tabris-plugin-camera v1.0.0

title: Camera

description: Take pictures with the device camera.

tabris-plugin-camera

This is a fork of cordova-plugin-camera, with adjustments made for compatibility with the Tabris.js framework.

This plugin defines a global navigator.camera object, which provides an API for taking pictures and for choosing images from the system's image library.

Installation

You can add this to your Tabris.js project by includin the followin line in your config.xml:

<plugin name="tabris-plugin-camera" spec="1.0.0" />

To fetch the latest development version, use the URL of the repository:

<plugin name="tabris-plugin-camera" spec="https://github.com/eclipsesource/tabris-plugin-camera.git" />

How to Contribute

Contributors are welcome! And we need your contributions to keep the project moving forward. You can report bugs or contribute code.

In order for your changes to be accepted, you need to add yourself as a contributer in the license heady of every modified file.

And don't forget to test and document your code.

iOS Quirks

Since iOS 10 it's mandatory to add a NSCameraUsageDescription and NSPhotoLibraryUsageDescription in the info.plist.

• NSCameraUsageDescription describes the reason that the app accesses the user’s camera.
• NSPhotoLibraryUsageDescription describes the reason the app accesses the user's photo library.

When the system prompts the user to allow access, this string is displayed as part of the dialog box.

To add this entry you can pass the following variables on plugin install.

• CAMERA_USAGE_DESCRIPTION for NSCameraUsageDescription
• PHOTOLIBRARY_USAGE_DESCRIPTION for NSPhotoLibraryUsageDescription

Example:

cordova plugin add cordova-plugin-camera --variable CAMERA_USAGE_DESCRIPTION="your usage message" --variable PHOTOLIBRARY_USAGE_DESCRIPTION="your usage message"

If you don't pass the variable, the plugin will add an empty string as value.

API Reference

• camera
  • .getPicture(successCallback, errorCallback, options)
  • .cleanup()
  • .onError : function
  • .onSuccess : function
  • .CameraOptions : Object

• Camera

  • .DestinationType : enum
  • .EncodingType : enum
  • .MediaType : enum
  • .PictureSourceType : enum
  • .PopoverArrowDirection : enum
  • .Direction : enum

• CameraPopoverHandle

• CameraPopoverOptions

camera

camera.getPicture(successCallback, errorCallback, options)

Takes a photo using the camera, or retrieves a photo from the device's image gallery. The image is passed to the success callback as a Base64-encoded String, or as the URI for the image file.

The camera.getPicture function opens the device's default camera application that allows users to snap pictures by default - this behavior occurs, when Camera.sourceType equals Camera.PictureSourceType.CAMERA. Once the user snaps the photo, the camera application closes and the application is restored.

If Camera.sourceType is Camera.PictureSourceType.PHOTOLIBRARY or Camera.PictureSourceType.SAVEDPHOTOALBUM, then a dialog displays that allows users to select an existing image.

The return value is sent to the cameraSuccess callback function, in one of the following formats, depending on the specified cameraOptions:

• A String containing the Base64-encoded photo image.
• A String representing the image file location on local storage (default).

You can do whatever you want with the encoded image or URI, for example:

• Render the image in an <img> tag, as in the example below
• Save the data locally (LocalStorage, Lawnchair, etc.)
• Post the data to a remote server

NOTE: Photo resolution on newer devices is quite good. Photos selected from the device's gallery are not downscaled to a lower quality, even if a quality parameter is specified. To avoid common memory problems, set Camera.destinationType to FILE_URI rather than DATA_URL.

Supported Platforms

• Android
• iOS
• Windows

More examples here. Quirks here.

Kind: static method of camera

Example

navigator.camera.getPicture(cameraSuccess, cameraError, cameraOptions);

camera.cleanup()

Removes intermediate image files that are kept in temporary storage after calling camera.getPicture. Applies only when the value of Camera.sourceType equals Camera.PictureSourceType.CAMERA and the Camera.destinationType equals Camera.DestinationType.FILE_URI.

Supported Platforms

• iOS

Kind: static method of camera Example

navigator.camera.cleanup(onSuccess, onFail);

function onSuccess() {
    console.log("Camera cleanup success.")
}

function onFail(message) {
    alert('Failed because: ' + message);
}

camera.onError : function

Callback function that provides an error message.

Kind: static typedef of camera

camera.onSuccess : function

Callback function that provides the image data.

Kind: static typedef of camera

Example

// Show image
//
function cameraCallback(imageData) {
   var image = document.getElementById('myImage');
   image.src = "data:image/jpeg;base64," + imageData;
}

camera.CameraOptions : Object

Optional parameters to customize the camera settings.

• Quirks

Kind: static typedef of camera Properties

Camera

Camera.DestinationType : enum

Defines the output format of Camera.getPicture call. Note: On iOS passing DestinationType.NATIVE_URI along with PictureSourceType.PHOTOLIBRARY or PictureSourceType.SAVEDPHOTOALBUM will disable any image modifications (resize, quality change, cropping, etc.) due to implementation specific.

