Mobile Device Features 1: Difference between revisions

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In the next two segments, we will talk about some features that are unique to mobile devices and how to use them.
In the next two segments, we will talk about some features that are unique to mobile devices and how to use them.


= Camera =
= Camera =
[[File:Cameraimage.jpg]]
* May not be supported on older devices
* Once the user has taken or selected a picture, a PictureBox on the form is updated.
* Reading the picture in is asynchronous: pictures can be large and take time to load.
* Pictures can then be emailed or manipulated.
<div class="page-break"></div>
= Emoji =
[[File:Emoji.png]]
* Emoji are extended characters that are built into mobile devices.
* There are hundreds of them: arrows, letters, roman numerals, pictures of food, building, transportation, flags, animals. And of course, happy faces, sad faces, crying faces.
* They are saved as standard characters: each has its own character code number.
* There is a complete list here: http://en.wikipedia.org/wiki/Emoji
* Support varies by browser
* Most mobile devices are OK
* Desktop Safari works
* Desktop Chrome needs an (but an [https://chrome.google.com/webstore/detail/chromoji-emoji-for-google/cahedbegdkagmcjfolhdlechbkeaieki extension] to see these)
* The characters are in the format &#xxxxxx; where xxxxxx is the decimal value
* Cheeseburger is &amp;#127828; (or &amp;#x1F354 in hex)
<div class="page-break"></div>
= Orientation =
Mobile devices can be rotated. It's up to you to decide how you want your app to handle this.
* The two orientations are referred to as Portrait and Landscape.
* The layout of your form will be completely different between the two.


* Being able to access the camera directly is a recent feature
* If you don't want to support rotation, add the [[Orientation]] control to your app. Set its screenOrientation property to portrait or landscape. When the screen is rotated, this message will appear:
* It may not be supported on older devices
[[File:Orientation.png||400px]]
* iOS has a serious bug - there is a workaround
 
* Done using a TextBox, with inputType set to 'file'.
* If you do want to support orientation, you will want to take action when the screen is rotated
* Once the user has taken or selected a picture, TxtBox_onchange is executed:
<pre>
<pre>
function txtGetPicture_onchange()
Function window_onorientationchange()
   reader.readAsDataURL(txtGetPicture.files[0])
   'This function is called if the orientation of the device is changed.
   e=event
   MsgBox "orientation changed to " & window.orientation
End function
End Function
</pre>
</pre>
* Reading the picture in is asynchronous: pictures can be large and take time to load.
 
* Once the read is complete, reader_onload is called:
* You can now resize and reposition your controls, using code like this:
<pre>
<pre>
function reader_onload(e)
Function window_onorientationchange()
   img.src=e.target.result
   If Abs(window.orientation)=90 Then 'Landscape
    btnSubmit.Left="100px"
    btnSubmit.Top="100px"
  Else                              'Portrait
    btnSubmit.Left="20px"
    btnSubmit.Top="120px"
  End If
End Function
End Function
</pre>
</pre>
* To display the picture, we need to put it into a PictureBox object.
* You will have to do this to all controls which are affected.
* Since this also can take some time, it is done asynchronously
* Once the loading is complete, img_onload is called.
<pre>
function img_onload()
  drawImageIOSFix(pb,img,0,0,img.width,img.height, _
    0,0,PictureBox1.width,PictureBox1.height)
End function
</pre>
* Normally, we would use the pb.drawImage function
* But there is a bug in iOS. The drawImageIOSFix function does it properly.
 
= Emoji =
 
 
= Rotation =

Latest revision as of 16:57, 22 April 2014

In the next two segments, we will talk about some features that are unique to mobile devices and how to use them.


Camera

  • May not be supported on older devices
  • Once the user has taken or selected a picture, a PictureBox on the form is updated.
  • Reading the picture in is asynchronous: pictures can be large and take time to load.
  • Pictures can then be emailed or manipulated.

Emoji

  • Emoji are extended characters that are built into mobile devices.
  • There are hundreds of them: arrows, letters, roman numerals, pictures of food, building, transportation, flags, animals. And of course, happy faces, sad faces, crying faces.
  • They are saved as standard characters: each has its own character code number.
  • There is a complete list here: http://en.wikipedia.org/wiki/Emoji
  • Support varies by browser
  • Most mobile devices are OK
  • Desktop Safari works
  • Desktop Chrome needs an (but an extension to see these)
  • The characters are in the format &#xxxxxx; where xxxxxx is the decimal value
  • Cheeseburger is &#127828; (or &#x1F354 in hex)

Orientation

Mobile devices can be rotated. It's up to you to decide how you want your app to handle this.

  • The two orientations are referred to as Portrait and Landscape.
  • The layout of your form will be completely different between the two.
  • If you don't want to support rotation, add the Orientation control to your app. Set its screenOrientation property to portrait or landscape. When the screen is rotated, this message will appear:

  • If you do want to support orientation, you will want to take action when the screen is rotated
Function window_onorientationchange()
  'This function is called if the orientation of the device is changed.
  MsgBox "orientation changed to " & window.orientation
End Function
  • You can now resize and reposition your controls, using code like this:
Function window_onorientationchange()
  If Abs(window.orientation)=90 Then 'Landscape
    btnSubmit.Left="100px"
    btnSubmit.Top="100px"
  Else                               'Portrait 
    btnSubmit.Left="20px"
    btnSubmit.Top="120px"
  End If
End Function
  • You will have to do this to all controls which are affected.
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