Fixes part of #59: Translate binding adapter files to java [BLOCKED: #1514]

WORKSPACE

@@ -113,6 +113,8 @@ maven_install(
         "androidx.core:core-ktx:1.0.1",
         "androidx.lifecycle:lifecycle-livedata-ktx:2.2.0-alpha03",
         "androidx.test.ext:junit:1.1.1",
+        "android.arch.core:core-testing:1.1.1",
+        "androidx.arch.core:core-testing:2.1.0",
         "com.android.support:support-annotations:28.0.0",
         "com.caverock:androidsvg-aar:1.4",
         "com.crashlytics.sdk.android:crashlytics:2.9.8",

app/src/main/java/org/oppia/app/databinding/DrawableBindingAdapters.java

@@ -0,0 +1,57 @@
+package org.oppia.app.databinding;
+
+import android.graphics.drawable.GradientDrawable;
+import android.view.View;
+import android.widget.Button;
+
+import androidx.annotation.ColorInt;
+import androidx.annotation.DrawableRes;
+import androidx.annotation.NonNull;
+import androidx.databinding.BindingAdapter;
+
+import org.oppia.app.R;
+
+/**
+ * Holds all the custom binding adapters that set background drawables.
+ */
+public final class DrawableBindingAdapters {
+  /**
+   * Used to set a rounded-rect background drawable with a data-bound color.
+   */
+  @BindingAdapter("app:roundedRectDrawableWithColor")
+  public static void setBackgroundDrawable(@NonNull View view, @ColorInt int colorRgb) {
+    view.setBackgroundResource(R.drawable.rounded_rect_background);
+    // The input color needs to have alpha channel prepended to it.
+    GradientDrawable background = (GradientDrawable) view.getBackground();
+    background.setColor(0xff000000 | colorRgb);
+  }
+
+  @BindingAdapter("app:topRoundedRectDrawableWithColor")
+  public static void setTopBackgroundDrawable(@NonNull View view, @ColorInt int colorRgb) {
+    view.setBackgroundResource(R.drawable.top_rounded_rect_background);
+    // The input color needs to have alpha channel prepended to it.
+    GradientDrawable background = (GradientDrawable) view.getBackground();
+    background.setColor(0xff000000 | colorRgb);
+  }
+
+  @BindingAdapter("app:bottomRoundedRectDrawableWithColor")
+  public static void setBottomBackgroundDrawable(@NonNull View view, @ColorInt int colorRgb) {
+    view.setBackgroundResource(R.drawable.bottom_rounded_rect_background);
+    // The input color needs to have alpha channel prepended to it.
+    GradientDrawable background = (GradientDrawable) view.getBackground();
+    background.setColor(0xff000000 | colorRgb);
+  }
+
+  @BindingAdapter("app:rectangleDrawableWithColor")
+  public static void setRectangleBackgroundDrawable(@NonNull View view, @ColorInt int colorRgb) {
+    view.setBackgroundResource(R.drawable.rectangle_background);
+    // The input color needs to have alpha channel prepended to it.
+    GradientDrawable background = (GradientDrawable) view.getBackground();
+    background.setColor(0xff000000 | colorRgb);
+  }
+
+  @BindingAdapter("android:button")
+  public static void setBackgroundResource(@NonNull Button button, @DrawableRes int resource) {
+    button.setBackgroundResource(resource);
+  }
+}

app/src/main/java/org/oppia/app/databinding/EditTextBindingAdapters.java

@@ -0,0 +1,20 @@
+package org.oppia.app.databinding;
+
+import android.text.TextWatcher;
+import android.widget.EditText;
+
+import androidx.annotation.NonNull;
+import androidx.databinding.BindingAdapter;
+
+/**
+ * Holds all the custom binding adapters that bind to [EditText] adapters.
+ */
+public final class EditTextBindingAdapters {
+  /**
+   * Binding adapter for setting a [TextWatcher] as a change listener for an [EditText].
+   */
+  @BindingAdapter("app:textChangedListener")
+  public static void bindTextWatcher(@NonNull EditText editText, TextWatcher textWatcher) {
+    editText.addTextChangedListener(textWatcher);
+  }
+}

