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

package com.termux.app;

import android.content.Context;
import android.content.SharedPreferences;
import android.preference.PreferenceManager;
import android.support.annotation.IntDef;
import android.util.Log;
import android.util.TypedValue;
import android.widget.Toast;

import com.termux.terminal.TerminalSession;

import java.io.File;
import java.io.FileInputStream;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.util.ArrayList;
import java.util.List;
import java.util.Properties;

final class TermuxPreferences {

    @IntDef({BELL_VIBRATE, BELL_BEEP, BELL_IGNORE})
    @Retention(RetentionPolicy.SOURCE)
    public @interface AsciiBellBehaviour {
    }

    static final int BELL_VIBRATE = 1;
    static final int BELL_BEEP = 2;
    static final int BELL_IGNORE = 3;

    private final int MIN_FONTSIZE;
    private static final int MAX_FONTSIZE = 256;

    private static final String FULLSCREEN_KEY = "fullscreen";
    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 SHOW_WELCOME_DIALOG_KEY = "intro_dialog";

    private boolean mFullScreen;
    private int mFontSize;

    @AsciiBellBehaviour
    int mBellBehaviour = BELL_VIBRATE;

    boolean mBackIsEscape;
    boolean mShowExtraKeys;

    TermuxPreferences(Context context) {
        reloadFromProperties(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);

        mFullScreen = prefs.getBoolean(FULLSCREEN_KEY, false);
        mShowExtraKeys = prefs.getBoolean(SHOW_EXTRA_KEYS_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 = Math.max(MIN_FONTSIZE, Math.min(mFontSize, MAX_FONTSIZE));
    }

    boolean isFullScreen() {
        return mFullScreen;
    }

    void setFullScreen(Context context, boolean newValue) {
        mFullScreen = newValue;
        PreferenceManager.getDefaultSharedPreferences(context).edit().putBoolean(FULLSCREEN_KEY, newValue).apply();
    }

    boolean isShowExtraKeys() {
        return mShowExtraKeys;
    }

    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();
    }

    static void storeCurrentSession(Context context, TerminalSession session) {
        PreferenceManager.getDefaultSharedPreferences(context).edit().putString(TermuxPreferences.CURRENT_SESSION_KEY, session.mHandle).commit();
    }

    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;
    }

    public static boolean isShowWelcomeDialog(Context context) {
        return PreferenceManager.getDefaultSharedPreferences(context).getBoolean(SHOW_WELCOME_DIALOG_KEY, true);
    }

    public static void disableWelcomeDialog(Context context) {
        PreferenceManager.getDefaultSharedPreferences(context).edit().putBoolean(SHOW_WELCOME_DIALOG_KEY, false).apply();
    }

    public void reloadFromProperties(Context context) {
        try {
            File propsFile = new File(TermuxService.HOME_PATH + "/.termux/termux.properties");
            if (!propsFile.exists())
                propsFile = new File(TermuxService.HOME_PATH + "/.config/termux/termux.properties");

            Properties props = new Properties();
            if (propsFile.isFile() && propsFile.canRead()) {
                try (FileInputStream in = new FileInputStream(propsFile)) {
                    props.load(in);
                }
            }

            switch (props.getProperty("bell-character", "vibrate")) {
                case "beep":
                    mBellBehaviour = BELL_BEEP;
                    break;
                case "ignore":
                    mBellBehaviour = BELL_IGNORE;
                    break;
                default: // "vibrate".
                    mBellBehaviour = BELL_VIBRATE;
                    break;
            }

            mBackIsEscape = "escape".equals(props.getProperty("back-key", "back"));

            shortcuts.clear();
            parseAction("shortcut.create-session", SHORTCUT_ACTION_CREATE_SESSION, props);
            parseAction("shortcut.next-session", SHORTCUT_ACTION_NEXT_SESSION, props);
            parseAction("shortcut.previous-session", SHORTCUT_ACTION_PREVIOUS_SESSION, props);
            parseAction("shortcut.rename-session", SHORTCUT_ACTION_RENAME_SESSION, props);
        } catch (Exception e) {
            Toast.makeText(context, "Error loading properties: " + e.getMessage(), Toast.LENGTH_LONG).show();
            Log.e("termux", "Error loading props", e);
        }
    }

    public static final int SHORTCUT_ACTION_CREATE_SESSION = 1;
    public static final int SHORTCUT_ACTION_NEXT_SESSION = 2;
    public static final int SHORTCUT_ACTION_PREVIOUS_SESSION = 3;
    public static final int SHORTCUT_ACTION_RENAME_SESSION = 4;

    public final static class KeyboardShortcut {

        public KeyboardShortcut(int codePoint, int shortcutAction) {
            this.codePoint = codePoint;
            this.shortcutAction = shortcutAction;
        }

        final int codePoint;
        final int shortcutAction;
    }

    final List<KeyboardShortcut> shortcuts = new ArrayList<>();

    private void parseAction(String name, int shortcutAction, Properties props) {
        String value = props.getProperty(name);
        if (value == null) return;
        String[] parts = value.toLowerCase().trim().split("\\+");
        String input = parts.length == 2 ? parts[1].trim() : null;
        if (!(parts.length == 2 && parts[0].trim().equals("ctrl")) || input.isEmpty() || input.length() > 2) {
            Log.e("termux", "Keyboard shortcut '" + name + "' is not Ctrl+<something>");
            return;
        }

        char c = input.charAt(0);
        int codePoint = c;
        if (Character.isLowSurrogate(c)) {
            if (input.length() != 2 || Character.isHighSurrogate(input.charAt(1))) {
                Log.e("termux", "Keyboard shortcut '" + name + "' is not Ctrl+<something>");
                return;
            } else {
                codePoint = Character.toCodePoint(input.charAt(1), c);
            }
        }
        shortcuts.add(new KeyboardShortcut(codePoint, shortcutAction));
    }

}