Move terminal io related classed to com.termux.app.terminal.io package

app/src/main/java/com/termux/app/settings/properties/TermuxSharedProperties.java

@@ -5,8 +5,8 @@ import android.content.res.Configuration;
 
 import androidx.annotation.Nullable;
 
-import com.termux.app.terminal.extrakeys.ExtraKeysInfo;
+import com.termux.app.terminal.io.extrakeys.ExtraKeysInfo;
-import com.termux.app.terminal.KeyboardShortcut;
+import com.termux.app.terminal.io.KeyboardShortcut;
 import com.termux.app.utils.Logger;
 
 import org.json.JSONException;

app/src/main/java/com/termux/app/terminal/io/BellHandler.java

@@ -0,0 +1,63 @@
+package com.termux.app.terminal.io;
+
+import android.content.Context;
+import android.os.Handler;
+import android.os.Looper;
+import android.os.SystemClock;
+import android.os.Vibrator;
+
+public class BellHandler {
+    private static BellHandler instance = null;
+    private static final Object lock = new Object();
+
+    public static BellHandler getInstance(Context context) {
+        if (instance == null) {
+            synchronized (lock) {
+                if (instance == null) {
+                    instance = new BellHandler((Vibrator) context.getApplicationContext().getSystemService(Context.VIBRATOR_SERVICE));
+                }
+            }
+        }
+
+        return instance;
+    }
+
+    private static final long DURATION = 50;
+    private static final long MIN_PAUSE = 3 * DURATION;
+
+    private final Handler handler = new Handler(Looper.getMainLooper());
+    private long lastBell = 0;
+    private final Runnable bellRunnable;
+
+    private BellHandler(final Vibrator vibrator) {
+        bellRunnable = new Runnable() {
+            @Override
+            public void run() {
+                if (vibrator != null) {
+                    vibrator.vibrate(DURATION);
+                }
+            }
+        };
+    }
+
+    public synchronized void doBell() {
+        long now = now();
+        long timeSinceLastBell = now - lastBell;
+
+        if (timeSinceLastBell < 0) {
+            // there is a next bell pending; don't schedule another one
+        } else if (timeSinceLastBell < MIN_PAUSE) {
+            // there was a bell recently, scheudle the next one
+            handler.postDelayed(bellRunnable, MIN_PAUSE - timeSinceLastBell);
+            lastBell = lastBell + MIN_PAUSE;
+        } else {
+            // the last bell was long ago, do it now
+            bellRunnable.run();
+            lastBell = now;
+        }
+    }
+
+    private long now() {
+        return SystemClock.uptimeMillis();
+    }
+}

