Add support for layer blend mode "bm" for NORMAL, SCREEN, OVERLAY, DARKEN, LIGHTEN, and ADD

lottie/src/main/java/com/airbnb/lottie/animation/content/FillContent.java

@@ -1,17 +1,16 @@
 package com.airbnb.lottie.animation.content;
 
-import static com.airbnb.lottie.utils.MiscUtils.clamp;
-
 import android.graphics.BlurMaskFilter;
 import android.graphics.Canvas;
 import android.graphics.ColorFilter;
 import android.graphics.Matrix;
 import android.graphics.Paint;
 import android.graphics.Path;
 import android.graphics.RectF;
-
+import android.os.Build;
 import androidx.annotation.Nullable;
-
+import androidx.core.graphics.BlendModeCompat;
+import androidx.core.graphics.PaintCompat;
 import com.airbnb.lottie.L;
 import com.airbnb.lottie.LottieDrawable;
 import com.airbnb.lottie.LottieProperty;
@@ -29,6 +28,8 @@
 import java.util.ArrayList;
 import java.util.List;
 
+import static com.airbnb.lottie.utils.MiscUtils.clamp;
+
 public class FillContent
     implements DrawingContent, BaseKeyframeAnimation.AnimationListener, KeyPathElementContent {
   private final Path path = new Path();
@@ -120,6 +121,12 @@ public FillContent(final LottieDrawable lottieDrawable, BaseLayer layer, ShapeFi
       dropShadowAnimation.applyTo(paint);
     }
 
+    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
+      final BlendModeCompat blendMode = layer.getBlendMode().toCoreBlendMode();
+      if(blendMode!=null)
+        PaintCompat.setBlendMode(paint, blendMode);
+    }
+
     path.reset();
     for (int i = 0; i < paths.size(); i++) {
       path.addPath(paths.get(i).getPath(), parentMatrix);

lottie/src/main/java/com/airbnb/lottie/model/content/LBlendMode.java

@@ -0,0 +1,78 @@
+package com.airbnb.lottie.model.content;
+
+import android.os.Build;
+import androidx.annotation.Nullable;
+import androidx.annotation.RequiresApi;
+import androidx.core.graphics.BlendModeCompat;
+
+/**
+ * Lottie BlendMode,
+ * not to be confused with Paint.BlendMode in android graphics core,
+ * which we will rely on for rendering.
+ */
+public enum LBlendMode {
+  NORMAL,
+  MULTIPLY,
+  SCREEN,
+  OVERLAY,
+  DARKEN,
+  LIGHTEN,
+  COLOR_DODGE,
+  COLOR_BURN,
+  HARD_LIGHT,
+  SOFT_LIGHT,
+  DIFFERENCE,
+  EXCLUSION,
+  HUE,
+  SATURATION,
+  COLOR,
+  LUMINOSITY,
+  ADD,
+  HARD_MIX;
+
+  @Nullable
+  @RequiresApi(api = Build.VERSION_CODES.Q)
+  public BlendModeCompat toCoreBlendMode() {
+    switch (this){
+      case NORMAL:
+        return null; // BlendMode.CLEAR?
+      case MULTIPLY:
+        return BlendModeCompat.MULTIPLY;
+      case SCREEN:
+        return BlendModeCompat.SCREEN;
+      case OVERLAY:
+        return BlendModeCompat.OVERLAY;
+      case DARKEN:
+        return BlendModeCompat.DARKEN;
+      case LIGHTEN:
+        return BlendModeCompat.LIGHTEN;
+      case COLOR_DODGE:
+        return BlendModeCompat.COLOR_DODGE;
+      case COLOR_BURN:
+        return BlendModeCompat.COLOR_BURN;
+      case HARD_LIGHT:
+        return BlendModeCompat.HARD_LIGHT;
+      case SOFT_LIGHT:
+        return BlendModeCompat.SOFT_LIGHT;
+      case DIFFERENCE:
+        return BlendModeCompat.DIFFERENCE;
+      case EXCLUSION:
+        return BlendModeCompat.EXCLUSION;
+      case HUE:
+        return BlendModeCompat.HUE;
+      case SATURATION:
+        return BlendModeCompat.SATURATION;
+      case COLOR:
+        return BlendModeCompat.COLOR;
+      case LUMINOSITY:
+        return BlendModeCompat.LUMINOSITY;
+      case ADD:
+        return BlendModeCompat.PLUS;
+      case HARD_MIX:
+        return null;  // todo: fix this
+      default:
+        return null;
+    }
+  }
+
+}

lottie/src/main/java/com/airbnb/lottie/model/layer/BaseLayer.java

@@ -28,6 +28,7 @@
 import com.airbnb.lottie.model.KeyPath;
 import com.airbnb.lottie.model.KeyPathElement;
 import com.airbnb.lottie.model.content.BlurEffect;
+import com.airbnb.lottie.model.content.LBlendMode;
 import com.airbnb.lottie.model.content.Mask;
 import com.airbnb.lottie.model.content.ShapeData;
 import com.airbnb.lottie.parser.DropShadowEffect;
@@ -628,6 +629,10 @@ public BlurEffect getBlurEffect() {
     return layerModel.getBlurEffect();
   }
 
