Mobile Device Features 1

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

Camera

• Being able to access the camera directly is a recent feature
• It may not be supported on older devices
• 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:

function txtGetPicture_onchange()
  reader.readAsDataURL(txtGetPicture.files[0])
  e=event
End function

• Reading the picture in is asynchronous: pictures can be large and take time to load.
• Once the read is complete, reader_onload is called:

function reader_onload(e)
  img.src=e.target.result
End Function

• 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.

function img_onload()
  drawImageIOSFix(pb,img,0,0,img.width,img.height, _
     0,0,PictureBox1.width,PictureBox1.height)
End function

• Normally, we would use the pb.drawImage function
• But there is a bug in iOS. The drawImageIOSFix function does it properly.