Android Code Snippet [B4X] [XUI] Create a round image

Better implementation in B4XImageView (XUI Views)

This code snippet is based on XUI library and it is compatible with B4A, B4i and B4J.
The input is a bitmap and the output is a round bitmap (with no distortions).

'xui is a global XUI variable.
Sub CreateRoundBitmap (Input As B4XBitmap, Size As Int) As B4XBitmap
   If Input.Width <> Input.Height Then
       'if the image is not square then we crop it to be a square.
       Dim l As Int = Min(Input.Width, Input.Height)
       Input = Input.Crop(Input.Width / 2 - l / 2, Input.Height / 2 - l / 2, l, l)
   End If
   Dim c As B4XCanvas
   Dim xview As B4XView = xui.CreatePanel("")
   xview.SetLayoutAnimated(0, 0, 0, Size, Size)
   c.Initialize(xview)
   Dim path As B4XPath
   path.InitializeOval(c.TargetRect)
   c.ClipPath(path)
   c.DrawBitmap(Input.Resize(Size, Size, False), c.TargetRect)
   c.RemoveClip
   c.DrawCircle(c.TargetRect.CenterX, c.TargetRect.CenterY, c.TargetRect.Width / 2 - 2dip, xui.Color_White, False, 5dip) 'comment this line to remove the border
   c.Invalidate
   Dim res As B4XBitmap = c.CreateBitmap
   c.Release
   Return res
End Sub

Usage example:

'ImageView1 type is B4XView
Dim img As B4XBitmap = xui.LoadBitmap(File.DirAssets, "myimage.jpg")
ImageView1.SetBitmap(CreateRoundBitmap(img, ImageView1.Width))

If you don't want to set the ImageView type to B4XView then you can do it locally:

Dim xIV As B4XView = ImageView1
xIV.SetBitmap(CreateRoundBitmap(img, xIV .Width))

 

[Erel]

Code updated.

B4XCanvas.Release should be called when the canvas is no longer required.

 

[NJDude]

I don't understand this

'xui is a global XUI variable.

xui is declared as what?

 

[stevel05]

https://www.b4x.com/android/forum/threads/b4x-xui-cross-platform-native-ui-library.84359/

 

[NJDude]

Well, I've read that, but then again that "xui" variable, what goes there?, in this line:

Dim xview As B4XView = xui.CreatePanel("")

I get: "Undeclared variable xui", what am I missing? you declare that variable as what? that's my question.

 

[stevel05]

If you have the library loaded you should have an Xui Class. So it would be Dim Xui As XUI

 

[NJDude]

Ooooooohhh! I see, well, wasn't clear enough for me.

I need a larger beer

Thanks.

 

[DonManfred]

I need a larger beer

Try it without a beer

 

[NJDude]

Try it without a beer

Hell no!! it's the weekend, a beer is must.

 

[Emme Developer]

Sorry, maybe i don't understand something, but when i try this code i get an error on line:

Dim xview As B4XView = xui.CreatePanel("")