app/src/main/java/com/termux/app/terminal/io/FullScreenWorkAround.java

@@ -0,0 +1,68 @@
+package com.termux.app.terminal.io;
+
+import android.graphics.Rect;
+import android.view.View;
+import android.view.ViewGroup;
+
+import com.termux.app.TermuxActivity;
+
+/**
+ * Work around for fullscreen mode in Termux to fix ExtraKeysView not being visible.
+ * This class is derived from:
+ * https://stackoverflow.com/questions/7417123/android-how-to-adjust-layout-in-full-screen-mode-when-softkeyboard-is-visible
+ * and has some additional tweaks
+ * ---
+ * For more information, see https://issuetracker.google.com/issues/36911528
+ */
+public class FullScreenWorkAround {
+    private final View mChildOfContent;
+    private int mUsableHeightPrevious;
+    private final ViewGroup.LayoutParams mViewGroupLayoutParams;
+
+    private final int mNavBarHeight;
+
+
+    public static void apply(TermuxActivity activity) {
+        new FullScreenWorkAround(activity);
+    }
+
+    private FullScreenWorkAround(TermuxActivity activity) {
+        ViewGroup content = activity.findViewById(android.R.id.content);
+        mChildOfContent = content.getChildAt(0);
+        mViewGroupLayoutParams = mChildOfContent.getLayoutParams();
+        mNavBarHeight = activity.getNavBarHeight();
+        mChildOfContent.getViewTreeObserver().addOnGlobalLayoutListener(this::possiblyResizeChildOfContent);
+    }
+
+    private void possiblyResizeChildOfContent() {
+        int usableHeightNow = computeUsableHeight();
+        if (usableHeightNow != mUsableHeightPrevious) {
+            int usableHeightSansKeyboard = mChildOfContent.getRootView().getHeight();
+            int heightDifference = usableHeightSansKeyboard - usableHeightNow;
+            if (heightDifference > (usableHeightSansKeyboard / 4)) {
+                // keyboard probably just became visible
+
+                // ensures that usable layout space does not extend behind the
+                // soft keyboard, causing the extra keys to not be visible
+                mViewGroupLayoutParams.height = (usableHeightSansKeyboard - heightDifference) + getNavBarHeight();
+            } else {
+                // keyboard probably just became hidden
+                mViewGroupLayoutParams.height = usableHeightSansKeyboard;
+            }
+            mChildOfContent.requestLayout();
+            mUsableHeightPrevious = usableHeightNow;
+        }
+    }
+
+    private int getNavBarHeight() {
+        return mNavBarHeight;
+    }
+
+    private int computeUsableHeight() {
+        Rect r = new Rect();
+        mChildOfContent.getWindowVisibleDisplayFrame(r);
+        return (r.bottom - r.top);
+    }
+
+}
+

app/src/main/java/com/termux/app/terminal/io/KeyboardShortcut.java

@@ -0,0 +1,13 @@
+package com.termux.app.terminal.io;
+
+public class KeyboardShortcut {
+
+    public final int codePoint;
+    public final int shortcutAction;
+
+    public KeyboardShortcut(int codePoint, int shortcutAction) {
+        this.codePoint = codePoint;
+        this.shortcutAction = shortcutAction;
+    }
+
+}

app/src/main/java/com/termux/app/terminal/io/extrakeys/ExtraKeyButton.java

@@ -0,0 +1,92 @@
+package com.termux.app.terminal.io.extrakeys;
+
+import android.text.TextUtils;
+
+import androidx.annotation.Nullable;
+
+import org.json.JSONException;
+import org.json.JSONObject;
+
+import java.util.Arrays;
+import java.util.stream.Collectors;
+
+public class ExtraKeyButton {
+
+    /**
+     * The key that will be sent to the terminal, either a control character
+     * defined in ExtraKeysView.keyCodesForString (LEFT, RIGHT, PGUP...) or
+     * some text.
+     */
+    private final String key;
+
+    /**
+     * If the key is a macro, i.e. a sequence of keys separated by space.
+     */
+    private final boolean macro;
+
+    /**
+     * The text that will be shown on the button.
+     */
+    private final String display;
+
+    /**
+     * The information of the popup (triggered by swipe up).
+     */
+    @Nullable
+    private ExtraKeyButton popup = null;
+
+    public ExtraKeyButton(ExtraKeysInfo.CharDisplayMap charDisplayMap, JSONObject config) throws JSONException {
+        this(charDisplayMap, config, null);
+    }
+
+    public ExtraKeyButton(ExtraKeysInfo.CharDisplayMap charDisplayMap, JSONObject config, @Nullable ExtraKeyButton popup) throws JSONException {
+        String keyFromConfig = config.optString("key", null);
+        String macroFromConfig = config.optString("macro", null);
+        String[] keys;
+        if (keyFromConfig != null && macroFromConfig != null) {
+            throw new JSONException("Both key and macro can't be set for the same key");
+        } else if (keyFromConfig != null) {
+            keys = new String[]{keyFromConfig};
+            this.macro = false;
+        } else if (macroFromConfig != null) {
+            keys = macroFromConfig.split(" ");
+            this.macro = true;
+        } else {
+            throw new JSONException("All keys have to specify either key or macro");
+        }
+
+        for (int i = 0; i < keys.length; i++) {
+            keys[i] = ExtraKeysInfo.replaceAlias(keys[i]);
+        }
+
+        this.key = TextUtils.join(" ", keys);
+
+        String displayFromConfig = config.optString("display", null);
+        if (displayFromConfig != null) {
+            this.display = displayFromConfig;
+        } else {
+            this.display = Arrays.stream(keys)
+                .map(key -> charDisplayMap.get(key, key))
+                .collect(Collectors.joining(" "));
+        }
+
+        this.popup = popup;
+    }
+
+    public String getKey() {
+        return key;
+    }
+
+    public boolean isMacro() {
+        return macro;
+    }
+
+    public String getDisplay() {
+        return display;
+    }
+
+    @Nullable
+    public ExtraKeyButton getPopup() {
+        return popup;
+    }
+}

