Adds hint for date/time task fields (#2782)

* addedhint

* nit revert

* fix with function

* locale fix

ground/src/main/java/com/google/android/ground/ui/datacollection/tasks/date/DateTaskFragment.kt

@@ -20,13 +20,15 @@ import android.text.format.DateFormat
 import android.view.LayoutInflater
 import android.view.View
 import androidx.lifecycle.LiveData
+import androidx.lifecycle.MutableLiveData
 import androidx.lifecycle.asLiveData
 import com.google.android.ground.databinding.DateTaskFragBinding
 import com.google.android.ground.model.submission.DateTimeTaskData
 import com.google.android.ground.ui.datacollection.components.TaskView
 import com.google.android.ground.ui.datacollection.components.TaskViewFactory
 import com.google.android.ground.ui.datacollection.tasks.AbstractTaskFragment
 import dagger.hilt.android.AndroidEntryPoint
+import java.text.SimpleDateFormat
 import java.util.Calendar
 import kotlinx.coroutines.flow.filterIsInstance
 import kotlinx.coroutines.flow.map
@@ -38,6 +40,7 @@ class DateTaskFragment : AbstractTaskFragment<DateTaskViewModel>() {
   private var datePickerDialog: DatePickerDialog? = null
 
   lateinit var dateText: LiveData<String>
+  lateinit var dateTextHint: LiveData<String>
 
   override fun onTaskViewAttached() {
     super.onTaskViewAttached()
@@ -54,6 +57,14 @@ class DateTaskFragment : AbstractTaskFragment<DateTaskViewModel>() {
           }
         }
         .asLiveData()
+
+    dateTextHint =
+      MutableLiveData<String>().apply {
+        val dateFormat = DateFormat.getDateFormat(requireContext()) as SimpleDateFormat
+        val pattern = dateFormat.toPattern()
+        val hint = pattern.uppercase()
+        value = hint
+      }
   }
 
   override fun onCreateTaskView(inflater: LayoutInflater): TaskView =

ground/src/main/java/com/google/android/ground/ui/datacollection/tasks/time/TimeTaskFragment.kt

@@ -20,13 +20,15 @@ import android.text.format.DateFormat
 import android.view.LayoutInflater
 import android.view.View
 import androidx.lifecycle.LiveData
+import androidx.lifecycle.MutableLiveData
 import androidx.lifecycle.asLiveData
 import com.google.android.ground.databinding.TimeTaskFragBinding
 import com.google.android.ground.model.submission.DateTimeTaskData
 import com.google.android.ground.ui.datacollection.components.TaskView
 import com.google.android.ground.ui.datacollection.components.TaskViewFactory
 import com.google.android.ground.ui.datacollection.tasks.AbstractTaskFragment
 import dagger.hilt.android.AndroidEntryPoint
+import java.text.SimpleDateFormat
 import java.util.Calendar
 import kotlinx.coroutines.flow.filterIsInstance
 import kotlinx.coroutines.flow.map
@@ -38,6 +40,7 @@ class TimeTaskFragment : AbstractTaskFragment<TimeTaskViewModel>() {
   private var timePickerDialog: TimePickerDialog? = null
 
   lateinit var timeText: LiveData<String>
+  lateinit var timeTextHint: LiveData<String>
 
   override fun onTaskViewAttached() {
     super.onTaskViewAttached()
@@ -54,6 +57,18 @@ class TimeTaskFragment : AbstractTaskFragment<TimeTaskViewModel>() {
           }
         }
         .asLiveData()
+
+    timeTextHint =
+      MutableLiveData<String>().apply {
+        val timeFormat = DateFormat.getTimeFormat(requireContext())
+        val hint =
+          if (timeFormat is SimpleDateFormat) {
+            timeFormat.toPattern().uppercase()
+          } else {
+            "HH:MM AM/PM" // Fallback hint if DateFormat is not SimpleDateFormat
+          }
+        value = hint
+      }
   }
 
   override fun onCreateTaskView(inflater: LayoutInflater): TaskView =

ground/src/main/res/layout/date_task_frag.xml

@@ -42,6 +42,7 @@
       android:maxLines="1"
       android:onClick="@{__ -> fragment.showDateDialog()}"
       android:text="@{fragment.dateText}"
+      android:hint="@{fragment.dateTextHint}"
       tools:text="@string/date" />
   </com.google.android.material.textfield.TextInputLayout>
 </layout>

ground/src/main/res/layout/time_task_frag.xml

@@ -42,6 +42,7 @@
       android:maxLines="1"
       android:onClick="@{__ -> fragment.showTimeDialog()}"
       android:text="@{fragment.timeText}"
+      android:hint="@{fragment.timeTextHint}"
       tools:text="@string/time" />
   </com.google.android.material.textfield.TextInputLayout>
 </layout>

ground/src/test/java/com/google/android/ground/ui/datacollection/tasks/date/DateTaskFragmentTest.kt

@@ -114,6 +114,12 @@ class DateTaskFragmentTest : BaseTaskFragmentTest<DateTaskFragment, DateTaskView
     assertThat(fragment.dateText.value).isEqualTo("10/10/24")
   }
 
+  @Test
+  fun `hint text is visible`() {
+    setupTaskFragment<DateTaskFragment>(job, task)
+    assertThat(fragment.dateTextHint.value).isEqualTo("M/D/YY")
+  }
+
   @Test
   fun testActionButtons() {
     setupTaskFragment<DateTaskFragment>(job, task)

ground/src/test/java/com/google/android/ground/ui/datacollection/tasks/time/TimeTaskFragmentTest.kt

@@ -109,4 +109,10 @@ class TimeTaskFragmentTest : BaseTaskFragmentTest<TimeTaskFragment, TimeTaskView
 
     runner().assertButtonIsDisabled("Next").assertButtonIsHidden("Skip")
   }
+
+  @Test
+  fun `hint text is visible`() {
+    setupTaskFragment<TimeTaskFragment>(job, task)
+    assertThat(fragment.timeTextHint.value).isEqualTo("H:MM A")
+  }
 }