libcosmic/cosmic/widget/fn.canvas.html
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<!DOCTYPE html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta name="generator" content="rustdoc"><meta name="description" content="Creates a new `Canvas`."><title>canvas in cosmic::widget - Rust</title><script>if(window.location.protocol!=="file:")document.head.insertAdjacentHTML("beforeend","SourceSerif4-Regular-6b053e98.ttf.woff2,FiraSans-Italic-81dc35de.woff2,FiraSans-Regular-0fe48ade.woff2,FiraSans-MediumItalic-ccf7e434.woff2,FiraSans-Medium-e1aa3f0a.woff2,SourceCodePro-Regular-8badfe75.ttf.woff2,SourceCodePro-Semibold-aa29a496.ttf.woff2".split(",").map(f=>`<link rel="preload" as="font" type="font/woff2" crossorigin href="../../static.files/${f}">`).join(""))</script><link rel="stylesheet" href="../../static.files/normalize-9960930a.css"><link rel="stylesheet" href="../../static.files/rustdoc-aa0817cf.css"><meta name="rustdoc-vars" data-root-path="../../" data-static-root-path="../../static.files/" data-current-crate="cosmic" data-themes="" data-resource-suffix="" data-rustdoc-version="1.90.0-nightly (3048886e5 2025-07-30)" data-channel="nightly" data-search-js="search-fa3e91e5.js" data-settings-js="settings-5514c975.js" ><script src="../../static.files/storage-68b7e25d.js"></script><script defer src="sidebar-items.js"></script><script defer src="../../static.files/main-eebb9057.js"></script><noscript><link rel="stylesheet" href="../../static.files/noscript-32bb7600.css"></noscript><link rel="alternate icon" type="image/png" href="../../static.files/favicon-32x32-6580c154.png"><link rel="icon" type="image/svg+xml" href="../../static.files/favicon-044be391.svg"></head><body class="rustdoc fn"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="mobile-topbar"><button class="sidebar-menu-toggle" title="show sidebar"></button></nav><nav class="sidebar"><div class="sidebar-crate"><h2><a href="../../cosmic/index.html">cosmic</a><span class="version">1.0.0</span></h2></div><div class="sidebar-elems"><section id="rustdoc-toc"><h2 class="location"><a href="#">canvas</a></h2><h3><a href="#">Sections</a></h3><ul class="block top-toc"><li><a href="#example-drawing-a-simple-circle" title="Example: Drawing a Simple Circle">Example: Drawing a Simple Circle</a></li></ul></section><div id="rustdoc-modnav"><h2><a href="index.html">In cosmic::<wbr>widget</a></h2></div></div></nav><div class="sidebar-resizer" title="Drag to resize sidebar"></div><main><div class="width-limiter"><rustdoc-search></rustdoc-search><section id="main-content" class="content"><div class="main-heading"><div class="rustdoc-breadcrumbs"><a href="../index.html">cosmic</a>::<wbr><a href="index.html">widget</a></div><h1>Function <span class="fn">canvas</span><button id="copy-path" title="Copy item path to clipboard">Copy item path</button></h1><rustdoc-toolbar></rustdoc-toolbar><span class="sub-heading"></span></div><pre class="rust item-decl"><code>pub fn canvas&lt;P, Message, Theme, Renderer&gt;(
program: P,
) -&gt; <a class="struct" href="struct.Canvas.html" title="struct cosmic::widget::Canvas">Canvas</a>&lt;P, Message, Theme, Renderer&gt;<div class="where">where
Renderer: <a class="trait" href="../iced/daemon/program/graphics/geometry/trait.Renderer.html" title="trait cosmic::iced::daemon::program::graphics::geometry::Renderer">Renderer</a>,
P: <a class="trait" href="canvas/trait.Program.html" title="trait cosmic::widget::canvas::Program">Program</a>&lt;Message, Theme, Renderer&gt;,</div></code></pre><details class="toggle top-doc" open><summary class="hideme"><span>Expand description</span></summary><div class="docblock"><p>Creates a new <a href="struct.Canvas.html" title="struct cosmic::widget::Canvas"><code>Canvas</code></a>.</p>
<p>Canvases can be leveraged to draw interactive 2D graphics.</p>
<h2 id="example-drawing-a-simple-circle"><a class="doc-anchor" href="#example-drawing-a-simple-circle">§</a>Example: Drawing a Simple Circle</h2>
<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>iced::mouse;
<span class="kw">use </span>iced::widget::canvas;
<span class="kw">use </span>iced::{Color, Rectangle, Renderer, Theme};
<span class="comment">// First, we define the data we need for drawing
</span><span class="attr">#[derive(Debug)]
</span><span class="kw">struct </span>Circle {
radius: f32,
}
<span class="comment">// Then, we implement the `Program` trait
</span><span class="kw">impl</span>&lt;Message&gt; canvas::Program&lt;Message&gt; <span class="kw">for </span>Circle {
<span class="comment">// No internal state
</span><span class="kw">type </span>State = ();
<span class="kw">fn </span>draw(
<span class="kw-2">&amp;</span><span class="self">self</span>,
_state: <span class="kw-2">&amp;</span>(),
renderer: <span class="kw-2">&amp;</span>Renderer,
_theme: <span class="kw-2">&amp;</span>Theme,
bounds: Rectangle,
_cursor: mouse::Cursor
) -&gt; Vec&lt;canvas::Geometry&gt; {
<span class="comment">// We prepare a new `Frame`
</span><span class="kw">let </span><span class="kw-2">mut </span>frame = canvas::Frame::new(renderer, bounds.size());
<span class="comment">// We create a `Path` representing a simple circle
</span><span class="kw">let </span>circle = canvas::Path::circle(frame.center(), <span class="self">self</span>.radius);
<span class="comment">// And fill it with some color
</span>frame.fill(<span class="kw-2">&amp;</span>circle, Color::BLACK);
<span class="comment">// Then, we produce the geometry
</span><span class="macro">vec!</span>[frame.into_geometry()]
}
}
<span class="comment">// Finally, we simply use our `Circle` to create the `Canvas`!
</span><span class="kw">fn </span>view&lt;<span class="lifetime">'a</span>, Message: <span class="lifetime">'a</span>&gt;(_state: <span class="kw-2">&amp;</span><span class="lifetime">'a </span>State) -&gt; Element&lt;<span class="lifetime">'a</span>, Message&gt; {
canvas(Circle { radius: <span class="number">50.0 </span>}).into()
}</code></pre></div>
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