仿QQ空间标题栏渐变

https://github.com/Hankkin/GradationTitleBar

public class GradationScrollView extends ScrollView {

    public interface ScrollViewListener {

        void onScrollChanged(GradationScrollView scrollView, int x, int y,
                             int oldx, int oldy);

    }

    private ScrollViewListener scrollViewListener = null;

    public GradationScrollView(Context context) {
        super(context);
    }

    public GradationScrollView(Context context, AttributeSet attrs,
                               int defStyle) {
        super(context, attrs, defStyle);
    }

    public GradationScrollView(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public void setScrollViewListener(ScrollViewListener scrollViewListener) {
        this.scrollViewListener = scrollViewListener;
    }

    @Override
    protected void onScrollChanged(int x, int y, int oldx, int oldy) {
        super.onScrollChanged(x, y, oldx, oldy);
        if (scrollViewListener != null) {
            scrollViewListener.onScrollChanged(this, x, y, oldx, oldy);
        }
    }

}

public class QQSpeakActivity extends AppCompatActivity implements GradationScrollView.ScrollViewListener{
    private GradationScrollView scrollView;

    private ListView listView;

    private TextView textView;
    private int height;
    private ImageView ivBanner;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        getWindow().requestFeature(Window.FEATURE_NO_TITLE);
        StatusBarUtil.setImgTransparent(this);
        setContentView(R.layout.activity_qqspeak);

        scrollView = (GradationScrollView) findViewById(R.id.scrollview);
        listView = (ListView) findViewById(R.id.listview);
        textView = (TextView) findViewById(R.id.textview);
        ivBanner = (ImageView) findViewById(R.id.iv_banner);

        ivBanner.setFocusable(true);
        ivBanner.setFocusableInTouchMode(true);
        ivBanner.requestFocus();

        initListeners();
        initData();
    }

    /**
     * 获取顶部图片高度后，设置滚动监听
     */
    private void initListeners() {

        ViewTreeObserver vto = ivBanner.getViewTreeObserver();
        vto.addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
            @Override
            public void onGlobalLayout() {
                textView.getViewTreeObserver().removeGlobalOnLayoutListener(
                        this);
                height = ivBanner.getHeight();

                scrollView.setScrollViewListener(QQSpeakActivity.this);
            }
        });
    }



    private void initData() {
        ArrayAdapter<String> adapter = new ArrayAdapter<String>(QQSpeakActivity.this, android.R.layout.simple_list_item_1, getResources().getStringArray(R.array.data));
        listView.setAdapter(adapter);
    }


    /**
     * 滑动监听
     * @param scrollView
     * @param x
     * @param y
     * @param oldx
     * @param oldy
     */
    @Override
    public void onScrollChanged(GradationScrollView scrollView, int x, int y,
                                int oldx, int oldy) {
        // TODO Auto-generated method stub
        if (y <= 0) {   //设置标题的背景颜色
            textView.setBackgroundColor(Color.argb((int) 0, 144,151,166));
        } else if (y > 0 && y <= height) { //滑动距离小于banner图的高度时，设置背景和字体颜色颜色透明度渐变
            float scale = (float) y / height;
            float alpha = (255 * scale);
            textView.setTextColor(Color.argb((int) alpha, 255,255,255));
            textView.setBackgroundColor(Color.argb((int) alpha, 144,151,166));
        } else {    //滑动到banner下面设置普通颜色
            textView.setBackgroundColor(Color.argb((int) 255, 144,151,166));
        }
    }
}

 

public class StatusBarUtil {

    public static final int DEFAULT_STATUS_BAR_ALPHA = 112;

    /**
     * 设置状态栏颜色
     *
     * @param activity 需要设置的 activity
     * @param color    状态栏颜色值
     */
    public static void setColor(Activity activity, int color) {
        setColor(activity, color, DEFAULT_STATUS_BAR_ALPHA);
    }

    /**
     * 设置状态栏颜色
     *
     * @param activity       需要设置的activity
     * @param color          状态栏颜色值
     * @param statusBarAlpha 状态栏透明度
     */
    public static void setColor(Activity activity, int color, int statusBarAlpha) {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
            activity.getWindow().addFlags(WindowManager.LayoutParams.FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS);
            activity.getWindow().clearFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);
            activity.getWindow().setStatusBarColor(calculateStatusColor(color, statusBarAlpha));
        } else if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
            activity.getWindow().addFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);
            // 生成一个状态栏大小的矩形
            View statusView = createStatusBarView(activity, color, statusBarAlpha);
            // 添加 statusView 到布局中
            ViewGroup decorView = (ViewGroup) activity.getWindow().getDecorView();
            decorView.addView(statusView);
            setRootView(activity);
        }
    }

