Scale image if the dp scale changes

lottie/src/main/java/com/airbnb/lottie/LottieComposition.java

@@ -19,15 +19,18 @@
 import com.airbnb.lottie.parser.moshi.JsonReader;
 import com.airbnb.lottie.utils.Logger;
 import com.airbnb.lottie.utils.MiscUtils;
+import com.airbnb.lottie.utils.Utils;
 
 import org.json.JSONObject;
 
 import java.io.InputStream;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collection;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
+import java.util.Set;
 
 /**
  * After Effects/Bodymovin composition model. This is the serialized model from which the
@@ -44,6 +47,7 @@ public class LottieComposition {
   private final HashSet<String> warnings = new HashSet<>();
   private Map<String, List<Layer>> precomps;
   private Map<String, LottieImageAsset> images;
+  private float imagesDpScale = Utils.dpScale();
   /**
    * Map of font names to fonts
    */
@@ -208,8 +212,19 @@ public boolean hasImages() {
    * Returns a map of image asset id to {@link LottieImageAsset}. These assets contain image metadata exported
    * from After Effects or other design tool. The resulting Bitmaps can be set directly on the image asset so
    * they can be loaded once and reused across compositions.
+   *
+   * If the context dp scale has changed since the last time images were retrieved, images will be rescaled.
    */
   public Map<String, LottieImageAsset> getImages() {
+    float dpScale = Utils.dpScale();
+    if (dpScale != imagesDpScale) {
+      imagesDpScale = dpScale;
+      Set<Map.Entry<String, LottieImageAsset>> entries = images.entrySet();
+
+      for (Map.Entry<String, LottieImageAsset> entry : entries) {
+        images.put(entry.getKey(), entry.getValue().copyWithScale(imagesDpScale / dpScale));
+      }
+    }
     return images;
   }
 
@@ -237,6 +252,7 @@ public String toString() {
    */
   @Deprecated
   public static class Factory {
+
     private Factory() {
     }
 
@@ -363,6 +379,7 @@ public static LottieComposition fromJsonSync(JsonReader reader) {
 
     @SuppressWarnings("deprecation")
     private static final class ListenerAdapter implements LottieListener<LottieComposition>, Cancellable {
+
       private final OnCompositionLoadedListener listener;
       private boolean cancelled = false;
 
@@ -382,4 +399,4 @@ private ListenerAdapter(OnCompositionLoadedListener listener) {
       }
     }
   }
-}
+}

lottie/src/main/java/com/airbnb/lottie/LottieImageAsset.java

@@ -70,6 +70,21 @@ public void setBitmap(@Nullable Bitmap bitmap) {
     this.bitmap = bitmap;
   }
 
+  /**
+   * Returns a new {@link LottieImageAsset} with the same properties as this one but with the
+   * dimensions and bitmap scaled.
+   */
+  public LottieImageAsset copyWithScale(float scale) {
+    if (bitmap == null) {
+      return new LottieImageAsset(width, height, id, fileName, dirName);
+    }
+    // scale bitmap by scale
+    LottieImageAsset newAsset = new LottieImageAsset((int) (width * scale), (int) (height * scale), id, fileName, dirName);
+    Bitmap scaledBitmap = Bitmap.createScaledBitmap(bitmap, newAsset.width, newAsset.height, true);
+    newAsset.setBitmap(scaledBitmap);
+    return newAsset;
+  }
+
   /**
    * Returns whether this asset has an embedded Bitmap or whether the fileName is a base64 encoded bitmap.
    */