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Mobile applications Development - Lecture 15

Mobile applications Development - Lecture 15

Accessing Device Features:

Camera
Accelerometer
Contacts
Events

This presentation has been developed in the context of the Mobile Applications Development course at the Computer Science Department of the University of L’Aquila (Italy).

http://www.di.univaq.it/malavolta

Ivano Malavolta

May 21, 2012
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Transcript

  1. Accessing
    Accessing
    Device Features
    Ivano Malavolta
    Ivano Malavolta
    [email protected]
    http://www.di.univaq.it/malavolta

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  2. Roadmap
    • Media Capture
    • Camera
    • Camera
    • Contacts
    • Events
    • Accelerometer

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  3. Media Capture
    navigator.device.capture
    Provides access for capturing
    • Audio
    Audio
    Audio
    Audio
    • Image
    Image
    Image
    Image
    • Video
    Video
    Video
    Video
    • Video
    Video
    Video
    Video
    directly from the device

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  4. The Capture Object
    navigator.device.capture
    Properties
    Properties
    supportedAudioModes
    supportedAudioModes
    supportedAudioModes
    supportedAudioModes
    The audio recording formats supported by the device
    supportedImageModes
    supportedImageModes
    supportedImageModes
    supportedImageModes
    The recording image sizes and formats supported by
    the device
    the device
    supportedVideoModes
    supportedVideoModes
    supportedVideoModes
    supportedVideoModes
    The recording video resolutions and formats supported
    by the device
    They all contain an array of ConfigurationData
    ConfigurationData
    ConfigurationData
    ConfigurationData objects

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  5. ConfigurationData
    It is used to describe media capture modes
    media capture modes
    media capture modes
    media capture modes supported
    by the device
    Properties:
    1.
    1.
    1.
    1. Type
    Type
    Type
    Type: String
    The string in lower case representing the media type
    The string in lower case representing the media type
    – video/3gpp
    – video/quicktime
    – image/jpeg
    – audio/amr
    – audio/wav

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  6. ConfigurationData
    2.
    2.
    2.
    2. height
    height
    height
    height: integer
    The height of the image or video in pixels
    The height of the image or video in pixels
    3.
    3.
    3.
    3. width
    width
    width
    width: integer
    The width of the image or video in pixels
    In the case of a sound clip, the value of these attributes
    In the case of a sound clip, the value of these attributes
    is 0

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  7. Example
    var imageModes =
    navigator.device.capture.supportedImageModes;
    navigator.device.capture.supportedImageModes;
    for each (var mode in imageModes) {
    console.log(mode.type);
    console.log(mode.height);
    console.log(mode.width);
    }
    }

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  8. Capturing Audio
    It is called on the capture object
    Start the audio recorder application and return
    information about captured audio clip files

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  9. Capturing Audio
    It starts an asynchronous operation
    asynchronous operation
    asynchronous operation
    asynchronous operation to capture audio
    recordings
    recordings
    It uses the device's default audio recording
    default audio recording
    default audio recording
    default audio recording app
    app
    app
    app
    The operation allows the device user to capture
    multiple recordings
    multiple recordings
    multiple recordings
    multiple recordings in a single session
    multiple recordings
    multiple recordings
    multiple recordings
    multiple recordings in a single session

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  10. Capturing Audio
    When the capture operation is finished, it will invoke
    the CaptureCB
    CaptureCB
    CaptureCB
    CaptureCB callback with an array
    the CaptureCB
    CaptureCB
    CaptureCB
    CaptureCB callback with an array
    of MediaFile objects
    If the operation is terminated by the user before an
    audio clip is captured, the CaptureErrorCB
    CaptureErrorCB
    CaptureErrorCB
    CaptureErrorCB
    callback will be invoked
    callback will be invoked

