CanvasCamera

The purpose of the plugin is to create an platform independent javascript interface for Cordova based mobile applications to preview camera and to take picture.
Donald Pae1.0.0dev19
platforms: ios,android
$ cordova plugin add com.keith.cordova.plugin.canvascamera

CanvasCameraPlugin

Cordova canvas camera plugin for iOS/Android, supports camera preview and taking photos.

Plugin's Purpose

The purpose of the plugin is to capture video to preview camera on web page(canvas tag) and to take photos with user defined quality / dimension.

Supported Platforms

  • iOS
  • Android

Dependencies

Cordova will check all dependencies and install them if they are missing.

Installation

The plugin can either be installed into the local development environment or cloud based through PhoneGap Build.

Adding the Plugin to your project

Through the Command-line Interface:

# ~~ from master ~~
cordova plugin add https://github.com/donaldp24/CanvasCameraPlugin.git && cordova prepare

or to use the last stable version:

# ~~ stable version ~~
cordova plugin add com.keith.cordova.plugin.canvascamera && cordova prepare

Removing the Plugin from your project

Through the Command-line Interface:

cordova plugin rm com.keith.cordova.plugin.canvascamera

PhoneGap Build

Add the following xml to your config.xml to always use the latest version of this plugin:

<gap:plugin name="com.keith.cordova.plugin.canvascamera" />

or to use an specific version:

<gap:plugin name="com.keith.cordova.plugin.canvascamera" version="1.0.1" />

More informations can be found here.

ChangeLog

Version 1.0.0 (not yet released)

  • [feature:] Create plugin

Using the plugin

The plugin creates the object window.plugin.CanvasCamera with the following methods:

Plugin initialization

The plugin and its methods are not available before the deviceready event has been fired. Have to call [initialize][initialize] with canvas object(canvas tag to preview camera).

document.addEventListener('deviceready', function () {

    // have to call initialize function with canvas object
    var objCanvas = document.getElementById("canvas");
    window.plugin.CanvasCamera.initialize(objCanvas);

    // window.plugin.CanvasCamera is now available
}, false);

start

start capture video as images from camera to preview camera on web page.
[capture][capture] callback function will be called with image data(image file url) at each time when the plugin take an image for a frame.

window.CanvasCamera.start(options);

This function start video capturing session, then the plugin takes each frame as a jpeg image and gives it's url to web page calling [capture][capture] callback function with the image url.
[capture][capture] callback function will draw the image to play video.

Example

function onStartClicked()
{
    var options = {
        quality: 75,
        destinationType: CanvasCamera.DestinationType.DATA_URL,
        encodingType: CanvasCamera.EncodingType.JPEG,
        width: 640,
        height: 480
    };
    window.plugin.CanvasCamera.start(options);
}

takePicture

take a photo.

window.plugin.takePicture(onSuccess);

This function takes a photo. When taked a photo successfully, then the plugin calls onSuccess callback function with image URI or data URL according to options. If options.saveToPhotoAlbum is true, then this function saves taked photo to photo album, too.

// if options.destinationType == CanvasCamera.DestinationType.IMAGE_URI
function onSuccess(data) {
    image.src = data; // URI
}

// else if options.destinationType == CanvasCamera.DestinationType.DATA_URL
function onSuccess(data) {
    image.src = "data:image/jpeg;base64," + data; // options.encodingType == CanvasCamera.EncodingType.JPEG
    // image.src = "data:image/png;base64," + data; // options.encodingType == CanvasCamera.EncodingType.PNG
}

setFlashMode

Set flash mode for camera.

window.plugin.CanvasCamera.setFlashMode(flashMode);
flashMode

Value of flashMode can be one of the followings;

CanvasCamera.FlashMode = 
{
    OFF : 0,
    ON : 1,
    AUTO : 2
};
window.plugin.CanvasCamera.setFlashMode(CanvasCamera.FlashMode.AUTO);

setCameraPosition

Change input camera to front or back camera.

window.plugin.CanvasCamera.setCameraPosition(cameraPosition);

cameraPosition

Value of cameraPosition can be one of the followings;

CanvasCamera.CameraPosition =
{
    BACK : 1,
    FRONT : 2
};
window.plugin.CanvasCamera.setCameraPosition(CanvasCamera.CameraPosition.FRONT);

capture

callback function. User could override this function to draw images on a canvas tag.

options

Optional parameters to customize the settings.

{ quality : 75, 
  destinationType : CanvasCamera.DestinationType.DATA_URL,
  sourceType : CanvasCamera.PictureSourceType.CAMERA,
  allowEdit : true,
  encodingType: CanvasCamera.EncodingType.JPEG,
  correctOrientation: true,
  saveToPhotoAlbum: false,
  width: 640,
  height: 480
  };
  • quality: Quality of saved image. Range is [0, 100]. (Number)
  • destinationType: Choose the format of the return value. Defined in Camera.DestinationType (Number)
    CanvasCamera.DestinationType = {
        DATA_URL : 0,                // Return image as base64 encoded string
        FILE_URI : 1                 // Return image file URI
    };
  • sourceType: Set the source of the picture. Defined in Camera.PictureSourceType (Number)
CanvasCamera.PictureSourceType = {
    PHOTOLIBRARY : 0,
    CAMERA : 1,
    SAVEDPHOTOALBUM : 2
};
  • allowEdit: Allow simple editing of image before selection. (Boolean)
  • encodingType: Choose the encoding of the returned image file. Defined in Camera.EncodingType (Number)
    CanvasCamera.EncodingType = {
        JPEG : 0,               // Return JPEG encoded image
        PNG : 1                 // Return PNG encoded image
    };
  • width: Width in pixels to scale image. Could be used with targetHeight. Aspect ratio is keeped. (Number)
  • height: Height in pixels to scale image. Could be used with targetWidth. Aspect ratio is keeped. (Number)
  • correctOrientation: Rotate the image to correct for the orientation of the device during capture. (Boolean)
  • saveToPhotoAlbum: Save the image to the photo album on the device after capture. (Boolean)

