Hi. Thank you for your button. I added one more.

.gitignore

@@ -1,32 +1,32 @@
-# built application files
+Application files
 *.apk
 *.ap_
 
-# files for the dex VM
+# Files for the Dalvik VM
 *.dex
 
 # Java class files
 *.class
 
-# generated files
+# Generated files
 bin/
 gen/
 
+# Gradle files
+.gradle/
+build/
+
 # Local configuration file (sdk path, etc)
 local.properties
 
-# Eclipse project files
-.classpath
-.project
-
 # Proguard folder generated by Eclipse
 proguard/
 
+# Log Files
+*.log
+
 # Intellij project files
 *.iml
 *.ipr
 *.iws
-.idea/
-.gradle/
-
-build
+.idea/

build.gradle

@@ -5,14 +5,14 @@ buildscript {
     }
 
     dependencies {
-        classpath 'com.android.tools.build:gradle:0.12.+'
+        classpath 'com.android.tools.build:gradle:1.2.2'
         classpath 'com.jakewharton.sdkmanager:gradle-plugin:0.12.+'
     }
 }
 
 ext {
-    compileSdkVersion = 19
-    buildToolsVersion = "19.1.0"
+    compileSdkVersion = 22
+    buildToolsVersion = "22.0.1"
 }
 
 def isReleaseBuild() {

example/build.gradle

@@ -3,36 +3,37 @@ buildscript {
         mavenCentral()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:0.12.+'
+        classpath 'com.android.tools.build:gradle:1.1.0'
     }
 }
-apply plugin: 'android'
+apply plugin: 'com.android.application'
 
 repositories {
     mavenCentral()
 }
 
 android {
-    compileSdkVersion 19
-    buildToolsVersion "19.1"
+    compileSdkVersion 22
+    buildToolsVersion "22.0.1"
 
     defaultConfig {
         minSdkVersion 11
-        targetSdkVersion 19
+        targetSdkVersion 22
         versionCode 1
         versionName "1.0"
     }
 
     buildTypes {
         release {
-            runProguard true
+            minifyEnabled false
             proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.txt'
         }
     }
 }
 
 dependencies {
     compile fileTree(dir: 'libs', include: ['*.jar', '*.aar'])
-    compile 'com.android.support:appcompat-v7:19.1.0'
-    compile 'com.github.markushi:circlebutton:1.1'
+    compile 'com.android.support:appcompat-v7:22.0.0'
+    //compile 'com.github.markushi:circlebutton:1.1'
+    compile project(':library')
 }

example/src/main/java/at/markushi/circlebutton/example/MainActivity.java

@@ -8,6 +8,8 @@
 import android.view.ViewGroup;
 import android.widget.Toast;
 
+import at.markushi.ui.CheckableCircleButton;
+
 public class MainActivity extends ActionBarActivity {
 
 	@Override
@@ -20,7 +22,7 @@ protected void onCreate(Bundle savedInstanceState) {
 		}
 	}
 
-	public static class PlaceholderFragment extends Fragment implements View.OnClickListener {
+	public static class PlaceholderFragment extends Fragment implements View.OnClickListener, CheckableCircleButton.OnCheckedChangeListener {
 
 		public PlaceholderFragment() {
 		}
@@ -31,7 +33,8 @@ public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle sa
 
 			rootView.findViewById(R.id.button0).setOnClickListener(this);
 			rootView.findViewById(R.id.button1).setOnClickListener(this);
-			rootView.findViewById(R.id.button2).setOnClickListener(this);
+			CheckableCircleButton ccb = (CheckableCircleButton) rootView.findViewById(R.id.button2);
+            ccb.setOnCheckedChangeListener(this);
 
 			return rootView;
 		}
@@ -40,6 +43,11 @@ public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle sa
 		public void onClick(View view) {
 			Toast.makeText(getActivity(), "Button clicked", Toast.LENGTH_SHORT).show();
 		}
-	}
 
+        @Override
+        public void onCheckedChanged(CheckableCircleButton button, boolean isChecked) {
+            String state = isChecked ? "checked": "unchecked";
+            Toast.makeText(getActivity(), "Button in " + state +" state", Toast.LENGTH_SHORT).show();
+        }
+    }
 }

example/src/main/res/layout/fragment_main.xml

@@ -31,15 +31,18 @@
             android:src="@drawable/ic_action_tick"
             app:cb_color="#FFBB33" />
 
-        <at.markushi.ui.CircleButton
+        <at.markushi.ui.CheckableCircleButton
             android:id="@+id/button2"
-            android:layout_width="64dip"
-            android:layout_height="64dip"
+            android:layout_width="96dip"
+            android:layout_height="96dip"
             android:layout_centerHorizontal="true"
             android:layout_alignParentBottom="true"
             android:layout_marginBottom="8dip"
-            android:src="@drawable/ic_action_tick"
-            app:cb_color="#FF4444" />
+            android:src="@drawable/ic_play_arrow_white_36dp"
+            app:cb_pressedRingWidth="8dp"
+            app:cb_checkedSrc="@drawable/ic_pause_white_36dp"
+            app:cb_color="#B48CF4"
+            app:cb_checkedColor="#AF5555"/>
 
