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| author | Craig Jennings <c@cjennings.net> | 2024-04-07 13:41:34 -0500 |
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| committer | Craig Jennings <c@cjennings.net> | 2024-04-07 13:41:34 -0500 |
| commit | 754bbf7a25a8dda49b5d08ef0d0443bbf5af0e36 (patch) | |
| tree | f1190704f78f04a2b0b4c977d20fe96a828377f1 /devdocs/html/element%2Finput%2Fbutton.html | |
new repository
Diffstat (limited to 'devdocs/html/element%2Finput%2Fbutton.html')
| -rw-r--r-- | devdocs/html/element%2Finput%2Fbutton.html | 290 |
1 files changed, 290 insertions, 0 deletions
diff --git a/devdocs/html/element%2Finput%2Fbutton.html b/devdocs/html/element%2Finput%2Fbutton.html new file mode 100644 index 00000000..b926aa14 --- /dev/null +++ b/devdocs/html/element%2Finput%2Fbutton.html @@ -0,0 +1,290 @@ +<header><h1><input type="button"></h1></header><div class="section-content"><p><a href="../input"><code><input></code></a> elements of type <code>button</code> are rendered as simple push buttons, which can be programmed to control custom functionality anywhere on a webpage as required when assigned an event handler function (typically for the <a href="https://developer.mozilla.org/en-US/docs/Web/API/Element/click_event"><code>click</code></a> event).</p></div> +<h2 id="try_it">Try it</h2> +<div class="section-content"> +<iframe class="interactive is-tabbed-shorter-height" height="200" src="https://interactive-examples.mdn.mozilla.net/pages/tabbed/input-button.html" title="MDN Web Docs Interactive Example" loading="lazy"></iframe> <div class="notecard note" id="sect1"> <p><strong>Note:</strong> While <code><input></code> elements of type <code>button</code> are still perfectly valid HTML, the newer <a href="../button"><code><button></code></a> element is now the favored way to create buttons. Given that a <a href="../button"><code><button></code></a>'s label text is inserted between the opening and closing tags, you can include HTML in the label, even images.</p> </div> +</div> +<h2 id="value">Value</h2> + +<h3 id="button_with_a_value">Button with a value</h3> +<div class="section-content"> +<p>An <code><input type="button"></code> elements' <a href="../input#value"><code>value</code></a> attribute contains a string that is used as the button's label.</p> <div class="code-example"> +<p class="example-header"><span class="language-name">html</span></p> +<pre data-signature="JqVC4tPMlE5RotIvKU43OjyMFWO8EuqD99h7OrpW+Zw=" data-language="html"><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>input</span> <span class="token attr-name">type</span><span class="token attr-value"><span class="token punctuation attr-equals">=</span><span class="token punctuation">"</span>button<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation attr-equals">=</span><span class="token punctuation">"</span>Click Me<span class="token punctuation">"</span></span> <span class="token punctuation">/></span></span> +</pre> +</div> +<div class="code-example" id="sect2"> + +<iframe class="sample-code-frame" title="Button with a value sample" id="frame_button_with_a_value" width="650" height="60" src="https://live.mdnplay.dev/en-US/docs/Web/HTML/Element/input/button/runner.html?id=button_with_a_value" loading="lazy"></iframe> +</div> +</div> +<h3 id="button_without_a_value">Button without a value</h3> +<div class="section-content"> +<p>If you don't specify a <code>value</code>, you get an empty button:</p> <div class="code-example"> +<p class="example-header"><span class="language-name">html</span></p> +<pre data-signature="mMdnhOsT5+XbTJb8nEC8Q3CWQ34A0vwjTvDpBOB+UaY=" data-language="html"><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>input</span> <span class="token attr-name">type</span><span class="token attr-value"><span class="token punctuation attr-equals">=</span><span class="token punctuation">"</span>button<span class="token punctuation">"</span></span> <span class="token punctuation">/></span></span> +</pre> +</div> +<div class="code-example" id="sect3"> + +<iframe class="sample-code-frame" title="Button without a value sample" id="frame_button_without_a_value" width="650" height="60" src="https://live.mdnplay.dev/en-US/docs/Web/HTML/Element/input/button/runner.html?id=button_without_a_value" loading="lazy"></iframe> +</div> +</div> +<h2 id="using_buttons">Using buttons</h2> +<div class="section-content"><p><code><input type="button"></code> elements have no default behavior (their cousins, <code><input type="submit"></code> and <a href="reset"><code><input type="reset"></code></a> are used to submit and reset forms, respectively). To make buttons do anything, you have to write JavaScript code to do the work.