Kind: static enum property of Camera Properties

Camera.EncodingType : enum

Kind: static enum property of Camera Properties

Camera.MediaType : enum

Kind: static enum property of Camera Properties

Camera.PictureSourceType : enum

Defines the output format of Camera.getPicture call. Note: On iOS passing PictureSourceType.PHOTOLIBRARY or PictureSourceType.SAVEDPHOTOALBUM along with DestinationType.NATIVE_URI will disable any image modifications (resize, quality change, cropping, etc.) due to implementation specific.

Kind: static enum property of Camera Properties

Camera.PopoverArrowDirection : enum

Matches iOS UIPopoverArrowDirection constants to specify arrow location on popover.

Kind: static enum property of Camera Properties

Camera.Direction : enum

Kind: static enum property of Camera Properties

CameraPopoverOptions

iOS-only parameters that specify the anchor element location and arrow direction of the popover when selecting images from an iPad's library or album. Note that the size of the popover may change to adjust to the direction of the arrow and orientation of the screen. Make sure to account for orientation changes when specifying the anchor element location.

CameraPopoverHandle

A handle to an image picker popover.

Supported Platforms

• iOS

Example

navigator.camera.getPicture(onSuccess, onFail,
{
    destinationType: Camera.DestinationType.FILE_URI,
    sourceType: Camera.PictureSourceType.PHOTOLIBRARY,
    popoverOptions: new CameraPopoverOptions(300, 300, 100, 100, Camera.PopoverArrowDirection.ARROW_ANY)
});

// Reposition the popover if the orientation changes.
window.onorientationchange = function() {
    var cameraPopoverHandle = new CameraPopoverHandle();
    var cameraPopoverOptions = new CameraPopoverOptions(0, 0, 100, 100, Camera.PopoverArrowDirection.ARROW_ANY);
    cameraPopoverHandle.setPosition(cameraPopoverOptions);
}

camera.getPicture Errata

Example

Take a photo and retrieve the image's file location:

navigator.camera.getPicture(onSuccess, onFail, { quality: 50,
    destinationType: Camera.DestinationType.FILE_URI });

function onSuccess(imageURI) {
    var image = document.getElementById('myImage');
    image.src = imageURI;
}

function onFail(message) {
    console.log('Failed because: ' + message);
}

Take a photo and retrieve it as a Base64-encoded image:

/**
 * Warning: Using DATA_URL is not recommended! The DATA_URL destination
 * type is very memory intensive, even with a low quality setting. Using it
 * can result in out of memory errors and application crashes. Use FILE_URI
 * or NATIVE_URI instead.
 */
navigator.camera.getPicture(onSuccess, onFail, { quality: 25,
    destinationType: Camera.DestinationType.DATA_URL
});

function onSuccess(imageData) {
    var image = document.getElementById('myImage');
    image.src = "data:image/jpeg;base64," + imageData;
}

function onFail(message) {
    console.log('Failed because: ' + message);
}

Preferences (iOS)

• CameraUsesGeolocation (boolean, defaults to false). For capturing JPEGs, set to true to get geolocation data in the EXIF header. This will trigger a request for geolocation permissions if set to true.

   <preference name="CameraUsesGeolocation" value="false" />

Android Quirks

Android uses intents to launch the camera activity on the device to capture images, and on phones with low memory, the Cordova activity may be killed. In this scenario, the result from the plugin call will be delivered via the resume event. See the Android Lifecycle guide for more information. The pendingResult.result value will contain the value that would be passed to the callbacks (either the URI/URL or an error message). Check the pendingResult.pluginStatus to determine whether or not the call was successful.

CameraOptions Errata

Android Quirks

• Any cameraDirection value results in a back-facing photo.

• allowEdit is unpredictable on Android and it should not be used! The Android implementation of this plugin tries to find and use an application on the user's device to do image cropping. The plugin has no control over what application the user selects to perform the image cropping and it is very possible that the user could choose an incompatible option and cause the plugin to fail. This sometimes works because most devices come with an application that handles cropping in a way that is compatible with this plugin (Google Plus Photos), but it is unwise to rely on that being the case. If image editing is essential to your application, consider seeking a third party library or plugin that provides its own image editing utility for a more robust solution.

• Camera.PictureSourceType.PHOTOLIBRARY and Camera.PictureSourceType.SAVEDPHOTOALBUM both display the same photo album.

• Ignores the encodingType parameter if the image is unedited (i.e. quality is 100, correctOrientation is false, and no targetHeight or targetWidth are specified). The CAMERA source will always return the JPEG file given by the native camera and the PHOTOLIBRARY and SAVEDPHOTOALBUM sources will return the selected file in its existing encoding.

iOS Quirks

• When using destinationType.FILE_URI, photos are saved in the application's temporary directory. The contents of the application's temporary directory is deleted when the application ends.

• When using destinationType.NATIVE_URI and sourceType.CAMERA, photos are saved in the saved photo album regardless on the value of saveToPhotoAlbum parameter.

