Move Termux Preferences to com.termux.app.settings.preferences package

The termux preferences handling was mixed in with termux properties before an earlier commit. They are now moved out of into a separate sub package, the following classes are added:

- `TermuxPreferenceConstants` class that defines shared constants of the preferences used by Termux app and its plugins. This class should be imported by other termux plugin apps instead of copying and defining their own constants.
- `TermuxSharedPreferences` class that acts as manager for handling termux preferences.

app/src/main/java/com/termux/app/TermuxActivity.java

@@ -48,6 +48,7 @@ import android.widget.Toast;
 
 import com.termux.R;
 import com.termux.app.TermuxConstants.TERMUX_APP.TERMUX_ACTIVITY;
+import com.termux.app.settings.preferences.TermuxSharedPreferences;
 import com.termux.app.terminal.BellHandler;
 import com.termux.app.terminal.TermuxViewClient;
 import com.termux.app.terminal.extrakeys.ExtraKeysView;
@@ -119,9 +120,9 @@ public final class TermuxActivity extends Activity implements ServiceConnection
 
     ExtraKeysView mExtraKeysView;
 
-    TermuxPreferences mSettings;
+    private TermuxSharedPreferences mPreferences;
 
-    TermuxSharedProperties mProperties;
+    private TermuxSharedProperties mProperties;
 
     /** Initialized in {@link #onServiceConnected(ComponentName, IBinder)}. */
     ArrayAdapter<TerminalSession> mListViewAdapter;
@@ -212,7 +213,7 @@ public final class TermuxActivity extends Activity implements ServiceConnection
 
     @Override
     public void onCreate(Bundle bundle) {
-        mSettings = new TermuxPreferences(this);
+        mPreferences = new TermuxSharedPreferences(this);
         mProperties = new TermuxSharedProperties(this);
 
         mIsUsingBlackUI = mProperties.isUsingBlackUI();
@@ -246,12 +247,12 @@ public final class TermuxActivity extends Activity implements ServiceConnection
         mTerminalView = findViewById(R.id.terminal_view);
         mTerminalView.setOnKeyListener(new TermuxViewClient(this));
 
-        mTerminalView.setTextSize(mSettings.getFontSize());
-        mTerminalView.setKeepScreenOn(mSettings.isScreenAlwaysOn());
+        mTerminalView.setTextSize(mPreferences.getFontSize());
+        mTerminalView.setKeepScreenOn(mPreferences.getKeepScreenOn());
         mTerminalView.requestFocus();
 
         final ViewPager viewPager = findViewById(R.id.viewpager);
-        if (mSettings.mShowExtraKeys) viewPager.setVisibility(View.VISIBLE);
+        if (mPreferences.getShowExtraKeys()) viewPager.setVisibility(View.VISIBLE);
 
 
         ViewGroup.LayoutParams layoutParams = viewPager.getLayoutParams();
@@ -382,7 +383,7 @@ public final class TermuxActivity extends Activity implements ServiceConnection
 
