Add debug settings so that you can toggle LeakCanary (and other settings in the future) in debug

app/src/main/java/acr/browser/lightning/activity/SettingsActivity.java

@@ -15,13 +15,15 @@ import android.widget.LinearLayout;
 import com.anthonycr.grant.PermissionsManager;
 
 import java.util.ArrayList;
+import java.util.Iterator;
 import java.util.List;
 
 import acr.browser.lightning.R;
+import acr.browser.lightning.app.BrowserApp;
 
 public class SettingsActivity extends ThemableSettingsActivity {
 
-    private static final List<String> mFragments = new ArrayList<>(6);
+    private static final List<String> mFragments = new ArrayList<>(7);
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
@@ -45,12 +47,23 @@ public class SettingsActivity extends ThemableSettingsActivity {
     public void onBuildHeaders(List<Header> target) {
         loadHeadersFromResource(R.xml.preferences_headers, target);
         mFragments.clear();
-        for (Header header : target) {
+        Iterator<Header> headerIterator = target.iterator();
+        while (headerIterator.hasNext()) {
+            Header header = headerIterator.next();
             if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP) {
                 // Workaround for bug in the AppCompat support library
                 header.iconRes = R.drawable.empty;
             }
-            mFragments.add(header.fragment);
+
+            if (header.titleRes == R.string.debug_title) {
+                if (BrowserApp.isRelease()) {
+                    headerIterator.remove();
+                } else {
+                    mFragments.add(header.fragment);
+                }
+            } else {
+                mFragments.add(header.fragment);
+            }
         }
     }
 

app/src/main/java/acr/browser/lightning/app/AppComponent.java

@@ -1,5 +1,7 @@
 package acr.browser.lightning.app;
 
+import android.preference.PreferenceFragment;
+
 import javax.inject.Singleton;
 
 import acr.browser.lightning.activity.BrowserActivity;
@@ -13,6 +15,7 @@ import acr.browser.lightning.dialog.LightningDialogBuilder;
 import acr.browser.lightning.download.LightningDownloadListener;
 import acr.browser.lightning.fragment.BookmarkSettingsFragment;
 import acr.browser.lightning.fragment.BookmarksFragment;
+import acr.browser.lightning.fragment.DebugSettingsFragment;
 import acr.browser.lightning.fragment.LightningPreferenceFragment;
 import acr.browser.lightning.fragment.PrivacySettingsFragment;
 import acr.browser.lightning.fragment.TabsFragment;
@@ -67,4 +70,6 @@ public interface AppComponent {
 
     void inject(TabsManager manager);
 
+    void inject(DebugSettingsFragment fragment);
+
 }

app/src/main/java/acr/browser/lightning/app/BrowserApp.java

@@ -15,6 +15,7 @@ import java.util.concurrent.Executors;
 import javax.inject.Inject;
 
 import acr.browser.lightning.BuildConfig;
+import acr.browser.lightning.preference.PreferenceManager;
 
 public class BrowserApp extends Application {
 
@@ -23,14 +24,18 @@ public class BrowserApp extends Application {
     private static final Executor mTaskThread = Executors.newCachedThreadPool();
 
     @Inject Bus mBus;
+    @Inject PreferenceManager mPreferenceManager;
 
     @Override
     public void onCreate() {
         super.onCreate();
         mAppComponent = DaggerAppComponent.builder().appModule(new AppModule(this)).build();
         mAppComponent.inject(this);
-        LeakCanary.install(this);
+
-        if (BuildConfig.DEBUG && Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
+        if (mPreferenceManager.getUseLeakCanary() && !isRelease()) {
+            LeakCanary.install(this);
+        }
+        if (!isRelease() && Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
             WebView.setWebContentsDebuggingEnabled(true);
         }
     }
@@ -58,4 +63,13 @@ public class BrowserApp extends Application {
         return get(context).mBus;
     }
 
