Mobile Device Features 1: Difference between revisions

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= Camera =
= Camera =
[[File:Cameraimage.jpg]]
[[File:Cameraimage.jpg]]
* Being able to access the camera directly is a recent feature
* May not be supported on older devices
* It may not be supported on older devices
* Once the user has taken or selected a picture, a PictureBox on the form is updated.
* iOS has a serious bug - there is a workaround
* Done using a TextBox, with inputType set to 'file'.
* Once the user has taken or selected a picture, TxtBox_onchange is executed:
<pre>
function txtGetPicture_onchange()
  reader.readAsDataURL(txtGetPicture.files[0])
  e=event
End function
</pre>
* Reading the picture in is asynchronous: pictures can be large and take time to load.
* Reading the picture in is asynchronous: pictures can be large and take time to load.
* Once the read is complete, reader_onload is called:
* Pictures can then be emailed or manipulated.
<pre>
 
function reader_onload(e)
<div class="page-break"></div>
  img.src=e.target.result
End Function
</pre>
* To display the picture, we need to put it into a PictureBox object.
* 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 =
= Emoji =
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* Most mobile devices are OK
* Most mobile devices are OK
* Desktop Safari works
* Desktop Safari works
* Desktop Chrome does not (but an extension may fix this)
* 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
* The characters are in the format &#xxxxxx; where xxxxxx is the decimal value
* Cheeseburger is &amp;#127828; (or &amp;#x1F354 in hex)
* Cheeseburger is &amp;#127828; (or &amp;#x1F354 in hex)


= Rotation =
<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.
Mobile devices can be rotated. It's up to you to decide how you want your app to handle this.
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* The layout of your form will be completely different between the two.
* 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 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:
[[File:Orientation.png]]
[[File:Orientation.png||400px]]


* If you do want to support orientation, you will want to take action when the screen is rotated
* If you do want to support orientation, you will want to take action when the screen is rotated

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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