    /**
     * 设置状态栏纯色 不加半透明效果
     *
     * @param activity 需要设置的 activity
     * @param color    状态栏颜色值
     */
    public static void setColorNoTranslucent(Activity activity, int color) {
        setColor(activity, color, 0);
    }

    /**
     * 设置状态栏颜色(5.0以下无半透明效果,不建议使用)
     *
     * @param activity 需要设置的 activity
     * @param color    状态栏颜色值
     */
    public static void setColorDiff(Activity activity, int color) {
        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.KITKAT) {
            return;
        }
        activity.getWindow().addFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);
        // 生成一个状态栏大小的矩形
        View statusView = createStatusBarView(activity, color);
        // 添加 statusView 到布局中
        ViewGroup decorView = (ViewGroup) activity.getWindow().getDecorView();
        decorView.addView(statusView);
        setRootView(activity);
    }

    /**
     * 使状态栏半透明
     *
     * 适用于图片作为背景的界面,此时需要图片填充到状态栏
     *
     * @param activity 需要设置的activity
     */
    public static void setTranslucent(Activity activity) {
        setTranslucent(activity, DEFAULT_STATUS_BAR_ALPHA);
    }

    /**
     * 使状态栏半透明
     *
     * 适用于图片作为背景的界面,此时需要图片填充到状态栏
     *
     * @param activity       需要设置的activity
     * @param statusBarAlpha 状态栏透明度
     */
    public static void setTranslucent(Activity activity, int statusBarAlpha) {
        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.KITKAT) {
            return;
        }
        setTransparent(activity);
        addTranslucentView(activity, statusBarAlpha);
    }

    /**
     * 设置状态栏全透明
     *
     * @param activity 需要设置的activity
     */
    public static void setTransparent(Activity activity) {
        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.KITKAT) {
            return;
        }
        transparentStatusBar(activity);
        setRootView(activity);
    }

    /**
     * 使状态栏透明(5.0以上半透明效果,不建议使用)
     *
     * 适用于图片作为背景的界面,此时需要图片填充到状态栏
     *
     * @param activity 需要设置的activity
     */
    public static void setTranslucentDiff(Activity activity) {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
            // 设置状态栏透明
            activity.getWindow().addFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);
            setRootView(activity);
        }
    }

    /**
     * 为DrawerLayout 布局设置状态栏变色
     *
     * @param activity     需要设置的activity
     * @param drawerLayout DrawerLayout
     * @param color        状态栏颜色值
     */
    public static void setColorForDrawerLayout(Activity activity, DrawerLayout drawerLayout, int color) {
        setColorForDrawerLayout(activity, drawerLayout, color, DEFAULT_STATUS_BAR_ALPHA);
    }

    /**
     * 为DrawerLayout 布局设置状态栏颜色,纯色
     *
     * @param activity     需要设置的activity
     * @param drawerLayout DrawerLayout
     * @param color        状态栏颜色值
     */
    public static void setColorNoTranslucentForDrawerLayout(Activity activity, DrawerLayout drawerLayout, int color) {
        setColorForDrawerLayout(activity, drawerLayout, color, 0);
    }

    /**
     * 为DrawerLayout 布局设置状态栏变色
     *
     * @param activity       需要设置的activity
     * @param drawerLayout   DrawerLayout
     * @param color          状态栏颜色值
     * @param statusBarAlpha 状态栏透明度
     */
    public static void setColorForDrawerLayout(Activity activity, DrawerLayout drawerLayout, int color, int statusBarAlpha) {
        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.KITKAT) {
            return;
        }
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
            activity.getWindow().addFlags(WindowManager.LayoutParams.FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS);
            activity.getWindow().clearFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);
            activity.getWindow().setStatusBarColor(Color.TRANSPARENT);
        } else {
            activity.getWindow().addFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);
        }
        // 生成一个状态栏大小的矩形
        View statusBarView = createStatusBarView(activity, color);
        // 添加 statusBarView 到布局中
        ViewGroup contentLayout = (ViewGroup) drawerLayout.getChildAt(0);
        contentLayout.addView(statusBarView, 0);
        // 内容布局不是 LinearLayout 时,设置padding top
        if (!(contentLayout instanceof LinearLayout) && contentLayout.getChildAt(1) != null) {
            contentLayout.getChildAt(1).setPadding(0, getStatusBarHeight(activity), 0, 0);
        }
        // 设置属性
        ViewGroup drawer = (ViewGroup) drawerLayout.getChildAt(1);
        drawerLayout.setFitsSystemWindows(false);
        contentLayout.setFitsSystemWindows(false);
        contentLayout.setClipToPadding(true);
        drawer.setFitsSystemWindows(false);

