I wrote utility class EdgeChanger, which is mixture of my previous post, @Jared Hummler code and @Eugen Pechanec code.
This utility class use reflection to change color of edge glow for
ScrollView, NestedScrollView, ListView, ViewPager and RecyclerView
and works with Marshmallow, Lollipop and pre-Lollipop devices when using AppCompat so you don't need to use third party libraries like EdgeEffectOverride or use different layouts.
Use this only when you want to change edge glow colors after onCreate(), otherwise you should use setTheme and different themes with different color attribute colorPrimary or colorEdgeEffect.
public class EdgeChanger {
private static final Class<?> CLASS_SCROLL_VIEW = ScrollView.class;
private static Field SCROLL_VIEW_FIELD_EDGE_GLOW_TOP;
private static Field SCROLL_VIEW_FIELD_EDGE_GLOW_BOTTOM;
private static final Class<?> CLASS_LIST_VIEW = AbsListView.class;
private static Field LIST_VIEW_FIELD_EDGE_GLOW_TOP;
private static Field LIST_VIEW_FIELD_EDGE_GLOW_BOTTOM;
private static final Class<?> CLASS_NESTED_SCROLL_VIEW = NestedScrollView.class;
private static Field NESTED_SCROLL_VIEW_FIELD_EDGE_GLOW_TOP;
private static Field NESTED_SCROLL_VIEW_FIELD_EDGE_GLOW_BOTTOM;
private static Method NESTED_SCROLL_VIEW_METHOD_ENSURE_GLOWS;
private static final Class<?> CLASS_RECYCLER_VIEW = RecyclerView.class;
private static Field RECYCLER_VIEW_FIELD_EDGE_GLOW_TOP;
private static Field RECYCLER_VIEW_FIELD_EDGE_GLOW_BOTTOM;
private static Method RECYCLER_VIEW_METHOD_ENSURE_GLOW_TOP;
private static Method RECYCLER_VIEW_METHOD_ENSURE_GLOW_BOTTOM;
private static final Class<?> CLASS_VIEW_PAGER = ViewPager.class;
private static Field VIEW_PAGER_FIELD_EDGE_GLOW_LEFT;
private static Field VIEW_PAGER_FIELD_EDGE_GLOW_RIGHT;
static {
Field edgeGlowTop = null, edgeGlowBottom = null;
Method ensureGlowTop = null, ensureGlowBottom = null;
for (Field f : CLASS_SCROLL_VIEW.getDeclaredFields()) {
switch (f.getName()) {
case "mEdgeGlowTop":
f.setAccessible(true);
edgeGlowTop = f;
break;
case "mEdgeGlowBottom":
f.setAccessible(true);
edgeGlowBottom = f;
break;
}
}
SCROLL_VIEW_FIELD_EDGE_GLOW_TOP = edgeGlowTop;
SCROLL_VIEW_FIELD_EDGE_GLOW_BOTTOM = edgeGlowBottom;
for (Field f : CLASS_LIST_VIEW.getDeclaredFields()) {
switch (f.getName()) {
case "mEdgeGlowTop":
f.setAccessible(true);
edgeGlowTop = f;
break;
case "mEdgeGlowBottom":
f.setAccessible(true);
edgeGlowBottom = f;
break;
}
}
LIST_VIEW_FIELD_EDGE_GLOW_TOP = edgeGlowTop;
LIST_VIEW_FIELD_EDGE_GLOW_BOTTOM = edgeGlowBottom;
for (Field f : CLASS_NESTED_SCROLL_VIEW.getDeclaredFields()) {
switch (f.getName()) {
case "mEdgeGlowTop":
f.setAccessible(true);
edgeGlowTop = f;
break;
case "mEdgeGlowBottom":
f.setAccessible(true);
edgeGlowBottom = f;
break;
}
}
for (Method m : CLASS_NESTED_SCROLL_VIEW.getDeclaredMethods()) {
switch (m.getName()) {
case "ensureGlows":
m.setAccessible(true);
ensureGlowTop = m;
break;
}
}
NESTED_SCROLL_VIEW_FIELD_EDGE_GLOW_TOP = edgeGlowTop;
NESTED_SCROLL_VIEW_FIELD_EDGE_GLOW_BOTTOM = edgeGlowBottom;
NESTED_SCROLL_VIEW_METHOD_ENSURE_GLOWS = ensureGlowTop;
for (Field f : CLASS_RECYCLER_VIEW.getDeclaredFields()) {
switch (f.getName()) {
case "mTopGlow":
f.setAccessible(true);
edgeGlowTop = f;
break;
case "mBottomGlow":
f.setAccessible(true);
edgeGlowBottom = f;
break;
}
}
for (Method m : CLASS_RECYCLER_VIEW.getDeclaredMethods()) {
switch (m.getName()) {
case "ensureTopGlow":
m.setAccessible(true);
ensureGlowTop = m;
break;
case "ensureBottomGlow":
m.setAccessible(true);
ensureGlowBottom = m;
break;
}
}
RECYCLER_VIEW_FIELD_EDGE_GLOW_TOP = edgeGlowTop;
