Use android.support.v7.widget.GridLayout

am: e564d23a5d

Change-Id: Ibd91859800eda9c6143ec2871aa513ec97758ec9

7 files changed, 305 insertions, 297 deletions

diff --git a/res/layout/pad_advanced_3x5.xml b/res/layout/pad_advanced_3x5.xml
index e303133..ece7003 100644
--- a/res/layout/pad_advanced_3x5.xml
+++ b/res/layout/pad_advanced_3x5.xml
@@ -15,193 +15,194 @@
   limitations under the License.
   -->
 
-<GridLayout
+<android.support.v7.widget.GridLayout
     xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
     android:id="@+id/pad_advanced"
     style="@style/PadLayoutStyle.Advanced"
-    android:rowCount="5"
-    android:columnCount="3"
-    android:background="@color/pad_advanced_background_color">
+    android:background="@color/pad_advanced_background_color"
+    app:rowCount="5"
+    app:columnCount="3">
 
     <Button
         android:id="@+id/toggle_inv"
         style="@style/PadButtonStyle.Advanced.Text"
-        android:layout_row="0"
-        android:layout_column="0"
         android:background="@drawable/pad_button_inverse_background"
         android:contentDescription="@string/desc_inv_off"
-        android:text="@string/inv" />
+        android:text="@string/inv"
+        app:layout_row="0"
+        app:layout_column="0" />
 
     <Button
         android:id="@+id/toggle_mode"
         style="@style/PadButtonStyle.Advanced.Text"
-        android:layout_row="0"
-        android:layout_column="1"
         android:contentDescription="@string/desc_switch_deg"
-        android:text="@string/mode_deg" />
+        android:text="@string/mode_deg"
+        app:layout_row="0"
+        app:layout_column="1" />
 
     <Button
         android:id="@+id/op_pct"
         style="@style/PadButtonStyle.Advanced"
-        android:layout_row="0"
-        android:layout_column="2"
         android:contentDescription="@string/desc_op_pct"
-        android:text="@string/op_pct" />
+        android:text="@string/op_pct"
+        app:layout_row="0"
+        app:layout_column="2" />
 
     <Button
         android:id="@+id/fun_sin"
         style="@style/PadButtonStyle.Advanced"
-        android:layout_row="1"
-        android:layout_column="0"
         android:contentDescription="@string/desc_fun_sin"
-        android:text="@string/fun_sin" />
+        android:text="@string/fun_sin"
+        app:layout_row="1"
+        app:layout_column="0" />
 
     <Button
         android:id="@+id/fun_arcsin"
         style="@style/PadButtonStyle.Advanced"
-        android:layout_row="1"
-        android:layout_column="0"
         android:contentDescription="@string/desc_fun_arcsin"
         android:fontFamily="sans-serif-medium"
         android:text="@string/fun_arcsin"
-        android:visibility="gone" />
+        android:visibility="gone"
+        app:layout_row="1"
+        app:layout_column="0" />
 
     <Button
         android:id="@+id/fun_cos"
         style="@style/PadButtonStyle.Advanced"
-        android:layout_row="1"
-        android:layout_column="1"
         android:contentDescription="@string/desc_fun_cos"
-        android:text="@string/fun_cos" />
+        android:text="@string/fun_cos"
+        app:layout_row="1"
+        app:layout_column="1" />
 
     <Button
         android:id="@+id/fun_arccos"
         style="@style/PadButtonStyle.Advanced"
-        android:layout_row="1"
-        android:layout_column="1"
         android:contentDescription="@string/desc_fun_arccos"
         android:fontFamily="sans-serif-medium"
         android:text="@string/fun_arccos"
-        android:visibility="gone" />
+        android:visibility="gone"
+        app:layout_row="1"
+        app:layout_column="1" />
 
     <Button
         android:id="@+id/fun_tan"
         style="@style/PadButtonStyle.Advanced"
-        android:layout_row="1"
-        android:layout_column="2"
         android:contentDescription="@string/desc_fun_tan"
-        android:text="@string/fun_tan" />
+        android:text="@string/fun_tan"
+        app:layout_row="1"
+        app:layout_column="2" />
 
     <Button
         android:id="@+id/fun_arctan"
         style="@style/PadButtonStyle.Advanced"
-        android:layout_row="1"
-        android:layout_column="2"
         android:contentDescription="@string/desc_fun_arctan"
         android:fontFamily="sans-serif-medium"
         android:text="@string/fun_arctan"
-        android:visibility="gone" />
+        android:visibility="gone"
+        app:layout_row="1"
+        app:layout_column="2" />
 
     <Button
         android:id="@+id/fun_ln"
         style="@style/PadButtonStyle.Advanced"
-        android:layout_row="2"
-        android:layout_column="0"
         android:contentDescription="@string/desc_fun_ln"
-        android:text="@string/fun_ln" />
+        android:text="@string/fun_ln"
+        app:layout_row="2"
+        app:layout_column="0" />
 