</p></div> +<h3 id="a_simple_button">A simple button</h3> +<div class="section-content"> +<p>We'll begin by creating a simple button with a <a href="https://developer.mozilla.org/en-US/docs/Web/API/Element/click_event"><code>click</code></a> event handler that starts our machine (well, it toggles the <code>value</code> of the button and the text content of the following paragraph):</p> <div class="code-example"> +<p class="example-header"><span class="language-name">html</span></p> +<pre data-signature="PLjFPG/OxR4+QwFk/mzvDznf06zy3luT81D7/VBDbY8=" data-language="html"><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>form</span><span class="token punctuation">></span></span> + <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>input</span> <span class="token attr-name">type</span><span class="token attr-value"><span class="token punctuation attr-equals">=</span><span class="token punctuation">"</span>button<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation attr-equals">=</span><span class="token punctuation">"</span>Start machine<span class="token punctuation">"</span></span> <span class="token punctuation">/></span></span> +<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>form</span><span class="token punctuation">></span></span> +<span class="token tag"><span class="token tag"><span class="token punctuation"><</span>p</span><span class="token punctuation">></span></span>The machine is stopped.<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>p</span><span class="token punctuation">></span></span> +</pre> +</div> <div class="code-example"> +<p class="example-header"><span class="language-name">js</span></p> +<pre data-signature="f+xxWKdnLr42gCDMy8ZqE2Q8nRTzncoE7P05FUQHha4=" data-language="js"><span class="token keyword">const</span> button <span class="token operator">=</span> document<span class="token punctuation">.</span><span class="token function">querySelector</span><span class="token punctuation">(</span><span class="token string">"input"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> +<span class="token keyword">const</span> paragraph <span class="token operator">=</span> document<span class="token punctuation">.</span><span class="token function">querySelector</span><span class="token punctuation">(</span><span class="token string">"p"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> + +button<span class="token punctuation">.</span><span class="token function">addEventListener</span><span class="token punctuation">(</span><span class="token string">"click"</span><span class="token punctuation">,</span> updateButton<span class="token punctuation">)</span><span class="token punctuation">;</span> + +<span class="token keyword">function</span> <span class="token function">updateButton</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span> + <span class="token keyword">if</span> <span class="token punctuation">(</span>button<span class="token punctuation">.</span>value <span class="token operator">===</span> <span class="token string">"Start machine"</span><span class="token punctuation">)</span> <span class="token punctuation">{</span> + button<span class="token punctuation">.</span>value <span class="token operator">=</span> <span class="token string">"Stop machine"</span><span class="token punctuation">;</span> + paragraph<span class="token punctuation">.</span>textContent <span class="token operator">=</span> <span class="token string">"The machine has started!"</span><span class="token punctuation">;</span> + <span class="token punctuation">}</span> <span class="token keyword">else</span> <span class="token punctuation">{</span> + button<span class="token punctuation">.</span>value <span class="token operator">=</span> <span class="token string">"Start machine"</span><span class="token punctuation">;</span> + paragraph<span class="token punctuation">.</span>textContent <span class="token operator">=</span> <span class="token string">"The machine is stopped."</span><span class="token punctuation">;</span> + <span class="token punctuation">}</span> +<span class="token punctuation">}</span> +</pre> +</div> <p>The script gets a reference to the <a href="https://developer.mozilla.org/en-US/docs/Web/API/HTMLInputElement"><code>HTMLInputElement</code></a> object representing the <code><input></code> in the DOM, saving this reference in the variable <code>button</code>. <a href="https://developer.mozilla.org/en-US/docs/Web/API/EventTarget/addEventListener"><code>addEventListener()</code></a> is then used to establish a function that will be run when <a href="https://developer.mozilla.org/en-US/docs/Web/API/Element/click_event"><code>click</code></a> events occur on the button.</p> +<div class="code-example" id="sect4"> + +<iframe class="sample-code-frame" title="A simple button sample" id="frame_a_simple_button" width="650" height="100" src="https://live.mdnplay.dev/en-US/docs/Web/HTML/Element/input/button/runner.html?id=a_simple_button" loading="lazy"></iframe> +</div> +</div> +<h3 id="adding_keyboard_shortcuts_to_buttons">Adding keyboard shortcuts to buttons</h3> +<div class="section-content"> +<p>Keyboard shortcuts, also known as access keys and keyboard equivalents, let the user trigger a button using a key or combination of keys on the keyboard. To add a keyboard shortcut to a button — just as you would with any <a href="../input"><code><input></code></a> for which it makes sense — you use the <a href="../../global_attributes/accesskey"><code>accesskey</code></a> global attribute.