Android - how to define ShapeDrawables programmatically?

Question

What I'm trying to achieve is to use a Drawable with a couple of layers inside it, but control some values at runtime such as the startColor for the gradient. Here's what I have in my_layered_shape.xml:

<?xml version="1.0" encoding="utf-8"?> <layer-list xmlns:android="http://schemas.android.com/apk/res/android" >   <item>     <shape android:shape="rectangle">       <stroke android:width="1dp" android:color="#FF000000" />       <solid android:color="#FFFFFFFF" />     </shape>   </item>   <item android:top="1dp" android:bottom="1dp">      <shape android:shape="rectangle">     <stroke android:width="1dp" android:color="#FF000000" />     <gradient       android:startColor="#FFFFFFFF"       android:centerColor="#FFFFFF88"       android:endColor="#FFFFFFFF"       android:gradientRadius="250"       android:centerX="1"       android:centerY="0"       android:angle="315"     />                 </shape>   </item> </layer-list> 

And if I use mMyImageView.setBackgroundResource(R.drawable.my_layered_shape) it works. I don't mind splitting the xml if I have to, or doing the whole thing programatically as long as there's a way to get at the various color values. The concept I'm going for programmatically (i.e. my best shot at doing the same in code as this xml) is:

Drawable[] layers = new Drawable[2];  ShapeDrawable sd1 = new ShapeDrawable(new RectShape()); sd1.getPaint().setColor(0xFFFFFFFF); sd1.getPaint().setStyle(Style.STROKE); sd1.getPaint().setStrokeWidth(1); // sd1.getPaint().somehow_set_stroke_color?  ShapeDrawable sd2 = new ShapeDrawable(new RectShape()); sd2.getPaint().setColor(0xFF000000); sd2.getPaint().setStyle(Style.STROKE); // sd2.getPaint().somehow_set_stroke_color? // sd2.getPaint().somehow_set_gradient_params?  layers[0] = sd1; layers[1] = sd2; LayerDrawable composite = new LayerDrawable(layers); mMyImageView.setBackgroundDrawable(composite); 

Thanks.

Answer 1

It seems that is does not work with ShapeDrawable, but take a look at my GradientDrawable example:

GradientDrawable gd = new GradientDrawable(Orientation.BOTTOM_TOP, new int[]{Color.RED, Color.GREEN}); gd.setStroke(10, Color.BLUE); 

You may also need following method:

gd.setGradientCenter(float x, float y); gd.setGradientRadius(float gradientRadius); 

Answer 2

Just gonna leave this here... Not tested yet

 /**  * Created by Nedo on 09.04.2015.  */ public class ShapeBuilder {      public static Drawable generateSelectorFromDrawables(Drawable pressed, Drawable normal) {         StateListDrawable states = new StateListDrawable();         states.addState(new int[]{ -android.R.attr.state_focused, -android.R.attr.state_pressed, -android.R.attr.state_selected}, normal);         states.addState(new int[]{ android.R.attr.state_pressed}, pressed);         states.addState(new int[]{ android.R.attr.state_focused}, pressed);         states.addState(new int[]{ android.R.attr.state_selected}, pressed);          return states;     }      public static Drawable generateShape(String colorTop, String colorBot, String colorStroke, int stokeSize, float strokeRadius) {         int top, bot, stroke;         top = Color.parseColor(colorTop);         bot = Color.parseColor(colorBot);         stroke = Color.parseColor(colorStroke);          GradientDrawable drawable = new GradientDrawable(GradientDrawable.Orientation.BOTTOM_TOP, new int[]{top, bot});         drawable.setStroke(stokeSize, stroke);         drawable.setCornerRadius(strokeRadius);          return drawable;     }      public static Drawable buildSelectorShapeFromColors(String colorNormalStroke, String colorNormalBackTop, String colorNormalBackBot,                                                         String colorPressedStroke, String colorPressedBackTop, String colorPressedBackBot,                                                         int strokeSize, float strokeRadius) {          Drawable pressed = generateShape(colorPressedBackTop, colorPressedBackBot, colorPressedStroke, strokeSize, strokeRadius);         Drawable normal = generateShape(colorNormalBackTop, colorNormalBackBot, colorNormalStroke, strokeSize, strokeRadius);         return generateSelectorFromDrawables(pressed, normal);     } } 

Edit: tested Now, had one mistake. You actually have to describe every single state. If you group states they will only be triggered if all of them accure at once...