     <Button
         android:id="@+id/fun_exp"
         style="@style/PadButtonStyle.Advanced"
-        android:layout_row="2"
-        android:layout_column="0"
         android:contentDescription="@string/desc_fun_exp"
         android:fontFamily="sans-serif-medium"
         android:text="@string/fun_exp"
-        android:visibility="gone" />
+        android:visibility="gone"
+        app:layout_row="2"
+        app:layout_column="0" />
 
     <Button
         android:id="@+id/fun_log"
         style="@style/PadButtonStyle.Advanced"
-        android:layout_row="2"
-        android:layout_column="1"
         android:contentDescription="@string/desc_fun_log"
-        android:text="@string/fun_log" />
+        android:text="@string/fun_log"
+        app:layout_row="2"
+        app:layout_column="1" />
 
     <Button
         android:id="@+id/fun_10pow"
         style="@style/PadButtonStyle.Advanced"
-        android:layout_row="2"
-        android:layout_column="1"
         android:contentDescription="@string/desc_fun_10pow"
         android:fontFamily="sans-serif-medium"
         android:text="@string/fun_10pow"
-        android:visibility="gone" />
+        android:visibility="gone"
+        app:layout_row="2"
+        app:layout_column="1" />
 
     <Button
         android:id="@+id/op_fact"
         style="@style/PadButtonStyle.Advanced"
-        android:layout_row="2"
-        android:layout_column="2"
         android:contentDescription="@string/desc_op_fact"
-        android:text="@string/op_fact" />
+        android:text="@string/op_fact"
+        app:layout_row="2"
+        app:layout_column="2" />
 
     <Button
         android:id="@+id/const_pi"
         style="@style/PadButtonStyle.Advanced"
-        android:layout_row="3"
-        android:layout_column="0"
         android:contentDescription="@string/desc_const_pi"
-        android:text="@string/const_pi" />
+        android:text="@string/const_pi"
+        app:layout_row="3"
+        app:layout_column="0" />
 
     <Button
         android:id="@+id/const_e"
         style="@style/PadButtonStyle.Advanced"
-        android:layout_row="3"
-        android:layout_column="1"
         android:contentDescription="@string/desc_const_e"
-        android:text="@string/const_e" />
+        android:text="@string/const_e"
+        app:layout_row="3"
+        app:layout_column="1" />
 
     <Button
         android:id="@+id/op_pow"
         style="@style/PadButtonStyle.Advanced"
-        android:layout_row="3"
-        android:layout_column="2"
         android:contentDescription="@string/desc_op_pow"
-        android:text="@string/op_pow" />
+        android:text="@string/op_pow"
+        app:layout_row="3"
+        app:layout_column="2" />
 
     <Button
         android:id="@+id/lparen"
         style="@style/PadButtonStyle.Advanced"
-        android:layout_row="4"
-        android:layout_column="0"
         android:contentDescription="@string/desc_lparen"
-        android:text="@string/lparen" />
+        android:text="@string/lparen"
+        app:layout_row="4"
+        app:layout_column="0" />
 
     <Button
         android:id="@+id/rparen"
         style="@style/PadButtonStyle.Advanced"
-        android:layout_row="4"
-        android:layout_column="1"
         android:contentDescription="@string/desc_rparen"
-        android:text="@string/rparen" />
+        android:text="@string/rparen"
+        app:layout_row="4"
+        app:layout_column="1" />
 
     <Button
         android:id="@+id/op_sqrt"
         style="@style/PadButtonStyle.Advanced"
-        android:layout_row="4"
-        android:layout_column="2"
         android:contentDescription="@string/desc_op_sqrt"
-        android:text="@string/op_sqrt" />
+        android:text="@string/op_sqrt"
+        app:layout_row="4"
+        app:layout_column="2" />
 
     <Button
         android:id="@+id/op_sqr"
         style="@style/PadButtonStyle.Advanced"
-        android:layout_row="4"
-        android:layout_column="2"
         android:contentDescription="@string/desc_op_sqr"
         android:fontFamily="sans-serif-medium"
         android:text="@string/op_sqr"
-        android:visibility="gone" />
+        android:visibility="gone"
+        app:layout_row="4"
+        app:layout_column="2" />
 
-</GridLayout>
+</android.support.v7.widget.GridLayout>
diff --git a/res/layout/pad_advanced_4x4.xml b/res/layout/pad_advanced_4x4.xml
index ddbee47..70a520e 100644
--- a/res/layout/pad_advanced_4x4.xml
+++ b/res/layout/pad_advanced_4x4.xml
@@ -15,193 +15,194 @@
   limitations under the License.
   -->
 
-<GridLayout
+<android.support.v7.widget.GridLayout
     xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
     android:id="@+id/pad_advanced"
     style="@style/PadLayoutStyle.Advanced"
-    android:rowCount="4"
-    android:columnCount="4"
-    android:background="@color/pad_advanced_background_color">
+    android:background="@color/pad_advanced_background_color"
+    app:rowCount="4"
+    app:columnCount="4">
 
