stdweb/webapi/html_elements/
canvas.rs

1use webcore::value::Reference;
2use webcore::try_from::TryInto;
3use webcore::once::Once;
4use webapi::event_target::{IEventTarget, EventTarget};
5use webapi::node::{INode, Node};
6use webapi::element::{IElement, Element};
7use webapi::html_element::{IHtmlElement, HtmlElement};
8use webapi::blob::Blob;
9use webapi::rendering_context::RenderingContext;
10use private::TODO;
11
12/// The HTML `<canvas>` element provides an empty graphic zone on which specific JavaScript APIs
13/// can draw (such as Canvas 2D or WebGL).
14///
15/// [(JavaScript docs)](https://developer.mozilla.org/en-US/docs/Web/API/HTMLCanvasElement)
16// https://html.spec.whatwg.org/#htmlcanvaselement
17#[derive(Clone, Debug, PartialEq, Eq, ReferenceType)]
18#[reference(instance_of = "HTMLCanvasElement")]
19#[reference(subclass_of(EventTarget, Node, Element, HtmlElement))]
20pub struct CanvasElement( Reference );
21
22impl IEventTarget for CanvasElement {}
23impl INode for CanvasElement {}
24impl IElement for CanvasElement {}
25impl IHtmlElement for CanvasElement {}
26
27impl CanvasElement {
28    /// Returns a positive integer reflecting the height HTML attribute of the <canvas> element
29    /// interpreted in CSS pixels. When the attribute is not specified, or if it is set to an
30    /// invalid value, like a negative, the default value of 150 is used.
31    ///
32    /// [(JavaScript docs)](https://developer.mozilla.org/en-US/docs/Web/API/HTMLCanvasElement/height)
33    // https://html.spec.whatwg.org/#the-canvas-element:dom-canvas-height
34    pub fn height( &self ) -> u32 {
35        js! (
36            return @{self}.height;
37        ).try_into().unwrap()
38    }
39
40    /// Sets a positive integer reflecting the height HTML attribute of the <canvas> element
41    /// interpreted in CSS pixels. When the attribute is not specified, or if it is set to an
42    /// invalid value, like a negative, the default value of 150 is used.
43    ///
44    /// [(JavaScript docs)](https://developer.mozilla.org/en-US/docs/Web/API/HTMLCanvasElement/height)
45    // https://html.spec.whatwg.org/#the-canvas-element:dom-canvas-height
46    pub fn set_height( &self, value: u32 ) {
47        js! { @(no_return)
48            @{self}.height = @{value};
49        }
50    }
51
52    /// Returns a positive integer reflecting the width HTML attribute of the <canvas> element
53    /// interpreted in CSS pixels. When the attribute is not specified, or if it is set to an
54    /// invalid value, like a negative, the default value of 300 is used.
55    ///
56    /// [(JavaScript docs)](https://developer.mozilla.org/en-US/docs/Web/API/HTMLCanvasElement/width)
57    // https://html.spec.whatwg.org/#the-canvas-element:dom-canvas-width
58    pub fn width( &self ) -> u32 {
59        js! (
60            return @{self}.width;
61        ).try_into().unwrap()
62    }
63
64    /// Sets a positive integer reflecting the width HTML attribute of the <canvas> element
65    /// interpreted in CSS pixels. When the attribute is not specified, or if it is set to an
66    /// invalid value, like a negative, the default value of 300 is used.
67    ///
68    /// [(JavaScript docs)](https://developer.mozilla.org/en-US/docs/Web/API/HTMLCanvasElement/width)
69    // https://html.spec.whatwg.org/#the-canvas-element:dom-canvas-width
70    pub fn set_width( &self, value: u32 ) {
71        js! { @(no_return)
72            @{self}.width = @{value};
73        }
74    }
75
76    /// Returns a drawing context on the canvas, or None if the context identifier is not supported.
77    ///
78    /// [(JavaScript docs)](https://developer.mozilla.org/en-US/docs/Web/API/HTMLCanvasElement/getContext)
79    // https://html.spec.whatwg.org/#the-canvas-element:dom-canvas-getcontext
80    pub fn get_context<T: RenderingContext>( &self ) -> Result<T, T::Error> {
81        T::from_canvas(self)
82    }
83
84    /// Returns a data URI containing a representation of the image in the format specified by the
85    /// type parameter (defaults to PNG). The returned image is in a resolution of 96 dpi.
86    ///
87    /// [(JavaScript docs)](https://developer.mozilla.org/en-US/docs/Web/API/HTMLCanvasElement/toDataUrl)
88    // https://html.spec.whatwg.org/#the-canvas-element:dom-canvas-todataurl
89    pub fn to_data_url( &self, mime_type: Option<&str>, quality: Option<f64> ) -> Result< String, TODO > {
90        Ok( js! (
91            return @{self}.toDataURL(@{mime_type}, @{quality});
92        ).try_into().unwrap() )
93    }
94
95    /// Creates a Blob object representing the image contained in the canvas; this file may be
96    /// cached on the disk or stored in memory at the discretion of the user agent.
97    ///
98    /// [(JavaScript docs)](https://developer.mozilla.org/en-US/docs/Web/API/HTMLCanvasElement/toBlob)
99    // https://html.spec.whatwg.org/#the-canvas-element:dom-canvas-toblob
100    pub fn to_blob<F: FnOnce(Blob) + 'static>( &self, f: F, mime_type: Option<&str>, quality: Option<f64> ) -> Result< (), TODO > {
101        js! { @(no_return)
102            @{self}.toBlob(@{Once(f)}, @{mime_type}, @{quality});
103        }
104
105        Ok(())
106    }
107}
stdweb/webapi/html_elements/canvas.rs

stdweb/webapi/html_elements/
canvas.rs