</p> <p>In this example, <kbd>s</kbd> is specified as the access key (you'll need to press <kbd>s</kbd> plus the particular modifier keys for your browser/OS combination; see <a href="../../global_attributes/accesskey">accesskey</a> for a useful list of those).</p> <div class="code-example"> +<p class="example-header"><span class="language-name">html</span></p> +<pre data-signature="2NF/PTOO1F74Yq9VWxzWmZO3eTsPetLDrRYqKnfVJrc=" data-language="html"><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>form</span><span class="token punctuation">></span></span> + <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>input</span> <span class="token attr-name">type</span><span class="token attr-value"><span class="token punctuation attr-equals">=</span><span class="token punctuation">"</span>button<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation attr-equals">=</span><span class="token punctuation">"</span>Start machine<span class="token punctuation">"</span></span> <span class="token attr-name">accesskey</span><span class="token attr-value"><span class="token punctuation attr-equals">=</span><span class="token punctuation">"</span>s<span class="token punctuation">"</span></span> <span class="token punctuation">/></span></span> +<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>form</span><span class="token punctuation">></span></span> +<span class="token tag"><span class="token tag"><span class="token punctuation"><</span>p</span><span class="token punctuation">></span></span>The machine is stopped.<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>p</span><span class="token punctuation">></span></span> +</pre> +</div> +<div class="code-example" id="sect5"> + +<iframe class="sample-code-frame" title="Adding keyboard shortcuts to buttons sample" id="frame_adding_keyboard_shortcuts_to_buttons" width="650" height="100" src="https://live.mdnplay.dev/en-US/docs/Web/HTML/Element/input/button/runner.html?id=adding_keyboard_shortcuts_to_buttons" loading="lazy"></iframe> +</div> <div class="notecard note" id="sect6"> <p><strong>Note:</strong> The problem with the above example of course is that the user will not know what the access key is! In a real site, you'd have to provide this information in a way that doesn't interfere with the site design (for example by providing an easily accessible link that points to information on what the site accesskeys are).</p> </div> +</div> +<h3 id="disabling_and_enabling_a_button">Disabling and enabling a button</h3> +<div class="section-content"> +<p>To disable a button, specify the <a href="../../attributes/disabled"><code>disabled</code></a> global attribute on it, like so:</p> <div class="code-example"> +<p class="example-header"><span class="language-name">html</span></p> +<pre data-signature="rDS6mN6lj6mRA+fz2xx7Z1aPGKQtynRevZ9ne8lzyr4=" data-language="html"><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>input</span> <span class="token attr-name">type</span><span class="token attr-value"><span class="token punctuation attr-equals">=</span><span class="token punctuation">"</span>button<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation attr-equals">=</span><span class="token punctuation">"</span>Disable me<span class="token punctuation">"</span></span> <span class="token attr-name">disabled</span> <span class="token punctuation">/></span></span> +</pre> +</div> <h4 id="setting_the_disabled_attribute">Setting the disabled attribute</h4> <p>You can enable and disable buttons at run time by setting <code>disabled</code> to <code>true</code> or <code>false</code>. In this example our button starts off enabled, but if you press it, it is disabled using <code>button.disabled = true</code>. A <a href="https://developer.mozilla.org/en-US/docs/Web/API/setTimeout"><code>setTimeout()</code></a> function is then used to reset the button back to its enabled state after two seconds.</p> <div class="code-example"> +<p class="example-header"><span class="language-name">html</span></p> +<pre data-signature="bryPS5bkVfBZClS3Lc+gFYRjDWAjxWu74gJwXtKZLMA=" data-language="html"><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>input</span> <span class="token attr-name">type</span><span class="token attr-value"><span class="token punctuation attr-equals">=</span><span class="token punctuation">"</span>button<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation attr-equals">=</span><span class="token punctuation">"</span>Enabled<span class="token punctuation">"</span></span> <span class="token punctuation">/></span></span> +</pre> +</div> <div class="code-example"> +<p class="example-header"><span class="language-name">js</span></p> +<pre data-signature="B/vdg8GzQ9ZBMKZ+v9aUD+VUEkMuwWPr1T7sFMOtWsk=" data-language="js"><span class="token keyword">const</span> button <span class="token operator">=</span> document<span class="token punctuation">.</span><span class="token function">querySelector</span><span class="token punctuation">(</span><span class="token string">"input"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> + +button<span class="token punctuation">.