B4J Question [ non-ui ] How can i draw custom Canvas img ?

[Waldemar Lima]

Hello everyone !
How can i draw a custom Canvas img using non-ui project and send using smtp ?

 

[emexes]

Did you try it?

My recollection is that you just include the graphics library (jFX, or maybe now it's jXUI) and then you can Dim a Canvas and have access to the associated drawing methods.

Then use .CreateBitmap to get the final pixels as a Bitmap which you can .WriteToStream as JPEG or PNG ready for emailing.

Admittedly, that does sound too easy to be true, so perhaps I am missing something ;-)

 

[DonManfred]

so perhaps I am missing something

Maybe that he is writing a NONUI app. You can not include UI Elements in a NONUI app. At least that´s what i have in mind....

 

[Cableguy]

Canvas is not a UI element so it can be used in non-ui apps, but the result cannot be attributed to a canvas capable UI element, like a button or imageview, it has to be saved thought using stream if I'm not mistaken

 

[klaus]

Are you sure?
What you are saying is for B4A where you can define a Bitmap and set a Canvas for this Bitmap which aren't UI objects.
But in B4J, a Canvas is a Node on its own, therefore a UI object.

 

[Cableguy]

80% sure... But, I never tried it though

 

[klaus]

You are right, it works.
Below my test code and project.

Sub AppStart (Form1 As Form, Args() As String)
'    MainForm = Form1
    'MainForm.RootPane.LoadLayout("Layout1") 'Load the layout file.
'    MainForm.Show

    File.WriteString("D:\", "1.png", "")
    Private imv As Image
    imv.Initialize("D:\", "1.png")
    Private cvs As Canvas
    cvs.Initialize("")
    cvs.PrefWidth = 100
    cvs.PrefHeight = 100
    cvs.DrawLine(10, 10, 100, 100, fx.Colors.Red, 2)
    imv = cvs.Snapshot
    Private Out As OutputStream = File.OpenOutput("D:\", "1.png", False)
    imv.WriteToStream(Out)
    Out.Close
End Sub

 

[Waldemar Lima]

You are right, it works.
Below my test code and project.

Sub AppStart (Form1 As Form, Args() As String)
'    MainForm = Form1
    'MainForm.RootPane.LoadLayout("Layout1") 'Load the layout file.
'    MainForm.Show

    File.WriteString("D:\", "1.png", "")
    Private imv As Image
    imv.Initialize("D:\", "1.png")
    Private cvs As Canvas
    cvs.Initialize("")
    cvs.PrefWidth = 100
    cvs.PrefHeight = 100
    cvs.DrawLine(10, 10, 100, 100, fx.Colors.Red, 2)
    imv = cvs.Snapshot
    Private Out As OutputStream = File.OpenOutput("D:\", "1.png", False)
    imv.WriteToStream(Out)
    Out.Close
End Sub

this works on "Console Project" application ?

 

[Cableguy]

Have you even tried it?

 

[Waldemar Lima]

Have you even tried it?

dont works ... because javafx dont is initialized on non-ui ( console ) project ...

 

[klaus]

What exactly is a Console Project?

 

[DonManfred]

What exactly is a Console Project?

It is a app which you can run, for example, in a dos box (cmd-prompt under windows).

See https://www.b4x.com/android/forum/threads/non-ui-applications.34657/#content

 

[Cableguy]

Non-ui and console app behave the same, IDE wise... The major difference is that you can output to screen in text format and prompt the user for text input.

 

[Cableguy]

dont works ... because javafx dont is initialized on non-ui ( console ) project ...

Can you share your test project and/or error message that is given!?

 

[Erel]

There are differences between UI apps and non-ui apps. JavaFX elements will not work properly in a non-ui app. You can create a UI app and don't show any form.

 

[klaus]

You can create a UI app and don't show any form.

That's what I tested in post #7.

 

[Waldemar Lima]

There are differences between UI apps and non-ui apps. JavaFX elements will not work properly in a non-ui app. You can create a UI app and don't show any form.

it will works fine in vps ubuntu ?

 

[Cableguy]

In a VPS, yes, it will.
It's a jar file, so it works in ANY system that is capable of running a jar file!

 

[MarkusR]

hmm, in a linux vps enviroment u can have trouble to make a ui app auto run (start at/after boot)

 

[Waldemar Lima]

O

In a VPS, yes, it will.
It's a jar file, so it works in ANY system that is capable of running a jar file!

Need i install JavaFX dependencies ?