RECYCLER_VIEW_FIELD_EDGE_GLOW_BOTTOM = edgeGlowBottom;
RECYCLER_VIEW_METHOD_ENSURE_GLOW_TOP = ensureGlowTop;
RECYCLER_VIEW_METHOD_ENSURE_GLOW_BOTTOM = ensureGlowBottom;
for (Field f : CLASS_VIEW_PAGER.getDeclaredFields()) {
switch (f.getName()) {
case "mLeftEdge":
f.setAccessible(true);
edgeGlowTop = f;
break;
case "mRightEdge":
f.setAccessible(true);
edgeGlowBottom = f;
break;
}
}
VIEW_PAGER_FIELD_EDGE_GLOW_LEFT = edgeGlowTop;
VIEW_PAGER_FIELD_EDGE_GLOW_RIGHT = edgeGlowBottom;
}
public static void setEdgeGlowColor(AbsListView listView, int color) {
try {
setEdgeEffectColor(LIST_VIEW_FIELD_EDGE_GLOW_TOP.get(listView), color);
setEdgeEffectColor(LIST_VIEW_FIELD_EDGE_GLOW_BOTTOM.get(listView), color);
} catch (Exception e) {
e.printStackTrace();
}
}
public static void setEdgeGlowColor(ScrollView scrollView, int color) {
try {
setEdgeEffectColor(SCROLL_VIEW_FIELD_EDGE_GLOW_TOP.get(scrollView), color);
setEdgeEffectColor(SCROLL_VIEW_FIELD_EDGE_GLOW_BOTTOM.get(scrollView), color);
} catch (Exception e) {
e.printStackTrace();
}
}
public static void setEdgeGlowColor(final ViewPager viewPager, final int color) {
try {
setEdgeEffectColor(VIEW_PAGER_FIELD_EDGE_GLOW_LEFT.get(viewPager), color);
setEdgeEffectColor(VIEW_PAGER_FIELD_EDGE_GLOW_RIGHT.get(viewPager), color);
} catch (final Exception e) {
e.printStackTrace();
}
}
public static void setEdgeGlowColor(NestedScrollView scrollView, int color) {
try {
NESTED_SCROLL_VIEW_METHOD_ENSURE_GLOWS.invoke(scrollView);
setEdgeEffectColor(NESTED_SCROLL_VIEW_FIELD_EDGE_GLOW_TOP.get(scrollView), color);
setEdgeEffectColor(NESTED_SCROLL_VIEW_FIELD_EDGE_GLOW_BOTTOM.get(scrollView), color);
} catch (final Exception | NoClassDefFoundError e) {
e.printStackTrace();
}
}
public static void setEdgeGlowColor(final RecyclerView recyclerView, final int color) {
try {
RECYCLER_VIEW_METHOD_ENSURE_GLOW_TOP.invoke(recyclerView);
RECYCLER_VIEW_METHOD_ENSURE_GLOW_BOTTOM.invoke(recyclerView);
setEdgeEffectColor(RECYCLER_VIEW_FIELD_EDGE_GLOW_TOP.get(recyclerView), color);
setEdgeEffectColor(RECYCLER_VIEW_FIELD_EDGE_GLOW_BOTTOM.get(recyclerView), color);
} catch (final Exception | NoClassDefFoundError e) {
e.printStackTrace();
}
}
private static void setEdgeEffectColor(Object object, int color) {
try {
EdgeEffect edgeEffect = null;
if (object instanceof EdgeEffectCompat) {
final Field fEdgeEffect = object.getClass().getDeclaredField("mEdgeEffect");
fEdgeEffect.setAccessible(true);
edgeEffect = (EdgeEffect) fEdgeEffect.get(object);
} else if (object instanceof EdgeEffect) {
edgeEffect = (EdgeEffect) object;
}
if (Build.VERSION.SDK_INT >= 21) {
edgeEffect.setColor(color);
} else {
for (String name : new String[] {"mEdge", "mGlow"}) {
final Field field = EdgeEffect.class.getDeclaredField(name);
field.setAccessible(true);
final Drawable drawable = (Drawable) field.get(edgeEffect);
drawable.setColorFilter(color, PorterDuff.Mode.SRC_IN);
drawable.setCallback(null);
}
}
} catch (final Exception | NoClassDefFoundError e) {
e.printStackTrace();
}
}
}
If you're using ProGuard, don't forget to add these rules (to not renaming fields with which you want work using reflection):
-keepnames class android.widget.ScrollView { *; }
-keepnames class android.widget.AbsListView { *; }
-keepnames class android.support.v4.widget.NestedScrollView { *; }
-keepnames class android.support.v7.widget.RecyclerView { *; }
-keepnames class android.support.v4.view.ViewPager { *; }
-keepnames class android.widget.EdgeEffect { *; }
-keepnames class android.support.v4.widget.EdgeEffectCompat { *; }