     <Button
         android:id="@+id/toggle_inv"
         style="@style/PadButtonStyle.Advanced.Text"
-        android:layout_row="0"
-        android:layout_column="0"
         android:background="@drawable/pad_button_inverse_background"
         android:contentDescription="@string/desc_inv_off"
-        android:text="@string/inv" />
+        android:text="@string/inv"
+        app:layout_row="0"
+        app:layout_column="0" />
 
     <Button
         android:id="@+id/toggle_mode"
         style="@style/PadButtonStyle.Advanced.Text"
-        android:layout_row="0"
-        android:layout_column="1"
         android:contentDescription="@string/desc_switch_deg"
-        android:text="@string/mode_deg" />
+        android:text="@string/mode_deg"
+        app:layout_row="0"
+        app:layout_column="1" />
 
     <Button
         android:id="@+id/op_pct"
         style="@style/PadButtonStyle.Advanced"
-        android:layout_row="0"
-        android:layout_column="2"
         android:contentDescription="@string/desc_op_pct"
-        android:text="@string/op_pct" />
+        android:text="@string/op_pct"
+        app:layout_row="0"
+        app:layout_column="2" />
 
     <Button
         android:id="@+id/fun_sin"
         style="@style/PadButtonStyle.Advanced"
-        android:layout_row="1"
-        android:layout_column="0"
         android:contentDescription="@string/desc_fun_sin"
-        android:text="@string/fun_sin" />
+        android:text="@string/fun_sin"
+        app:layout_row="1"
+        app:layout_column="0" />
 
     <Button
         android:id="@+id/fun_arcsin"
         style="@style/PadButtonStyle.Advanced"
-        android:layout_row="1"
-        android:layout_column="0"
         android:contentDescription="@string/desc_fun_arcsin"
         android:fontFamily="sans-serif-medium"
         android:text="@string/fun_arcsin"
-        android:visibility="gone" />
+        android:visibility="gone"
+        app:layout_row="1"
+        app:layout_column="0" />
 
     <Button
         android:id="@+id/fun_cos"
         style="@style/PadButtonStyle.Advanced"
-        android:layout_row="1"
-        android:layout_column="1"
         android:contentDescription="@string/desc_fun_cos"
-        android:text="@string/fun_cos" />
+        android:text="@string/fun_cos"
+        app:layout_row="1"
+        app:layout_column="1" />
 
     <Button
         android:id="@+id/fun_arccos"
         style="@style/PadButtonStyle.Advanced"
-        android:layout_row="1"
-        android:layout_column="1"
         android:contentDescription="@string/desc_fun_arccos"
         android:fontFamily="sans-serif-medium"
         android:text="@string/fun_arccos"
-        android:visibility="gone" />
+        android:visibility="gone"
+        app:layout_row="1"
+        app:layout_column="1" />
 
     <Button
         android:id="@+id/fun_tan"
         style="@style/PadButtonStyle.Advanced"
-        android:layout_row="1"
-        android:layout_column="2"
         android:contentDescription="@string/desc_fun_tan"
-        android:text="@string/fun_tan" />
+        android:text="@string/fun_tan"
+        app:layout_row="1"
+        app:layout_column="2" />
 
     <Button
         android:id="@+id/fun_arctan"
         style="@style/PadButtonStyle.Advanced"
-        android:layout_row="1"
-        android:layout_column="2"
         android:contentDescription="@string/desc_fun_arctan"
         android:fontFamily="sans-serif-medium"
         android:text="@string/fun_arctan"
-        android:visibility="gone" />
+        android:visibility="gone"
+        app:layout_row="1"
+        app:layout_column="2" />
 
     <Button
         android:id="@+id/const_pi"
         style="@style/PadButtonStyle.Advanced"
-        android:layout_row="1"
-        android:layout_column="3"
         android:contentDescription="@string/desc_const_pi"
-        android:text="@string/const_pi" />
+        android:text="@string/const_pi"
+        app:layout_row="1"
+        app:layout_column="3" />
 
     <Button
         android:id="@+id/fun_ln"
         style="@style/PadButtonStyle.Advanced"
-        android:layout_row="2"
-        android:layout_column="0"
         android:contentDescription="@string/desc_fun_ln"
-        android:text="@string/fun_ln" />
+        android:text="@string/fun_ln"
+        app:layout_row="2"
+        app:layout_column="0" />
 
     <Button
         android:id="@+id/fun_exp"
         style="@style/PadButtonStyle.Advanced"
-        android:layout_row="2"
-        android:layout_column="0"
         android:contentDescription="@string/desc_fun_exp"
         android:fontFamily="sans-serif-medium"
         android:text="@string/fun_exp"
-        android:visibility="gone" />
+        android:visibility="gone"
+        app:layout_row="2"
+        app:layout_column="0" />
 
