Add a sample code that dynamically sets drawable to SegmentedButton.

sample/src/main/java/co/ceryle/segmentedbutton/sample/MainActivity.java

@@ -1,12 +1,15 @@
 package co.ceryle.segmentedbutton.sample;
 
+import android.graphics.Color;
 import android.os.Handler;
 import android.support.v7.app.AppCompatActivity;
 import android.os.Bundle;
 import android.view.View;
 import android.widget.Button;
 
+import co.ceryle.segmentedbutton.SegmentedButton;
 import co.ceryle.segmentedbutton.SegmentedButtonGroup;
+import co.ceryle.segmentedbutton.sample.drawable.BadgeDrawable;
 
 public class MainActivity extends AppCompatActivity {
 
@@ -51,9 +54,31 @@ public void run() {
             }
         };
         handler.postDelayed(runnable, 5000);
+
+        setupDynamicDrawables();
+    }
+
+    private void setupDynamicDrawables() {
+        final BadgeDrawable drawable = new BadgeDrawable(Color.RED, 80, 50, 3, 3);
+        final SegmentedButton leftButton = (SegmentedButton) findViewById(R.id.left_button);
+        leftButton.setDrawable(drawable);
+
+        SegmentedButtonGroup group = (SegmentedButtonGroup)findViewById(R.id.dynamic_drawable_group);
+        group.setOnClickedButtonListener(new SegmentedButtonGroup.OnClickedButtonListener() {
+            @Override
+            public void onClickedButton(int position) {
+                if(position == 0){
+                    drawable.setCount(drawable.getCount() + 1);
+                    leftButton.requestLayout();
+                }
+            }
+        });
+
+        final SegmentedButton rightButton = (SegmentedButton) findViewById(R.id.right_button);
+        rightButton.setDrawable(R.drawable.ic_b1);
     }
 
     private void updateButton(int position) {
         button.setText("Position: " + position);
     }
-}
+}

sample/src/main/java/co/ceryle/segmentedbutton/sample/drawable/BadgeDrawable.java

@@ -0,0 +1,101 @@
+package co.ceryle.segmentedbutton.sample.drawable;
+
+import android.graphics.Canvas;
+import android.graphics.ColorFilter;
+import android.graphics.Paint;
+import android.graphics.Path;
+import android.graphics.PixelFormat;
+import android.graphics.Rect;
+import android.graphics.RectF;
+import android.graphics.drawable.Drawable;
+import android.support.annotation.NonNull;
+
+public class BadgeDrawable extends Drawable {
+
+    private Paint paint;
+    private int color;
+    private int width;
+    private int height;
+    private int borderWidth;
+    private int borderRadius;
+
+    private RectF rect;
+    private Path path;
+    private int count = 10;
+
+    public BadgeDrawable(int color, int width, int height, int borderWidth, int borderRadius) {
+        paint = new Paint(Paint.ANTI_ALIAS_FLAG);
+        paint.setStyle(Paint.Style.FILL);
+        paint.setTextSize(32);
+
+        path = new Path();
+        path.setFillType(Path.FillType.EVEN_ODD);
+
+        rect = new RectF();
+
+        this.color = color;
+        this.width = width;
+        this.height = height;
+        this.borderWidth = borderWidth;
+        this.borderRadius = borderRadius;
+    }
+
+    @Override
+    public int getIntrinsicWidth() {
+        return width;
+    }
+
+    @Override
+    public int getIntrinsicHeight() {
+        return height;
+    }
+
+    @Override
+    protected void onBoundsChange(Rect bounds) {
+        path.reset();
+
+        path.addRect(bounds.left, bounds.top, bounds.right, bounds.bottom, Path.Direction.CW);
+        rect.set(bounds.left + borderWidth, bounds.top + borderWidth,
+                bounds.right - borderWidth, bounds.bottom - borderWidth);
+        path.addRoundRect(rect, borderRadius, borderRadius, Path.Direction.CW);
+    }
+
+    @Override
+    public void draw(@NonNull Canvas canvas) {
+        paint.setColor(color);
+        canvas.drawPath(path, paint);
+
+        Rect textBounds = new Rect();
+        String countString = String.valueOf(count);
+        paint.getTextBounds(countString, 0, countString.length(), textBounds);
+        canvas.drawText(
+                countString,
+                rect.right - (rect.right - rect.left) / 2 - textBounds.width() / 2,
+                rect.top + textBounds.height() / 2 + (rect.bottom - rect.top) / 2,
+                paint
+        );
+    }
+
+    @Override
+    public void setAlpha(int alpha) {
+        paint.setAlpha(alpha);
+    }
+
+    @Override
+    public void setColorFilter(ColorFilter cf) {
+        paint.setColorFilter(cf);
+    }
+
+    @Override
+    public int getOpacity() {
+        return PixelFormat.TRANSLUCENT;
+    }
+
+    public int getCount() {
+        return count;
+    }
+
+    public void setCount(int count) {
+        this.count = count;
+    }
+}

sample/src/main/res/layout/activity_main.xml

@@ -393,5 +393,49 @@
 
     </co.ceryle.segmentedbutton.SegmentedButtonGroup>
 
+    <TextView
+        android:layout_marginStart="10dp"
+        android:layout_marginLeft="10dp"
+        android:layout_marginTop="10dp"
+        android:textSize="12sp"
+        android:text="Using dynamic drawable:"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content" />
 
-</LinearLayout>
+    <co.ceryle.segmentedbutton.SegmentedButtonGroup
+        android:id="@+id/dynamic_drawable_group"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:layout_margin="4dp"
+        android:elevation="2dp"
+        app:sbg_animateSelector="fastOutSlowIn"
+        app:sbg_animateSelectorDuration="1000"
+        app:sbg_backgroundColor="@color/black"
+        app:sbg_position="0"
+        app:sbg_radius="2dp"
+        app:sbg_rippleColor="@color/white"
+        app:sbg_selectorColor="@color/white">
+
+        <co.ceryle.segmentedbutton.SegmentedButton
+            android:id="@+id/left_button"
+            android:layout_width="0dp"
+            android:layout_height="match_parent"
+            android:layout_weight="1"
+            app:sb_drawablePadding="8dp"
+            app:sb_drawableGravity="right"
+            app:sb_text="Left"
+            app:sb_drawableTint="@color/white"
+            app:sb_drawableTint_onSelection="@color/black"/>
+
+        <co.ceryle.segmentedbutton.SegmentedButton
+            android:id="@+id/right_button"
+            android:layout_width="0dp"
+            android:layout_height="match_parent"
+            android:layout_weight="1"
+            app:sb_drawableGravity="right"
+            app:sb_text="Right"
+            app:sb_drawableTint="@color/white"
+            app:sb_drawableTint_onSelection="@color/black"/>
+
+    </co.ceryle.segmentedbutton.SegmentedButtonGroup>
+</LinearLayout>