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  11. Capture Audio Options
    Encapsulates audio capture configuration options
    Properties:
    • limit
    limit
    limit
    limit (not supported in iOS only 1 recording at a time)
    The maximum number of audio clips the device user can record
    in a single capture operation
    • Duration
    Duration
    Duration
    Duration (not supported in Android unlimited)
    • Duration
    Duration
    Duration
    Duration (not supported in Android unlimited)
    The maximum duration of an audio sound clip, in seconds
    • Mode
    Mode
    Mode
    Mode (not supported in Android and iOS)
    The selected audio mode, it must match one of the elements
    in capture.supportedAudioModes
    audio/wav
    audio/amr

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  12. Audio Example
    var options = { limit: 2, duration: 5 };
    navigator.device.capture.captureAudio(win, fail, options);
    function win(mediaFiles) {
    var i;
    for (i=0; iconsole.log(mediaFiles[i]);
    }
    }
    }
    function fail(error) {
    console.log(‘Error with code: ' + error.code);
    }

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  13. Capturing Images
    It is called on the capture object
    Start the camera application and return information
    about captured image file(s)

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  14. Capturing Images
    It starts an asynchronous operation
    asynchronous operation
    asynchronous operation
    asynchronous operation to capture
    images
    images
    It uses the device camera application
    device camera application
    device camera application
    device camera application
    The operation allows the device user to capture
    multiple
    multiple
    multiple
    multiple images
    images
    images
    images in a single session
    multiple
    multiple
    multiple
    multiple images
    images
    images
    images in a single session

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  15. Capturing Images
    Similarly to captureAudio...
    When the capture operation is finished, it will invoke
    the CaptureCB
    CaptureCB
    CaptureCB
    CaptureCB callback with an array
    of MediaFile objects
    If the operation is terminated by the user before any
    If the operation is terminated by the user before any
    image is captured, the CaptureErrorCB
    CaptureErrorCB
    CaptureErrorCB
    CaptureErrorCB callback
    will be invoked

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  16. Capture Image Options
    Encapsulates image capture configuration options
    Properties:
    • limit
    limit
    limit
    limit (not supported in iOS only 1 image at a time)
    The maximum number of images the device user can capture in
    a single capture operation
    • Mode
    Mode
    Mode
    Mode (not supported in Android and iOS image/jpeg only)
    The selected image mode, it must match one of the elements
    in capture.supportedImageModes

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  17. Image Example
    var options = { limit: 3};
    navigator.device.capture.captureImage(win, fail,
    navigator.device.capture.captureImage(win, fail,
    options);
    function win(mediaFiles) {
    var i;
    for (i=0; iupload(mediaFiles[i]);
    }
    }
    It is very
    similar to
    the audio
    example!
    }
    function fail(error) {
    console.log(‘Error with code: ' + error.code);
    }

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  18. Recording Videos
    It is called on the capture object
    Start the video recorder application and return
    information about captured video clip file(s).

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  19. Recording Videos
    It starts an asynchronous operation
    asynchronous operation
    asynchronous operation
    asynchronous operation to record videos
    It uses the device video recording application
    device video recording application
    device video recording application
    device video recording application
    The operation allows the device user to capture
    multiple
    multiple
    multiple
    multiple recordings
    recordings
    recordings
    recordings in a single session

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  20. Capturing Videos
    Similarly to captureAudio...
    When the capture operation is finished, it will invoke
    the CaptureCB
    CaptureCB
    CaptureCB
    CaptureCB callback with an array
    of MediaFile objects
    If the operation is terminated by the user before any
    If the operation is terminated by the user before any
    video is recorded, the CaptureErrorCB
    CaptureErrorCB
    CaptureErrorCB
    CaptureErrorCB callback
    will be invoked

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  21. Capture Video Options
    Encapsulates video recording configuration options
    Properties:
    • limit
    limit
    limit
    limit (not supported in iOS only 1 video at a time)
    The maximum number of video clips the device user can record in a
    single capture operation
    • duration
    duration
    duration
    duration (not supported in Android and iOS unlimited)
    • duration
    duration
    duration
    duration (not supported in Android and iOS unlimited)
    The maximum duration of a video clip, in seconds
    • m
    m
    m
    mode
    ode
    ode
    ode (not supported in Android and iOS)
    The selected video recording mode, it must match one of the
    elements in capture.supportedVideoModes
    video/quicktime
    video/3gpp