</span><span class="token function">addEventListener</span><span class="token punctuation">(</span><span class="token string">"click"</span><span class="token punctuation">,</span> disableButton<span class="token punctuation">)</span><span class="token punctuation">;</span> + +<span class="token keyword">function</span> <span class="token function">disableButton</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span> + button<span class="token punctuation">.</span>disabled <span class="token operator">=</span> <span class="token boolean">true</span><span class="token punctuation">;</span> + button<span class="token punctuation">.</span>value <span class="token operator">=</span> <span class="token string">"Disabled"</span><span class="token punctuation">;</span> + <span class="token function">setTimeout</span><span class="token punctuation">(</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token operator">=></span> <span class="token punctuation">{</span> + button<span class="token punctuation">.</span>disabled <span class="token operator">=</span> <span class="token boolean">false</span><span class="token punctuation">;</span> + button<span class="token punctuation">.</span>value <span class="token operator">=</span> <span class="token string">"Enabled"</span><span class="token punctuation">;</span> + <span class="token punctuation">}</span><span class="token punctuation">,</span> <span class="token number">2000</span><span class="token punctuation">)</span><span class="token punctuation">;</span> +<span class="token punctuation">}</span> +</pre> +</div> +<div class="code-example" id="sect7"> + +<iframe class="sample-code-frame" title="Setting the disabled attribute sample" id="frame_setting_the_disabled_attribute" width="650" height="60" src="https://live.mdnplay.dev/en-US/docs/Web/HTML/Element/input/button/runner.html?id=setting_the_disabled_attribute" loading="lazy"></iframe> +</div> <h4 id="inheriting_the_disabled_state">Inheriting the disabled state</h4> <p>If the <code>disabled</code> attribute isn't specified, the button inherits its <code>disabled</code> state from its parent element. This makes it possible to enable and disable groups of elements all at once by enclosing them in a container such as a <a href="../fieldset"><code><fieldset></code></a> element, and then setting <code>disabled</code> on the container.</p> <p>The example below shows this in action. This is very similar to the previous example, except that the <code>disabled</code> attribute is set on the <code><fieldset></code> when the first button is pressed — this causes all three buttons to be disabled until the two second timeout has passed.</p> <div class="code-example"> +<p class="example-header"><span class="language-name">html</span></p> +<pre data-signature="JnkRu+XGwp9oqq8oaAbUhr598DUU2f2WnaPIWo3kXko=" data-language="html"><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>fieldset</span><span class="token punctuation">></span></span> + <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>legend</span><span class="token punctuation">></span></span>Button group<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>legend</span><span class="token punctuation">></span></span> + <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>input</span> <span class="token attr-name">type</span><span class="token attr-value"><span class="token punctuation attr-equals">=</span><span class="token punctuation">"</span>button<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation attr-equals">=</span><span class="token punctuation">"</span>Button 1<span class="token punctuation">"</span></span> <span class="token punctuation">/></span></span> + <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>input</span> <span class="token attr-name">type</span><span class="token attr-value"><span class="token punctuation attr-equals">=</span><span class="token punctuation">"</span>button<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation attr-equals">=</span><span class="token punctuation">"</span>Button 2<span class="token punctuation">"</span></span> <span class="token punctuation">/></span></span> + <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>input</span> <span class="token attr-name">type</span><span class="token attr-value"><span class="token punctuation attr-equals">=</span><span class="token punctuation">"</span>button<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation attr-equals">=</span><span class="token punctuation">"</span>Button 3<span class="token punctuation">"</span></span> <span class="token punctuation">/></span></span> +<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>fieldset</span><span class="token punctuation">></span></span> +</pre> +</div> <div class="code-example"> +<p class="example-header"><span class="language-name">js</span></p> +<pre data-signature="P96vgeHqZ1re8w9f+UAlQY6q1jAtvrVX5rMWwhNyKL4=" data-language="js"><span class="token keyword">const</span> button <span class="token operator">=</span> document<span class="token punctuation">.</span><span class="token function">querySelector</span><span class="token punctuation">(</span><span class="token string">"input"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> +<span class="token keyword">const</span> fieldset <span class="token operator">=</span> document<span class="token punctuation">.