nativeImage
In Electron, for the APIs that take images, you can pass either file paths or
nativeImage
instances. An empty image will be used when null
is passed.
For example, when creating a tray or setting a window's icon, you can pass an
image file path as a String
:
var appIcon = new Tray('/Users/somebody/images/icon.png');
var window = new BrowserWindow({icon: '/Users/somebody/images/window.png'});
Or read the image from the clipboard which returns a nativeImage
:
var image = clipboard.readImage();
var appIcon = new Tray(image);
Supported Formats
Currently PNG
and JPEG
image formats are supported. PNG
is recommended
because of its support for transparency and lossless compression.
On Windows, you can also load an ICO
icon from a file path.
High Resolution Image
On platforms that have high-DPI support, you can append @2x
after image's
base filename to mark it as a high resolution image.
For example if icon.png
is a normal image that has standard resolution, then
[email protected]
will be treated as a high resolution image that has double DPI
density.
If you want to support displays with different DPI densities at the same time, you can put images with different sizes in the same folder and use the filename without DPI suffixes. For example:
images/
├── icon.png
├── [email protected]
└── [email protected]
var appIcon = new Tray('/Users/somebody/images/icon.png');
Following suffixes for DPI 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 images for a menu bar icon so it can adapt to both light and dark menu bars.
Note: Template image is only supported on OS X.
To mark an image as a template image, its filename should end with the word
Template
. For example:
xxxTemplate.png
[email protected]
Methods
The nativeImage
class has the following methods:
nativeImage.createEmpty()
Creates an empty nativeImage
instance.
nativeImage.createFromPath(path)
path
String
Creates a new nativeImage
instance from a file located at path
.
nativeImage.createFromBuffer(buffer[, scaleFactor])
buffer
BufferscaleFactor
Double (optional)
Creates a new nativeImage
instance from buffer
. The default scaleFactor
is
1.0.
nativeImage.createFromDataURL(dataURL)
dataURL
String
Creates a new nativeImage
instance from dataURL
.
Instance Methods
The following methods are available on instances of nativeImage
:
const nativeImage = require('electron').nativeImage;
var image = nativeImage.createFromPath('/Users/somebody/images/icon.png');
image.toPng()
Returns a Buffer that contains the image's PNG
encoded data.
image.toJpeg(quality)
quality
Integer between 0 - 100 (required)
Returns a Buffer that contains the image's JPEG
encoded data.
image.toDataURL()
Returns the data URL of the image.
image.isEmpty()
Returns a boolean whether the image is empty.
image.getSize()
Returns the size of the image.
image.setTemplateImage(option)
option
Boolean
Marks the image as template image.
image.isTemplateImage()
Returns a boolean whether the image is a template image.