Android Question android.support.v4.print.PrintHelper ClassNotFoundException

[MitchBu]

I have a working example of printing from a WebView.

I copied it's methods to my app, and made sure to copy the content of #Region ActivityAttributes.

Sub PrintBitmap (mybmp As Bitmap)
   Dim ctxt As JavaObject
   ctxt.InitializeContext
   Dim photoPrinter As JavaObject
   photoPrinter.InitializeNewInstance("android.support.v4.print.PrintHelper", Array(ctxt))
   If photoPrinter.RunMethod("systemSupportsPrint", Null) = True Then
     'FIT = 1, FILL = 2
     photoPrinter.RunMethod("setScaleMode", Array(1))
     photoPrinter.RunMethod("printBitmap", Array("Printer Job Name", _
       mybmp, Null))
   Else
     Log("Printing not supported.")
   End If
End Sub

Now I get an error in the line photoPrinter.InitializeNewInstance( :


Error occurred on line: 573 (Main)
java.lang.ClassNotFoundException: android.support$v4$print$PrintHelper
at anywheresoftware.b4j.object.JavaObject.getCorrectClassName(JavaObject.java:288)
at anywheresoftware.b4j.object.JavaObject.InitializeNewInstance(JavaObject.java:83)
at java.lang.reflect.Method.invoke(Native Method)
...

I am lost. What can I do to make that code work ?

I will appreciate any help.

 

[Erel]

Better to use the Printing library: https://www.b4x.com/android/forum/threads/printing-and-pdf-creation.76712/

 

[MitchBu]

Better to use the Printing library: https://www.b4x.com/android/forum/threads/printing-and-pdf-creation.76712/

Thank you Erel. I went there and it does seem real nice. I downloaded the zip file, but I don't know what to do with Printing.jar and Printing.xml.

I tried putting them in the additional libraries folder, but it does not seem to do anything.

And when I paste the example code in a project, printer is an unknown type.

Any ideas ?

TIA

 

[Erel]

And when I paste the example code in a project, printer is an unknown type.

Go to the libraries tab, right click, choose Refresh. The Printing library should appear. Check it.

 

[MitchBu]

That was it. The library is now checked.

And it prints like a charm.

Thank you Erel

 

[MitchBu]

I just experimented with both the older canvas.b4a project that I was referring to in the OP, and the printing library.

Unfortunately, none of them print with sufficient resolution for what I need.

I need a minimum of 600 dpi. At present, I believe the printed resolution is 72 dpi, barely what an antique dot matrix printer from the eighties would do.

I have an app I got in the Play Store that prints at a much higher resolution, so I know it is possible to get much better results.

I found this in the Android Reference that apparently addresses directly my concern :
https://developer.android.com/reference/android/print/PrintAttributes.Resolution

Taking as example the program that prints using JavaObject, it seems to work somewhat like mediaSize.

Unfortunately, I am not familiar enough with JavaObject to create the code.

And I don't see how this could be applied to the Printer class.

Unless I find a way to print at minimum 600 dpi, this will stop any chance of completing my current project.

I will appreciate any assistance.

 

[Erel]

I need to check it, however you should start a new thread for this as each forum thread should discuss one specific question.

 

[MitchBu]

Sorry about that. I just started a new thread under the title "Getting and setting the printer resolution".

Thank you Erel