From 33058f2b292b3a581333bdfb21b8f671898c5060 Mon Sep 17 00:00:00 2001 From: Peter Bengtsson Date: Tue, 8 Dec 2020 14:40:17 -0500 Subject: initial commit --- files/ja/web/api/htmlcanvaselement/index.html | 250 ++++++++++++++++++++++++++ 1 file changed, 250 insertions(+) create mode 100644 files/ja/web/api/htmlcanvaselement/index.html (limited to 'files/ja/web/api/htmlcanvaselement/index.html') diff --git a/files/ja/web/api/htmlcanvaselement/index.html b/files/ja/web/api/htmlcanvaselement/index.html new file mode 100644 index 0000000000..dbb7b8508a --- /dev/null +++ b/files/ja/web/api/htmlcanvaselement/index.html @@ -0,0 +1,250 @@ +--- +title: HTMLCanvasElement +slug: Web/API/HTMLCanvasElement +tags: + - API + - Canvas + - HTML DOM + - Interface + - NeedsTranslation + - Reference + - TopicStub +translation_of: Web/API/HTMLCanvasElement +--- +
+
{{APIRef("Canvas API")}}
+
+ +

HTMLCanvasElementインタフェースはcanvas要素のレイアウトや表現の操作のための属性やメソッドを提供します。HTMLCanvasElementは{{domxref("HTMLElement")}}インタフェースのプロパティやメソッドも利用可能です。

+ +

属性

+ +

{{domxref("HTMLElement")}}から継承する属性の他に以下の属性を持ちます。

+ +
+
{{domxref("HTMLCanvasElement.height")}}
+
正のinteger で {{htmlattrxref("height", "canvas")}} というHTMLの{{HTMLElement("canvas")}}要素の属性で指定されたCSSピクセルの値です。もしこの属性が指定されていないか、無効な値であるならば、デフォルト値として150を用います。
+
{{domxref("HTMLCanvasElement.mozOpaque")}} {{non-standard_inline}}
+
{{jsxref("Boolean")}}で{{htmlattrxref("moz-opaque", "canvas")}}という{{HTMLElement("canvas")}}要素で指定されたものを反映したものです。この属性はcanvasが半透明であることが重要か否かを指定します。もし半透明がないならば、描画を最適化できます。
+
{{domxref("HTMLCanvasElement.width")}}
+
正のinteger で{{htmlattrxref("width", "canvas")}} というHTMLの{{HTMLElement("canvas")}}要素の属性で指定されたCSSピクセルの値です。もしこの属性が指定されていないか、無効な値であるならば、デフォルト値として300を用います。
+
+ +

メソッド

+ +

{{domxref("HTMLElement")}}から継承するメソッドの他に以下のメソッドを持ちます。

+ +
+
{{domxref("HTMLCanvasElement.captureStream()")}} {{experimental_inline}}
+
Returns a {{domxref("CanvasCaptureMediaStream")}} that is a real-time video capture of the surface of the canvas.
+
{{domxref("HTMLCanvasElement.getContext()")}}
+
+

Canvasの描画コンテキストを返すか、サポートされていないコンテキストIDの場合nullを返します。
+ 描画コンテキストを用いてCanvasに描画することができます。
+ getContextの引数に"2d"を渡すと{{domxref("CanvasRenderingContext2D")}} オブジェクトを、"experimental-webgl"(または"webgl")を渡すと {{domxref("WebGLRenderingContext")}}オブジェクトを返します。
+ "experimental-webgl"または"webgl"コンテキストは、ブラウザがWebGLに対応している場合に限り使用できます。

+
+
{{domxref("HTMLCanvasElement.toDataURL()")}}
+
Returns a data-URL containing a representation of the image in the format specified by the type parameter (defaults to png). The returned image is in a resolution of 96dpi.
+
{{domxref("HTMLCanvasElement.toBlob()")}}
+
Creates a {{domxref("Blob")}} object representing the image contained in the canvas; this file may be cached on the disk or stored in memory at the discretion of the user agent.
+
{{domxref("HTMLCanvasElement.transferControlToOffscreen()")}} {{experimental_inline}}
+
Transfers control to an {{domxref("OffscreenCanvas")}} object, either on the main thread or on a worker.
+
{{domxref("HTMLCanvasElement.mozGetAsFile()")}} {{non-standard_inline}} {{deprecated_inline}}
+
Returns a {{domxref("File")}} object representing the image contained in the canvas; this file is a memory-based file, with the specified name. If type is not specified, the image type is image/png.
+
+ +

