Eventually fix some rare crashes

app/src/main/java/io/timelimit/android/ui/view/SafeViewFlipper.kt

@@ -0,0 +1,35 @@
+/*
+ * Open TimeLimit Copyright <C> 2019 Jonas Lochmann
+ *
+ * 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 version 3 of the License.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ */
+package io.timelimit.android.ui.view
+
+import android.content.Context
+import android.util.AttributeSet
+import android.widget.ViewFlipper
+
+// based on https://stackoverflow.com/a/8208874
+// this should fix some rare crashes at Android 4.4
+class SafeViewFlipper: ViewFlipper {
+    constructor(context: Context) : this(context, null)
+    constructor(context: Context, attrs: AttributeSet?) : super(context, attrs)
+
+    override fun onDetachedFromWindow() {
+        try {
+            super.onDetachedFromWindow()
+        } catch (ex: IllegalArgumentException) {
+            stopFlipping()
+        }
+    }
+}