     <Button
         android:id="@+id/fun_log"
         style="@style/PadButtonStyle.Advanced"
-        android:layout_row="2"
-        android:layout_column="1"
         android:contentDescription="@string/desc_fun_log"
-        android:text="@string/fun_log" />
+        android:text="@string/fun_log"
+        app:layout_row="2"
+        app:layout_column="1" />
 
     <Button
         android:id="@+id/fun_10pow"
         style="@style/PadButtonStyle.Advanced"
-        android:layout_row="2"
-        android:layout_column="1"
         android:contentDescription="@string/desc_fun_10pow"
         android:fontFamily="sans-serif-medium"
         android:text="@string/fun_10pow"
-        android:visibility="gone" />
+        android:visibility="gone"
+        app:layout_row="2"
+        app:layout_column="1" />
 
     <Button
         android:id="@+id/op_fact"
         style="@style/PadButtonStyle.Advanced"
-        android:layout_row="2"
-        android:layout_column="2"
         android:contentDescription="@string/desc_op_fact"
-        android:text="@string/op_fact" />
+        android:text="@string/op_fact"
+        app:layout_row="2"
+        app:layout_column="2" />
 
     <Button
         android:id="@+id/const_e"
         style="@style/PadButtonStyle.Advanced"
-        android:layout_row="2"
-        android:layout_column="3"
         android:contentDescription="@string/desc_const_e"
-        android:text="@string/const_e" />
+        android:text="@string/const_e"
+        app:layout_row="2"
+        app:layout_column="3" />
 
     <Button
         android:id="@+id/lparen"
         style="@style/PadButtonStyle.Advanced"
-        android:layout_row="3"
-        android:layout_column="0"
         android:contentDescription="@string/desc_lparen"
-        android:text="@string/lparen" />
+        android:text="@string/lparen"
+        app:layout_row="3"
+        app:layout_column="0" />
 
     <Button
         android:id="@+id/rparen"
         style="@style/PadButtonStyle.Advanced"
-        android:layout_row="3"
-        android:layout_column="1"
         android:contentDescription="@string/desc_rparen"
-        android:text="@string/rparen" />
+        android:text="@string/rparen"
+        app:layout_row="3"
+        app:layout_column="1" />
 
     <Button
         android:id="@+id/op_sqrt"
         style="@style/PadButtonStyle.Advanced"
-        android:layout_row="3"
-        android:layout_column="2"
         android:contentDescription="@string/desc_op_sqrt"
-        android:text="@string/op_sqrt" />
+        android:text="@string/op_sqrt"
+        app:layout_row="3"
+        app:layout_column="2" />
 
     <Button
         android:id="@+id/op_sqr"
         style="@style/PadButtonStyle.Advanced"
-        android:layout_row="3"
-        android:layout_column="2"
         android:contentDescription="@string/desc_op_sqr"
         android:fontFamily="sans-serif-medium"
         android:text="@string/op_sqr"
-        android:visibility="gone" />
+        android:visibility="gone"
+        app:layout_row="3"
+        app:layout_column="2" />
 
     <Button
         android:id="@+id/op_pow"
         style="@style/PadButtonStyle.Advanced"
-        android:layout_row="3"
-        android:layout_column="3"
         android:contentDescription="@string/desc_op_pow"
-        android:text="@string/op_pow" />
+        android:text="@string/op_pow"
+        app:layout_row="3"
+        app:layout_column="3" />
 
-</GridLayout>
\ No newline at end of file
+</android.support.v7.widget.GridLayout>
diff --git a/res/layout/pad_advanced_5x3.xml b/res/layout/pad_advanced_5x3.xml
index b8de7fd..95a0fc1 100644
--- a/res/layout/pad_advanced_5x3.xml
+++ b/res/layout/pad_advanced_5x3.xml
@@ -15,193 +15,194 @@
   limitations under the License.
   -->
 
-<GridLayout
+<android.support.v7.widget.GridLayout
     xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
     android:id="@+id/pad_advanced"
     style="@style/PadLayoutStyle.Advanced"
-    android:rowCount="3"
-    android:columnCount="5"
-    android:background="@color/pad_advanced_background_color">
+    android:background="@color/pad_advanced_background_color"
+    app:rowCount="3"
+    app:columnCount="5">
 
     <Button
         android:id="@+id/toggle_inv"
         style="@style/PadButtonStyle.Advanced.Text"
-        android:layout_row="0"
-        android:layout_column="0"
         android:background="@drawable/pad_button_inverse_background"
         android:contentDescription="@string/desc_inv_off"
-        android:text="@string/inv" />
+        android:text="@string/inv"
+        app:layout_row="0"
+        app:layout_column="0" />
 
     <Button
         android:id="@+id/toggle_mode"
         style="@style/PadButtonStyle.Advanced.Text"
-        android:layout_row="0"
-        android:layout_column="1"
         android:contentDescription="@string/desc_switch_deg"
-        android:text="@string/mode_deg" />
+        android:text="@string/mode_deg"
+        app:layout_row="0"
+        app:layout_column="1" />
 
