Now it is possible to disable on next month change trigger when scrolling to a certain date

- Update test activity
- Add functions to add and remove calendar pages scroll listeners

Author: dmanluc

app/src/main/java/com/uxsmobile/materialkalendar/BasicCalendarTestActivity.kt

@@ -10,7 +10,9 @@ import com.uxsmobile.materialkalendar.presentation.ui.MaterialKalendar
 import com.uxsmobile.materialkalendar.presentation.ui.common.formatter.KalendarDayMonthYearDateFormatter
 import kotlinx.android.synthetic.main.activity_basic_calendar.calendarView
 import kotlinx.android.synthetic.main.activity_basic_calendar.dateTextView
+import kotlinx.android.synthetic.main.activity_basic_calendar.disableNextOnMonthChangedTrigger
 import kotlinx.android.synthetic.main.activity_basic_calendar.monthYearTextView
+import kotlinx.android.synthetic.main.activity_basic_calendar.scrollCurrentDay
 import org.threeten.bp.format.DateTimeFormatter
 import java.util.Locale
 
@@ -69,6 +71,7 @@ class BasicCalendarTestActivity: AppCompatActivity() {
 
         dateTextView.text = calendarView.selectedDay?.date?.format(DateTimeFormatter.ofPattern("dd MMMM yyyy", Locale.getDefault()))
         calendarView.selectedDay?.let { monthYearTextView.text = monthYearFormatter.format(it) }
+        scrollCurrentDay.setOnClickListener { calendarView.scrollToDate(KalendarDay.today(), disableNextOnMonthChangedTrigger.isChecked) }
     }
 
     private fun buildMonthlyAggregationData(day: KalendarDay) {

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

@@ -34,9 +34,29 @@
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:layout_gravity="center"
-        android:layout_margin="16dp"
+        android:layout_margin="@dimen/space_16dp"
         android:textAppearance="?android:attr/textAppearanceMedium"
         android:textColor="@android:color/white"
         />
 
+    <Button
+        android:id="@+id/scrollCurrentDay"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:text="Scroll Current Day"
+        android:layout_margin="@dimen/space_16dp"
+        android:layout_gravity="center"/>
+
+    <CheckBox
+        android:id="@+id/disableNextOnMonthChangedTrigger"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:textColor="@android:color/white"
+        android:buttonTint="@android:color/white"
+        android:paddingStart="@dimen/space_8dp"
+        android:layout_margin="@dimen/space_8dp"
+        android:text="Disable Next OnMonthChanged Trigger"
+        android:textAllCaps="true"
+        android:layout_gravity="center"/>
+
 </LinearLayout>

dependencies.gradle

@@ -4,7 +4,7 @@ ext {
     targetSdkVersion = 28
     versionMajor = 1
     versionMinor = 0
-    versionPatch = 6
+    versionPatch = 7
     versionClassifier = null
     isSnapshot = true
 

library/src/main/java/com/uxsmobile/materialkalendar/presentation/ui/MaterialKalendar.kt

@@ -56,7 +56,7 @@ class MaterialKalendar
             pagerScrollState = state
             pagerScrollState.let {
                 if (it == ViewPager.SCROLL_STATE_IDLE) {
-                    dispatchOnMonthChanged(adapter.getItem(pager.currentItem))
+                    if (triggerOnMonthChanged) dispatchOnMonthChanged(adapter.getItem(pager.currentItem)) else triggerOnMonthChanged = true
                 }
             }
         }
@@ -87,6 +87,7 @@ class MaterialKalendar
     private var allowDynamicWeeksHeightResize: Boolean = false
     private var weekLabelsArray: Array<CharSequence>? = null
     private var shouldShowWeekDays: Boolean = true
+    private var triggerOnMonthChanged: Boolean = true
 
     init {
         clipToPadding = false
@@ -266,7 +267,8 @@ class MaterialKalendar
         scrollToDate(if (minDate.isAfter(currentDay)) minDate else currentDay)
     }
 
-    fun scrollToDate(date: KalendarDay) {
+    fun scrollToDate(date: KalendarDay, disableNextOnMonthChangedTrigger: Boolean = false) {
+        triggerOnMonthChanged = !disableNextOnMonthChangedTrigger
         pager.setCurrentItem(adapter.getIndexForDay(date), true)
     }
 
@@ -340,6 +342,14 @@ class MaterialKalendar
         monthChangedListener = null
     }
 
+    fun addOnCalendarPageScrollChangeListener(listener: ViewPager.OnPageChangeListener) {
+        pager.addOnPageChangeListener(listener)
+    }
+
+    fun removeOnCalendarPageScrollChangeListener(listener: ViewPager.OnPageChangeListener) {
+        pager.removeOnPageChangeListener(listener)
+    }
+
     fun setMonthlyAggregationData(data: KalendarMonthlyAggregation) {
         (adapter as? KalendarMonthPagerAdapter)?.setMonthlyAggregationData(pager.findViewWithTag(data.provideMonthAggregationDate().date.withDayOfMonth(1).toString()), data)
     }