</span><span class="token function">querySelector</span><span class="token punctuation">(</span><span class="token string">"fieldset"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> + +button<span class="token punctuation">.</span><span class="token function">addEventListener</span><span class="token punctuation">(</span><span class="token string">"click"</span><span class="token punctuation">,</span> disableButton<span class="token punctuation">)</span><span class="token punctuation">;</span> + +<span class="token keyword">function</span> <span class="token function">disableButton</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span> + fieldset<span class="token punctuation">.</span>disabled <span class="token operator">=</span> <span class="token boolean">true</span><span class="token punctuation">;</span> + <span class="token function">setTimeout</span><span class="token punctuation">(</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token operator">=></span> <span class="token punctuation">{</span> + fieldset<span class="token punctuation">.</span>disabled <span class="token operator">=</span> <span class="token boolean">false</span><span class="token punctuation">;</span> + <span class="token punctuation">}</span><span class="token punctuation">,</span> <span class="token number">2000</span><span class="token punctuation">)</span><span class="token punctuation">;</span> +<span class="token punctuation">}</span> +</pre> +</div> +<div class="code-example" id="sect8"> + +<iframe class="sample-code-frame" title="Inheriting the disabled state sample" id="frame_inheriting_the_disabled_state" width="650" height="100" src="https://live.mdnplay.dev/en-US/docs/Web/HTML/Element/input/button/runner.html?id=inheriting_the_disabled_state" loading="lazy"></iframe> +</div> <div class="notecard note" id="sect9"> <p><strong>Note:</strong> Firefox will, unlike other browsers, by default, <a href="https://stackoverflow.com/questions/5985839/bug-with-firefox-disabled-attribute-of-input-not-resetting-when-refreshing" target="_blank">persist the dynamic disabled state</a> of a <a href="../button"><code><button></code></a> across page loads. Use the <a href="../button#autocomplete"><code>autocomplete</code></a> attribute to control this feature.</p> </div> +</div> +<h2 id="validation">Validation</h2> +<div class="section-content"><p>Buttons don't participate in constraint validation; they have no real value to be constrained.</p></div> +<h2 id="examples">Examples</h2> +<div class="section-content"> +<p>The below example shows a very simple drawing app created using a <a href="../canvas"><code><canvas></code></a> element and some simple CSS and JavaScript (we'll hide the CSS for brevity). The top two controls allow you to choose the color and size of the drawing pen. The button, when clicked, invokes a function that clears the canvas.</p> <div class="code-example"> +<p class="example-header"><span class="language-name">html</span></p> +<pre data-signature="GZUVlWpo/6YLdmNkqn42E5TfsF22ieGpf24HkIN26YY=" data-language="html"><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>div</span> <span class="token attr-name">class</span><span class="token attr-value"><span class="token punctuation attr-equals">=</span><span class="token punctuation">"</span>toolbar<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> + <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>input</span> <span class="token attr-name">type</span><span class="token attr-value"><span class="token punctuation attr-equals">=</span><span class="token punctuation">"</span>color<span class="token punctuation">"</span></span> <span class="token attr-name">aria-label</span><span class="token attr-value"><span class="token punctuation attr-equals">=</span><span class="token punctuation">"</span>select pen color<span class="token punctuation">"</span></span> <span class="token punctuation">/></span></span> + <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>input</span> + <span class="token attr-name">type</span><span class="token attr-value"><span class="token punctuation attr-equals">=</span><span class="token punctuation">"</span>range<span class="token punctuation">"</span></span> + <span class="token attr-name">min</span><span class="token attr-value"><span class="token punctuation attr-equals">=</span><span class="token punctuation">"</span>2<span class="token punctuation">"</span></span> + <span class="token attr-name">max</span><span class="token attr-value"><span class="token punctuation attr-equals">=</span><span class="token punctuation">"</span>50<span class="token punctuation">"</span></span> + <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation attr-equals">=</span><span class="token punctuation">"</span>30<span class="token punctuation">"</span></span> + <span class="token attr-name">aria-label</span><span class="token attr-value"><span class="token punctuation attr-equals">=</span><span class="token punctuation">"</span>select pen size<span class="token punctuation">"</span></span> <span class="token punctuation">/></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>span</span> <span class="token