     <Button
         android:id="@+id/fun_sin"
         style="@style/PadButtonStyle.Advanced"
-        android:layout_row="0"
-        android:layout_column="2"
         android:contentDescription="@string/desc_fun_sin"
-        android:text="@string/fun_sin" />
+        android:text="@string/fun_sin"
+        app:layout_row="0"
+        app:layout_column="2" />
 
     <Button
         android:id="@+id/fun_arcsin"
         style="@style/PadButtonStyle.Advanced"
-        android:layout_row="0"
-        android:layout_column="2"
         android:contentDescription="@string/desc_fun_arcsin"
         android:fontFamily="sans-serif-medium"
         android:text="@string/fun_arcsin"
-        android:visibility="gone" />
+        android:visibility="gone"
+        app:layout_row="0"
+        app:layout_column="2" />
 
     <Button
         android:id="@+id/fun_cos"
         style="@style/PadButtonStyle.Advanced"
-        android:layout_row="0"
-        android:layout_column="3"
         android:contentDescription="@string/desc_fun_cos"
-        android:text="@string/fun_cos" />
+        android:text="@string/fun_cos"
+        app:layout_row="0"
+        app:layout_column="3" />
 
     <Button
         android:id="@+id/fun_arccos"
         style="@style/PadButtonStyle.Advanced"
-        android:layout_row="0"
-        android:layout_column="3"
         android:contentDescription="@string/desc_fun_arccos"
         android:fontFamily="sans-serif-medium"
         android:text="@string/fun_arccos"
-        android:visibility="gone" />
+        android:visibility="gone"
+        app:layout_row="0"
+        app:layout_column="3" />
 
     <Button
         android:id="@+id/fun_tan"
         style="@style/PadButtonStyle.Advanced"
-        android:layout_row="0"
-        android:layout_column="4"
         android:contentDescription="@string/desc_fun_tan"
-        android:text="@string/fun_tan" />
+        android:text="@string/fun_tan"
+        app:layout_row="0"
+        app:layout_column="4" />
 
     <Button
         android:id="@+id/fun_arctan"
         style="@style/PadButtonStyle.Advanced"
-        android:layout_row="0"
-        android:layout_column="4"
         android:contentDescription="@string/desc_fun_arctan"
         android:fontFamily="sans-serif-medium"
         android:text="@string/fun_arctan"
-        android:visibility="gone" />
+        android:visibility="gone"
+        app:layout_row="0"
+        app:layout_column="4" />
 
     <Button
         android:id="@+id/op_pct"
         style="@style/PadButtonStyle.Advanced"
-        android:layout_row="1"
-        android:layout_column="0"
         android:contentDescription="@string/desc_op_pct"
-        android:text="@string/op_pct" />
+        android:text="@string/op_pct"
+        app:layout_row="1"
+        app:layout_column="0" />
 
     <Button
         android:id="@+id/fun_ln"
         style="@style/PadButtonStyle.Advanced"
-        android:layout_row="1"
-        android:layout_column="1"
         android:contentDescription="@string/desc_fun_ln"
-        android:text="@string/fun_ln" />
+        android:text="@string/fun_ln"
+        app:layout_row="1"
+        app:layout_column="1" />
 
     <Button
         android:id="@+id/fun_exp"
         style="@style/PadButtonStyle.Advanced"
-        android:layout_row="1"
-        android:layout_column="1"
         android:contentDescription="@string/desc_fun_exp"
         android:fontFamily="sans-serif-medium"
         android:text="@string/fun_exp"
-        android:visibility="gone" />
+        android:visibility="gone"
+        app:layout_row="1"
+        app:layout_column="1" />
 
     <Button
         android:id="@+id/fun_log"
         style="@style/PadButtonStyle.Advanced"
-        android:layout_row="1"
-        android:layout_column="2"
         android:contentDescription="@string/desc_fun_log"
-        android:text="@string/fun_log" />
+        android:text="@string/fun_log"
+        app:layout_row="1"
+        app:layout_column="2" />
 
     <Button
         android:id="@+id/fun_10pow"
         style="@style/PadButtonStyle.Advanced"
-        android:layout_row="1"
-        android:layout_column="2"
         android:contentDescription="@string/desc_fun_10pow"
         android:fontFamily="sans-serif-medium"
         android:text="@string/fun_10pow"
-        android:visibility="gone" />
+        android:visibility="gone"
+        app:layout_row="1"
+        app:layout_column="2" />
 
     <Button
         android:id="@+id/op_fact"
         style="@style/PadButtonStyle.Advanced"
-        android:layout_row="1"
-        android:layout_column="3"
         android:contentDescription="@string/desc_op_fact"
-        android:text="@string/op_fact" />
+        android:text="@string/op_fact"
+        app:layout_row="1"
+        app:layout_column="3" />
 