+  public LBlendMode getBlendMode() {
+    return layerModel.getBlendMode();
+  }
+
   public BlurMaskFilter getBlurMaskFilter(float radius) {
     if (blurMaskFilterRadius == radius) {
       return blurMaskFilter;

lottie/src/main/java/com/airbnb/lottie/model/layer/Layer.java

@@ -1,14 +1,14 @@
 package com.airbnb.lottie.model.layer;
 
 import androidx.annotation.Nullable;
-
 import com.airbnb.lottie.LottieComposition;
 import com.airbnb.lottie.model.animatable.AnimatableFloatValue;
 import com.airbnb.lottie.model.animatable.AnimatableTextFrame;
 import com.airbnb.lottie.model.animatable.AnimatableTextProperties;
 import com.airbnb.lottie.model.animatable.AnimatableTransform;
 import com.airbnb.lottie.model.content.BlurEffect;
 import com.airbnb.lottie.model.content.ContentModel;
+import com.airbnb.lottie.model.content.LBlendMode;
 import com.airbnb.lottie.model.content.Mask;
 import com.airbnb.lottie.parser.DropShadowEffect;
 import com.airbnb.lottie.value.Keyframe;
@@ -61,6 +61,8 @@ public enum MatteType {
   private final boolean hidden;
   @Nullable private final BlurEffect blurEffect;
   @Nullable private final DropShadowEffect dropShadowEffect;
+  private final LBlendMode blendMode;
+
 
   public Layer(List<ContentModel> shapes, LottieComposition composition, String layerName, long layerId,
       LayerType layerType, long parentId, @Nullable String refId, List<Mask> masks,
@@ -69,7 +71,7 @@ public Layer(List<ContentModel> shapes, LottieComposition composition, String la
       @Nullable AnimatableTextFrame text, @Nullable AnimatableTextProperties textProperties,
       List<Keyframe<Float>> inOutKeyframes, MatteType matteType,
       @Nullable AnimatableFloatValue timeRemapping, boolean hidden, @Nullable BlurEffect blurEffect,
-      @Nullable DropShadowEffect dropShadowEffect) {
+      @Nullable DropShadowEffect dropShadowEffect, LBlendMode blendMode) {
     this.shapes = shapes;
     this.composition = composition;
     this.layerName = layerName;
@@ -94,6 +96,7 @@ public Layer(List<ContentModel> shapes, LottieComposition composition, String la
     this.hidden = hidden;
     this.blurEffect = blurEffect;
     this.dropShadowEffect = dropShadowEffect;
+    this.blendMode = blendMode;
   }
 
   LottieComposition getComposition() {
@@ -188,6 +191,11 @@ public boolean isHidden() {
     return hidden;
   }
 
+  @Nullable
+  public LBlendMode getBlendMode() {
+    return blendMode;
+  }
+
   @Nullable public BlurEffect getBlurEffect() {
     return blurEffect;
   }

lottie/src/main/java/com/airbnb/lottie/parser/LayerParser.java

@@ -8,6 +8,7 @@
 import com.airbnb.lottie.model.animatable.AnimatableTextFrame;
 import com.airbnb.lottie.model.animatable.AnimatableTextProperties;
 import com.airbnb.lottie.model.animatable.AnimatableTransform;
+import com.airbnb.lottie.model.content.LBlendMode;
 import com.airbnb.lottie.model.content.BlurEffect;
 import com.airbnb.lottie.model.content.ContentModel;
 import com.airbnb.lottie.model.content.Mask;
@@ -49,7 +50,8 @@ private LayerParser() {
       "op", // 19
       "tm", // 20
       "cl", // 21
-      "hd" // 22
+      "hd", // 22
+      "bm" // 23
   );
 
   public static Layer parse(LottieComposition composition) {
@@ -59,7 +61,8 @@ public static Layer parse(LottieComposition composition) {
         Layer.LayerType.PRE_COMP, -1, null, Collections.<Mask>emptyList(),
         new AnimatableTransform(), 0, 0, 0, 0, 0,
         bounds.width(), bounds.height(), null, null, Collections.<Keyframe<Float>>emptyList(),
-        Layer.MatteType.NONE, null, false, null, null);
+        Layer.MatteType.NONE, null, false, null, null,
+        LBlendMode.NORMAL);
   }
 
   private static final JsonReader.Options TEXT_NAMES = JsonReader.Options.of(
@@ -95,6 +98,7 @@ public static Layer parse(JsonReader reader, LottieComposition composition) thro
     DropShadowEffect dropShadowEffect = null;
 
     Layer.MatteType matteType = Layer.MatteType.NONE;
+    LBlendMode blendMode = LBlendMode.NORMAL;
     AnimatableTransform transform = null;
     AnimatableTextFrame text = null;
     AnimatableTextProperties textProperties = null;
@@ -256,6 +260,15 @@ public static Layer parse(JsonReader reader, LottieComposition composition) thro
         case 22:
           hidden = reader.nextBoolean();
           break;
+        case 23:
+          int blendModeIndex = reader.nextInt();
+          if (blendModeIndex >= LBlendMode.values().length) {
+            composition.addWarning("Unsupported Blend Mode: " + blendModeIndex);
+            blendMode = LBlendMode.NORMAL;
+            break;
+          }
+          blendMode = LBlendMode.values()[blendModeIndex];
+          break;
         default:
           reader.skipName();
           reader.skipValue();
@@ -287,6 +300,6 @@ public static Layer parse(JsonReader reader, LottieComposition composition) thro
     return new Layer(shapes, composition, layerName, layerId, layerType, parentId, refId,
         masks, transform, solidWidth, solidHeight, solidColor, timeStretch, startFrame,
         preCompWidth, preCompHeight, text, textProperties, inOutKeyframes, matteType,
-        timeRemapping, hidden, blurEffect, dropShadowEffect);
+        timeRemapping, hidden, blurEffect, dropShadowEffect, blendMode);
   }
 }