attr-name">class</span><span class="token attr-value"><span class="token punctuation attr-equals">=</span><span class="token punctuation">"</span>output<span class="token punctuation">"</span></span><span class="token punctuation">></span></span>30<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>span</span><span class="token punctuation">></span></span> + <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>input</span> <span class="token attr-name">type</span><span class="token attr-value"><span class="token punctuation attr-equals">=</span><span class="token punctuation">"</span>button<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation attr-equals">=</span><span class="token punctuation">"</span>Clear canvas<span class="token punctuation">"</span></span> <span class="token punctuation">/></span></span> +<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>div</span><span class="token punctuation">></span></span> + +<span class="token tag"><span class="token tag"><span class="token punctuation"><</span>canvas</span> <span class="token attr-name">class</span><span class="token attr-value"><span class="token punctuation attr-equals">=</span><span class="token punctuation">"</span>myCanvas<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> + <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>p</span><span class="token punctuation">></span></span>Add suitable fallback here.<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>p</span><span class="token punctuation">></span></span> +<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>canvas</span><span class="token punctuation">></span></span> +</pre> +</div> <div class="code-example"> +<p class="example-header"><span class="language-name">js</span></p> +<pre data-signature="pl16qvUsaGbCDn3Syt8kp4auFvHU+9kpEPisWMjf3uQ=" data-language="js"><span class="token keyword">const</span> canvas <span class="token operator">=</span> document<span class="token punctuation">.</span><span class="token function">querySelector</span><span class="token punctuation">(</span><span class="token string">".myCanvas"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> +<span class="token keyword">const</span> width <span class="token operator">=</span> <span class="token punctuation">(</span>canvas<span class="token punctuation">.</span>width <span class="token operator">=</span> window<span class="token punctuation">.</span>innerWidth<span class="token punctuation">)</span><span class="token punctuation">;</span> +<span class="token keyword">const</span> height <span class="token operator">=</span> <span class="token punctuation">(</span>canvas<span class="token punctuation">.</span>height <span class="token operator">=</span> window<span class="token punctuation">.</span>innerHeight <span class="token operator">-</span> <span class="token number">85</span><span class="token punctuation">)</span><span class="token punctuation">;</span> +<span class="token keyword">const</span> ctx <span class="token operator">=</span> canvas<span class="token punctuation">.</span><span class="token function">getContext</span><span class="token punctuation">(</span><span class="token string">"2d"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> + +ctx<span class="token punctuation">.</span>fillStyle <span class="token operator">=</span> <span class="token string">"rgb(0,0,0)"</span><span class="token punctuation">;</span> +ctx<span class="token punctuation">.</span><span class="token function">fillRect</span><span class="token punctuation">(</span><span class="token number">0</span><span class="token punctuation">,</span> <span class="token number">0</span><span class="token punctuation">,</span> width<span class="token punctuation">,</span> height<span class="token punctuation">)</span><span class="token punctuation">;</span> + +<span class="token keyword">const</span> colorPicker <span class="token operator">=</span> document<span class="token punctuation">.</span><span class="token function">querySelector</span><span class="token punctuation">(</span><span class="token string">'input[type="color"]'</span><span class="token punctuation">)</span><span class="token punctuation">;</span> +<span class="token keyword">const</span> sizePicker <span class="token operator">=</span> document<span class="token punctuation">.</span><span class="token function">querySelector</span><span class="token punctuation">(</span><span class="token string">'input[type="range"]'</span><span class="token punctuation">)</span><span class="token punctuation">;</span> +<span class="token keyword">const</span> output <span class="token operator">=</span> document<span class="token punctuation">.</span><span class="token function">querySelector</span><span class="token punctuation">(</span><span class="token string">".output"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> +<span class="token keyword">const</span> clearBtn <span class="token operator">=</span> document<span class="token punctuation">.