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  22. Video Example
    navigator.device.capture.captureVideo(win, fail, {});
    navigator.device.capture.captureVideo(win, fail, {});
    function win(mediaFiles) {
    var i;
    for (i=0; iupload(mediaFiles[i]);
    }
    }
    It is very
    similar to the
    image & audio
    examples!
    }
    function fail(error) {
    console.log(‘Error with code: ' + error.code);
    }

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  23. Media Files
    A MediaFile encapsulates properties of a media capture file
    Name
    Name
    Name
    Name (String)
    The name of the file, without path information
    fullPath
    fullPath
    fullPath
    fullPath (String)
    The full path of the file, including the name
    Type
    Type
    Type
    Type (String)
    Type
    Type
    Type
    Type (String)
    The mime type
    lastModifiedDate
    lastModifiedDate
    lastModifiedDate
    lastModifiedDate (Date)
    The date and time that the file was last modified
    Size
    Size
    Size
    Size (Integer)
    The size of the file, in bytes

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  24. Capture Errors
    Encapsulates the error code resulting from a failed
    media capture operation
    media capture operation
    It contains a pre
    pre
    pre
    pre-
    -
    -
    -defined
    defined
    defined
    defined error
    error
    error
    error code
    code
    code
    code
    CaptureError.CAPTURE_INTERNAL_ERR
    CaptureError.CAPTURE_APPLICATION_BUSY
    CaptureError.CAPTURE_APPLICATION_BUSY
    CaptureError.CAPTURE_INVALID_ARGUMENT
    CaptureError.CAPTURE_NO_MEDIA_FILES
    CaptureError.CAPTURE_NOT__SUPPORTED

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  25. Roadmap
    • Media Capture
    • Camera
    • Camera
    • Contacts
    • Events
    • Accelerometer

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  26. Camera
    A dedicated API for capturing images from the device’s
    default camera application
    default camera application
    Takes a photo using the camera or retrieves a photo
    from the device's album

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  27. Camera
    The result of a call to getPicture() can be:
    • a base64 encoded string, or
    • the URI of an image file
    Encoding the image using Base64 has caused memory
    Encoding the image using Base64 has caused memory
    issues on some of these devices
    it is recommended to use the URI of the image file

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  28. Camera Options
    getPicture() can be called with the following options

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  29. Camera Options
    q
    q
    q
    quality
    uality
    uality
    uality (integer)
    Quality of saved image
    Quality of saved image
    Range [0, 100]
    d
    d
    d
    destinationType
    estinationType
    estinationType
    estinationType (Integer)

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  30. Camera Options
    s
    s
    s
    sourceType
    ourceType
    ourceType
    ourceType (integer)
    allowEdit
    allowEdit
    allowEdit
    allowEdit (Boolean)
    Allow simple editing of image before selection

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  31. Camera Options
    encodingType
    encodingType
    encodingType
    encodingType (integer)
    targetWidth
    targetWidth
    targetWidth
    targetWidth,
    , ,
    , targetHeight
    targetHeight
    targetHeight
    targetHeight (Integer)
    Width/height in pixels to scale image

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  32. Camera Options
    mediaType
    mediaType
    mediaType
    mediaType (integer)
    correctOrientation
    correctOrientation
    correctOrientation
    correctOrientation (Boolean)
    Rotate the image to correct for the orientation of the
    device during capture

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  33. Camera Options
    saveToPhotoAlbum
    saveToPhotoAlbum
    saveToPhotoAlbum
    saveToPhotoAlbum (Boolean)
    Save the image to the photo album on the device after
    Save the image to the photo album on the device after
    capture
    Every platform has its own quirks, you better check
    Every platform has its own quirks, you better check
    them on the Cordova documentation

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  34. Camera Example
    navigator.camera.getPicture(win, fail,
    { quality: 50,
    { quality: 50,
    destinationType: destinationType.FILE_URI,
    pictureSource.PHOTOLIBRARY
    });
    function win(imageURI) {
    var element = $(“#block”);
    element.src(imageURI);
    element.src(imageURI);
    }
    // fail function omitted here