     </LinearLayout>
 </FrameLayout>

gradle/wrapper/gradle-wrapper.properties

@@ -0,0 +1,6 @@
+#Wed Apr 10 15:27:10 PDT 2013
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-2.2.1-all.zip

library/build.gradle

@@ -3,20 +3,20 @@ buildscript {
         mavenCentral()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:0.12.+'
+        classpath 'com.android.tools.build:gradle:1.2.2'
     }
 }
 
 apply plugin: 'android-sdk-manager'
-apply plugin: 'android-library'
+apply plugin: 'com.android.library'
 
 repositories {
     mavenCentral()
 }
 
 android {
-    compileSdkVersion 19
-    buildToolsVersion "19.1"
+    compileSdkVersion 22
+    buildToolsVersion "22.0.1"
 
     defaultConfig {
         versionName = VERSION_NAME

library/src/main/java/at/markushi/ui/CheckableCircleButton.java

@@ -0,0 +1,170 @@
+package at.markushi.ui;
+
+import android.annotation.TargetApi;
+import android.content.Context;
+import android.content.res.TypedArray;
+import android.graphics.Color;
+import android.graphics.drawable.Drawable;
+import android.os.Build;
+import android.os.Parcel;
+import android.os.Parcelable;
+import android.util.AttributeSet;
+import android.widget.Checkable;
+
+import at.markushi.circlebutton.R;
+
+public class CheckableCircleButton extends  CircleButton implements Checkable {
+    private boolean mChecked = false;
+
+    private int mDefaultColor = Color.RED;
+    private int mCheckedColor = Color.BLUE;
+
+    private Drawable mDefaultDrawable;
+    private Drawable mCheckedDrawable;
+
+    private OnCheckedChangeListener mListener;
+    private boolean mBroadcasting;
+
+    public CheckableCircleButton(Context context) {
+        super(context);
+    }
+
+    public CheckableCircleButton(Context context, AttributeSet attrs) {
+        super(context, attrs);
+        init(context, attrs);
+    }
+
+    public CheckableCircleButton(Context context, AttributeSet attrs, int defStyle) {
+        super(context, attrs, defStyle);
+        init(context, attrs);
+    }
+
+    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
+    public CheckableCircleButton(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
+        super(context, attrs, defStyleAttr, defStyleRes);
+        init(context, attrs);
+    }
+
+    @Override
+    public void setPressed(boolean pressed) {
+        super.setPressed(pressed);
+        toggle();
+    }
+
+    @Override
+    public void setChecked(boolean b) {
+        if (mChecked != b) {
+            mChecked = b;
+            setVisualState(mChecked);
+            // Avoid infinite recursions if setChecked() is called from a listener
+            if (mBroadcasting) {
+                return;
+            }
+            mBroadcasting = true;
+            if (mListener != null) {
+                mListener.onCheckedChanged(this, mChecked);
+            }
+            mBroadcasting = false;
+        }
+    }
+
+    @Override
+    public boolean isChecked() {
+        return mChecked;
+    }
+
+    @Override
+    public void toggle() {
+        setChecked(!mChecked);
+    }
+
+    private void init(Context context, AttributeSet attrs) {
+        if (attrs != null) {
+            final TypedArray ta = context.obtainStyledAttributes(attrs, R.styleable.CircleButton);
+            mDefaultColor = ta.getColor(R.styleable.CircleButton_cb_color, mDefaultColor);
+            ta.recycle();
+
+            final TypedArray ta_ccb = context.obtainStyledAttributes(attrs, R.styleable.CheckableCircleButton);
+            mCheckedColor = ta_ccb.getColor(R.styleable.CircleButton_cb_color, mCheckedColor);
+            mCheckedDrawable = ta_ccb.getDrawable(R.styleable.CheckableCircleButton_cb_checkedSrc);
+            ta_ccb.recycle();
+        }
+        mDefaultDrawable = getDrawable();
+    }
+
+    private void setVisualState(boolean isChecked) {
+        setColor(isChecked ? mCheckedColor: mDefaultColor);
+        setImageDrawable(isChecked ? mCheckedDrawable: mDefaultDrawable);
+    }
+
+    public void setCheckedState(boolean isChecked) {
+        if (mChecked != isChecked) {
+            mChecked = isChecked;
+            setVisualState(mChecked);
+        }
+    }
+
+    public void setOnCheckedChangeListener(OnCheckedChangeListener listener) {
+        mListener = listener;
+    }
+
+    public interface OnCheckedChangeListener {
+        void onCheckedChanged(CheckableCircleButton button, boolean isChecked);
+    }
+
+
+    static class SavedState extends BaseSavedState {
+        boolean checked;
+
+        SavedState(Parcelable superState) {
+            super(superState);
+        }
+
+        private SavedState(Parcel in) {
+            super(in);
+            checked = (Boolean)in.readValue(null);
+        }
+
+        @Override
+        public void writeToParcel(Parcel out, int flags) {
+            super.writeToParcel(out, flags);
+            out.writeValue(checked);
+        }
+
+        @Override
+        public String toString() {
+            return "CheckableCircleButton.SavedState{"
+                    + Integer.toHexString(System.identityHashCode(this))
+                    + " checked=" + checked + "}";
+        }
+
+        public static final Parcelable.Creator<SavedState> CREATOR
+                = new Parcelable.Creator<SavedState>() {
+            public SavedState createFromParcel(Parcel in) {
+                return new SavedState(in);
+            }
+
+            public SavedState[] newArray(int size) {
+                return new SavedState[size];
+            }
+        };
+    }
+
+    @Override
+    public Parcelable onSaveInstanceState() {
+        Parcelable superState = super.onSaveInstanceState();
+        SavedState ss = new SavedState(superState);
+        ss.checked = mChecked;
+        return ss;
+    }
+
+    @Override
+    public void onRestoreInstanceState(Parcelable state) {
+        SavedState ss = (SavedState) state;
+
+        super.onRestoreInstanceState(ss.getSuperState());
+        mChecked = ss.checked;
+        setVisualState(ss.checked);
+        requestLayout();
+    }
+}