利用懸浮窗進一步降低屏幕亮度保護眼睛(app based on Android)，appandroid
項目地址：https://github.com/hwding/make-it-darker
歡迎star、fork以及一切建議和意見！
在完全黑暗中看手機眼睛會非常容易疲勞，即使將手機亮度調整到最低也會讓自己在完全適應後感到非常刺眼。
利用android的懸浮窗將半透明的黑色layout覆蓋在屏幕上進一步降低亮度。
同時通過改變濾鏡顏色可以過濾藍光等等。
出於自身需求給自己寫了一個小玩意~
效果：
懸浮窗作為服務啟動：
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1 package com.amastigote.darker.service;
2
3 import android.app.Service;
4 import android.content.Context;
5 import android.content.Intent;
6 import android.os.IBinder;
7 import android.support.annotation.Nullable;
8 import android.view.LayoutInflater;
9 import android.view.WindowManager;
10 import android.widget.LinearLayout;
11 import com.amastigote.darker.R;
12 import com.amastigote.darker.model.DarkerSettings;
13
14 public class ScreenFilterService extends Service{
15 static LinearLayout linearLayout;
16 static WindowManager.LayoutParams layoutParams;
17 static WindowManager windowManager;
18
19 @Override
20 public void onCreate() {
21 super.onCreate();
22 createScreenFilter();
23 }
24
25 @Override
26 public void onDestroy() {
27 super.onDestroy();
28 if (linearLayout != null)
29 windowManager.removeView(linearLayout);
30 }
31
32 @Nullable
33 @Override
34 public IBinder onBind(Intent intent) {
35 return null;
36 }
37
38 @SuppressWarnings(value = "all")
39 private void createScreenFilter() {
40 layoutParams = new WindowManager.LayoutParams();
41 windowManager = (WindowManager) getApplication().getSystemService(Context.WINDOW_SERVICE);
42 layoutParams.type = WindowManager.LayoutParams.TYPE_PRIORITY_PHONE;
43 layoutParams.flags = WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE
44 | WindowManager.LayoutParams.FLAG_NOT_TOUCH_MODAL
45 | WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE;
46 layoutParams.width = WindowManager.LayoutParams.MATCH_PARENT;
47 layoutParams.height = WindowManager.LayoutParams.MATCH_PARENT;
48
49 LayoutInflater layoutInflater = LayoutInflater.from(getApplication());
50 linearLayout = (LinearLayout) layoutInflater.inflate(R.layout.screen_filter, null);
51 windowManager.addView(linearLayout, layoutParams);
52 removeScreenFilter();
53 }
54
55 public static void updateScreenFilter(DarkerSettings darkerSettings) {
56 layoutParams.screenBrightness = darkerSettings.getBrightness();
57 layoutParams.alpha = darkerSettings.getAlpha();
58 windowManager.updateViewLayout(linearLayout, layoutParams);
59 }
60
61 public static void removeScreenFilter() {
62 layoutParams.screenBrightness = DarkerSettings.BRIGHTNESS_AUTO;
63 layoutParams.alpha = DarkerSettings.ALPHA_MINIMUM;
64 windowManager.updateViewLayout(linearLayout, layoutParams);
65 }
66 }
ScreenFilterService.java
此處應注意，給layoutParams設置屬性type時需要用到類型TYPE_PRIORITY_PHONE，可以覆蓋一切屏幕上的內容。
關於此項類型需要特定的permission申請，此處不表，見下。
screenBrightness為懸浮窗自身亮度，這裡默認為最低0.0F
alpha為懸浮窗layout的透明度，默認為0.4F，最高設定為0.8F防止全黑導致無法操作。
update...()方法用於讀入用戶在app控制面版上的配置並更新filter
remove...()方法並沒有移除filter而是將filter的亮度恢復為自動並設置為全透明，方便下一次啟動filter。
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1 package com.amastigote.darker.activity;
2
3 import android.content.Intent;
4 import android.net.Uri;
5 import android.os.Build;
6 import android.os.Bundle;
7 import android.provider.Settings;
8 import android.support.v7.app.AppCompatActivity;
9 import android.support.v7.widget.Toolbar;
10 import android.view.Menu;
11 import android.view.MenuItem;
12 import android.view.View;
13 import android.view.animation.AlphaAnimation;