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  35. Roadmap
    • Media Capture
    • Camera
    • Camera
    • Contacts
    • Events
    • Accelerometer

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  36. Contacts
    navigator.contacts
    It is a global object that provides access to the device
    contacts DB
    You can call 2 methods on
    You can call 2 methods on navigator.contacts
    • contacts.create
    contacts.create
    contacts.create
    contacts.create
    • contacts.find
    contacts.find
    contacts.find
    contacts.find

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  37. Creating contacts
    navigator.contacts.create(properties)
    It is a synchronous
    synchronous
    synchronous
    synchronous function that returns a new
    Contact
    Contact
    Contact
    Contact object
    To persist the Contact object to the device, you have
    to invoke the Contact.save method
    to invoke the Contact.save method

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  38. Creating contacts
    navigator.contacts.create(properties)
    the properties parameter is a map of properties of the
    new Contact object
    ex.
    ex.
    var contact = navigator.contacts.create({
    "displayName": “Ivano“
    });

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  39. The Contact Object
    It represents a user contact
    It represents a user contact
    It represents a user contact
    It represents a user contact
    A contact can be created, saved or removed from the
    device contacts database
    The contacts.find method is used for retrieving one
    or more Contacts from the device contacts database
    or more Contacts from the device contacts database

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  40. Contact Properties
    It contains all the properties that a contact can have
    Every platform has its own quirks, you better check
    them on the Cordova documentation

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  41. Contact Methods
    A contact object provides the following methods
    • clone()
    clone()
    clone()
    clone()
    • clone()
    clone()
    clone()
    clone()
    Returns a new Contact object that is a deep copy of the
    calling object, its id property is null
    • remove(win, fail)
    remove(win, fail)
    remove(win, fail)
    remove(win, fail)
    Removes the contact from the device contacts database
    Removes the contact from the device contacts database
    • save(win, fail)
    save(win, fail)
    save(win, fail)
    save(win, fail)
    Saves a new contact to the device contacts database, or
    updates an existing contact if a contact with the same id
    id
    id
    id
    already exists

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  42. Create Contact Example
    var contact = navigator.contacts.create({
    "displayName": “Ivano“
    });
    });
    var name = new ContactName();
    name.givenName = “Ivano“;
    name.familyName = “Malavolta“;
    contact.name = name;
    contact.birthday = new Date(“19 July 1983");
    contact.save(win, fail);
    function win(contact) {
    alert("Save Success");
    };
    function fail(contactError) {
    alert("Error = " + contactError.code);
    };

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  43. Finding contacts
    navigator.contacts.find(
    contactFields,
    contactFields,
    contactSuccess,
    contactError,
    contactFindOptions
    );
    It is an asyncronous
    asyncronous
    asyncronous
    asyncronous function that queries the device
    It is an asyncronous
    asyncronous
    asyncronous
    asyncronous function that queries the device
    contacts database and returns an array of Contact
    Contact
    Contact
    Contact
    objects

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  44. Find Parameters
    contactFields
    contactFields
    contactFields
    contactFields, String
    Contact fields to be used as search qualifier. Only these
    Contact fields to be used as search qualifier. Only these
    fields will have values in the resulting Contact objects
    contactSuccess
    contactSuccess
    contactSuccess
    contactSuccess
    Success callback function that is invoked with the array of
    contacts returned from the contacts database
    contactError
    contactError
    contactError
    contactError [optional]
    Error callback function
    contactFindOptions
    contactFindOptions
    contactFindOptions
    contactFindOptions [Optional]
    Search options to filter contacts

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  45. Contact Fields
    Specifies which fields should be included in the Contact
    objects resulting from a find operation
    objects resulting from a find operation
    var fields = ["displayName", "name"]; // or [“*”]
    navigator.contacts.find(fields, win, fail);
    function win(contacts) {
    function win(contacts) {
    console.log(‘ok');
    };
    function fail(err) {
    console.log(err.code);
    };