Full Example

<!DOCTYPE html>
<html>
    <head>
        <meta charset="utf-8" />
        <meta name="format-detection" content="telephone=no" />
        <!-- WARNING: for iOS 7, remove the width=device-width and height=device-height attributes. See https://issues.apache.org/jira/browse/CB-4323 -->
        <meta name="viewport" content="user-scalable=no, initial-scale=1, maximum-scale=1, minimum-scale=1, width=device-width, height=device-height, target-densitydpi=device-dpi" />
        <link rel="stylesheet" type="text/css" href="css/index.css" />
        <meta name="msapplication-tap-highlight" content="no" />
        <title>Hello World</title>
    </head>
    <body>
        <div class="app">
            <h1>Apache Cordova</h1>
            <div id="deviceready" class="blink">
                <p class="event listening">Connecting to Device</p>
                <p class="event received">Device is Ready</p>
            </div>

            <h2> Camera Position </h2>
            <input type="radio" name="deviceposition" id="deviceposition_back" value="Back" onclick="onChangeDevicePosition();"/>
            <label for="deviceposition_back">Back</label>
            <br/>
            <input type="radio" name="deviceposition" id="deviceposition_front" value="Front" onclick="onChangeDevicePosition();"/>
            <label for="deviceposition_front">Front</label>


            <h2> Flash Mode </h2>
            <input type="radio" name="flashmode" id="flashmode_off" value="Off" onclick="onChangeFlashMode();"/>
            <label for="flashmode_off">Off</label>
            <br/>
            <input type="radio" name="flashmode" id="flashmode_on" value="On" onclick="onChangeFlashMode();"/>
            <label for="flashmode_on">On</label>
            <br/>
            <input type="radio" name="flashmode" id="flashmode_auto" value="Auto" onclick="onChangeFlashMode();"/>
            <label for="flashmode_auto">Auto</label>
            <br/>

            <input type="button" value="Take a picture" onclick="onTakePicture();" />


        </div>

    <!— camera preview canvas —>
        <canvas id="camera" width="352" height="288" style="border:2px"></canvas>

        <script type="text/javascript" src="cordova.js"></script>
        <script type="text/javascript" src="js/index.js"></script>
        <script type="text/javascript">
            app.initialize();
        </script>

        <script>
            document.addEventListener("deviceready", function() {
                                          canvasMain = document.getElementById("camera");
                                          CanvasCamera.initialize(canvasMain);
                                          // define options
                                          var opt = {
                                              quality: 75,
                                              destinationType: CanvasCamera.DestinationType.DATA_URL,
                                              encodingType: CanvasCamera.EncodingType.JPEG,
                                              saveToPhotoAlbum:true,
                                              correctOrientation:true,
                                              width:640,
                                              height:480
                                          };
                                          CanvasCamera.start(opt);
                                      });

            function onChangeDevicePosition() {

                var newDevicePosition = CanvasCamera.CameraPosition.BACK;
                if (document.getElementById("deviceposition_back").checked)
                {
                    newDevicePosition = CanvasCamera.CameraPosition.BACK;
                }
                else if (document.getElementById("deviceposition_front").checked)
                {
                    newDevicePosition = CanvasCamera.CameraPosition.FRONT;
                }
                //
                CanvasCamera.setCameraPosition(newDevicePosition);
            }

            function onChangeFlashMode() {

                var newFlashMode = CanvasCamera.FlashMode.OFF;
                if (document.getElementById("flashmode_off").checked)
                {
                    newFlashMode = CanvasCamera.FlashMode.OFF;
                }
                else if (document.getElementById("flashmode_on").checked)
                {
                    newFlashMode = CanvasCamera.FlashMode.ON;
                }
                else if (document.getElementById("flashmode_auto").checked)
                {
                    newFlashMode = CanvasCamera.FlashMode.AUTO;
                }

                CanvasCamera.setFlashMode(newFlashMode);
            }

            function onTakePicture() {
                CanvasCamera.takePicture(onTakeSuccess);
            }

            function onTakeSuccess(data) {
                //
            }
        </script>
    </body>
</html>

Contributing

  1. Fork it
  2. Create your feature branch (git checkout -b my-new-feature)
  3. Commit your changes (git commit -am 'Add some feature')
  4. Push to the branch (git push origin my-new-feature)
  5. Create new Pull Request

License

This software is released under the Apache 2.0 License.

© 2013-2014 Snaphappi, Inc. All rights reserved