</span><span class="token function">querySelector</span><span class="token punctuation">(</span><span class="token string">'input[type="button"]'</span><span class="token punctuation">)</span><span class="token punctuation">;</span> + +<span class="token comment">// covert degrees to radians</span> +<span class="token keyword">function</span> <span class="token function">degToRad</span><span class="token punctuation">(</span><span class="token parameter">degrees</span><span class="token punctuation">)</span> <span class="token punctuation">{</span> + <span class="token keyword">return</span> <span class="token punctuation">(</span>degrees <span class="token operator">*</span> Math<span class="token punctuation">.</span><span class="token constant">PI</span><span class="token punctuation">)</span> <span class="token operator">/</span> <span class="token number">180</span><span class="token punctuation">;</span> +<span class="token punctuation">}</span> + +<span class="token comment">// update sizepicker output value</span> + +sizePicker<span class="token punctuation">.</span><span class="token function-variable function">oninput</span> <span class="token operator">=</span> <span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token operator">=></span> <span class="token punctuation">{</span> + output<span class="token punctuation">.</span>textContent <span class="token operator">=</span> sizePicker<span class="token punctuation">.</span>value<span class="token punctuation">;</span> +<span class="token punctuation">}</span><span class="token punctuation">;</span> + +<span class="token comment">// store mouse pointer coordinates, and whether the button is pressed</span> +<span class="token keyword">let</span> curX<span class="token punctuation">;</span> +<span class="token keyword">let</span> curY<span class="token punctuation">;</span> +<span class="token keyword">let</span> pressed <span class="token operator">=</span> <span class="token boolean">false</span><span class="token punctuation">;</span> + +<span class="token comment">// update mouse pointer coordinates</span> +document<span class="token punctuation">.</span><span class="token function-variable function">onmousemove</span> <span class="token operator">=</span> <span class="token punctuation">(</span><span class="token parameter">e</span><span class="token punctuation">)</span> <span class="token operator">=></span> <span class="token punctuation">{</span> + curX <span class="token operator">=</span> e<span class="token punctuation">.</span>pageX<span class="token punctuation">;</span> + curY <span class="token operator">=</span> e<span class="token punctuation">.</span>pageY<span class="token punctuation">;</span> +<span class="token punctuation">}</span><span class="token punctuation">;</span> + +canvas<span class="token punctuation">.</span><span class="token function-variable function">onmousedown</span> <span class="token operator">=</span> <span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token operator">=></span> <span class="token punctuation">{</span> + pressed <span class="token operator">=</span> <span class="token boolean">true</span><span class="token punctuation">;</span> +<span class="token punctuation">}</span><span class="token punctuation">;</span> + +canvas<span class="token punctuation">.</span><span class="token function-variable function">onmouseup</span> <span class="token operator">=</span> <span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token operator">=></span> <span class="token punctuation">{</span> + pressed <span class="token operator">=</span> <span class="token boolean">false</span><span class="token punctuation">;</span> +<span class="token punctuation">}</span><span class="token punctuation">;</span> + +clearBtn<span class="token punctuation">.</span><span class="token function-variable function">onclick</span> <span class="token operator">=</span> <span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token operator">=></span> <span class="token punctuation">{</span> + ctx<span class="token punctuation">.</span>fillStyle <span class="token operator">=</span> <span class="token string">"rgb(0,0,0)"</span><span class="token punctuation">;</span> + ctx<span class="token punctuation">.</span><span class="token function">fillRect</span><span class="token punctuation">(</span><span class="token number">0</span><span class="token punctuation">,</span> <span class="token number">0</span><span class="token punctuation">,</span> width<span class="token punctuation">,</span> height<span class="token punctuation">)</span><span class="token punctuation">;</span> +<span class="token punctuation">}</span><span class="token punctuation">;</span> + +<span class="token keyword">function</span> <span class="token function">draw</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span> + <span class="token keyword">if</span> <span class="token punctuation">(</span>pressed<span class="token punctuation">)</span> <span class="token punctuation">{</span> + ctx<span class="token punctuation">.</span>fillStyle <span class="token operator">=</span> colorPicker<span class="token punctuation">.</span>value<span class="token punctuation">;</span> + ctx<span class="token punctuation">.</span><span class="token function">beginPath</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> + ctx<span class="token punctuation">.