I need to change the stroke color to a user defined color. Nothing to do with the state

I need to change the stroke color from the app. The user is able to change the background color so I need to also let them change the stroke (outline) of the button. As its is already set in the drawable (sample below) I have not found a way to change this. Seems like all of the other questions like this just said to use the XML file.... but that doesnt let me make it dynamic. Thank you for any help!

I need to change the stroke color to a user defined color. Nothing to do with the state.

<?xml version="1.0" encoding="UTF-8"?> 
<shape xmlns:android="http://schemas.android.com/apk/res/android"> 

    <solid android:color="#ffffffff"/>    
      <stroke
                android:width="3dp"
                android:color="@color/Dim_Gray" />  <<<<--- This is what I need to change


    <padding android:left="10dp"
             android:top="10dp"
             android:right="10dp"
             android:bottom="10dp"
             /> 

    <corners android:bottomRightRadius="12dp" android:bottomLeftRadius="12dp" 
     android:topLeftRadius="12dp" android:topRightRadius="12dp"/> 

</shape>

1. If you have drawable file for a "view" like this

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android" >

<corners android:radius="5dp" />

<solid android:color="@android:color/white" />

<stroke
    android:width="3px"
    android:color="@color/blue" />

</shape>

Then you can change
a. Stroke color :

GradientDrawable drawable = (GradientDrawable)view.getBackground();
drawable.setStroke(3, Color.RED); // set stroke width and stroke color 

b. Solid color :

GradientDrawable drawable = (GradientDrawable)view.getBackground();
drawable.setColor(Color.RED); // set solid color

2. If you have drawable file for a "view" like this

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_checked="true" android:id="@+id/buttonSelected">
        <shape>
            <solid android:color="@color/blue" />
            <stroke android:width="1px" android:color="@color/blue" />
        </shape>
    </item>
    <item android:state_checked="false" android:id="@+id/buttonNotSelected">
        <shape android:shape="rectangle">
            <solid android:color="@color/white" />
            <stroke android:width="1px" android:color="@color/blue" />
        </shape>
    </item>
</selector>

Then you can change the individual item attributes by taking separate drawable objects by there positions.

StateListDrawable drawable = (StateListDrawable)view.getBackground();
DrawableContainerState dcs = (DrawableContainerState)drawable.getConstantState();
Drawable[] drawableItems = dcs.getChildren();
GradientDrawable gradientDrawableChecked = (GradientDrawable)drawableItems[0]; // item 1 
GradientDrawable gradientDrawableUnChecked = (GradientDrawable)drawableItems[1]; // item 2

now to change stroke or solid color :

//solid color
gradientDrawableChecked.setColor(Color.BLUE);
gradientDrawableUnChecked.setColor(Color.RED);

//stroke
gradientDrawableChecked.setStroke(1, Color.RED);
gradientDrawableUnChecked.setStroke(1, Color.BLUE);

I needed a way to change the stroke color of any GradientDrawable without knowing the width of the stroke. My goal was to do this using Drawable.setTint. I had to add a transparent solid element to my shape xml to get it to work:

<!-- stroke_background.xml -->
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle">
    <stroke
        android:width="4dp"
        android:color="@android:color/white" />
    <!-- Need transparent solid to get tint applied to only the stroke -->
    <solid android:color="@android:color/transparent"/>
</shape>

// StrokeView.kt
setBackgroundResource(R.drawable.stroke_background)
// Set the color of your stroke
drawable.setTint(Color.BLUE)

In your case, since you have both a solid and stroke, then you'll need to use a layer-list, where the stroke is added AFTER the solid (so that it's drawn on top). This will let you set different colors on the solid and the stroke without knowing in advance what the stroke width is:

<!-- stroke_solid_background.xml -->
<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:drawable="@drawable/solid_background" />
    <item android:drawable="@drawable/stroke_background" />
</layer-list>

// StrokeSolidView.kt
setBackgroundResource(R.drawable.stroke_solid_background)
(drawable as LayerDrawable).apply {
    // Set the color of your solid
    getDrawable(0).setTint(Color.GREEN)
    // Set the color of your stroke
    getDrawable(1).setTint(Color.BLUE)
}

Please look at the LayerDrawable because it created from your XML and used at runtime.

Here is a Demo Example:

<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <item>
        <shape android:shape="rectangle" >
            <solid android:color="@android:color/transparent" />
        </shape>
    </item>
    <item android:id="@+id/itemId" android:top="-4dp" android:right="-4dp" android:left="-4dp">
        <shape>
            <solid android:color="@android:color/transparent"/>
            <stroke
                android:width="1.5dp"
                android:color="#06C1D7" >
            </stroke>
            <padding
                android:bottom="-2dp"/>

        </shape>
    </item>
</layer-list>

You can modify it at runtime like:

 LayerDrawable layerDrawable = (LayerDrawable) getResources()
                .getDrawable(R.drawable.only_one_bottom_line);
        GradientDrawable gradientDrawable = (GradientDrawable) layerDrawable.findDrawableByLayerId(R.id.itemId);
        int px = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 1.5f, getResources().getDisplayMetrics());

        gradientDrawable.setStroke(px, getResources().getColor(R.color.theme_color));
        tv_select_city_name.setBackground(layerDrawable);