        addTranslucentView(activity, statusBarAlpha);
    }

    /**
     * 为DrawerLayout 布局设置状态栏变色(5.0以下无半透明效果,不建议使用)
     *
     * @param activity     需要设置的activity
     * @param drawerLayout DrawerLayout
     * @param color        状态栏颜色值
     */
    public static void setColorForDrawerLayoutDiff(Activity activity, DrawerLayout drawerLayout, int color) {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
            activity.getWindow().addFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);
            // 生成一个状态栏大小的矩形
            View statusBarView = createStatusBarView(activity, color);
            // 添加 statusBarView 到布局中
            ViewGroup contentLayout = (ViewGroup) drawerLayout.getChildAt(0);
            contentLayout.addView(statusBarView, 0);
            // 内容布局不是 LinearLayout 时,设置padding top
            if (!(contentLayout instanceof LinearLayout) && contentLayout.getChildAt(1) != null) {
                contentLayout.getChildAt(1).setPadding(0, getStatusBarHeight(activity), 0, 0);
            }
            // 设置属性
            ViewGroup drawer = (ViewGroup) drawerLayout.getChildAt(1);
            drawerLayout.setFitsSystemWindows(false);
            contentLayout.setFitsSystemWindows(false);
            contentLayout.setClipToPadding(true);
            drawer.setFitsSystemWindows(false);
        }
    }

    /**
     * 为 DrawerLayout 布局设置状态栏透明
     *
     * @param activity     需要设置的activity
     * @param drawerLayout DrawerLayout
     */
    public static void setTranslucentForDrawerLayout(Activity activity, DrawerLayout drawerLayout) {
        setTranslucentForDrawerLayout(activity, drawerLayout, DEFAULT_STATUS_BAR_ALPHA);
    }

    /**
     * 为 DrawerLayout 布局设置状态栏透明
     *
     * @param activity     需要设置的activity
     * @param drawerLayout DrawerLayout
     */
    public static void setTranslucentForDrawerLayout(Activity activity, DrawerLayout drawerLayout, int statusBarAlpha) {
        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.KITKAT) {
            return;
        }
        setTransparentForDrawerLayout(activity, drawerLayout);
        addTranslucentView(activity, statusBarAlpha);
    }

    /**
     * 为 DrawerLayout 布局设置状态栏透明
     *
     * @param activity     需要设置的activity
     * @param drawerLayout DrawerLayout
     */
    public static void setTransparentForDrawerLayout(Activity activity, DrawerLayout drawerLayout) {
        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.KITKAT) {
            return;
        }
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
            activity.getWindow().addFlags(WindowManager.LayoutParams.FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS);
            activity.getWindow().clearFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);
            activity.getWindow().setStatusBarColor(Color.TRANSPARENT);
        } else {
            activity.getWindow().addFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);
        }

        ViewGroup contentLayout = (ViewGroup) drawerLayout.getChildAt(0);
        // 内容布局不是 LinearLayout 时,设置padding top
        if (!(contentLayout instanceof LinearLayout) && contentLayout.getChildAt(1) != null) {
            contentLayout.getChildAt(1).setPadding(0, getStatusBarHeight(activity), 0, 0);
        }

        // 设置属性
        ViewGroup drawer = (ViewGroup) drawerLayout.getChildAt(1);
        drawerLayout.setFitsSystemWindows(false);
        contentLayout.setFitsSystemWindows(false);
        contentLayout.setClipToPadding(true);
        drawer.setFitsSystemWindows(false);
    }

    /**
     * 为 DrawerLayout 布局设置状态栏透明(5.0以上半透明效果,不建议使用)
     *
     * @param activity     需要设置的activity
     * @param drawerLayout DrawerLayout
     */
    public static void setTranslucentForDrawerLayoutDiff(Activity activity, DrawerLayout drawerLayout) {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
            // 设置状态栏透明
            activity.getWindow().addFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);
            // 设置内容布局属性
            ViewGroup contentLayout = (ViewGroup) drawerLayout.getChildAt(0);
            contentLayout.setFitsSystemWindows(true);
            contentLayout.setClipToPadding(true);
            // 设置抽屉布局属性
            ViewGroup vg = (ViewGroup) drawerLayout.getChildAt(1);
            vg.setFitsSystemWindows(false);
            // 设置 DrawerLayout 属性
            drawerLayout.setFitsSystemWindows(false);
        }
    }

