Fix #259 and part of #163: Finish state fragment overall UI structure (…

…#270)

* Attempt to rebase content-card onto develop.

* Manually apply rejections and remove rej files.

* Add missing pieces implied in merge-fix that are needed for this branch.

* Maunally apply multiple-single-input-interaction changes to develop
branch (with patch rejections).

* Manually apply rejected diffs.

* Fix broken build after merges.

* Add missing changes from merge-fix that are needed to enable state
content binding.

* Resolve unresolved conflicts.

* Make an exploration with all prototype interactions work end-to-end.

This includes:
- Introducing an exploration with all prototype interactions
- Introducing support for binding all interaction types
- Fixing some parsing issues with fractions
- Rewiring the interaction object creation for views to be generic
- Removing temporary answer handling everywhere
- Other random fixes

This includes no tests, and there are a few other fixes still necessary
for the core learning experience to fully work.

* Add support for displaying feedback items.

* Add support for reshowing submitted answers.

* Make 'Continue' button a separate interaction (but keep the existing
general 'Continue' navigation button). Rework how navigation buttons
behave. Introduce automatic answer submission for some interactions
(Continue, ItemSelection if it shows radio buttons, and MultipleChoice).

* Move audio functionality to a custom toolbar, remove the dummy audio
button, and remove the transient state name at the top of the state
fragment.

* Simplify the presenter by updating ExplorationProgressController to feed
information about the next and current state to allow the state presenter
to only focus on rendering the current state.

* First batch of work corresponding to moving the entirety of state
fragment's recycler view (and child views/recycler view) to be bound via
data-binding.

* Finish updating item selection recycler view to use data binding. This
required introducing a ViewComponent that inherits from FragmentComponent
in the Dagger dependency graph. This also involved updating the app to use
a newer AndroidX fragment library that's still pre-release in order to
gain access to the necessary functionality to associate views with their
fragments.

The two custom adapters have been removed in this change.

* Some minor fixes to polish up the experience a bit and reduce jank.

* Fix broken voiceover audio button.

* Address one TODO to generalize adding interactions by leveraging a Dagger
module.

* Fix broken test.

* Fix broken domain tests by allowing feedback to be either a string or an
object, and loading about_oppia instead of oppia_exploration since the
former is expected by ExplorationProgressControllerTest.

* Fix broken app test builds (tests still fail, but at least run now).

* Add TODO to fix feedback parsing hack.

* Remove TODOs in StringToFractionParser.

* Resolve open TODOs for the state portion of the player, or associate
them with issues.

* Associate 2 more TODOs with issues.

* Add tests for new next state behavior in ExplorationProgressController,
and resolve last unattributed TODO.

* Remove number with units support.

* Post-merge fixes and clean-ups.

* Post-merge fix.

* Remove number with units tests.

* First round of addressing reviewer comments.

* Remove view scope & component.

* Second round of addressing reviewer comments. Includes a project-wide
optimization of all imports.

* Round 3 of addressing reviewer changes: removed UrlImageParserTest since
it was pulled in with earlier, unfinalized changes and we have since
realized it's not possible to test the image parser based on the current
project setup.

* Round 4 of addressing reviewer comments: reformat all layout XML files.

* Round 5 of addressing reviewer comments.

* Revert "Remove view scope & component."

This reverts commit 99783d5.

* Post-clean up fixes and other minor adjustments.

* Ensure ExplorationActivityTest passes even though it doesn't have
interesting tests yet.

* Temporary workaround to make the prototype exploration accessible with
recent topic & home fragment changes.

Also, hide the topic button in the home fragment since the topic is
accessible directly via the home fragment tiles.

* Round 6 of addressing review comments.

