Button Bitmap image Pressed Drawable

[klaus]

Is there a possibility to chage by code the Bitmap for the Pressed Drawable of a Button ?

Best regards.

 

[agraham]

I don't think you can change the existing one but you can replace it.

   Dim gd1 As GradientDrawable
   Dim gd2 As GradientDrawable
   Dim cols(2) As Int
   cols(0) = Colors.Cyan
   cols(1) = Colors.Red
   gd1.Initialize("TL_BR",cols)
   gd2.Initialize("TR_BL",cols)
   Dim states(1) As Int
   Dim sd As StateListDrawable
   sd.Initialize
   Dim states(2) As Int
   states(0) = sd.state_enabled
   states(1) = -sd.state_pressed
   sd.addState(states, gd1)
   Dim states(1) As Int
   states(0) = sd.state_pressed
   sd.addState(states, gd2)
   Button1.Background = sd

The order the states are added is important because the Android state matching algorithm is a simple linear search. Unfortunately I can't get a state to show for the unpressed condition so the button is black until pressed. Most likely I'm not understanding something or the StateListDrawable is missing a state constant. Erel did say it wasn't finished. I've tried various integer constants to define the unpressed state but can't hit on the right one.

EDIT:- I've got it work and changed the code above but I have to admit I don't understand why it needs the enabled and unpressed combination to display the unpressed state instead of just the unpressed (-ve) state when it doesn't appear to need it for the pressed state.

 

[agraham]

Isn't the Android documentation wonderful compared to .NET Not!

I found this in the documentation for a related method "setState" and it seems to me it might hold (undocumented!) for addState as well.

"Note: The Drawable holds a reference on to stateSet until a new state array is given to it, so you must not modify this array during that time."

I was reusing the state array passed to addState. By Dimming a new states(1) array I got it to work with just "states(0) = -sd.state_pressed".

 

[Erel]

Very good point. I'm going to reiterate the StateListDrawable and I will change it to create a new array each time (among other changes).

 

[klaus]

Thank you Andrew,

It's not exaclty what I wanted to do but you showed me the way how to do it !
I wanted to change the bitmaps to simulate a ToggleButton, when pressing the bitmaps change and remain when unpressed and on the next press.
Attached a small test program for others who might be interested in.
Playing with 3 buttons Bitmap-, Gradient-, Color Drawable

Best regards.

EDIT: Updated the file.

 

[Cor]

Hello,

the TestButtons.b4a file is empty

only the standard definitions

grCor

 

[Erel]

You should use File -> Export As Zip. Otherwise you are uploading many unnecessary file.

 

[klaus]

Sorry, I don't know what I did wrong.
The file has been updated in post #5, ziped with Export As Zip.

Best regards.

 

[Cor]

Works on HTC Magic 1.6

ps
For running on device, please add graphics to files tab

grCor

 

[klaus]

It's done, file updated in post#5.

Best regards.