Scrollview & RecycleView & ListView & Viewpager Top/Bottom Shadow Color Change

0 Using Theme Settings

 <style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
        <!-- Customize your theme here. -->
        <item name="colorPrimary">@color/colorPrimary</item>
        <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
        <item name="colorAccent">@color/colorAccent</item>
        <item name="android:colorEdgeEffect">@color/colorAccent</item>
    </style>

Note, however, that you can only set it above api21

The following methods are reflection settings

1 Scrollview

The two attributes involved, mEdgeGlowTop and mEdgeGlowBottom, are of EdgeEffect type

Direct de-reflection to change color
Take mEdgeGlowTop as an example

Field topMethod = ScrollView.class.getDeclaredField("mEdgeGlowTop");
topMethod.setAccessible(true);
EdgeEffect top = (EdgeEffect) topMethod.get(scrollView);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
    top.setColor(Color.RED);
}

2 RecycleView

RecycleView has four attributes, mLeftGlow, mTopGlow, mRightGlow, mBottomGlow

It can be done in the same way as Scrollview

3 ListView

listview has a public method

    /**
     * Sets the drawable that will be drawn above all other list content.
     * This area can become visible when the user overscrolls the list.
     *
     * @param header The drawable to use
     */
    public void setOverscrollHeader(Drawable header) {
        mOverScrollHeader = header;
        if (mScrollY < 0) {
            invalidate();
        }
    }


    /**
     * Sets the drawable that will be drawn below all other list content.
     * This area can become visible when the user overscrolls the list,
     * or when the list's content does not fully fill the container area.
     *
     * @param footer The drawable to use
     */
    public void setOverscrollFooter(Drawable footer) {
        mOverScrollFooter = footer;
        invalidate();
    }

4 viewpager

Viewpager also has two attributes, right and left. The reflection mode is also applicable to Scrollview. The attributes are mLeftEdge and mRightEdge.