* Update prototype exploration to provide feedback after the multi-item
item selection state for the correct answer so that the player doesn't
seem broken.

app/build.gradle

@@ -62,6 +62,7 @@ dependencies {
       'androidx.appcompat:appcompat:1.0.2',
       'androidx.constraintlayout:constraintlayout:1.1.3',
       'androidx.core:core-ktx:1.0.2',
+      "androidx.fragment:fragment:$fragment_version",
       'androidx.lifecycle:lifecycle-runtime-ktx:2.2.0-alpha03',
       'androidx.multidex:multidex:2.0.1',
       'androidx.recyclerview:recyclerview:1.0.0',
@@ -72,6 +73,7 @@ dependencies {
       "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version",
       'org.jetbrains.kotlinx:kotlinx-coroutines-core:1.2.1',
       'org.jetbrains.kotlinx:kotlinx-coroutines-android:1.2.1',
+      'org.mockito:mockito-core:2.7.22',
   )
   testImplementation(
       'androidx.test:core:1.2.0',
@@ -82,6 +84,7 @@ dependencies {
       'com.google.truth:truth:0.43',
       'org.robolectric:robolectric:4.3',
       'org.jetbrains.kotlinx:kotlinx-coroutines-test:1.2.2',
+      'org.mockito:mockito-core:2.7.22',
   )
   androidTestImplementation(
       'androidx.test:core:1.2.0',
@@ -91,7 +94,8 @@ dependencies {
       'androidx.test.ext:junit:1.1.1',
       'androidx.test:runner:1.2.0',
       'com.google.truth:truth:0.43',
-      'org.jetbrains.kotlinx:kotlinx-coroutines-test:1.2.2'
+      'org.jetbrains.kotlinx:kotlinx-coroutines-test:1.2.2',
+      'org.mockito:mockito-android:2.7.22',
   )
   androidTestUtil(
       'androidx.test:orchestrator:1.2.0',

app/src/main/AndroidManifest.xml

@@ -15,7 +15,9 @@
     <activity android:name=".testing.ContinuePlayingFragmentTestActivity" />
     <activity android:name=".home.HomeActivity" />
     <activity android:name=".player.audio.testing.AudioFragmentTestActivity" />
-    <activity android:name=".player.exploration.ExplorationActivity" />
+    <activity
+      android:name=".player.exploration.ExplorationActivity"
+      android:theme="@style/OppiaThemeWithoutActionBar" />
     <activity android:name=".player.state.testing.StateFragmentTestActivity" />
     <activity android:name=".profile.ProfileActivity" />
     <activity

app/src/main/java/org/oppia/app/activity/ActivityComponent.kt

@@ -4,8 +4,8 @@ import androidx.appcompat.app.AppCompatActivity
 import dagger.BindsInstance
 import dagger.Subcomponent
 import org.oppia.app.fragment.FragmentComponent
-import org.oppia.app.home.continueplaying.ContinuePlayingActivity
 import org.oppia.app.home.HomeActivity
+import org.oppia.app.home.continueplaying.ContinuePlayingActivity
 import org.oppia.app.player.audio.testing.AudioFragmentTestActivity
 import org.oppia.app.player.exploration.ExplorationActivity
 import org.oppia.app.player.state.testing.StateFragmentTestActivity

app/src/main/java/org/oppia/app/application/ApplicationComponent.kt

@@ -27,8 +27,8 @@ import javax.inject.Singleton
 @Component(modules = [
   ApplicationModule::class, DispatcherModule::class, NetworkModule::class, LoggerModule::class,
   ContinueModule::class, FractionInputModule::class, ItemSelectionInputModule::class, MultipleChoiceInputModule::class,
-  NumberWithUnitsRuleModule::class, NumericInputRuleModule::class, TextInputRuleModule::class, InteractionsModule::class,
-  GcsResourceModule::class, ImageParsingModule::class, GlideImageLoaderModule::class,
+  NumberWithUnitsRuleModule::class, NumericInputRuleModule::class, TextInputRuleModule::class,
+  InteractionsModule::class, GcsResourceModule::class, GlideImageLoaderModule::class, ImageParsingModule::class,
   HtmlParserEntityTypeModule::class
 ])
 interface ApplicationComponent {

app/src/main/java/org/oppia/app/customview/interaction/FractionInputInteractionView.kt

