Backed out changeset a53711ef58c9 (bug 1707959) for linting failures. CLOSED TREE

mobile/android/geckoview/src/main/java/org/mozilla/geckoview/OverscrollEdgeEffect.java

@@ -8,7 +8,6 @@ package org.mozilla.geckoview;
 import org.mozilla.gecko.util.ThreadUtils;
 
 import android.content.Context;
-import android.graphics.BlendMode;
 import android.graphics.Canvas;
 import android.graphics.Paint;
 import android.graphics.PorterDuff;
@@ -18,13 +17,9 @@ import android.os.Build;
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.annotation.UiThread;
-import androidx.core.os.BuildCompat;
-
 import android.widget.EdgeEffect;
 
 import java.lang.reflect.Field;
-import java.lang.reflect.InvocationTargetException;
-import java.lang.reflect.Method;
 
 @UiThread
 public final class OverscrollEdgeEffect {
@@ -49,61 +44,6 @@ public final class OverscrollEdgeEffect {
         mSession = session;
     }
 
-    private static Field sPaintField;
-    private static Method sSetType;
-
-    // By default on SDK_INT 31 and above the edge effect default changed to "TYPE_STRETCH"
-    // which is an effect that we can't support due to using SurfaceTexture.
-    // This restores the edge effect type to TYPE_GLOW which is the default (and only option) on
-    // lower versions.
-    private void setType(final EdgeEffect edgeEffect) {
-        if (Build.VERSION.SDK_INT < 31 && !Build.VERSION.CODENAME.equals("S")) {
-            // setType is only available on 31 (early builds advertise themselves as 30,
-            // with codename S)
-            return;
-        }
-
-        // TODO: remove reflection once 31 is stable
-        if (sSetType == null) {
-            try {
-                sSetType = EdgeEffect.class.getDeclaredMethod("setType", int.class);
-            } catch (NoSuchMethodException e) {
-                // Nothing we can do here
-                return;
-            }
-        }
-
-        try {
-            sSetType.invoke(edgeEffect, /* TYPE_GLOW */ 0);
-        } catch (Exception ex) {
-        }
-    }
-
-    private void setBlendMode(EdgeEffect edgeEffect) {
-        if (Build.VERSION.SDK_INT >= 29) {
-            edgeEffect.setBlendMode(BlendMode.SRC);
-            return;
-        }
-
-        if (sPaintField == null) {
-            try {
-                sPaintField = EdgeEffect.class.getDeclaredField("mPaint");
-                sPaintField.setAccessible(true);
-            } catch (final NoSuchFieldException e) {
-                // Cannot get the field, nothing we can do here
-                return;
-            }
-        }
-
-        try {
-            final Paint paint = (Paint) sPaintField.get(edgeEffect);
-            final PorterDuffXfermode mode = new PorterDuffXfermode(PorterDuff.Mode.SRC);
-            paint.setXfermode(mode);
-        } catch (final IllegalAccessException ex) {
-            // Nothing we can do
-        }
-    }
-
     /**
      * Set the theme to use for overscroll from a given Context.
      *
@@ -112,11 +52,34 @@ public final class OverscrollEdgeEffect {
     public void setTheme(final @NonNull Context context) {
         ThreadUtils.assertOnUiThread();
 
+        final PorterDuffXfermode mode = new PorterDuffXfermode(PorterDuff.Mode.SRC);
+        Field paintField = null;
+
+        if (Build.VERSION.SDK_INT >= 21) {
+            try {
+                paintField = EdgeEffect.class.getDeclaredField("mPaint");
+                paintField.setAccessible(true);
+            } catch (final NoSuchFieldException e) {
+            }
+        }
+
         for (int i = 0; i < mEdges.length; i++) {
-            final EdgeEffect edgeEffect = new EdgeEffect(context);
-            setBlendMode(edgeEffect);
-            setType(edgeEffect);
-            mEdges[i] = edgeEffect;
+            mEdges[i] = new EdgeEffect(context);
+
+            if (paintField == null) {
+                continue;
+            }
+
+            try {
+                final Paint p = (Paint) paintField.get(mEdges[i]);
+
+                // The Android EdgeEffect class uses a mode of SRC_ATOP here, which means
+                // it will only draw the effect where there are non-transparent pixels in
+                // the destination. Since the LayerView itself is fully transparent, it
+                // doesn't display at all. We need to use SRC instead.
+                p.setXfermode(mode);
+            } catch (final IllegalAccessException e) {
+            }
         }
     }