     public void toggleShowExtraKeys() {
         final ViewPager viewPager = findViewById(R.id.viewpager);
-        final boolean showNow = mSettings.toggleShowExtraKeys(TermuxActivity.this);
+        final boolean showNow = mPreferences.toggleShowExtraKeys();
         viewPager.setVisibility(showNow ? View.VISIBLE : View.GONE);
         if (showNow && viewPager.getCurrentItem() == 1) {
             // Focus the text input view if just revealed.
@@ -636,7 +637,7 @@ public final class TermuxActivity extends Activity implements ServiceConnection
         super.onStop();
         mIsVisible = false;
         TerminalSession currentSession = getCurrentTermSession();
-        if (currentSession != null) TermuxPreferences.storeCurrentSession(this, currentSession);
+        if (currentSession != null) mPreferences.setCurrentSession(currentSession.mHandle);
         unregisterReceiver(mBroadcastReceiever);
         getDrawer().closeDrawers();
     }
@@ -739,7 +740,7 @@ public final class TermuxActivity extends Activity implements ServiceConnection
         menu.add(Menu.NONE, CONTEXTMENU_RESET_TERMINAL_ID, Menu.NONE, R.string.reset_terminal);
         menu.add(Menu.NONE, CONTEXTMENU_KILL_PROCESS_ID, Menu.NONE, getResources().getString(R.string.kill_process, getCurrentTermSession().getPid())).setEnabled(currentSession.isRunning());
         menu.add(Menu.NONE, CONTEXTMENU_STYLING_ID, Menu.NONE, R.string.style_terminal);
-        menu.add(Menu.NONE, CONTEXTMENU_TOGGLE_KEEP_SCREEN_ON, Menu.NONE, R.string.toggle_keep_screen_on).setCheckable(true).setChecked(mSettings.isScreenAlwaysOn());
+        menu.add(Menu.NONE, CONTEXTMENU_TOGGLE_KEEP_SCREEN_ON, Menu.NONE, R.string.toggle_keep_screen_on).setCheckable(true).setChecked(mPreferences.getKeepScreenOn());
         menu.add(Menu.NONE, CONTEXTMENU_HELP_ID, Menu.NONE, R.string.help);
     }
 
@@ -950,10 +951,10 @@ public final class TermuxActivity extends Activity implements ServiceConnection
             case CONTEXTMENU_TOGGLE_KEEP_SCREEN_ON: {
                 if(mTerminalView.getKeepScreenOn()) {
                     mTerminalView.setKeepScreenOn(false);
-                    mSettings.setScreenAlwaysOn(this, false);
+                    mPreferences.setKeepScreenOn(false);
                 } else {
                     mTerminalView.setKeepScreenOn(true);
-                    mSettings.setScreenAlwaysOn(this, true);
+                    mPreferences.setKeepScreenOn(true);
                 }
                 return true;
             }
@@ -978,8 +979,8 @@ public final class TermuxActivity extends Activity implements ServiceConnection
     }
 
     public void changeFontSize(boolean increase) {
-        mSettings.changeFontSize(this, increase);
-        mTerminalView.setTextSize(mSettings.getFontSize());
+        mPreferences.changeFontSize(this, increase);
+        mTerminalView.setTextSize(mPreferences.getFontSize());
     }
 
     public void doPaste() {
@@ -995,12 +996,21 @@ public final class TermuxActivity extends Activity implements ServiceConnection
 
     /** The current session as stored or the last one if that does not exist. */
     public TerminalSession getStoredCurrentSessionOrLast() {
-        TerminalSession stored = TermuxPreferences.getCurrentSession(this);
+        TerminalSession stored = getCurrentSession(this);
         if (stored != null) return stored;
         List<TerminalSession> sessions = mTermService.getSessions();
         return sessions.isEmpty() ? null : sessions.get(sessions.size() - 1);
     }
 
+    private TerminalSession getCurrentSession(TermuxActivity context) {
+        String sessionHandle = mPreferences.getCurrentSession();
+        for (int i = 0, len = context.getTermService().getSessions().size(); i < len; i++) {
+            TerminalSession session = context.getTermService().getSessions().get(i);
+            if (session.mHandle.equals(sessionHandle)) return session;
+        }
+        return null;
+    }
+
     /** Show a toast and dismiss the last one if still visible. */
     void showToast(String text, boolean longDuration) {
         if (mLastToast != null) mLastToast.cancel();