     <Button
         android:id="@+id/op_pow"
         style="@style/PadButtonStyle.Advanced"
-        android:layout_row="1"
-        android:layout_column="4"
         android:contentDescription="@string/desc_op_pow"
-        android:text="@string/op_pow" />
+        android:text="@string/op_pow"
+        app:layout_row="1"
+        app:layout_column="4" />
 
     <Button
         android:id="@+id/const_pi"
         style="@style/PadButtonStyle.Advanced"
-        android:layout_row="2"
-        android:layout_column="0"
         android:contentDescription="@string/desc_const_pi"
-        android:text="@string/const_pi" />
+        android:text="@string/const_pi"
+        app:layout_row="2"
+        app:layout_column="0" />
 
     <Button
         android:id="@+id/const_e"
         style="@style/PadButtonStyle.Advanced"
-        android:layout_row="2"
-        android:layout_column="1"
         android:contentDescription="@string/desc_const_e"
-        android:text="@string/const_e" />
+        android:text="@string/const_e"
+        app:layout_row="2"
+        app:layout_column="1" />
 
     <Button
         android:id="@+id/lparen"
         style="@style/PadButtonStyle.Advanced"
-        android:layout_row="2"
-        android:layout_column="2"
         android:contentDescription="@string/desc_lparen"
-        android:text="@string/lparen" />
+        android:text="@string/lparen"
+        app:layout_row="2"
+        app:layout_column="2" />
 
     <Button
         android:id="@+id/rparen"
         style="@style/PadButtonStyle.Advanced"
-        android:layout_row="2"
-        android:layout_column="3"
         android:contentDescription="@string/desc_rparen"
-        android:text="@string/rparen" />
+        android:text="@string/rparen"
+        app:layout_row="2"
+        app:layout_column="3" />
 
     <Button
         android:id="@+id/op_sqrt"
         style="@style/PadButtonStyle.Advanced"
-        android:layout_row="2"
-        android:layout_column="4"
         android:contentDescription="@string/desc_op_sqrt"
-        android:text="@string/op_sqrt" />
+        android:text="@string/op_sqrt"
+        app:layout_row="2"
+        app:layout_column="4" />
 
     <Button
         android:id="@+id/op_sqr"
         style="@style/PadButtonStyle.Advanced"
-        android:layout_row="2"
-        android:layout_column="4"
         android:contentDescription="@string/desc_op_sqr"
         android:fontFamily="sans-serif-medium"
         android:text="@string/op_sqr"
-        android:visibility="gone" />
+        android:visibility="gone"
+        app:layout_row="2"
+        app:layout_column="4" />
 
-</GridLayout>
+</android.support.v7.widget.GridLayout>
diff --git a/res/layout/pad_numeric.xml b/res/layout/pad_numeric.xml
index 34e9dbc..e9f7c9b 100644
--- a/res/layout/pad_numeric.xml
+++ b/res/layout/pad_numeric.xml
@@ -15,98 +15,99 @@
   limitations under the License.
   -->
 
-<GridLayout
+<android.support.v7.widget.GridLayout
     xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
     android:id="@+id/pad_numeric"
     style="@style/PadLayoutStyle.Numeric"
-    android:rowCount="4"
-    android:columnCount="3"
-    android:background="@color/pad_numeric_background_color">
+    android:background="@color/pad_numeric_background_color"
+    app:rowCount="4"
+    app:columnCount="3">
 
     <Button
         android:id="@+id/digit_7"
         style="@style/PadButtonStyle.Numeric"
-        android:layout_row="0"
-        android:layout_column="0"
-        android:text="@string/digit_7" />
+        android:text="@string/digit_7"
+        app:layout_row="0"
+        app:layout_column="0" />
 
     <Button
         android:id="@+id/digit_8"
         style="@style/PadButtonStyle.Numeric"
-        android:layout_row="0"
-        android:layout_column="1"
-        android:text="@string/digit_8" />
+        android:text="@string/digit_8"
+        app:layout_row="0"
+        app:layout_column="1" />
 
     <Button
         android:id="@+id/digit_9"
         style="@style/PadButtonStyle.Numeric"
-        android:layout_row="0"
-        android:layout_column="2"
-        android:text="@string/digit_9" />
+        android:text="@string/digit_9"
+        app:layout_row="0"
+        app:layout_column="2" />
 
     <Button
         android:id="@+id/digit_4"
         style="@style/PadButtonStyle.Numeric"
-        android:layout_row="1"
-        android:layout_column="0"
-        android:text="@string/digit_4" />
+        android:text="@string/digit_4"
+        app:layout_row="1"
+        app:layout_column="0" />
 
     <Button
         android:id="@+id/digit_5"
         style="@style/PadButtonStyle.Numeric"
-        android:layout_row="1"
-        android:layout_column="1"
-        android:text="@string/digit_5" />
+        android:text="@string/digit_5"
+        app:layout_row="1"
+        app:layout_column="1" />
 