+    /**
+     * Determines whether this is a release build.
+     *
+     * @return true if this is a release build, false otherwise.
+     */
+    public static boolean isRelease() {
+        return !BuildConfig.DEBUG || BuildConfig.BUILD_TYPE.toLowerCase().equals("release");
+    }
+
 }

app/src/main/java/acr/browser/lightning/fragment/DebugSettingsFragment.java

@@ -0,0 +1,57 @@
+package acr.browser.lightning.fragment;
+
+import android.app.Activity;
+import android.os.Bundle;
+import android.preference.Preference;
+import android.preference.PreferenceFragment;
+import android.preference.SwitchPreference;
+import android.support.annotation.NonNull;
+
+import javax.inject.Inject;
+
+import acr.browser.lightning.R;
+import acr.browser.lightning.app.BrowserApp;
+import acr.browser.lightning.preference.PreferenceManager;
+import acr.browser.lightning.utils.Utils;
+
+public class DebugSettingsFragment extends PreferenceFragment implements Preference.OnPreferenceClickListener, Preference.OnPreferenceChangeListener {
+
+    private static final String LEAK_CANARY = "leak_canary_enabled";
+
+    @Inject PreferenceManager mPreferenceManager;
+
+    private SwitchPreference mSwitchLeakCanary;
+
+    @Override
+    public void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        BrowserApp.getAppComponent().inject(this);
+        addPreferencesFromResource(R.xml.preference_debug);
+
+        mSwitchLeakCanary = (SwitchPreference) findPreference(LEAK_CANARY);
+        mSwitchLeakCanary.setChecked(mPreferenceManager.getUseLeakCanary());
+        mSwitchLeakCanary.setOnPreferenceChangeListener(this);
+    }
+
+
+    @Override
+    public boolean onPreferenceClick(@NonNull Preference preference) {
+        return false;
+    }
+
+    @Override
+    public boolean onPreferenceChange(@NonNull Preference preference, @NonNull Object newValue) {
+        switch (preference.getKey()) {
+            case LEAK_CANARY:
+                boolean value = Boolean.TRUE.equals(newValue);
+                mPreferenceManager.setUseLeakCanary(value);
+                Activity activity = getActivity();
+                if (activity != null) {
+                    Utils.showSnackbar(activity, R.string.app_restart);
+                }
+                mSwitchLeakCanary.setChecked(value);
+                return true;
+        }
+        return false;
+    }
+}

app/src/main/java/acr/browser/lightning/preference/PreferenceManager.java

@@ -61,6 +61,8 @@ public class PreferenceManager {
         public static final String USE_PROXY_PORT = "useProxyPort";
         public static final String INITIAL_CHECK_FOR_TOR = "checkForTor";
         public static final String INITIAL_CHECK_FOR_I2P = "checkForI2P";
+
+        public static final String LEAK_CANARY = "leakCanary";
     }
 
     @NonNull private final SharedPreferences mPrefs;
@@ -423,6 +425,14 @@ public class PreferenceManager {
         putInt(Name.THEME, theme);
     }
 
+    public void setUseLeakCanary(boolean useLeakCanary) {
+        putBoolean(Name.LEAK_CANARY, useLeakCanary);
+    }
+
+    public boolean getUseLeakCanary() {
+        return mPrefs.getBoolean(Name.LEAK_CANARY, false);
+    }
+
     /**
      * Valid choices:
      * <ul>

app/src/main/res/values/strings.xml

@@ -237,4 +237,9 @@
 
     <string name="faq">FAQ</string>
     <string name="faq_description">Frequently Asked Questions</string>
+
+    <!-- debug strings -->
+    <string name="debug_title">Debug Settings</string>
+    <string name="debug_leak_canary">LeakCanary</string>
+    <string name="app_restart">Please restart the app for the change to take effect.</string>
 </resources>

app/src/main/res/xml/preference_debug.xml

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android">
+    <PreferenceCategory android:title="@string/debug_title">
+        <SwitchPreference
+            android:defaultValue="false"
+            android:key="leak_canary_enabled"
+            android:title="@string/debug_leak_canary"/>
+    </PreferenceCategory>
+</PreferenceScreen>

app/src/main/res/xml/preferences_headers.xml

@@ -30,4 +30,7 @@
                 android:value="SELF"/>
         </intent>
     </header>
+    <header
+        android:fragment="acr.browser.lightning.fragment.DebugSettingsFragment"
+        android:title="@string/debug_title"/>
 </preference-headers>