app/src/main/java/com/termux/app/TermuxPreferences.java

@@ -1,96 +0,0 @@
-package com.termux.app;
-
-import android.content.Context;
-import android.content.SharedPreferences;
-import android.preference.PreferenceManager;
-import android.util.TypedValue;
-
-import com.termux.terminal.TerminalSession;
-
-final class TermuxPreferences {
-
-    private final int MIN_FONTSIZE;
-    private static final int MAX_FONTSIZE = 256;
-
-    private static final String SHOW_EXTRA_KEYS_KEY = "show_extra_keys";
-    private static final String FONTSIZE_KEY = "fontsize";
-    private static final String CURRENT_SESSION_KEY = "current_session";
-    private static final String SCREEN_ALWAYS_ON_KEY = "screen_always_on";
-
-    private boolean mScreenAlwaysOn;
-    private int mFontSize;
-    boolean mShowExtraKeys;
-
-    TermuxPreferences(Context context) {
-        SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
-
-        float dipInPixels = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 1, context.getResources().getDisplayMetrics());
-
-        // This is a bit arbitrary and sub-optimal. We want to give a sensible default for minimum font size
-        // to prevent invisible text due to zoom be mistake:
-        MIN_FONTSIZE = (int) (4f * dipInPixels);
-
-        mShowExtraKeys = prefs.getBoolean(SHOW_EXTRA_KEYS_KEY, true);
-        mScreenAlwaysOn = prefs.getBoolean(SCREEN_ALWAYS_ON_KEY, false);
-
-        // http://www.google.com/design/spec/style/typography.html#typography-line-height
-        int defaultFontSize = Math.round(12 * dipInPixels);
-        // Make it divisible by 2 since that is the minimal adjustment step:
-        if (defaultFontSize % 2 == 1) defaultFontSize--;
-
-        try {
-            mFontSize = Integer.parseInt(prefs.getString(FONTSIZE_KEY, Integer.toString(defaultFontSize)));
-        } catch (NumberFormatException | ClassCastException e) {
-            mFontSize = defaultFontSize;
-        }
-        mFontSize = clamp(mFontSize, MIN_FONTSIZE, MAX_FONTSIZE);
-    }
-
-    boolean toggleShowExtraKeys(Context context) {
-        mShowExtraKeys = !mShowExtraKeys;
-        PreferenceManager.getDefaultSharedPreferences(context).edit().putBoolean(SHOW_EXTRA_KEYS_KEY, mShowExtraKeys).apply();
-        return mShowExtraKeys;
-    }
-
-    int getFontSize() {
-        return mFontSize;
-    }
-
-    void changeFontSize(Context context, boolean increase) {
-        mFontSize += (increase ? 1 : -1) * 2;
-        mFontSize = Math.max(MIN_FONTSIZE, Math.min(mFontSize, MAX_FONTSIZE));
-
-        SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
-        prefs.edit().putString(FONTSIZE_KEY, Integer.toString(mFontSize)).apply();
-    }
-
-    boolean isScreenAlwaysOn() {
-        return mScreenAlwaysOn;
-    }
-
-    void setScreenAlwaysOn(Context context, boolean newValue) {
-        mScreenAlwaysOn = newValue;
-        PreferenceManager.getDefaultSharedPreferences(context).edit().putBoolean(SCREEN_ALWAYS_ON_KEY, newValue).apply();
-    }
-
-    static void storeCurrentSession(Context context, TerminalSession session) {
-        PreferenceManager.getDefaultSharedPreferences(context).edit().putString(TermuxPreferences.CURRENT_SESSION_KEY, session.mHandle).apply();
-    }
-
-    static TerminalSession getCurrentSession(TermuxActivity context) {
-        String sessionHandle = PreferenceManager.getDefaultSharedPreferences(context).getString(TermuxPreferences.CURRENT_SESSION_KEY, "");
-        for (int i = 0, len = context.mTermService.getSessions().size(); i < len; i++) {
-            TerminalSession session = context.mTermService.getSessions().get(i);
-            if (session.mHandle.equals(sessionHandle)) return session;
-        }
-        return null;
-    }
-
-    /**
-     * If value is not in the range [min, max], set it to either min or max.
-     */
-    static int clamp(int value, int min, int max) {
-        return Math.min(Math.max(value, min), max);
-    }
-
-}

app/src/main/java/com/termux/app/TermuxService.java

@@ -24,6 +24,7 @@ import android.widget.ArrayAdapter;
 import com.termux.R;
 import com.termux.app.TermuxConstants.TERMUX_APP.TERMUX_ACTIVITY;
 import com.termux.app.TermuxConstants.TERMUX_APP.TERMUX_SERVICE;
+import com.termux.app.settings.preferences.TermuxSharedPreferences;
 import com.termux.terminal.EmulatorDebug;
 import com.termux.terminal.TerminalSession;
 import com.termux.terminal.TerminalSession.SessionChangedCallback;
@@ -148,7 +149,8 @@ public final class TermuxService extends Service implements SessionChangedCallba
                 }
 