     <Button
         android:id="@+id/digit_6"
         style="@style/PadButtonStyle.Numeric"
-        android:layout_row="1"
-        android:layout_column="2"
-        android:text="@string/digit_6" />
+        android:text="@string/digit_6"
+        app:layout_row="1"
+        app:layout_column="2" />
 
     <Button
         android:id="@+id/digit_1"
         style="@style/PadButtonStyle.Numeric"
-        android:layout_row="2"
-        android:layout_column="0"
-        android:text="@string/digit_1" />
+        android:text="@string/digit_1"
+        app:layout_row="2"
+        app:layout_column="0" />
 
     <Button
         android:id="@+id/digit_2"
         style="@style/PadButtonStyle.Numeric"
-        android:layout_row="2"
-        android:layout_column="1"
-        android:text="@string/digit_2" />
+        android:text="@string/digit_2"
+        app:layout_row="2"
+        app:layout_column="1" />
 
     <Button
         android:id="@+id/digit_3"
         style="@style/PadButtonStyle.Numeric"
-        android:layout_row="2"
-        android:layout_column="2"
-        android:text="@string/digit_3" />
+        android:text="@string/digit_3"
+        app:layout_row="2"
+        app:layout_column="2" />
 
     <Button
         android:id="@+id/dec_point"
         style="@style/PadButtonStyle.Numeric"
-        android:layout_row="3"
-        android:layout_column="0"
         android:contentDescription="@string/desc_dec_point"
-        android:text="@string/dec_point" />
+        android:text="@string/dec_point"
+        app:layout_row="3"
+        app:layout_column="0" />
 
     <Button
         android:id="@+id/digit_0"
         style="@style/PadButtonStyle.Numeric"
-        android:layout_row="3"
-        android:layout_column="1"
-        android:text="@string/digit_0" />
+        android:text="@string/digit_0"
+        app:layout_row="3"
+        app:layout_column="1" />
 
     <Button
         android:id="@+id/eq"
         style="@style/PadButtonStyle.Numeric.Equals"
-        android:layout_row="3"
-        android:layout_column="2"
         android:contentDescription="@string/desc_eq"
-        android:text="@string/eq" />
+        android:text="@string/eq"
+        app:layout_row="3"
+        app:layout_column="2" />
 
-</GridLayout>
+</android.support.v7.widget.GridLayout>
diff --git a/res/layout/pad_operator_one_col.xml b/res/layout/pad_operator_one_col.xml
index 1323b2c..3a6473a 100644
--- a/res/layout/pad_operator_one_col.xml
+++ b/res/layout/pad_operator_one_col.xml
@@ -15,62 +15,63 @@
   limitations under the License.
   -->
 
-<GridLayout
+<android.support.v7.widget.GridLayout
     xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
     android:id="@+id/pad_operator"
     style="@style/PadLayoutStyle.Operator"
-    android:rowCount="5"
-    android:columnCount="1"
-    android:background="@color/pad_operator_background_color">
+    android:background="@color/pad_operator_background_color"
+    app:rowCount="5"
+    app:columnCount="1">
 
     <Button
         android:id="@+id/del"
         style="@style/PadButtonStyle.Operator.Text"
-        android:layout_row="0"
-        android:layout_column="0"
         android:contentDescription="@string/desc_del"
-        android:text="@string/del" />
+        android:text="@string/del"
+        app:layout_row="0"
+        app:layout_column="0" />
 
     <Button
         android:id="@+id/clr"
         style="@style/PadButtonStyle.Operator.Text"
-        android:layout_row="0"
-        android:layout_column="0"
         android:contentDescription="@string/desc_clr"
         android:text="@string/clr"
-        android:visibility="gone" />
+        android:visibility="gone"
+        app:layout_row="0"
+        app:layout_column="0" />
 
 
     <Button
         android:id="@+id/op_div"
         style="@style/PadButtonStyle.Operator"
-        android:layout_row="1"
-        android:layout_column="0"
         android:contentDescription="@string/desc_op_div"
-        android:text="@string/op_div" />
+        android:text="@string/op_div"
+        app:layout_row="1"
+        app:layout_column="0" />
 
     <Button
         android:id="@+id/op_mul"
         style="@style/PadButtonStyle.Operator"
-        android:layout_row="2"
-        android:layout_column="0"
         android:contentDescription="@string/desc_op_mul"
-        android:text="@string/op_mul" />
+        android:text="@string/op_mul"
+        app:layout_row="2"
+        app:layout_column="0" />
 
     <Button
         android:id="@+id/op_sub"
         style="@style/PadButtonStyle.Operator"
-        android:layout_row="3"
-        android:layout_column="0"
         android:contentDescription="@string/desc_op_sub"
-        android:text="@string/op_sub" />
+        android:text="@string/op_sub"
+        app:layout_row="3"
+        app:layout_column="0" />
 