Specifications

+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
SpecificationStatusComment
{{SpecName('Media Capture DOM Elements', '#html-media-element-media-capture-extensions', 'HTMLCanvasElement')}}{{Spec2('Media Capture DOM Elements')}}Adds the method captureStream().
{{SpecName('HTML WHATWG', "#the-canvas-element", "HTMLCanvasElement")}}{{Spec2('HTML WHATWG')}}The method getContext() now returns a {{domxref("RenderingContext")}} rather than an opaque object.
+ The methods probablySupportsContext(), setContext() and transferControlToProxy()have been added.
{{SpecName('HTML5.1', "scripting-1.html#the-canvas-element", "HTMLCanvasElement")}}{{Spec2('HTML5.1')}} 
{{SpecName('HTML5 W3C', "scripting-1.html#the-canvas-element", "HTMLCanvasElement")}}{{Spec2('HTML5 W3C')}}Initial definition.
+ +

Browser compatibility

+ +
{{CompatibilityTable}}
+ +
+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
FeatureChromeFirefox (Gecko)Internet ExplorerOperaSafari
Basic support (2D context)4.0{{CompatGeckoDesktop('1.9.2')}}9.09.0 [1]3.1
toBlob(){{CompatNo}} (bug 67587){{CompatGeckoDesktop('19')}} [2]{{CompatUnknown}}{{CompatUnknown}}{{CompatNo}} (bug 71270)
probablySupportsContext(),
+ setContext(),
+ transferControlToProxy() {{experimental_inline}}		{{CompatNo}}{{CompatNo}}{{CompatNo}}{{CompatNo}}{{CompatNo}}
mozGetAsFile() {{non-standard_inline}} {{deprecated_inline}}{{CompatNo}}{{CompatGeckoDesktop('2')}}{{CompatNo}}{{CompatNo}}{{CompatNo}}
captureStream() {{experimental_inline}}{{CompatNo}}{{CompatGeckoDesktop('41')}}{{CompatNo}}{{CompatNo}}{{CompatNo}}
transferControlToOffscreen() {{experimental_inline}}{{CompatNo}}{{CompatGeckoDesktop(44)}} [3]{{CompatNo}}{{CompatNo}}{{CompatNo}}
+
+ +
+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
FeatureAndroidChrome for AndroidFirefox Mobile (Gecko)IE MobileOpera MobileSafari Mobile
Basic support (2D context)2.1{{CompatVersionUnknown}}{{CompatVersionUnknown}}{{CompatUnknown}}10.0 [1]3.2
webgl context{{CompatUnknown}}{{CompatUnknown}}{{CompatVersionUnknown}} as experimental-webgl{{CompatUnknown}}{{CompatUnknown}}{{CompatUnknown}}
toBlob(){{CompatNo}} (bug 67587){{CompatNo}} (bug 67587){{CompatGeckoMobile('18')}} [2]{{CompatUnknown}}{{CompatUnknown}}{{CompatNo}} (bug 71270)
probablySupportsContext(),
+ setContext(),
+ transferControlToProxy() {{experimental_inline}}		{{CompatNo}}{{CompatNo}}{{CompatNo}}{{CompatNo}}{{CompatNo}}{{CompatNo}}
mozGetAsFile() {{non-standard_inline}} {{deprecated_inline}}{{CompatNo}}{{CompatNo}}{{CompatGeckoMobile('2')}}{{CompatNo}}{{CompatNo}}{{CompatNo}}
captureStream() {{experimental_inline}}{{CompatNo}}{{CompatNo}}{{CompatGeckoMobile('41')}}{{CompatNo}}{{CompatNo}}{{CompatNo}}
transferControlToOffscreen() {{experimental_inline}}{{CompatNo}}{{CompatNo}}{{CompatGeckoMobile(44)}} [3]{{CompatNo}}{{CompatNo}}{{CompatNo}}
+
+ +

[1] Opera Mini 5.0 and later has partial support.

+ +

[2] Support for the third parameter, has been added in Gecko 25 only: when used with the "image/jpeg" type, this argument specifies the image quality.

+ +

[3] This feature is behind a feature preference setting. In about:config, set gfx.offscreencanvas.enabled to true.

+ +

See also

+ + -- cgit v1.2.3-54-g00ecf