Spoiler: Error

*** Service (starter) Create ***
** Service (starter) Start **
** Activity (main) Create, isFirst = true **
~w:1004,main,40
** Activity (main) Resume **
*** Service (httputils2service) Create ***
** Service (httputils2service) Start **
** Activity (main) Pause, UserClosed = false **
** Activity (presenter) Create, isFirst = true **
~w:1004,presenter,81
** Activity (presenter) Resume **
Presenter: Data refreshed
AdminService: Twitter data received
Presenter: Data refreshed
utils_createroundbitmap (B4A line: 64)
Dim xview As B4XView = xui.CreatePanel("")
java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.Object java.lang.ref.Reference.get()' on a null object reference
    at anywheresoftware.b4a.objects.B4XViewWrapper$XUI.CreatePanel(B4XViewWrapper.java:556)
    at b4a.example.utils._createroundbitmap(utils.java:160)
    at b4a.example.starter$ResumableSub_ShowCircleImage.resume(starter.java:952)
    at anywheresoftware.b4a.BA.checkAndRunWaitForEvent(BA.java:240)
    at anywheresoftware.b4a.BA.raiseEvent2(BA.java:180)
    at anywheresoftware.b4a.keywords.Common$11.run(Common.java:1151)
    at android.os.Handler.handleCallback(Handler.java:751)
    at android.os.Handler.dispatchMessage(Handler.java:95)
    at android.os.Looper.loop(Looper.java:154)
    at android.app.ActivityThread.main(ActivityThread.java:6776)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1520)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1410)
utils_createroundbitmap (B4A line: 64)
Dim xview As B4XView = xui.CreatePanel("")
java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.Object java.lang.ref.Reference.get()' on a null object reference
    at anywheresoftware.b4a.objects.B4XViewWrapper$XUI.CreatePanel(B4XViewWrapper.java:556)
    at b4a.example.utils._createroundbitmap(utils.java:160)
    at b4a.example.starter$ResumableSub_ShowCircleImage.resume(starter.java:952)
    at anywheresoftware.b4a.BA.checkAndRunWaitForEvent(BA.java:240)
    at anywheresoftware.b4a.BA.raiseEvent2(BA.java:180)
    at anywheresoftware.b4a.keywords.Common$11.run(Common.java:1151)
    at android.os.Handler.handleCallback(Handler.java:751)
    at android.os.Handler.dispatchMessage(Handler.java:95)
    at anywheresoftware.b4a.Msgbox.waitForMessage(Msgbox.java:231)
    at anywheresoftware.b4a.Msgbox.debugWait(Msgbox.java:190)
    at anywheresoftware.b4a.debug.Debug.wait(Debug.java:216)
    at anywheresoftware.b4a.debug.Debug.reachBP(Debug.java:362)
    at anywheresoftware.b4a.debug.Debug.ErrorCaught(Debug.java:148)
    at b4a.example.utils._createroundbitmap(utils.java:200)
    at b4a.example.starter$ResumableSub_ShowCircleImage.resume(starter.java:952)
    at anywheresoftware.b4a.BA.checkAndRunWaitForEvent(BA.java:240)
    at anywheresoftware.b4a.BA.raiseEvent2(BA.java:180)
    at anywheresoftware.b4a.keywords.Common$11.run(Common.java:1151)
    at android.os.Handler.handleCallback(Handler.java:751)
    at android.os.Handler.dispatchMessage(Handler.java:95)
    at android.os.Looper.loop(Looper.java:154)
    at android.app.ActivityThread.main(ActivityThread.java:6776)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1520)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1410)
java.lang.RuntimeException: java.lang.RuntimeException: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.Object java.lang.ref.Reference.get()' on a null object reference
    at anywheresoftware.b4a.keywords.Common$11.run(Common.java:1154)
    at android.os.Handler.handleCallback(Handler.java:751)
    at android.os.Handler.dispatchMessage(Handler.java:95)
    at android.os.Looper.loop(Looper.java:154)
    at android.app.ActivityThread.main(ActivityThread.java:6776)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1520)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1410)
Caused by: java.lang.RuntimeException: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.Object java.lang.ref.Reference.get()' on a null object reference
    at anywheresoftware.b4a.BA.raiseEvent2(BA.java:223)
    at anywheresoftware.b4a.keywords.Common$11.run(Common.java:1151)
    ... 7 more
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.Object java.lang.ref.Reference.get()' on a null object reference
    at anywheresoftware.b4a.objects.B4XViewWrapper$XUI.CreatePanel(B4XViewWrapper.java:556)
    at b4a.example.utils._createroundbitmap(utils.java:160)
    at b4a.example.starter$ResumableSub_ShowCircleImage.resume(starter.java:952)
    at anywheresoftware.b4a.BA.checkAndRunWaitForEvent(BA.java:240)
    at anywheresoftware.b4a.BA.raiseEvent2(BA.java:180)
    ... 8 more
*** Service (starter) Create ***
** Service (starter) Start **
** Activity (main) Create, isFirst = true **
~w:1004,main,40
** Activity (main) Resume **

 

[Erel]

You cannot call this code from a service context. Only from an Activity context. It can be in a code module but you can only call the sub from an Activity.

 

[Emme Developer]

You cannot call this code from a service context. Only from an Activity context. It can be in a code module but you can only call the sub from an Activity.

Ok thanks, tried in activity and it works. Is that wrote somewhere and i misread?

 

[Erel]

It was missing. Will be added to XUI.CreatePanel.

 

[dieterp]

I am trying to use the above example in a B4J project. When I run the line of code below I get an error "Object should first be initialized (B4XView)"

ImageView1.SetBitmap(CreateRoundBitmap(img, ImageView1.Width))

How do I Initialize the ImageView1 object?

 

[Erel]

It is up to you. What do you want to do with the round bitmap?

 

[dieterp]

As a start i just want to see how the canvas stuff works in B4J. I have successfully implemented the imaging functions in the B4A and B4I apps, I was hoping this part would be an easy port but it looks like it might be a bit trickier.

To summarize, I have an image that I want to be able to draw lines over. When I slide my finger on the screen of a smartphone that line then follows my finger. I achieve that in B4A and B4I using pnlxxx_Touch (Action As Int, X As Float, Y As Float). How would this be handled in a B4J pane? I also have functionality that when you click a 'Rotate' button, it rotates the image 90 degrees every time you click it.

 

[Erel]

The "usage example" code snippet shows you how you can use the round bitmap. It has nothing to do with the drawing.

As a start i just want to see how the canvas stuff works in B4J

You should start a new thread for this. Note that B4XCanvas is identical in B4A, B4i and B4J.

 

[dieterp]

Thanks Erel. Let me play around with this a bit more and try wrap my head around it. I'll start a new thread if I can't get that going

 

[klaus]

In B4J you need to handle the drawing in the Mouse_Pressed and Mouse_Moved event routines.
There is no Touch event in B4J.

 

[M.LAZ]

i get this error
java.lang.RuntimeException: java.lang.RuntimeException: Object should first be initialized (ImageView).

with this code

Dim img As B4XBitmap = Xui.LoadBitmap(File.DirAssets, "ff.jpg")
    'ImageView1.SetBitmap(CreateRoundBitmap(img, ImageView1.Width))
   
    Dim xIV As B4XView = ImageView1
    xIV.SetBitmap(CreateRoundBitmap(img, xIV .Width))

i add imageview1 with the designer