android: Add a linear layout that is checkable

src/frontends/android/app/src/main/java/org/strongswan/android/ui/widget/CheckableLinearLayout.java

@@ -0,0 +1,66 @@
+/*
+ * Copyright (C) 2017 Tobias Brunner
+ * HSR Hochschule fuer Technik Rapperswil
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * for more details.
+ */
+
+package org.strongswan.android.ui.widget;
+
+import android.content.Context;
+import android.support.annotation.Nullable;
+import android.util.AttributeSet;
+import android.widget.Checkable;
+import android.widget.LinearLayout;
+
+public class CheckableLinearLayout extends LinearLayout implements Checkable
+{
+	private static final int[] CHECKED_STATE_SET = {android.R.attr.state_checked};
+	private boolean mChecked;
+
+	public CheckableLinearLayout(Context context, @Nullable AttributeSet attrs)
+	{
+		super(context, attrs);
+	}
+
+	@Override
+	public void setChecked(boolean checked)
+	{
+		if (mChecked != checked)
+		{
+			mChecked = checked;
+			refreshDrawableState();
+		}
+	}
+
+	@Override
+	public boolean isChecked()
+	{
+		return mChecked;
+	}
+
+	@Override
+	public void toggle()
+	{
+		setChecked(!mChecked);
+	}
+
+	@Override
+	protected int[] onCreateDrawableState(int extraSpace)
+	{
+		final int[] drawableState = super.onCreateDrawableState(extraSpace + 1);
+		if (isChecked())
+		{
+			mergeDrawableStates(drawableState, CHECKED_STATE_SET);
+		}
+		return drawableState;
+	}
+}