
+					&lt;p>There are three types of lists in HTML which can contain list items (<code>li</code> elements.&lt;/p>
+					&lt;ul>
+						&lt;li>&lt;p>the <code>ul</code> element&lt;/li>
+						&lt;li>&lt;p>the <code>ol</code> element&lt;/li>
+						&lt;li>&lt;p>the <code>menu</code> element&lt;/li>
+					&lt;/ul>
+				&lt;/li>
+				&lt;li>
+					&lt;p>Another type of list, description lists, exist as well - but they do not contain list items (<code>li</code> elements).&lt;/p>
+				&lt;/li>
+			&lt;/ul>
+		&lt;/li>
+		&lt;li>
+			&lt;p>Neither the start or end tags of any of the HTML list elements are omissible.&lt;/p>
+			&lt;ul>
+				&lt;li>&lt;p>The end tags of <code>li</code> elements can be omitted if the <code>li</code> element is immeditely followed by another <code>li</code> element or there is no more content in the parent list element.&lt;/p>
+				</li>
+				<li><p>The list marker for each <code>li</code> element is initially based on the parent list element used.</p>
+					<ul>
+						<li><p>The list maker can be modified by using CSS,</p></li>
+						<li><p>or the list marker can be modifed by using the <code>type</code> attribute, if the parent list element is an <code>ol</code> element.</p></li>
+					</ul>
+				</li>
+			</ul>
+		</li>
+		<li>
+			<p>Validate your markup.</p>
+		</li>
+	</ul>
+</div>
+</pre>
+<pre>
+@media screen and (max-width: 640px) {
+	.example {
+		overflow: auto;
+		max-width: 640px;
+	}
+	ul {
+		padding-inline-start: 1em;
+	}
+	li p {
+		max-width: 320px;
+		margin: .5em 0;
+	}
+}
+</pre>
+      </section>
+
+      <section class="example">
+        <p>A website providing code snippets needs to maintain line indentations, as the indentations are meaningful not only to the structure of the code, but in some languages - such as with Python, are requirements when defining blocks of code.</p>
+        <p>As a user zooms in the web page, the CSS of the indentation can be adjusted to maintain this necessary structure, while also allowing more text to be visible on a single line.</p>
+
+        <p>The following represents a Python code example. The indentation of each line of text is necessary to create a group of statements that are executed as a block.</p>
+<pre>
+def complex_function(x):
+    if x > 0:
+        for i in range(x):
+            if i % 2 == 0:
+                print(f"{i} is even")
+                for a in range(i):
+                    if a % 5 == 0:
+                        print(f"  {a} can be divided by 5")
+                    else:
+                        print(f"  {a} cannot be divided by 5")
+            else:
+                print(f"{i} is odd")
+                for a in range(i):
+                    if a % 2 == 0:
+                        print(f"  {a} is even")
+                    else:
+                        print(f"  {a} is odd")
+    else:
+        print("x is not a positive number")
+</pre>
+        <p>The following code example demonstrates the use of indentation to convey the nesting of elements in an HTML document:</p>
+<pre>
+&lt;html lang=en>
+	&lt;head>...&lt;/head>
+	&lt;body>
+		&lt;div>
+			&lt;!-- ... keep indenting as necessary  -->
+		&lt;/div>
+	&lt;/body>
+&lt;/html>
+</pre>     
+        <p>The indentation of code blocks like these could be adjusted at different viewport sizies, via a CSS Media Query.</p>
+<pre>
+@media screen and ( min-width: 320px ) {
+	pre {
+		tab-size: 8px;
+	}
+}
+
+@media screen and ( min-width: 640px ) {
+	pre {
+		tab-size: 16px;
+	}
+}
+
+@media screen and ( min-width: 1280px ) {
+	pre {
+		tab-size: 32px;
+	}
+}
+</pre>
+        </section>
+    </section>
+
+    <section id="tests">
+      <h2>Tests</h2>
+      <section class="procedure"><h3>Procedure</h3>
+         <ol>
+            <li>Open the content that requires horizontal scrolling on a full screen window. </li>
+            <li>Zoom in or resize the browser window so that the viewport 
+         </ol>
+      </section>
+      <section class="results"><h3>Expected Results</h3>
+         <ul>
+            <li>Checks X are true.</li>
+         </ul>
+      </section>
+    </section>
+    <section id="related">
+      <h2>Related Techniques</h2>
+      <ul>
+      <li><a href="../css/C20">C20</a></li>
+      </ul>
+    </section>
+  </body>
+</html>
diff --git a/techniques/general/g20x2.html b/techniques/general/g20x2.html
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+<!DOCTYPE html>
+<html lang="en" xml:lang="en" xmlns="http://www.w3.org/1999/xhtml">
+   <head>
+      <title>Section panels that scroll horizontally are designed to fit within a width of 320 CSS pixels on a vertically scrolling page</title>
+      <link rel="stylesheet" type="text/css" href="../../css/sources.css" class="remove"/>
+   </head>
+   <body>