     <Button
         android:id="@+id/op_add"
         style="@style/PadButtonStyle.Operator"
-        android:layout_row="4"
-        android:layout_column="0"
         android:contentDescription="@string/desc_op_add"
-        android:text="@string/op_add" />
+        android:text="@string/op_add"
+        app:layout_row="4"
+        app:layout_column="0" />
 
-</GridLayout>
+</android.support.v7.widget.GridLayout>
diff --git a/res/layout/pad_operator_two_col.xml b/res/layout/pad_operator_two_col.xml
index 0d559d1..e056ba5 100644
--- a/res/layout/pad_operator_two_col.xml
+++ b/res/layout/pad_operator_two_col.xml
@@ -15,69 +15,70 @@
   limitations under the License.
   -->
 
-<GridLayout
+<android.support.v7.widget.GridLayout
     xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
     android:id="@+id/pad_operator"
     style="@style/PadLayoutStyle.Operator"
-    android:rowCount="4"
-    android:columnCount="2"
-    android:background="@color/pad_operator_background_color">
+    android:background="@color/pad_operator_background_color"
+    app:rowCount="4"
+    app:columnCount="2">
 
     <Button
         android:id="@+id/op_div"
         style="@style/PadButtonStyle.Operator"
-        android:layout_row="0"
-        android:layout_column="0"
         android:contentDescription="@string/desc_op_div"
-        android:text="@string/op_div" />
+        android:text="@string/op_div"
+        app:layout_row="0"
+        app:layout_column="0" />
 
     <Button
         android:id="@+id/del"
         style="@style/PadButtonStyle.Operator.Text"
-        android:layout_row="0"
-        android:layout_column="1"
         android:contentDescription="@string/desc_del"
-        android:text="@string/del" />
+        android:text="@string/del"
+        app:layout_row="0"
+        app:layout_column="1" />
 
     <Button
         android:id="@+id/clr"
         style="@style/PadButtonStyle.Operator.Text"
-        android:layout_row="0"
-        android:layout_column="1"
         android:contentDescription="@string/desc_clr"
         android:text="@string/clr"
-        android:visibility="gone" />
+        android:visibility="gone"
+        app:layout_row="0"
+        app:layout_column="1" />
 
     <Button
         android:id="@+id/op_mul"
         style="@style/PadButtonStyle.Operator"
-        android:layout_row="1"
-        android:layout_column="0"
         android:contentDescription="@string/op_mul"
-        android:text="@string/op_mul" />
+        android:text="@string/op_mul"
+        app:layout_row="1"
+        app:layout_column="0" />
 
     <Button
         android:id="@+id/op_sub"
         style="@style/PadButtonStyle.Operator"
-        android:layout_row="2"
-        android:layout_column="0"
         android:contentDescription="@string/desc_op_sub"
-        android:text="@string/op_sub" />
+        android:text="@string/op_sub"
+        app:layout_row="2"
+        app:layout_column="0" />
 
     <Button
         android:id="@+id/op_add"
         style="@style/PadButtonStyle.Operator"
-        android:layout_row="3"
-        android:layout_column="0"
         android:contentDescription="@string/desc_op_add"
-        android:text="@string/op_add" />
+        android:text="@string/op_add"
+        app:layout_row="3"
+        app:layout_column="0" />
 
     <Button
         android:id="@+id/eq"
         style="@style/PadButtonStyle.Operator"
-        android:layout_row="3"
-        android:layout_column="1"
         android:contentDescription="@string/desc_eq"
-        android:text="@string/eq" />
+        android:text="@string/eq"
+        app:layout_row="3"
+        app:layout_column="1" />
 
-</GridLayout>
+</android.support.v7.widget.GridLayout>
diff --git a/res/values/styles.xml b/res/values/styles.xml
index 4935103..ef3597a 100644
--- a/res/values/styles.xml
+++ b/res/values/styles.xml
@@ -29,9 +29,6 @@
     <style name="PadButtonStyle" parent="@android:style/Widget.Material.Light.Button.Borderless">
         <item name="android:layout_width">0dip</item>
         <item name="android:layout_height">0dip</item>
-        <item name="android:layout_rowWeight">1</item>
-        <item name="android:layout_columnWeight">1</item>
-        <item name="android:layout_gravity">fill</item>
         <item name="android:background">@drawable/pad_button_background</item>
         <item name="android:fontFamily">sans-serif-light</item>
         <item name="android:gravity">center</item>
@@ -41,6 +38,11 @@
         <item name="android:onClick">onButtonClick</item>
         <item name="android:textAllCaps">false</item>
         <item name="android:textColor">@color/pad_button_text_color</item>
+
+        <!-- Attributes from android.support.v7.gridlayout -->
+        <item name="layout_gravity">fill</item>
+        <item name="layout_rowWeight">1</item>
+        <item name="layout_columnWeight">1</item>
     </style>
 
     <style name="PadLayoutStyle">