Estimate offline map imagery download size and disable download for l…

…arger areas (#1846)
google · Sep 10, 2023 · bbb40fd · bbb40fd
1 parent 012ccbe
commit bbb40fd
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Showing 6 changed files with 102 additions and 15 deletions.
diff --git a/ground/src/main/java/com/google/android/ground/Config.kt b/ground/src/main/java/com/google/android/ground/Config.kt
@@ -26,7 +26,7 @@ object Config {
 
   // Local db settings.
   // TODO(#128): Reset version to 1 before releasing.
-  const val DB_VERSION = 103
+  const val DB_VERSION = 104
   const val DB_NAME = "ground.db"
 
   // Firebase Cloud Firestore settings.

diff --git a/ground/src/main/java/com/google/android/ground/repository/OfflineAreaRepository.kt b/ground/src/main/java/com/google/android/ground/repository/OfflineAreaRepository.kt
@@ -114,4 +114,10 @@ constructor(
   private fun getFirstTileSourceUrl() =
     surveyRepository.activeSurvey?.tileSources?.firstOrNull()?.url
       ?: error("Survey has no tile sources")
+
+  suspend fun estimateSizeOnDisk(bounds: Bounds): Int {
+    val client = getMogClient()
+    val requests = client.buildTilesRequests(bounds.toGoogleMapsObject())
+    return requests.sumOf { it.totalBytes }
+  }
 }
diff --git a/...java/com/google/android/ground/ui/offlinebasemap/selector/OfflineAreaSelectorViewModel.kt b/...java/com/google/android/ground/ui/offlinebasemap/selector/OfflineAreaSelectorViewModel.kt
@@ -15,8 +15,10 @@
  */
 package com.google.android.ground.ui.offlinebasemap.selector
 
+import android.content.res.Resources
 import androidx.lifecycle.MutableLiveData
 import androidx.lifecycle.viewModelScope
+import com.google.android.ground.R
 import com.google.android.ground.coroutines.IoDispatcher
 import com.google.android.ground.model.imagery.TileSource
 import com.google.android.ground.repository.LocationOfInterestRepository
@@ -30,11 +32,16 @@ import com.google.android.ground.ui.common.BaseMapViewModel
 import com.google.android.ground.ui.common.Navigator
 import com.google.android.ground.ui.common.SharedViewModel
 import com.google.android.ground.ui.map.Bounds
+import com.google.android.ground.ui.map.CameraPosition
 import com.google.android.ground.ui.map.Map
 import javax.inject.Inject
+import kotlin.math.ceil
 import kotlinx.coroutines.CoroutineDispatcher
 import kotlinx.coroutines.launch
 
+private const val MIN_DOWNLOAD_ZOOM_LEVEL = 9
+private const val MAX_AREA_DOWNLOAD_SIZE_MB = 50
+
 /** States and behaviors of Map UI used to select areas for download and viewing offline. */
 @SharedViewModel
 class OfflineAreaSelectorViewModel
@@ -43,6 +50,7 @@ internal constructor(
   private val offlineAreaRepository: OfflineAreaRepository,
   private val navigator: Navigator,
   @IoDispatcher private val ioDispatcher: CoroutineDispatcher,
+  private val resources: Resources,
   locationManager: LocationManager,
   surveyRepository: SurveyRepository,
   mapStateRepository: MapStateRepository,
@@ -60,16 +68,15 @@ internal constructor(
     locationOfInterestRepository,
     ioDispatcher
   ) {
-  enum class DownloadMessage {
-    STARTED,
-    FAILURE
-  }
 
   val tileSources: List<TileSource>
   private var viewport: Bounds? = null
   val isDownloadProgressVisible = MutableLiveData(false)
   val downloadProgressMax = MutableLiveData(0)
   val downloadProgress = MutableLiveData(0)
+  val sizeOnDisk = MutableLiveData<String>(null)
+  val visibleBottomTextViewId = MutableLiveData<Int>(null)
+  val downloadButtonEnabled = MutableLiveData(false)
 