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  46. Contact Find Options
    Contains properties that can be used to filter the results
    Properties
    Properties
    Properties
    Properties
    filter
    filter
    filter
    filter (String) (Default: "")
    The search string used to find contacts
    A case-insensitive, partial value match is applied to each
    A case-insensitive, partial value match is applied to each
    field specified in the contactFields
    contactFields
    contactFields
    contactFields parameter
    multiple
    multiple
    multiple
    multiple (Boolean) (default: false)
    Determines if the find operation should return multiple
    contacts

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  47. Find Contact Example
    var options = new ContactFindOptions();
    options.filter = “Ivano";
    options.multiple = true;
    filter = ["displayName",“birthday"];
    navigator.contacts.find(filter, win, fail, options);
    function win(contacts) {
    for (var i=0; iconsole.log(contacts[i].displayName);
    console.log(contacts[i].displayName);
    }
    };
    function fail(contactError) {
    alert("Error = " + contactError.code);
    };

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  48. ContactError
    It is always returned to the fail callback when an
    error occurs
    error occurs
    ContactError.UNKNOWN_ERROR
    ContactError.INVALID_ARGUMENT_ERROR
    ContactError.TIMEOUT_ERROR
    ContactError.PENDING_OPERATION_ERROR
    ContactError.IO_ERROR
    ContactError.IO_ERROR
    ContactError.NOT_SUPPORTED_ERROR
    ContactError.PERMISSION_DENIED_ERROR

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  49. Roadmap
    • Media Capture
    • Camera
    • Camera
    • Contacts
    • Events
    • Accelerometer

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  50. Events
    An event is an action that can be detected by your
    Javascript code
    Javascript code
    In traditional JS programs, any element of the page
    can have certain events
    – ontouchstart, onclick, ...
    – ontouchstart, onclick, ...

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  51. Listening to Events
    To use any event, you’ll want to use an event listener
    document.addEventListener(EVENTNAME, onEvent, false);
    function onEvent() {
    // handle the event
    }
    EVENTNAME is the name of the event you want to listen to
    onEvent() is the callback function triggered every time
    the event is fired

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  52. Main Cordova Events
    other events are specific to Cordova applications
    • deviceready
    • pause, resume
    • online, offline
    • batterycritical, batterylow, batterystatus
    • backbutton, menubutton, searchbutton
    • backbutton, menubutton, searchbutton

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  53. deviceready
    It is the most important in event in a Cordova app
    Cordova consists of two code bases:
    Cordova consists of two code bases:
    • native
    • JavaScript
    Once deviceready is fired, you know two things:
    1. The DOM has loaded
    1. The DOM has loaded
    2. the Cordova native API are loaded too
    Only at this point you can try to call Cordova APIs

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  54. App lifecycle Events
    Based on two main events:
    pause
    fires when an application is put into the background
    resume
    fires when a paused application is put back into the
    foreground

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  55. Connection Events
    Based on two main events:
    When running in the WP emulator,
    the connection.status of the
    device is always unknown
    online
    fires when the application's network connection changes to
    being online (that is, it is connected to the Internet)
    device is always unknown
    the online event will NOT fire
    offline
    fires when the application's network connection changes to
    being offline (that is, no Internet connection available)

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  56. Connection
    If you need to know the type of connection, you have to
    use the navigator.network.connection object
    use the navigator.network.connection object
    It has a type property with one of the following values:
    Connection.UNKNOWN
    Connection.ETHERNET
    Connection.ETHERNET
    Connection.WIFI
    Connection.CELL_2G
    Connection.CELL_3G
    Connection.CELL_4G
    Connection.NONE

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  57. Battery Events
    Based on three main events:
    this value is
    batterycritical
    fires when the battery has reached the critical level threshold
    batterylow
    similar to , but with a higher threeshold
    this value is
    device-specific
    similar to batterycritical, but with a higher threeshold
    batterystatus
    fires a change in the battery status is detected
    the battery status must
    change of at least 1%

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  58. Battery Events
    The handler of a battery event is always called with an
    object that contains two properties:
    level
    level
    level
    level (Integer)
    The percentage of battery (0-100)
    isPlugged
    isPlugged
    isPlugged
    isPlugged (Boolean)
    Represents whether or not the device is plugged in or not

