add arrow icons for switching the month

app/src/main/java/calendar/simplemobiletools/com/MainActivity.java

@@ -1,8 +1,10 @@
 package calendar.simplemobiletools.com;
 
+import android.graphics.PorterDuff;
 import android.os.Bundle;
 import android.support.v7.app.AppCompatActivity;
 import android.view.LayoutInflater;
+import android.widget.ImageView;
 import android.widget.TableLayout;
 import android.widget.TableRow;
 import android.widget.TextView;
@@ -12,19 +14,30 @@ import org.joda.time.DateTime;
 import java.text.DateFormatSymbols;
 
 public class MainActivity extends AppCompatActivity {
+    private DateTime targetDate;
+    private int grey;
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_main);
 
+        grey = getResources().getColor(R.color.darkGrey);
+
+        final ImageView leftArrow = (ImageView) findViewById(R.id.left_arrow);
+        leftArrow.getDrawable().mutate().setColorFilter(grey, PorterDuff.Mode.SRC_ATOP);
+
+        final ImageView rightArrow = (ImageView) findViewById(R.id.right_arrow);
+        rightArrow.getDrawable().mutate().setColorFilter(grey, PorterDuff.Mode.SRC_ATOP);
+
         final TextView monthTV = (TextView) findViewById(R.id.table_month);
 
         final TableLayout tableHolder = (TableLayout) findViewById(R.id.table_holder);
         final LayoutInflater inflater = getLayoutInflater();
 
         final DateTime now = new DateTime();
-        monthTV.setText(getMonthName(now));
+        targetDate = now;
+        monthTV.setText(getMonthName());
         final int currMonthDays = now.dayOfMonth().getMaximumValue();
 
         final int firstDayIndex = now.withDayOfMonth(1).getDayOfWeek() - 1;
@@ -44,7 +57,7 @@ public class MainActivity extends AppCompatActivity {
                     currDate = prevMonthStart + cur;
                 } else if (currDate <= currMonthDays) {
                     thisMonthDays++;
-                    day.setTextColor(getResources().getColor(R.color.darkGrey));
+                    day.setTextColor(grey);
                 } else {
                     currDate = nextMonthsDay++;
                 }
@@ -58,8 +71,8 @@ public class MainActivity extends AppCompatActivity {
         }
     }
 
-    private String getMonthName(DateTime dateTime) {
+    private String getMonthName() {
         final String[] months = new DateFormatSymbols().getMonths();
-        return months[dateTime.getMonthOfYear() - 1];
+        return months[targetDate.getMonthOfYear() - 1];
     }
 }

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

@@ -4,22 +4,44 @@
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
+    android:layout_margin="@dimen/activity_margin"
     tools:context="calendar.simplemobiletools.com.MainActivity">
 
+    <ImageView
+        android:id="@+id/left_arrow"
+        android:layout_width="wrap_content"
+        android:layout_height="match_parent"
+        android:layout_alignBottom="@+id/table_month"
+        android:layout_alignTop="@+id/table_month"
+        android:paddingRight="@dimen/activity_margin"
+        android:src="@mipmap/arrow_left"/>
+
     <TextView
         android:id="@+id/table_month"
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
-        android:layout_margin="@dimen/activity_margin"
         android:gravity="center_horizontal"
+        android:paddingBottom="@dimen/activity_margin"
+        android:paddingTop="@dimen/activity_margin"
         android:textColor="@color/darkGrey"
         android:textSize="24sp"/>
 
+    <ImageView
+        android:id="@+id/right_arrow"
+        android:layout_width="wrap_content"
+        android:layout_height="match_parent"
+        android:layout_alignBottom="@+id/table_month"
+        android:layout_alignParentRight="true"
+        android:layout_alignTop="@+id/table_month"
+        android:paddingLeft="@dimen/activity_margin"
+        android:src="@mipmap/arrow_right"/>
+
     <TableLayout
         android:id="@+id/table_holder"
         android:layout_width="match_parent"
         android:layout_height="match_parent"
         android:layout_below="@+id/table_month"
+        android:layout_marginBottom="@dimen/activity_margin"
         android:gravity="center">
 
     </TableLayout>