@@ -3,8 +3,6 @@ package org.oppia.app.customview.interaction
 import android.content.Context
 import android.util.AttributeSet
 import android.widget.EditText
-import org.oppia.app.model.InteractionObject
-import org.oppia.app.parser.StringToFractionParser
 
 // TODO(#249): These are the attributes which should be defined in XML, that are required for this interaction view to work correctly
 //  digits="0123456789/-"
@@ -18,13 +16,4 @@ class FractionInputInteractionView @JvmOverloads constructor(
   context: Context,
   attrs: AttributeSet? = null,
   defStyle: Int = android.R.attr.editTextStyle
-) : EditText(context, attrs, defStyle), InteractionAnswerRetriever {
-
-  override fun getPendingAnswer(): InteractionObject {
-    val interactionObjectBuilder = InteractionObject.newBuilder()
-    if (!text.isNullOrEmpty()) {
-      interactionObjectBuilder.fraction = StringToFractionParser().getFractionFromString(text = text.toString())
-    }
-    return interactionObjectBuilder.build()
-  }
-}
+) : EditText(context, attrs, defStyle)

app/src/main/java/org/oppia/app/customview/interaction/NumericInputInteractionView.kt

@@ -3,7 +3,6 @@ package org.oppia.app.customview.interaction
 import android.content.Context
 import android.util.AttributeSet
 import android.widget.EditText
-import org.oppia.app.model.InteractionObject
 
 // TODO(#249): These are the attributes which should be defined in XML, that are required for this interaction view to work correctly
 //  digits="0123456789."
@@ -17,13 +16,4 @@ class NumericInputInteractionView @JvmOverloads constructor(
   context: Context,
   attrs: AttributeSet? = null,
   defStyle: Int = android.R.attr.editTextStyle
-) : EditText(context, attrs, defStyle), InteractionAnswerRetriever {
-
-  override fun getPendingAnswer(): InteractionObject {
-    val interactionObjectBuilder = InteractionObject.newBuilder()
-    if (!text.isNullOrEmpty()) {
-      interactionObjectBuilder.real = text.toString().toDouble()
-    }
-    return interactionObjectBuilder.build()
-  }
-}
+) : EditText(context, attrs, defStyle)

app/src/main/java/org/oppia/app/customview/interaction/TextInputInteractionView.kt

@@ -3,7 +3,6 @@ package org.oppia.app.customview.interaction
 import android.content.Context
 import android.util.AttributeSet
 import android.widget.EditText
-import org.oppia.app.model.InteractionObject
 
 // TODO(#249): These are the attributes which should be defined in XML, that are required for this interaction view to work correctly
 //  hint="Write here."
@@ -16,13 +15,4 @@ class TextInputInteractionView @JvmOverloads constructor(
   context: Context,
   attrs: AttributeSet? = null,
   defStyle: Int = android.R.attr.editTextStyle
-) : EditText(context, attrs, defStyle), InteractionAnswerRetriever {
-
-  override fun getPendingAnswer(): InteractionObject {
-    val interactionObjectBuilder = InteractionObject.newBuilder()
-    if (!text.isNullOrEmpty()) {
-      interactionObjectBuilder.normalizedString = text.toString()
-    }
-    return interactionObjectBuilder.build()
-  }
-}
+) : EditText(context, attrs, defStyle)

app/src/main/java/org/oppia/app/databinding/ImageViewBindingAdapters.kt

@@ -3,8 +3,8 @@ package org.oppia.app.databinding
 import android.widget.ImageView
 import androidx.annotation.DrawableRes
 import androidx.databinding.BindingAdapter
-import com.bumptech.glide.request.RequestOptions
 import com.bumptech.glide.Glide
+import com.bumptech.glide.request.RequestOptions
 import org.oppia.app.R
 import org.oppia.app.model.LessonThumbnailGraphic
 