</span><span class="token function">arc</span><span class="token punctuation">(</span> + curX<span class="token punctuation">,</span> + curY <span class="token operator">-</span> <span class="token number">85</span><span class="token punctuation">,</span> + sizePicker<span class="token punctuation">.</span>value<span class="token punctuation">,</span> + <span class="token function">degToRad</span><span class="token punctuation">(</span><span class="token number">0</span><span class="token punctuation">)</span><span class="token punctuation">,</span> + <span class="token function">degToRad</span><span class="token punctuation">(</span><span class="token number">360</span><span class="token punctuation">)</span><span class="token punctuation">,</span> + <span class="token boolean">false</span><span class="token punctuation">,</span> + <span class="token punctuation">)</span><span class="token punctuation">;</span> + ctx<span class="token punctuation">.</span><span class="token function">fill</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> + <span class="token punctuation">}</span> + + <span class="token function">requestAnimationFrame</span><span class="token punctuation">(</span>draw<span class="token punctuation">)</span><span class="token punctuation">;</span> +<span class="token punctuation">}</span> + +<span class="token function">draw</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> +</pre> +</div> +<div class="code-example" id="sect10"> + +<iframe class="sample-code-frame" title="Examples sample" id="frame_examples" width="100%" height="600" src="https://live.mdnplay.dev/en-US/docs/Web/HTML/Element/input/button/runner.html?id=examples" loading="lazy"></iframe> +</div> +</div> +<h2 id="technical_summary">Technical summary</h2> +<div class="section-content"><figure class="table-container"><div class="_table"><table class="properties"> <tbody> <tr> <td><strong><a href="#value">Value</a></strong></td> <td>A string used as the button's label</td> </tr> <tr> <td><strong>Events</strong></td> <td><a href="https://developer.mozilla.org/en-US/docs/Web/API/Element/click_event"><code>click</code></a></td> </tr> <tr> <td><strong>Supported common attributes</strong></td> <td> <a href="../input#type"><code>type</code></a> and <a href="../input#value"><code>value</code></a> </td> </tr> <tr> <td><strong>IDL attributes</strong></td> <td><code>value</code></td> </tr> <tr> <td><strong>DOM interface</strong></td> <td> <p><a href="https://developer.mozilla.org/en-US/docs/Web/API/HTMLInputElement"><code>HTMLInputElement</code></a></p> </td> </tr> <tr> <td><strong>Methods</strong></td> <td>None</td> </tr> <tr> <td><strong>Implicit ARIA Role</strong></td> <td><a href="https://developer.mozilla.org/en-US/docs/Web/Accessibility/ARIA/Roles/button_role"><code>button</code></a></td> </tr> </tbody> </table></div></figure></div> +<h2 id="specifications">Specifications</h2> +<div class="_table"><table class="standard-table"> +<thead><tr><th scope="col">Specification</th></tr></thead> +<tbody><tr><td><a href="https://html.spec.whatwg.org/multipage/input.html#button-state-(type=button)">HTML Standard <br><small># button-state-(type=button)</small></a></td></tr></tbody> +</table></div> +<h2 id="browser_compatibility">Browser compatibility</h2> +<div class="_table"><table> +<thead> +<tr id="bct-browser-type"> +<th></th> +<th colspan="6">Desktop</th> +<th colspan="6">Mobile</th> +</tr> +<tr id="bct-browsers"> +<th></th> +<th>Chrome</th> +<th>Edge</th> +<th>Firefox</th> +<th>Internet Explorer</th> +<th>Opera</th> +<th>Safari</th> +<th>WebView Android</th> +<th>Chrome Android</th> +<th>Firefox for Android</th> +<th>Opera Android</th> +<th>Safari on IOS</th> +<th>Samsung Internet</th> +</tr> +</thead> +<tbody><tr> +<th><code>button</code></th> +<td class="bc-supports-yes">1</td> +<td class="bc-supports-yes">12</td> +<td class="bc-supports-yes">1</td> +<td class="bc-supports-yes">Yes</td> +<td class="bc-supports-yes">15</td> +<td class="bc-supports-yes">1</td> +<td class="bc-supports-yes">4.4</td> +<td class="bc-supports-yes">18</td> +<td class="bc-supports-yes">4</td> +<td class="bc-supports-yes">14</td> +<td class="bc-supports-yes">1</td> +<td class="bc-supports-yes">1.0</td> +</tr></tbody> +</table></div> +<h2 id="see_also">See also</h2> +<div class="section-content"><ul> <li> +<a href="../input"><code><input></code></a> and the <a href="https://developer.mozilla.org/en-US/docs/Web/API/HTMLInputElement"><code>HTMLInputElement</code></a> interface which implements it.</li> <li>The more modern <a href="../button"><code><button></code></a> element.</li> <li><a href="https://developer.mozilla.org/en-US/docs/Learn/Forms/Property_compatibility_table_for_form_controls">Compatibility of CSS properties</a></li> </ul></div><div class="_attribution"> + <p class="_attribution-p"> + © 2005–2023 MDN contributors.<br>Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.<br> + <a href="https://developer.mozilla.org/en-US/docs/Web/HTML/Element/input/button" class="_attribution-link">https://developer.mozilla.org/en-US/docs/Web/HTML/Element/input/button</a> + </p> +</div> |