app/src/main/java/org/oppia/app/databinding/GuidelineBindingAdapters.java

@@ -0,0 +1,22 @@
+package org.oppia.app.databinding;
+
+import androidx.annotation.NonNull;
+import androidx.constraintlayout.widget.Guideline;
+import androidx.constraintlayout.widget.ConstraintLayout;
+import androidx.databinding.BindingAdapter;
+
+/**
+ * Holds all the custom binding adapters that bind to [Guideline].
+ */
+public final class GuidelineBindingAdapters {
+  /**
+   * Binding adapter for setting the `guidePercent` for a [Guideline].
+   */
+  @BindingAdapter("app:layout_constraintGuide_percent")
+  public static void setGuidelinePercentage(@NonNull Guideline guideline, float percentage) {
+    ConstraintLayout.LayoutParams params =
+        (ConstraintLayout.LayoutParams) guideline.getLayoutParams();
+    params.guidePercent = percentage;
+    guideline.setLayoutParams(params);
+  }
+}

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

@@ -0,0 +1,156 @@
+package org.oppia.app.databinding;
+
+import android.graphics.PorterDuff;
+import android.graphics.drawable.Drawable;
+import android.widget.ImageView;
+
+import androidx.annotation.DrawableRes;
+import androidx.annotation.NonNull;
+import androidx.databinding.BindingAdapter;
+
+import com.bumptech.glide.Glide;
+import com.bumptech.glide.load.DataSource;
+import com.bumptech.glide.load.engine.GlideException;
+import com.bumptech.glide.request.RequestListener;
+import com.bumptech.glide.request.RequestOptions;
+import com.bumptech.glide.request.target.Target;
+
+import org.oppia.app.R;
+import org.oppia.app.model.LessonThumbnailGraphic;
+import org.oppia.app.model.ProfileAvatar;
+
+/**
+ * Holds all the custom binding adapters that bind to [ImageView] adapters.
+ */
+public final class ImageViewBindingAdapters {
+  /**
+   * Allows binding drawables to an [ImageView] via "android:src".
+   * Source: https://stackoverflow.com/a/35809319/3689782.
+   */
+  @BindingAdapter("android:src")
+  public static void setImageDrawable(@NonNull ImageView imageView, String imageUrl) {
+    RequestOptions requestOptions = new RequestOptions().placeholder(R.drawable.review_placeholder);
+    Glide.with(imageView.getContext())
+        .load(imageUrl)
+        .apply(requestOptions)
+        .into(imageView);
+  }
+
+  /**
+   * Allows binding drawables to an [ImageView] via "android:src".
+   * Source: https://stackoverflow.com/a/35809319/3689782.
+   */
+  @BindingAdapter("android:src")
+  public static void setImageDrawable(
+      @NonNull ImageView imageView,
+      @DrawableRes int drawableResourceId
+  ) {
+    imageView.setImageResource(drawableResourceId);
+  }
+
+  /**
+   * Binds the specified [LessonThumbnailGraphic] as the source for the [ImageView].
+   * The view should be specified to have no width/height (when sized in a constraint layout), and
+   * use centerCrop for the image to appear correctly.
+   */
+  @BindingAdapter("android:src")
+  public static void setImageDrawable(
+      ImageView imageView,
+      LessonThumbnailGraphic thumbnailGraphic
+  ) {
+    int drawableResourceId;
+    switch (thumbnailGraphic) {
+      case BAKER:
+        drawableResourceId = R.drawable.lesson_thumbnail_graphic_baker;
+      case CHILD_WITH_BOOK:
+        drawableResourceId = R.drawable.lesson_thumbnail_graphic_child_with_book;
+      case CHILD_WITH_CUPCAKES:
+        drawableResourceId = R.drawable.lesson_thumbnail_graphic_child_with_cupcakes;
+      case CHILD_WITH_FRACTIONS_HOMEWORK:
+        drawableResourceId = R.drawable.lesson_thumbnail_graphic_child_with_fractions_homework;
+      case DUCK_AND_CHICKEN:
+        drawableResourceId = R.drawable.lesson_thumbnail_graphic_duck_and_chicken;
+      case PERSON_WITH_PIE_CHART:
+        drawableResourceId = R.drawable.lesson_thumbnail_graphic_person_with_pie_chart;
+      case IDENTIFYING_THE_PARTS_OF_A_FRACTION:
+        drawableResourceId = R.drawable.topic_fractions_01;
+      case WRITING_FRACTIONS:
+        drawableResourceId = R.drawable.topic_fractions_02;
+      case EQUIVALENT_FRACTIONS:
+        drawableResourceId = R.drawable.topic_fractions_03;
+      case MIXED_NUMBERS_AND_IMPROPER_FRACTIONS:
+        drawableResourceId = R.drawable.topic_fractions_04;
+      case COMPARING_FRACTIONS:
+        drawableResourceId = R.drawable.topic_fractions_05;
+      case ADDING_AND_SUBTRACTING_FRACTIONS:
+        drawableResourceId = R.drawable.topic_fractions_06;
+      case MULTIPLYING_FRACTIONS:
+        drawableResourceId = R.drawable.topic_fractions_07;
+      case DIVIDING_FRACTIONS:
+        drawableResourceId = R.drawable.topic_fractions_08;
+      case DERIVE_A_RATIO:
+        drawableResourceId = R.drawable.topic_ratios_01;
+      case WHAT_IS_A_FRACTION:
+        drawableResourceId = R.drawable.topic_fractions_01;
+      case FRACTION_OF_A_GROUP:
+        drawableResourceId = R.drawable.topic_fractions_02;
+      case ADDING_FRACTIONS:
+        drawableResourceId = R.drawable.topic_fractions_03;
+      case MIXED_NUMBERS:
+        drawableResourceId = R.drawable.topic_fractions_04;
+      default:
+        drawableResourceId = R.drawable.topic_fractions_01;
+    }
+    setImageDrawable(
+        imageView,
+        drawableResourceId
+    );
+  }
+
+  /**
+   * Binding adapter for profile images. Used to either display a local image or custom
+   * colored avatar.
+   *
+   * @param imageView     View where the profile avatar will be loaded into.
+   * @param profileAvatar Represents either a colorId or local image uri.
+   */
+  @BindingAdapter("profile:src")
+  public static void setProfileImage(ImageView imageView, ProfileAvatar profileAvatar) {
+    if (profileAvatar != null) {
+      if (profileAvatar.getAvatarTypeCase() == ProfileAvatar.AvatarTypeCase.AVATAR_COLOR_RGB) {
+        Glide.with(imageView.getContext())
+            .load(R.drawable.ic_default_avatar)
+            .listener(new RequestListener<Drawable>() {
+              @Override
+              public boolean onLoadFailed(
+                  GlideException e,
+                  Object model,
+                  Target<Drawable> target,
+                  boolean isFirstResource) {
+                return false;
+              }
+
+              @Override
+              public boolean onResourceReady(
+                  Drawable resource,
+                  Object model,
+                  Target<Drawable> target,
+                  DataSource dataSource,
+                  boolean isFirstResource
+              ) {
+                imageView.setColorFilter(
+                    profileAvatar.getAvatarColorRgb(),
+                    PorterDuff.Mode.DST_OVER
+                );
+                return false;
+              }
+            }).into(imageView);
+      } else {
+        Glide.with(imageView.getContext())
+            .load(profileAvatar.getAvatarImageUri())
+            .placeholder(R.drawable.ic_default_avatar)
+            .into(imageView);
+      }
+    }
+  }
+}