Create tray, dock, and application icons using PNG or JPG files.
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
:
const {BrowserWindow, Tray} = require('electron')
const appIcon = new Tray('/Users/somebody/images/icon.png')
let win = new BrowserWindow({icon: '/Users/somebody/images/window.png'})
console.log(appIcon, win)
Or read the image from the clipboard which returns a NativeImage
:
const {clipboard, Tray} = require('electron')
const image = clipboard.readImage()
const appIcon = new Tray(image)
console.log(appIcon)
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 ICO
icons from file paths. For best visual quality it is recommended to include at least the following sizes in the:
Check the Size requirements section in this article.
On platforms that have high-DPI support such as Apple Retina displays, 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 icon@2x.png
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
├── icon@2x.png
└── icon@3x.png
const {Tray} = require('electron')
let appIcon = new Tray('/Users/somebody/images/icon.png')
console.log(appIcon)
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 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 macOS.
To mark an image as a template image, its filename should end with the word Template
. For example:
xxxTemplate.png
xxxTemplate@2x.png
The nativeImage
module has the following methods, all of which return an instance of the NativeImage
class:
nativeImage.createEmpty()
Returns NativeImage
Creates an empty NativeImage
instance.
nativeImage.createFromPath(path)
path
StringReturns NativeImage
Creates a new NativeImage
instance from a file located at path
. This method returns an empty image if the path
does not exist, cannot be read, or is not a valid image.
const nativeImage = require('electron').nativeImage
let image = nativeImage.createFromPath('/Users/somebody/images/icon.png')
console.log(image)
nativeImage.createFromBuffer(buffer[, options])
buffer
Bufferoptions
Object (optional)
width
Integer (optional) - Required for bitmap buffers.height
Integer (optional) - Required for bitmap buffers.scaleFactor
Double (optional) - Defaults to 1.0.Returns NativeImage
Creates a new NativeImage
instance from buffer
.
nativeImage.createFromDataURL(dataURL)
dataURL
StringReturns NativeImage
Creates a new NativeImage
instance from dataURL
.
Natively wrap images such as tray, dock, and application icons.
The following methods are available on instances of the NativeImage
class:
image.toPNG([options])
options
Object (optional)
scaleFactor
Double (optional) - Defaults to 1.0.Returns Buffer
- A Buffer that contains the image’s PNG
encoded data.
image.toJPEG(quality)
quality
Integer (required) - Between 0 - 100.Returns Buffer
- A Buffer that contains the image’s JPEG
encoded data.
image.toBitmap([options])
options
Object (optional)
scaleFactor
Double (optional) - Defaults to 1.0.Returns Buffer
- A Buffer that contains a copy of the image’s raw bitmap pixel data.
image.toDataURL([options])
options
Object (optional)
scaleFactor
Double (optional) - Defaults to 1.0.Returns String
- The data URL of the image.
image.getBitmap([options])
options
Object (optional)
scaleFactor
Double (optional) - Defaults to 1.0.Returns Buffer
- A Buffer that contains the image’s raw bitmap pixel data.
The difference between getBitmap()
and toBitmap()
is, getBitmap()
does not copy the bitmap data, so you have to use the returned Buffer immediately in current event loop tick, otherwise the data might be changed or destroyed.
image.getNativeHandle()
macOSReturns Buffer
- A Buffer that stores C pointer to underlying native handle of the image. On macOS, a pointer to NSImage
instance would be returned.
Notice that the returned pointer is a weak pointer to the underlying native image instead of a copy, so you must ensure that the associated nativeImage
instance is kept around.
image.isEmpty()
Returns Boolean
- Whether the image is empty.
image.getSize()
Returns Size
image.setTemplateImage(option)
option
BooleanMarks the image as a template image.
image.isTemplateImage()
Returns Boolean
- Whether the image is a template image.
image.crop(rect)
rect
Rectangle - The area of the image to cropReturns NativeImage
- The cropped image.
image.resize(options)
options
Object
width
Integer (optional) - Defaults to the image’s width.height
Integer (optional) - Defaults to the image’s heightquality
String (optional) - The desired quality of the resize image. Possible values are good
, better
or best
. The default is best
. These values express a desired quality/speed tradeoff. They are translated into an algorithm-specific method that depends on the capabilities (CPU, GPU) of the underlying platform. It is possible for all three methods to be mapped to the same algorithm on a given platform.Returns NativeImage
- The resized image.
If only the height
or the width
are specified then the current aspect ratio will be preserved in the resized image.
image.getAspectRatio()
Returns Float
- The image’s aspect ratio.
image.addRepresentation(options)
options
Object
scaleFactor
Double - The scale factor to add the image representation for.width
Integer (optional) - Defaults to 0. Required if a bitmap buffer is specified as buffer
.height
Integer (optional) - Defaults to 0. Required if a bitmap buffer is specified as buffer
.buffer
Buffer (optional) - The buffer containing the raw image data.dataURL
String (optional) - The data URL containing either a base 64 encoded PNG or JPEG image.Add an image representation for a specific scale factor. This can be used to explicitly add different scale factor representations to an image. This can be called on empty images.