Early snapshot

[boten]

I know it is posibble to take a snap shot of the app's screen using reflection lib.

Is it possible to take a snapshot of the screen shown BEFORE the app us started, snapshot of the device's screen from where the app was started.?

 

[thedesolatesoul]

Maybe use a service.
Do:
StartService
Activity.Finish
Take snapshot in service
StartActivity
StopService

 

[Erel]

Maybe you can start with a transparent activity, take a screenshot and then change the activity background.

 

[boten]

Activity.Color=Colors.Transparent

Doesn't do it. Still getting a black bg.

Also, taking a snapshot in a service pose a problem, as one line in the code of screen-capture is:

 Obj1.Target = Obj1.GetActivityBA

and can't be done in a srevice.

Any other ideas?

 

[JonPM]

See here

 

[boten]

Thx JonPM, I got a transparent activity. Alas - taking a picture using the reflection library produced a picture with black bg (plus any button or text i have on the activity) but not the home screen from which the app was launched.

I wonder how this should be done, as I can take picture of a home screen from outside an app, and I can take picture of a transparent activity, but NOT in combination of both.

 

[thedesolatesoul]

as I can take picture of a home screen from outside an app,

How do you manage to do this?

Are you working on rooted phones only?
If you are going too deep, I remember once reading the framebuffer

 

[boten]

How do you manage to do this?

I meant the volume up/down+power or in my ASUS JB long pressing the recent apps button.

No rooted device. I would just like my app to able to capture the home screen from which it was started and "work" on this picture withing the app as a bitmap.

 

[thedesolatesoul]

I dont think its possible without a rooted device, or if your app is a system app. To be a system app, your app has to be signed with the same key as the ROM/FW.
The only way I know is to directly read the framebuffer.

 

[boten]

Well, I was hoping to use something like the screen capture technique:

sub Btn1_Click
    Dim Obj1, Obj2 As Reflector
    Dim bmp As Bitmap
    Dim c As Canvas
    Obj1.Target = Obj1.GetActivityBA
    Obj1.Target = Obj1.GetField("vg")
    bmp.InitializeMutable(Activity.Width, Activity.Height)
    c.Initialize2(bmp)
    Dim args(1) As Object
    Dim types(1) As String
    Obj2.Target = c
    Obj2.Target = Obj2.GetField("canvas")
    args(0) = Obj2.Target
    types(0) = "android.graphics.Canvas"
    Obj1.RunMethod4("draw", args, types) 
    Dim Out As OutputStream
    Out = File.OpenOutput(File.DirRootExternal, "Test.png", False)
    bmp.WriteToStream(out, 100, "PNG")
    Out.Close
End Sub

but obviously it refers to the activity itself (as in GetActivityBA). I don't know enough about the internals to get the equivalent of this but from the home screen (??? GetOSBA ???).
You say it is only possible on a rooted device & from the framebuffer, so until someone will come up with a "simple" B4A solution, I might as well delve into other B4A projects.

 

[vb1992]

In the manifest editor add this line:

SetActivityAttribute(main, android:theme, "@android:style/Theme.Translucent.NoTitleBar")

 

[boten]

yes, this gives a transparent activity, but still can't take picture of the home screen.