   init {
     tileSources = surveyRepository.activeSurvey!!.tileSources
@@ -84,11 +91,11 @@ internal constructor(
     isDownloadProgressVisible.value = true
     downloadProgress.value = 0
     viewModelScope.launch(ioDispatcher) {
-      offlineAreaRepository.downloadTiles(viewport!!).collect { (byteDownloaded, totalBytes) ->
+      offlineAreaRepository.downloadTiles(viewport!!).collect { (bytesDownloaded, totalBytes) ->
         // Set total bytes / max value on first iteration.
         if (downloadProgressMax.value != totalBytes) downloadProgressMax.postValue(totalBytes)
         // Add number of bytes downloaded to progress.
-        downloadProgress.postValue(byteDownloaded)
+        downloadProgress.postValue(bytesDownloaded)
       }
       isDownloadProgressVisible.postValue(false)
       navigator.navigateUp()
@@ -103,4 +110,43 @@ internal constructor(
     tileSources.forEach { map.addTileOverlay(it) }
     disposeOnClear(cameraBoundUpdates.subscribe { viewport = it })
   }
+
+  override fun onMapCameraMoved(newCameraPosition: CameraPosition) {
+    super.onMapCameraMoved(newCameraPosition)
+    val bounds = newCameraPosition.bounds
+    val zoomLevel = newCameraPosition.zoomLevel
+    if (bounds == null || zoomLevel == null) return
+    if (zoomLevel < MIN_DOWNLOAD_ZOOM_LEVEL) {
+      onLargeAreaSelected()
+      return
+    }
+
+    viewModelScope.launch(ioDispatcher) { updateDownloadSize(bounds) }
+  }
+
+  private fun onStartEstimatingDownloadSize() {
+    sizeOnDisk.postValue(resources.getString(R.string.offline_area_size_loading_symbol))
+    visibleBottomTextViewId.postValue(R.id.size_on_disk_text_view)
+  }
+
+  private suspend fun updateDownloadSize(bounds: Bounds) {
+    onStartEstimatingDownloadSize()
+    val sizeInMb = offlineAreaRepository.estimateSizeOnDisk(bounds) / (1024f * 1024f)
+    if (sizeInMb > MAX_AREA_DOWNLOAD_SIZE_MB) {
+      onLargeAreaSelected()
+    } else {
+      onDownloadableAreaSelected(sizeInMb)
+    }
+  }
+
+  private fun onDownloadableAreaSelected(sizeInMb: Float) {
+    val sizeString = if (sizeInMb < 1f) "<1" else ceil(sizeInMb).toInt().toString()
+    sizeOnDisk.postValue(sizeString)
+    downloadButtonEnabled.postValue(true)
+  }
+
+  private fun onLargeAreaSelected() {
+    visibleBottomTextViewId.postValue(R.id.area_too_large_text_view)
+    downloadButtonEnabled.postValue(false)
+  }
 }
diff --git a/ground/src/main/res/layout/offline_base_map_selector_frag.xml b/ground/src/main/res/layout/offline_base_map_selector_frag.xml
@@ -20,6 +20,8 @@
   xmlns:app="http://schemas.android.com/apk/res-auto">
 
   <data>
+    <import type="com.google.android.ground.R" />
+    <import type="android.view.View" />
     <variable
       name="viewModel"
       type="com.google.android.ground.ui.offlinebasemap.selector.OfflineAreaSelectorViewModel" />
@@ -71,14 +73,6 @@
         android:alpha="0.4"
         app:layout_constraintTop_toBottomOf="@+id/offline_area_selector_toolbar" />
 
-      <View
-        android:id="@+id/bottom_mask"
-        android:layout_width="match_parent"
-        android:layout_height="80dp"
-        android:background="@color/blackMapOverlay"
-        android:alpha="0.4"
-        app:layout_constraintBottom_toTopOf="@id/button_buttons" />
-
       <View
         android:id="@+id/right_mask"
         android:layout_width="24dp"
@@ -109,6 +103,43 @@
         app:layout_constraintLeft_toRightOf="@id/left_mask"
         app:layout_constraintRight_toLeftOf="@id/right_mask"/>
 
+      <FrameLayout
+        android:id="@+id/bottom_mask"
+        android:layout_width="match_parent"
+        android:layout_height="80dp"
+        app:layout_constraintBottom_toTopOf="@id/button_buttons">
+
+        <View
+          android:layout_width="match_parent"
+          android:layout_height="match_parent"
+          android:background="@color/blackMapOverlay"
+          android:alpha="0.4"/>
+
+        <TextView
+          android:id="@+id/size_on_disk_text_view"
+          android:layout_width="match_parent"
+          android:layout_height="wrap_content"
+          android:layout_gravity="center"
+          android:textAlignment="center"
+          android:textSize="14sp"
+          android:textColor="@color/textOverMap"
+          android:layout_marginHorizontal="64dp"
+          android:visibility="@{viewModel.visibleBottomTextViewId == R.id.size_on_disk_text_view ? View.VISIBLE : View.GONE}"
+          android:text="@{@string/selected_offline_area_size(viewModel.sizeOnDisk)}"/>
+
+        <TextView
+          android:id="@+id/area_too_large_text_view"
+          android:layout_width="match_parent"
+          android:layout_height="wrap_content"
+          android:layout_gravity="center"
+          android:textAlignment="center"
+          android:textSize="14sp"
+          android:textColor="@color/textOverMap"
+          android:layout_marginHorizontal="64dp"
+          android:visibility="@{viewModel.visibleBottomTextViewId == R.id.area_too_large_text_view ? View.VISIBLE : View.GONE}"
+          android:text="@string/selected_offline_area_too_large"/>
+      </FrameLayout>
+
       <LinearLayout
         android:id="@+id/button_buttons"
         android:layout_width="match_parent"

diff --git a/ground/src/main/res/values/colors.xml b/ground/src/main/res/values/colors.xml
@@ -20,6 +20,7 @@
   <color name="colorMapAccent">#ff9131</color>
   <color name="clusterColor">#6DDD81</color>
   <color name="polyLineColor">#55ffffff</color>
+  <color name="textOverMap">#FCFDF7</color>
   <color name="blackMapOverlay">#000000</color>
   <color name="lightBackground">#EDEEE9</color>
 

diff --git a/ground/src/main/res/values/strings.xml b/ground/src/main/res/values/strings.xml
@@ -163,6 +163,9 @@
   <string name="contact_survey_organizer_to_obtain_access">Contact your system administrator to request access</string>
   <string name="close_app">Close app</string>
   <string name="warning_sign_out">Warning: If you sign out, all unsaved data will be lost </string>
+  <string name="selected_offline_area_size">The selected area may take up to %s\u00A0MB of space on your device</string>
+  <string name="selected_offline_area_too_large">Zoom in and select a smaller area to download to your device</string>
+  <string name="offline_area_size_loading_symbol">…</string>
   <string name="offline_area_select_cancel_button">Cancel</string>
   <string name="offline_area_selector_title">Download this area?</string>
 </resources>