133 lines
3.1 KiB
Markdown
133 lines
3.1 KiB
Markdown
# NativeImage
|
|
|
|
In atom-shell for the APIs that take images, you can pass either file paths or
|
|
`NativeImage` instances. When passing `null`, an empty image will be used.
|
|
|
|
For example when creating tray or setting window's icon, you can pass image's
|
|
file path as `String` to represent an image:
|
|
|
|
```javascript
|
|
var appIcon = new Tray('/Users/somebody/images/icon.png');
|
|
var window = new BrowserWindow({icon: '/Users/somebody/images/window.png'});
|
|
```
|
|
|
|
Or read the image from clipboard:
|
|
|
|
```javascript
|
|
var clipboard = require('clipboard');
|
|
var image = clipboard.readImage();
|
|
var appIcon = new Tray(image);
|
|
```
|
|
|
|
## Supported formats
|
|
|
|
Currently `PNG` and `JPEG` are supported, and it is recommended to use `PNG`
|
|
because it supports alpha channel and image is usually not compressed.
|
|
|
|
## High resolution image
|
|
|
|
On platforms that have high-DPI support, you can append `@2x` after image's
|
|
file name's base name to mark it as a high resolution image.
|
|
|
|
For example if `icon.png` is a normal image that has standard resolution, the
|
|
`icon@2x.png` would be treated as a high resolution image that has double DPI
|
|
dense.
|
|
|
|
If you want to support displays with different DPI denses at the same time, you
|
|
can put images with different sizes in the same folder, and use the filename
|
|
without DPI suffixes, like this:
|
|
|
|
```text
|
|
images/
|
|
├── icon.png
|
|
├── icon@2x.png
|
|
└── icon@3x.png
|
|
```
|
|
|
|
|
|
```javascript
|
|
var appIcon = new Tray('/Users/somebody/images/icon.png');
|
|
```
|
|
|
|
Following suffixes as DPI denses are also supported:
|
|
|
|
* `@1x`
|
|
* `@1.25x`
|
|
* `@1.33x`
|
|
* `@1.4x`
|
|
* `@1.5x`
|
|
* `@1.8x`
|
|
* `@2x`
|
|
* `@2.5x`
|
|
* `@3x`
|
|
* `@4x`
|
|
* `@5x`
|
|
|
|
## Template image
|
|
|
|
Template images consist of black and clear colors (and an alpha channel).
|
|
Template images are not intended to be used as standalone images and are usually
|
|
mixed with other content to create the desired final appearance.
|
|
|
|
The most common case is to use template image for menu bar icon so it can adapt
|
|
to both light and dark menu bars.
|
|
|
|
Template image is only supported on Mac.
|
|
|
|
To mark an image as template image, its filename should end with the word
|
|
`Template`, examples are:
|
|
|
|
* `xxxTemplate.png`
|
|
* `xxxTemplate@2x.png`
|
|
|
|
## nativeImage.createEmpty()
|
|
|
|
Creates an empty `NativeImage` instance.
|
|
|
|
## nativeImage.createFromPath(path)
|
|
|
|
* `path` String
|
|
|
|
Creates a new `NativeImage` instance from file located at `path`.
|
|
|
|
## nativeImage.createFromBuffer(buffer[, scaleFactor])
|
|
|
|
* `buffer` [Buffer][buffer]
|
|
* `scaleFactor` Double
|
|
|
|
Creates a new `NativeImage` instance from `buffer`. The `scaleFactor` is 1.0 by
|
|
default.
|
|
|
|
## nativeImage.createFromDataUrl(dataUrl)
|
|
|
|
* `dataUrl` String
|
|
|
|
Creates a new `NativeImage` instance from `dataUrl`.
|
|
|
|
## Class: NativeImage
|
|
|
|
This class is used to represent an image.
|
|
|
|
### NativeImage.toPng()
|
|
|
|
Returns a [Buffer][buffer] that contains image's `PNG` encoded data.
|
|
|
|
### NativeImage.toJpeg(quality)
|
|
|
|
* `quality` Integer
|
|
|
|
Returns a [Buffer][buffer] that contains image's `JPEG` encoded data.
|
|
|
|
### NativeImage.toDataUrl()
|
|
|
|
Returns the data URL of image.
|
|
|
|
### NativeImage.isEmpty()
|
|
|
|
Returns whether the image is empty.
|
|
|
|
### NativeImage.getSize()
|
|
|
|
Returns the size of the image.
|
|
|
|
[buffer]: https://iojs.org/api/buffer.html#buffer_class_buffer
|