app/src/main/java/org/oppia/app/fragment/FragmentComponent.kt

@@ -3,11 +3,12 @@ package org.oppia.app.fragment
 import androidx.fragment.app.Fragment
 import dagger.BindsInstance
 import dagger.Subcomponent
-import org.oppia.app.home.continueplaying.ContinuePlayingFragment
 import org.oppia.app.home.HomeFragment
+import org.oppia.app.home.continueplaying.ContinuePlayingFragment
 import org.oppia.app.player.audio.AudioFragment
 import org.oppia.app.player.exploration.ExplorationFragment
 import org.oppia.app.player.state.StateFragment
+import org.oppia.app.player.state.itemviewmodel.InteractionViewModelModule
 import org.oppia.app.profile.AddProfileFragment
 import org.oppia.app.profile.AdminAuthFragment
 import org.oppia.app.profile.ProfileChooserFragment
@@ -20,9 +21,11 @@ import org.oppia.app.topic.play.TopicPlayFragment
 import org.oppia.app.topic.questionplayer.QuestionPlayerFragment
 import org.oppia.app.topic.review.TopicReviewFragment
 import org.oppia.app.topic.train.TopicTrainFragment
+import org.oppia.app.view.ViewComponent
+import javax.inject.Provider
 
 /** Root subcomponent for all fragments. */
-@Subcomponent
+@Subcomponent(modules = [FragmentModule::class, InteractionViewModelModule::class])
 @FragmentScope
 interface FragmentComponent {
   @Subcomponent.Builder
@@ -33,6 +36,8 @@ interface FragmentComponent {
     fun build(): FragmentComponent
   }
 
+  fun getViewComponentBuilderProvider(): Provider<ViewComponent.Builder>
+
   fun inject(addProfileFragment: AddProfileFragment)
   fun inject(adminAuthFragment: AdminAuthFragment)
   fun inject(audioFragment: AudioFragment)

app/src/main/java/org/oppia/app/fragment/FragmentModule.kt

@@ -0,0 +1,7 @@
+package org.oppia.app.fragment
+
+import dagger.Module
+import org.oppia.app.view.ViewComponent
+
+/** Root fragment module. */
+@Module(subcomponents = [ViewComponent::class]) class FragmentModule

app/src/main/java/org/oppia/app/fragment/InjectableDialogFragment.kt

@@ -16,7 +16,7 @@ abstract class InjectableDialogFragment: DialogFragment() {
    */
   lateinit var fragmentComponent: FragmentComponent
 
-  override fun onAttach(context: Context?) {
+  override fun onAttach(context: Context) {
     super.onAttach(context)
     fragmentComponent = (requireActivity() as InjectableAppCompatActivity).createFragmentComponent(this)
   }

app/src/main/java/org/oppia/app/fragment/InjectableFragment.kt

@@ -1,8 +1,10 @@
 package org.oppia.app.fragment
 
 import android.content.Context
+import android.view.View
 import androidx.fragment.app.Fragment
 import org.oppia.app.activity.InjectableAppCompatActivity
+import org.oppia.app.view.ViewComponent
 
 /**
  * A fragment that facilitates field injection to children. This fragment can only be used with
@@ -16,8 +18,12 @@ abstract class InjectableFragment: Fragment() {
    */
   lateinit var fragmentComponent: FragmentComponent
 
-  override fun onAttach(context: Context?) {
+  override fun onAttach(context: Context) {
     super.onAttach(context)
     fragmentComponent = (requireActivity() as InjectableAppCompatActivity).createFragmentComponent(this)
   }
+
+  fun createViewComponent(view: View): ViewComponent {
+    return fragmentComponent.getViewComponentBuilderProvider().get().setView(view).build()
+  }
 }

app/src/main/java/org/oppia/app/home/HomeFragment.kt

@@ -14,7 +14,7 @@ import javax.inject.Inject
 class HomeFragment : InjectableFragment(), TopicSummaryClickListener {
   @Inject lateinit var homeFragmentPresenter: HomeFragmentPresenter
 