14 import android.widget.Button;
15 import android.widget.Switch;
16 import android.widget.Toast;
17 import android.widget.ToggleButton;
18 import com.amastigote.darker.R;
19 import com.amastigote.darker.model.DarkerSettings;
20 import com.amastigote.darker.service.ScreenFilterService;
21 import com.rtugeek.android.colorseekbar.ColorSeekBar;
22 import io.feeeei.circleseekbar.CircleSeekBar;
23
24 public class MainActivity extends AppCompatActivity {
25 DarkerSettings currentDarkerSettings = new DarkerSettings();
26 CircleSeekBar circleSeekBar_brightness;
27 CircleSeekBar circleSeekBar_alpha;
28 ColorSeekBar colorSeekBar;
29 Switch aSwitch;
30 Intent intent;
31
32 @Override
33 protected void onDestroy() {
34 if (intent != null)
35 stopService(intent);
36 super.onDestroy();
37 }
38
39 @Override
40 protected void onCreate(Bundle savedInstanceState) {
41 super.onCreate(savedInstanceState);
42 setContentView(R.layout.activity_main);
43 Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
44 toolbar.setTitle("make it darker!");
45 setSupportActionBar(toolbar);
46 DarkerSettings.initializeContext(getApplicationContext());
47
48 checkPermissions();
49
50 circleSeekBar_brightness = (CircleSeekBar) findViewById(R.id.cp_brightness_circleSeekBar);
51 circleSeekBar_alpha = (CircleSeekBar) findViewById(R.id.cp_alpha_circleSeekBar);
52 colorSeekBar = (ColorSeekBar) findViewById(R.id.cp_colorSeekBar);
53 aSwitch = (Switch) findViewById(R.id.cp_useColor_switch);
54 ToggleButton toggleButton = (ToggleButton) findViewById(R.id.cm_toggle_button);
55 Button restore_settings_button = (Button) findViewById(R.id.cm_restore_settings_button);
56
57 restoreLatestSettings();
58
59 toggleButton.setOnClickListener(new View.OnClickListener() {
60
61 @Override
62 public void onClick(View view) {
63 if (((ToggleButton) view).isChecked())
64 collectCurrentDarkerSettings();
65 else
66 ScreenFilterService.removeScreenFilter();
67 }
68 });
69
70 restore_settings_button.setOnClickListener(new View.OnClickListener() {
71
72 @Override
73 public void onClick(View view) {
74 DarkerSettings darkerSettings_default = DarkerSettings.getDefaultSettings();
75 circleSeekBar_brightness.setCurProcess((int) (darkerSettings_default.getBrightness() * 100));
76 circleSeekBar_alpha.setCurProcess((int) (darkerSettings_default.getAlpha() * 100));
77 if (aSwitch.isChecked() != darkerSettings_default.isUseColor()) {
78 aSwitch.setChecked(darkerSettings_default.isUseColor());
79 AlphaAnimation alphaAnimation_1 = new AlphaAnimation(1, 0);
80 alphaAnimation_1.setDuration(300);
81 colorSeekBar.startAnimation(alphaAnimation_1);
82 colorSeekBar.setVisibility(View.INVISIBLE);
83 }
84 }
85 });
86
87 aSwitch.setOnClickListener(new View.OnClickListener() {
88 @Override
89 public void onClick(View view) {
90 if (((Switch) view).isChecked()) {
91 AlphaAnimation alphaAnimation_0 = new AlphaAnimation(0, 1);
92 alphaAnimation_0.setDuration(300);
93 colorSeekBar.startAnimation(alphaAnimation_0);
94 colorSeekBar.setVisibility(View.VISIBLE);
95 }
96 else {
97 AlphaAnimation alphaAnimation_1 = new AlphaAnimation(1, 0);
98 alphaAnimation_1.setDuration(300);
99 colorSeekBar.startAnimation(alphaAnimation_1);
100 colorSeekBar.setVisibility(View.INVISIBLE);
101 }
102 }
103 });
104
105 }
106
107 @Override
108 public boolean onCreateOptionsMenu(Menu menu) {
109 // Inflate the menu; this adds items to the action bar if it is present.