+      <h1>Section panels that scroll horizontally are designed to fit within a width of 320 CSS pixels on a vertically scrolling page</h1>
+      <section class="meta">
+         <p class="id">ID: </p>
+         <p class="technology">Technology: general</p>
+         <p class="type">Type: Technique</p>
+      </section>
+      <section id="applicability">
+         <h2>When to Use</h2>
+         <p>All technologies.</p>
+      </section>
+      <section id="description">
+         <h2>Description</h2>
+         <p>The objective of this technique is to ensure that users can zoom in on text within a horizontally scrolling section, while not requiring horizontal scrolling to read the content of each individual panel. Although the entire section requires horizontal scrolling to navigate between panels, each panel is designed to fit within a fixed width of 320 CSS pixels. This ensures that when a 320 CSS pixel wide viewport is used, and the card is in the viewport, each card will remain fully visible without the need for additional horizontal scrolling to read its content.</p>
+      </section>
+      <section id="examples">
+         <h2>Examples</h2>
+         <section class="example">
+             <h3>A product carousel</h3>
+             <p>The homepage of an online retail website includes several informational sections, some of which feature carousels showcasing highlighted products. These carousels require horizontal scrolling and have a computed height greater than 256 CSS pixels. Each panel is 320 CSS pixels wide, allowing users to see the full width of the card without horizontal scrolling. Consequently, users only need to scroll vertically to view the entire card, ensuring compliance with success criterion 1.4.10 Reflow for that section.</p>
+             <p>Working example: <a href="../../working-examples/reflow-carousel-panel-horizontal-scroll/">Carousel panels that scroll horizontally are designed to fit within a width of 320 CSS pixels on a vertically scrolling page</a>.
+         </section>
+      </section>
+      <section id="tests">
+         <h2>Tests</h2>
+         <section class="procedure">
+            <h3>Procedure</h3>
+            <ol>
+              <li>Check that the layout includes sections of content that scroll horizontally within a vertically scrolling page.</li>
+              <li>Check that each horizontally scrolling section is divided into distinct panels.</li>
+              <li>Open the webpage in a user agent that supports 400% zoom, setting the viewport dimensions to 1280 CSS pixels in width.</li>
+              <li>Activate the zoom function to enlarge the view by 400%.</li>
+              <li>Check that the content of each individual panel within the horizontally scrolling sections is fully readable without the need for additional horizontal scrolling.</li>
+            </ol>
+            <div class="note">
+               <p class="note-title marker">Note</p>
+               <div>
+                  <p>The native browser scrollbar is not included in the viewport dimensions. Therefore, when setting the view to 1280 CSS pixels wide for a vertically scrolling page, make sure to exclude the scrollbar width.</p>
+               </div>
+            </div>
+         </section>
+         <section class="results">
+            <h3>Expected Results</h3>
+            <ul>
+              <li>All checks above are true.</li>
+            </ul>
+         </section>
+      </section>
+      <section id="related">
+         <h2>Related Techniques</h2>
+         <ul>
+            <li><a href="../general/G206">G206</a></li>
+            <li><a href="../client-side-script/SCR34">SCR34</a></li>
+         </ul>
+      </section>
+   </body>
+</html>
diff --git a/understanding/21/img/carousel-large-screen.png b/understanding/21/img/carousel-large-screen.png
diff --git a/understanding/21/img/code-diff.gif b/understanding/21/img/code-diff.gif
diff --git a/understanding/21/img/exception-does-not-extend.jpg b/understanding/21/img/exception-does-not-extend.jpg
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diff --git a/understanding/21/img/news-large-screen.png b/understanding/21/img/news-large-screen.png
diff --git a/understanding/21/img/news-reflow.png b/understanding/21/img/news-reflow.png
diff --git a/understanding/21/img/reflow-no-sticky-ad.png b/understanding/21/img/reflow-no-sticky-ad.png
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diff --git a/understanding/21/img/rich-document-with-comment.png b/understanding/21/img/rich-document-with-comment.png
diff --git a/understanding/21/img/single-carousel-panel.png b/understanding/21/img/single-carousel-panel.png
diff --git a/understanding/21/img/table-exception.jpg b/understanding/21/img/table-exception.jpg
diff --git a/understanding/21/img/unnecessary-horizontal-scrollbar.jpg b/understanding/21/img/unnecessary-horizontal-scrollbar.jpg