    /**
     * 添加半透明矩形条
     *
     * @param activity       需要设置的 activity
     * @param statusBarAlpha 透明值
     */
    private static void addTranslucentView(Activity activity, int statusBarAlpha) {
        ViewGroup contentView = (ViewGroup) activity.findViewById(android.R.id.content);
        // 移除半透明矩形,以免叠加
        if (contentView.getChildCount() > 1) {
            contentView.removeViewAt(1);
        }
        contentView.addView(createTranslucentStatusBarView(activity, statusBarAlpha));
    }

    /**
     * 生成一个和状态栏大小相同的彩色矩形条
     *
     * @param activity 需要设置的 activity
     * @param color    状态栏颜色值
     * @return 状态栏矩形条
     */
    private static View createStatusBarView(Activity activity, int color) {
        // 绘制一个和状态栏一样高的矩形
        View statusBarView = new View(activity);
        LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,
            getStatusBarHeight(activity));
        statusBarView.setLayoutParams(params);
        statusBarView.setBackgroundColor(color);
        return statusBarView;
    }

    /**
     * 生成一个和状态栏大小相同的半透明矩形条
     *
     * @param activity 需要设置的activity
     * @param color    状态栏颜色值
     * @param alpha    透明值
     * @return 状态栏矩形条
     */
    private static View createStatusBarView(Activity activity, int color, int alpha) {
        // 绘制一个和状态栏一样高的矩形
        View statusBarView = new View(activity);
        LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,
            getStatusBarHeight(activity));
        statusBarView.setLayoutParams(params);
        statusBarView.setBackgroundColor(calculateStatusColor(color, alpha));
        return statusBarView;
    }

    /**
     * 设置根布局参数
     */
    private static void setRootView(Activity activity) {
        ViewGroup rootView = (ViewGroup) ((ViewGroup) activity.findViewById(android.R.id.content)).getChildAt(0);
        rootView.setFitsSystemWindows(true);
        rootView.setClipToPadding(true);
    }

    /**
     * 使状态栏透明
     */
    @TargetApi(Build.VERSION_CODES.KITKAT)
    private static void transparentStatusBar(Activity activity) {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
            activity.getWindow().addFlags(WindowManager.LayoutParams.FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS);
            activity.getWindow().clearFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);
            activity.getWindow().addFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_NAVIGATION);
            activity.getWindow().setStatusBarColor(Color.TRANSPARENT);
        } else {
            activity.getWindow().addFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);
        }
    }

    /**
     * 创建半透明矩形 View
     *
     * @param alpha 透明值
     * @return 半透明 View
     */
    private static View createTranslucentStatusBarView(Activity activity, int alpha) {
        // 绘制一个和状态栏一样高的矩形
        View statusBarView = new View(activity);
        LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,
            getStatusBarHeight(activity));
        statusBarView.setLayoutParams(params);
        statusBarView.setBackgroundColor(Color.argb(alpha, 0, 0, 0));
        return statusBarView;
    }

    /**
     * 获取状态栏高度
     *
     * @param context context
     * @return 状态栏高度
     */
    private static int getStatusBarHeight(Context context) {
        // 获得状态栏高度
        int resourceId = context.getResources().getIdentifier("status_bar_height", "dimen", "android");
        return context.getResources().getDimensionPixelSize(resourceId);
    }

    /**
     * 计算状态栏颜色
     *
     * @param color color值
     * @param alpha alpha值
     * @return 最终的状态栏颜色
     */
    private static int calculateStatusColor(int color, int alpha) {
        float a = 1 - alpha / 255f;
        int red = color >> 16 & 0xff;
        int green = color >> 8 & 0xff;
        int blue = color & 0xff;
        red = (int) (red * a + 0.5);
        green = (int) (green * a + 0.5);
        blue = (int) (blue * a + 0.5);
        return 0xff << 24 | red << 16 | green << 8 | blue;
    }

    public static void setImgTransparent(Activity activity){
        if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
            Window window = activity.getWindow();
            window.clearFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS
                    | WindowManager.LayoutParams.FLAG_TRANSLUCENT_NAVIGATION);
            window.getDecorView().setSystemUiVisibility(View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN
                    | View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION
                    | View.SYSTEM_UI_FLAG_LAYOUT_STABLE);
            window.addFlags(WindowManager.LayoutParams.FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS);
            window.setStatusBarColor(Color.TRANSPARENT);
            window.setNavigationBarColor(Color.TRANSPARENT);
        }
    }
}