110 getMenuInflater().inflate(R.menu.menu_main, menu);
111 return true;
112 }
113
114 @Override
115 public boolean onOptionsItemSelected(MenuItem item) {
116 // Handle action bar item clicks here. The action bar will
117 // automatically handle clicks on the Home/Up button, so long
118 // as you specify a parent activity in AndroidManifest.xml.
119 int id = item.getItemId();
120
121 //noinspection SimplifiableIfStatement
122 if (id == R.id.action_settings) {
123 startActivity(new Intent(Intent.ACTION_VIEW,
124 Uri.parse("https://github.com/hwding/make-it-darker")));
125 }
126
127 if (id == R.id.action_licenses) {
128 startActivity(new Intent(MainActivity.this, LicenseActivity.class));
129 }
130
131 return super.onOptionsItemSelected(item);
132 }
133
134 private void collectCurrentDarkerSettings() {
135 currentDarkerSettings.setBrightness(((float) circleSeekBar_brightness.getCurProcess()) / 100);
136 currentDarkerSettings.setAlpha(((float) circleSeekBar_alpha.getCurProcess()) / 100);
137 currentDarkerSettings.setUseColor(aSwitch.isChecked());
138 currentDarkerSettings.setColor(colorSeekBar.getColor());
139 currentDarkerSettings.saveCurrentSettings();
140 ScreenFilterService.updateScreenFilter(currentDarkerSettings);
141 }
142
143 private void restoreLatestSettings() {
144 DarkerSettings latestDarkerSettings = DarkerSettings.getCurrentSettings();
145 circleSeekBar_alpha.setCurProcess((int) (latestDarkerSettings.getAlpha() * 100));
146 circleSeekBar_brightness.setCurProcess((int) (latestDarkerSettings.getBrightness() * 100));
147 if (latestDarkerSettings.isUseColor()) {
148 aSwitch.setChecked(true);
149 colorSeekBar.setVisibility(View.VISIBLE);
150 }
151 colorSeekBar.setColorBarValue(latestDarkerSettings.getColor());
152 }
153
154 private void checkPermissions() {
155 if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
156 if (!Settings.canDrawOverlays(getApplicationContext())) {
157 Intent intent = new Intent(Settings.ACTION_MANAGE_OVERLAY_PERMISSION);
158 intent.setData(Uri.parse("package:" + getPackageName()));
159 startActivityForResult(intent, 0);
160 }
161 else
162 prepareForService();
163 }
164 else
165 prepareForService();
166 }
167
168 @Override
169 protected void onActivityResult(int requestCode, int resultCode, Intent data) {
170 super.onActivityResult(requestCode, resultCode, data);
171 if (requestCode == 0) {
172 if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
173 if (Settings.canDrawOverlays(this))
174 prepareForService();
175 else {
176 Toast.makeText(getApplicationContext(), "權限請求被拒絕 無法正常工作 :(", Toast.LENGTH_LONG).show();
177 finish();
178 }
179 }
180 }
181 }
182
183 private void prepareForService() {
184 intent = new Intent(getApplicationContext(), ScreenFilterService.class);
185 startService(intent);
186 }
187 }
MainActivity.java
高優先級的懸浮窗是敏感權限，6.0以上系統需要特殊處理。
在啟動時，首先調用checkPermissions()方法，判斷系統版本為6.0及以上時，通過包裝一個intent的方式，使app專門請求用戶授權此項權限。
返回後通過接收result，再一次判斷是否具有drawOverlays的權限，如果沒有，則報錯並正常退出，如果獲取到權限則啟動service。
而如果系統版本低於6.0，則可以直接喚起service使系統自動向用戶請求該項權限。
請見文章：
http://pcedu.pconline.com.cn/692/6928996.html
http://blog.csdn.net/yangqingqo/article/details/48371123/
http://www.cnblogs.com/mengdd/p/3824782.html
另外需要在manifest中聲明權限 <uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW" />
尤其要注意在startService後不能立即讀寫ScreenFilterService類中的成員變量，否則會引null異常。
所以應首先同app一起自動啟動service，並在ScreenFilterService的onCreate方法中使用removeScreenFilter()方法防止filter自動生效。
還需注意應在manifest中將mainActivity的啟動模式設為單例模式以防止在childActivity中通過navigationIcon返回主activity後導致的重啟使filter消失。
:) 暑假好開心，月底就要去上海玩了。
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