-  override fun onAttach(context: Context?) {
+  override fun onAttach(context: Context) {
     super.onAttach(context)
     fragmentComponent.inject(this)
   }

app/src/main/java/org/oppia/app/home/HomeFragmentPresenter.kt

@@ -20,14 +20,14 @@ import org.oppia.app.model.TopicSummary
 import org.oppia.app.model.UserAppHistory
 import org.oppia.domain.UserAppHistoryController
 import org.oppia.domain.exploration.ExplorationDataController
-import org.oppia.domain.exploration.TEST_EXPLORATION_ID_5
+import org.oppia.domain.exploration.TEST_EXPLORATION_ID_30
 import org.oppia.domain.topic.TEST_TOPIC_ID_0
 import org.oppia.domain.topic.TopicListController
 import org.oppia.util.data.AsyncResult
 import org.oppia.util.logging.Logger
 import javax.inject.Inject
 
-private const val EXPLORATION_ID = TEST_EXPLORATION_ID_5
+private const val EXPLORATION_ID = TEST_EXPLORATION_ID_30
 private const val TAG_HOME_FRAGMENT = "HomeFragment"
 
 /** The presenter for [HomeFragment]. */
@@ -82,6 +82,7 @@ class HomeFragmentPresenter @Inject constructor(
   }
 
   fun playExplorationButton(v: View) {
+    explorationDataController.stopPlayingExploration()
     explorationDataController.startPlayingExploration(
       EXPLORATION_ID
     ).observe(fragment, Observer<AsyncResult<Any?>> { result ->

app/src/main/java/org/oppia/app/home/continueplaying/ContinuePlayingFragment.kt

@@ -13,7 +13,7 @@ import javax.inject.Inject
 class ContinuePlayingFragment : InjectableFragment(), OngoingStoryClickListener {
   @Inject lateinit var continuePlayingFragmentPresenter: ContinuePlayingFragmentPresenter
 
-  override fun onAttach(context: Context?) {
+  override fun onAttach(context: Context) {
     super.onAttach(context)
     fragmentComponent.inject(this)
   }

app/src/main/java/org/oppia/app/home/topiclist/PromotedStoryViewModel.kt

@@ -5,10 +5,10 @@ import androidx.appcompat.app.AppCompatActivity
 import androidx.databinding.ObservableField
 import androidx.lifecycle.LiveData
 import androidx.lifecycle.ViewModel
-import org.oppia.app.home.continueplaying.ContinuePlayingActivity
 import org.oppia.app.home.HomeItemViewModel
 import org.oppia.app.home.RouteToContinuePlayingListener
 import org.oppia.app.home.RouteToTopicPlayStoryListener
+import org.oppia.app.home.continueplaying.ContinuePlayingActivity
 import org.oppia.app.model.PromotedStory
 import org.oppia.app.topic.TopicActivity
 

app/src/main/java/org/oppia/app/home/topiclist/TopicSummaryViewModel.kt

@@ -3,7 +3,6 @@ package org.oppia.app.home.topiclist
 import android.graphics.Color
 import android.view.View
 import androidx.annotation.ColorInt
-import androidx.lifecycle.ViewModel
 import org.oppia.app.home.HomeItemViewModel
 import org.oppia.app.model.TopicSummary
 

app/src/main/java/org/oppia/app/parser/StringToFractionParser.kt

@@ -1,34 +1,56 @@
 package org.oppia.app.parser
 
 import org.oppia.app.model.Fraction
+import org.oppia.domain.util.normalizeWhitespace
 