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  59. Android buttons Events
    Based on three main events:
    backbutton
    fires when the user presses the “back” button
    menubutton
    fires when the user presses the “menu” button
    fires when the user presses the “menu” button
    searchbutton
    fires when the user presses the “search” button

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  60. Roadmap
    • Media Capture
    • Camera
    • Camera
    • Contacts
    • Events
    • Accelerometer

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  61. Accelerometer
    navigator.accelerometer
    It is a global object that captures device motion in
    the x, y, and z direction
    You can call 3 methods on it:
    You can call 3 methods on it:
    • accelerometer.getCurrentAcceleration
    accelerometer.getCurrentAcceleration
    accelerometer.getCurrentAcceleration
    accelerometer.getCurrentAcceleration
    • accelerometer.watchAcceleration
    accelerometer.watchAcceleration
    accelerometer.watchAcceleration
    accelerometer.watchAcceleration
    • accelerometer.clearWatch
    accelerometer.clearWatch
    accelerometer.clearWatch
    accelerometer.clearWatch

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  62. getCurrentAcceleration
    It gets the current acceleration along the x, y, and z
    axis
    axis
    getCurrentAcceleration(win, fail);
    win
    win
    win
    win
    callback function with an Acceleration
    Acceleration
    Acceleration
    Acceleration parameter
    fail
    fail
    fail
    fail
    error callback

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  63. watchAcceleration
    It gets the device's current acceleration at a regular interval
    var watchID =
    navigator.accelerometer.watchAcceleration(win, fail,
    [options]);
    win
    win
    win
    win
    callback function with an Acceleration
    Acceleration
    Acceleration
    Acceleration parameter, it is called
    at regular intervals
    fail
    fail
    fail
    fail
    fail
    fail
    fail
    fail
    error callback
    options
    options
    options
    options
    the interval is specified in the frequency parameter

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  64. clearWatch
    Stop watching the Acceleration referenced by the
    watch ID parameter
    watch ID parameter
    clearWatch(watchID);
    watchID
    watchID
    watchID
    watchID
    ID returned by accelerometer.watchAcceleration
    ID returned by accelerometer.watchAcceleration

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  65. Acceleration
    It contains Accelerometer data captured at a specific
    point in time
    point in time
    Properties
    Properties
    Properties
    Properties
    x
    x
    x
    x (Number)
    Amount of acceleration on the x-axis. (in m/s^2)
    y
    y
    y
    y (Number)
    these values include the effect of
    gravity (9.81 m/s^2)
    Amount of acceleration on the y-axis. (in m/s^2)
    z
    z
    z
    z (Number)
    Amount of acceleration on the z-axis. (in m/s^2)
    timestamp
    timestamp
    timestamp
    timestamp (Timestamp)
    Creation timestamp in milliseconds

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  66. Example
    var options = { frequency: 3000 };
    var watchID = navigator.accelerometer.watchAcceleration(win, fail,
    options);
    options);
    function win(acc) {
    if((acc.x == 0) && (acc.y == 0) && (acc.z == 9,81)) {
    console.log(“I am on a table”);
    stop();
    }
    }
    function fail() {
    console.log(“error”);
    console.log(“error”);
    }
    function stop() {
    if(watchID) {
    navigator.accelerometer.clearWatch(watchID);
    watchID = null;
    }
    }

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  67. Shake Detection
    var previousReading = {x: null, y: null, z: null};
    navigator.accelerometer.watchAcceleration(function (reading) {
    var changes = {},
    var changes = {},
    bound = 3;
    if (previousReading.x !== null) {
    changes.x = Math.abs(previousReading.x, reading.x);
    changes.y = Math.abs(previousReading.y, reading.y);
    changes.z = Math.abs(previousReading.z, reading.z);
    }
    if (changes.x>bound && changes.y>bound && changes.z>bound) {
    console.log(‹shake detected');
    console.log(‹shake detected');
    }
    previousReading = {
    x: reading.x,
    y: reading.y,
    z: reading.z
    }
    }, null, { frequency: 300 });

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