                 // Make the newly created session the current one to be displayed:
-                TermuxPreferences.storeCurrentSession(this, newSession);
+                TermuxSharedPreferences preferences = new TermuxSharedPreferences(this);
+                preferences.setCurrentSession(newSession.mHandle);
 
                 // Launch the main Termux app, which will now show the current session:
                 startActivity(new Intent(this, TermuxActivity.class).addFlags(Intent.FLAG_ACTIVITY_NEW_TASK));

app/src/main/java/com/termux/app/settings/preferences/TermuxPreferenceConstants.java

@@ -0,0 +1,50 @@
+package com.termux.app.settings.preferences;
+
+import com.termux.app.TermuxConstants;
+
+/*
+ * Version: v0.1.0
+ *
+ * Changelog
+ *
+ * - 0.1.0 (2021-03-12)
+ *      - Initial Release.
+ *
+ */
+
+/**
+ * A class that defines shared constants of the Shared preferences used by Termux app and its plugins.
+ * This class will be hosted by termux-app and should be imported by other termux plugin apps as is
+ * instead of copying constants to random classes. The 3rd party apps can also import it for
+ * interacting with termux apps. If changes are made to this file, increment the version number
+ * and add an entry in the Changelog section above.
+ *
+ * The properties are loaded from the first file found at
+ * {@link TermuxConstants#TERMUX_PROPERTIES_PRIMARY_FILE_PATH} or
+ * {@link TermuxConstants#TERMUX_PROPERTIES_SECONDARY_FILE_PATH}
+ */
+public final class TermuxPreferenceConstants {
+
+    /** Defines the key for whether to show extra keys in termux terminal view */
+    public static final String KEY_SHOW_EXTRA_KEYS = "show_extra_keys";
+    public static final boolean DEFAULT_VALUE_SHOW_EXTRA_KEYS = true;
+
+
+
+    /** Defines the key for whether to always keep screen on */
+    public static final String KEY_KEEP_SCREEN_ON = "screen_always_on";
+    public static final boolean DEFAULT_VALUE_KEEP_SCREEN_ON = true;
+
+
+
+    /** Defines the key for font size of termux terminal view */
+    public static final String KEY_FONTSIZE = "fontsize";
+
+
+
+    /** Defines the key for current termux terminal session */
+    public static final String KEY_CURRENT_SESSION = "current_session";
+
+
+
+}

app/src/main/java/com/termux/app/settings/preferences/TermuxSharedPreferences.java