 /** This class contains method that helps to parse string to fraction. */
 class StringToFractionParser {
+  private val wholeNumberOnlyRegex = """^-? ?(\d+)$""".toRegex()
+  private val fractionOnlyRegex = """^-? ?(\d+) ?/ ?(\d)+$""".toRegex()
+  private val mixedNumberRegex = """^-? ?(\d)+ ?(\d+) ?/ ?(\d)+$""".toRegex()
+
   fun getFractionFromString(text: String): Fraction {
-    var inputText: String = text
-    var isNegative = false
-    var numerator = "0"
-    var denominator = "0"
-    var wholeNumber = "0"
-    val fractionObjectBuilder = Fraction.newBuilder()
-    if (inputText.startsWith("-"))
-      isNegative = true
-    inputText = inputText.replace("-", "").trim()
-    wholeNumber = if (inputText.contains("/") && inputText.contains(" ")) {
-      inputText.substringBefore(" ")
-    } else if (inputText.contains("/")) {
-      wholeNumber
-    } else {
-      inputText
-    }
-    inputText =
-      if (inputText.contains(" ")) inputText.substringAfter(" ").replace(" ", "") else inputText.replace(" ", "")
-    if (inputText.contains("/")) {
-      numerator = inputText.substringBefore("/")
-      denominator = inputText.substringAfter("/")
-    }
-    fractionObjectBuilder.setIsNegative(isNegative).setNumerator(numerator.toInt())
-      .setDenominator(denominator.toInt()).wholeNumber = wholeNumber.toInt()
-    return fractionObjectBuilder.build()
+    // Normalize whitespace to ensure that answer follows a simpler subset of possible patterns.
+    val inputText: String = text.normalizeWhitespace()
+    return parseMixedNumber(inputText)
+      ?: parseFraction(inputText)
+      ?: parseWholeNumber(inputText)
+      ?: throw IllegalArgumentException("Incorrectly formatted fraction: $text")
+  }
+
+  private fun parseMixedNumber(inputText: String): Fraction? {
+    val mixedNumberMatch = mixedNumberRegex.matchEntire(inputText) ?: return null
+    val (_, wholeNumberText, numeratorText, denominatorText) = mixedNumberMatch.groupValues
+    return Fraction.newBuilder()
+      .setIsNegative(isInputNegative(inputText))
+      .setWholeNumber(wholeNumberText.toInt())
+      .setNumerator(numeratorText.toInt())
+      .setDenominator(denominatorText.toInt())
+      .build()
+  }
+
+  private fun parseFraction(inputText: String): Fraction? {
+    val fractionOnlyMatch = fractionOnlyRegex.matchEntire(inputText) ?: return null
+    val (_, numeratorText, denominatorText) = fractionOnlyMatch.groupValues
+    // Fraction-only numbers imply no whole number.
+    return Fraction.newBuilder()
+      .setIsNegative(isInputNegative(inputText))
+      .setNumerator(numeratorText.toInt())
+      .setDenominator(denominatorText.toInt())
+      .build()
+  }
+
+  private fun parseWholeNumber(inputText: String): Fraction? {
+    val wholeNumberMatch = wholeNumberOnlyRegex.matchEntire(inputText) ?: return null
+    val (_, wholeNumberText) = wholeNumberMatch.groupValues
+    // Whole number fractions imply '0/1' fractional parts.
+    return Fraction.newBuilder()
+      .setIsNegative(isInputNegative(inputText))
+      .setWholeNumber(wholeNumberText.toInt())
+      .setNumerator(0)
+      .setDenominator(1)
+      .build()
   }
+
+  private fun isInputNegative(inputText: String): Boolean = inputText.startsWith("-")
 }

app/src/main/java/org/oppia/app/player/audio/AudioFragment.kt

@@ -34,7 +34,7 @@ class AudioFragment : InjectableFragment(), LanguageInterface {
   @Inject
   lateinit var audioFragmentPresenter: AudioFragmentPresenter
 
-  override fun onAttach(context: Context?) {
+  override fun onAttach(context: Context) {
     super.onAttach(context)
     fragmentComponent.inject(this)
   }

app/src/main/java/org/oppia/app/player/audio/AudioFragmentPresenter.kt

@@ -19,7 +19,6 @@ import org.oppia.domain.exploration.ExplorationDataController
 import org.oppia.util.data.AsyncResult
 import org.oppia.util.logging.Logger
 import javax.inject.Inject
-import kotlin.collections.ArrayList
 
 private const val TAG_LANGUAGE_DIALOG = "LANGUAGE_DIALOG"
 private const val KEY_SELECTED_LANGUAGE = "SELECTED_LANGUAGE"