• When using destinationType.NATIVE_URI and sourceType.PHOTOLIBRARY or sourceType.SAVEDPHOTOALBUM, all editing options are ignored and link is returned to original picture.

Sample: Take Pictures, Select Pictures from the Picture Library, and Get Thumbnails

The Camera plugin allows you to do things like open the device's Camera app and take a picture, or open the file picker and select one. The code snippets in this section demonstrate different tasks including:

• Open the Camera app and take a Picture
• Take a picture and return thumbnails (resized picture)
• Take a picture and generate a FileEntry object
• Select a file from the picture library
• Select a JPEG image and return thumbnails (resized image)
• Select an image and generate a FileEntry object

Take a Picture

Before you can take a picture, you need to set some Camera plugin options to pass into the Camera plugin's getPicture function. Here is a common set of recommendations. In this example, you create the object that you will use for the Camera options, and set the sourceType dynamically to support both the Camera app and the file picker.

function setOptions(srcType) {
    var options = {
        // Some common settings are 20, 50, and 100
        quality: 50,
        destinationType: Camera.DestinationType.FILE_URI,
        // In this app, dynamically set the picture source, Camera or photo gallery
        sourceType: srcType,
        encodingType: Camera.EncodingType.JPEG,
        mediaType: Camera.MediaType.PICTURE,
        allowEdit: true,
        correctOrientation: true  //Corrects Android orientation quirks
    }
    return options;
}

You take a picture by passing in the options object to getPicture, which takes a CameraOptions object as the third argument. When you call setOptions, pass Camera.PictureSourceType.CAMERA as the picture source.

function openCamera(selection) {

    var srcType = Camera.PictureSourceType.CAMERA;
    var options = setOptions(srcType);
    var func = createNewFileEntry;

    navigator.camera.getPicture(function cameraSuccess(imageUri) {

        displayImage(imageUri);
        // You may choose to copy the picture, save it somewhere, or upload.
        func(imageUri);

    }, function cameraError(error) {
        console.debug("Unable to obtain picture: " + error, "app");

    }, options);
}

Once you take the picture, you can display it or do something else. In this example, call the app's displayImage function from the preceding code.

function displayImage(imgUri) {

    var elem = document.getElementById('imageFile');
    elem.src = imgUri;
}

To display the image on some platforms, you might need to include the main part of the URI in the Content-Security-Policy <meta> element in index.html. For example, on Windows 10, you can include ms-appdata: in your <meta> element. Here is an example.

<meta http-equiv="Content-Security-Policy" content="default-src 'self' data: gap: ms-appdata: https://ssl.gstatic.com 'unsafe-eval'; style-src 'self' 'unsafe-inline'; media-src *">

Take a Picture and Return Thumbnails (Resize the Picture)

To get smaller images, you can return a resized image by passing both targetHeight and targetWidth values with your CameraOptions object. In this example, you resize the returned image to fit in a 100px by 100px box (the aspect ratio is maintained, so 100px is either the height or width, whichever is greater in the source).

function openCamera(selection) {

    var srcType = Camera.PictureSourceType.CAMERA;
    var options = setOptions(srcType);
    var func = createNewFileEntry;

    if (selection == "camera-thmb") {
        options.targetHeight = 100;
        options.targetWidth = 100;
    }

    navigator.camera.getPicture(function cameraSuccess(imageUri) {

        // Do something

    }, function cameraError(error) {
        console.debug("Unable to obtain picture: " + error, "app");

    }, options);
}

Select a File from the Picture Library

When selecting a file using the file picker, you also need to set the CameraOptions object. In this example, set the sourceType to Camera.PictureSourceType.SAVEDPHOTOALBUM. To open the file picker, call getPicture just as you did in the previous example, passing in the success and error callbacks along with CameraOptions object.

function openFilePicker(selection) {

    var srcType = Camera.PictureSourceType.SAVEDPHOTOALBUM;
    var options = setOptions(srcType);
    var func = createNewFileEntry;

    navigator.camera.getPicture(function cameraSuccess(imageUri) {

        // Do something

    }, function cameraError(error) {
        console.debug("Unable to obtain picture: " + error, "app");

    }, options);
}

Select an Image and Return Thumbnails (resized images)

Resizing a file selected with the file picker works just like resizing using the Camera app; set the targetHeight and targetWidth options.

function openFilePicker(selection) {

    var srcType = Camera.PictureSourceType.SAVEDPHOTOALBUM;
    var options = setOptions(srcType);
    var func = createNewFileEntry;

    if (selection == "picker-thmb") {
        // To downscale a selected image,
        // Camera.EncodingType (e.g., JPEG) must match the selected image type.
        options.targetHeight = 100;
        options.targetWidth = 100;
    }

    navigator.camera.getPicture(function cameraSuccess(imageUri) {

        // Do something with image

    }, function cameraError(error) {
        console.debug("Unable to obtain picture: " + error, "app");

    }, options);
}