@@ -0,0 +1,138 @@
+package com.termux.app.settings.preferences;
+
+import android.content.Context;
+import android.content.SharedPreferences;
+import android.util.Log;
+import android.util.TypedValue;
+
+import com.termux.app.TermuxConstants;
+import com.termux.terminal.EmulatorDebug;
+
+import javax.annotation.Nonnull;
+
+public class TermuxSharedPreferences {
+
+    private final Context mContext;
+    private final SharedPreferences mSharedPreferences;
+
+
+    private int MIN_FONTSIZE;
+    private int MAX_FONTSIZE;
+    private int DEFAULT_FONTSIZE;
+
+    public TermuxSharedPreferences(@Nonnull Context context) {
+        Context mTempContext;
+
+        try {
+            mTempContext = context.createPackageContext(TermuxConstants.TERMUX_PACKAGE_NAME, Context.CONTEXT_RESTRICTED);
+        } catch (Exception e) {
+            Log.e(EmulatorDebug.LOG_TAG, "Failed to get \"" + TermuxConstants.TERMUX_PACKAGE_NAME + "\" package context", e);
+            Log.e(EmulatorDebug.LOG_TAG, "Force using current context");
+            mTempContext = context;
+        }
+
+        mContext = mTempContext;
+        mSharedPreferences = getSharedPreferences(mContext);
+
+        setFontVariables(context);
+    }
+
+    private static SharedPreferences getSharedPreferences(Context context) {
+        return context.getSharedPreferences(TermuxConstants.TERMUX_DEFAULT_PREFERENCES_FILE_BASENAME_WITHOUT_EXTENSION, Context.MODE_PRIVATE);
+    }
+
+
+
+    public boolean getShowExtraKeys() {
+        return mSharedPreferences.getBoolean(TermuxPreferenceConstants.KEY_SHOW_EXTRA_KEYS, TermuxPreferenceConstants.DEFAULT_VALUE_SHOW_EXTRA_KEYS);
+    }
+
+    public void setShowExtraKeys(boolean value) {
+        mSharedPreferences.edit().putBoolean(TermuxPreferenceConstants.KEY_SHOW_EXTRA_KEYS, value).apply();
+    }
+
+    public boolean toggleShowExtraKeys() {
+        boolean currentValue = getShowExtraKeys();
+        setShowExtraKeys(!currentValue);
+        return !currentValue;
+    }
+
+
+
+    public boolean getKeepScreenOn() {
+        return mSharedPreferences.getBoolean(TermuxPreferenceConstants.KEY_KEEP_SCREEN_ON, TermuxPreferenceConstants.DEFAULT_VALUE_KEEP_SCREEN_ON);
+    }
+
+    public void setKeepScreenOn(boolean value) {
+        mSharedPreferences.edit().putBoolean(TermuxPreferenceConstants.KEY_KEEP_SCREEN_ON, value).apply();
+    }
+
+
+
+    private void setFontVariables(Context context) {
+        float dipInPixels = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 1, context.getResources().getDisplayMetrics());
+
+        // This is a bit arbitrary and sub-optimal. We want to give a sensible default for minimum font size
+        // to prevent invisible text due to zoom be mistake:
+        MIN_FONTSIZE = (int) (4f * dipInPixels);
+
+        // http://www.google.com/design/spec/style/typography.html#typography-line-height
+        int defaultFontSize = Math.round(12 * dipInPixels);
+        // Make it divisible by 2 since that is the minimal adjustment step:
+        if (defaultFontSize % 2 == 1) defaultFontSize--;
+
+        DEFAULT_FONTSIZE = defaultFontSize;
+
+        MAX_FONTSIZE = 256;
+    }
+
+    public int getFontSize() {
+        int fontSize;
+        String fontString;
+
+        try {
+            fontString = mSharedPreferences.getString(TermuxPreferenceConstants.KEY_FONTSIZE, Integer.toString(DEFAULT_FONTSIZE));
+            if(fontString != null)
+                fontSize =  Integer.parseInt(fontString);
+            else
+                fontSize = DEFAULT_FONTSIZE;
+        } catch (NumberFormatException | ClassCastException e) {
+            fontSize = DEFAULT_FONTSIZE;
+        }
+        fontSize = clamp(fontSize, MIN_FONTSIZE, MAX_FONTSIZE);
+
+        return fontSize;
+    }
+
+    public void setFontSize(String value) {
+        mSharedPreferences.edit().putString(TermuxPreferenceConstants.KEY_FONTSIZE, value).apply();
+    }
+
+    public void changeFontSize(Context context, boolean increase) {
+
+        int fontSize = getFontSize();
+
+        fontSize += (increase ? 1 : -1) * 2;
+        fontSize = Math.max(MIN_FONTSIZE, Math.min(fontSize, MAX_FONTSIZE));
+
+        setFontSize(Integer.toString(fontSize));
+    }
+
+    /**
+     * If value is not in the range [min, max], set it to either min or max.
+     */
+    static int clamp(int value, int min, int max) {
+        return Math.min(Math.max(value, min), max);
+    }
+
+
+
+    public String getCurrentSession() {
+        return mSharedPreferences.getString(TermuxPreferenceConstants.KEY_CURRENT_SESSION, "");
+    }
+
+    public void setCurrentSession(String value) {
+        mSharedPreferences.edit().putString(TermuxPreferenceConstants.KEY_CURRENT_SESSION, value).apply();
+    }
+
+}