app/src/main/java/com/termux/app/terminal/io/extrakeys/ExtraKeysInfo.java

@@ -0,0 +1,253 @@
+package com.termux.app.terminal.io.extrakeys;
+
+import org.json.JSONArray;
+import org.json.JSONException;
+import org.json.JSONObject;
+
+import java.util.HashMap;
+
+public class ExtraKeysInfo {
+
+    /**
+     * Matrix of buttons displayed
+     */
+    private final ExtraKeyButton[][] buttons;
+
+    /**
+     * This corresponds to one of the CharMapDisplay below
+     */
+    private String style = "default";
+
+    public ExtraKeysInfo(String propertiesInfo, String style) throws JSONException {
+        this.style = style;
+
+        // Convert String propertiesInfo to Array of Arrays
+        JSONArray arr = new JSONArray(propertiesInfo);
+        Object[][] matrix = new Object[arr.length()][];
+        for (int i = 0; i < arr.length(); i++) {
+            JSONArray line = arr.getJSONArray(i);
+            matrix[i] = new Object[line.length()];
+            for (int j = 0; j < line.length(); j++) {
+                matrix[i][j] = line.get(j);
+            }
+        }
+
+        // convert matrix to buttons
+        this.buttons = new ExtraKeyButton[matrix.length][];
+        for (int i = 0; i < matrix.length; i++) {
+            this.buttons[i] = new ExtraKeyButton[matrix[i].length];
+            for (int j = 0; j < matrix[i].length; j++) {
+                Object key = matrix[i][j];
+
+                JSONObject jobject = normalizeKeyConfig(key);
+
+                ExtraKeyButton button;
+
+                if(! jobject.has("popup")) {
+                    // no popup
+                    button = new ExtraKeyButton(getSelectedCharMap(), jobject);
+                } else {
+                    // a popup
+                    JSONObject popupJobject = normalizeKeyConfig(jobject.get("popup"));
+                    ExtraKeyButton popup = new ExtraKeyButton(getSelectedCharMap(), popupJobject);
+                    button = new ExtraKeyButton(getSelectedCharMap(), jobject, popup);
+                }
+
+                this.buttons[i][j] = button;
+            }
+        }
+    }
+
+    /**
+     * "hello" -> {"key": "hello"}
+     */
+    private static JSONObject normalizeKeyConfig(Object key) throws JSONException {
+        JSONObject jobject;
+        if(key instanceof String) {
+            jobject = new JSONObject();
+            jobject.put("key", key);
+        } else if(key instanceof JSONObject) {
+            jobject = (JSONObject) key;
+        } else {
+            throw new JSONException("An key in the extra-key matrix must be a string or an object");
+        }
+        return jobject;
+    }
+
+    public ExtraKeyButton[][] getMatrix() {
+        return buttons;
+    }
+
+    /**
+     * HashMap that implements Python dict.get(key, default) function.
+     * Default java.util .get(key) is then the same as .get(key, null);
+     */
+    static class CleverMap<K,V> extends HashMap<K,V> {
+        V get(K key, V defaultValue) {
+            if(containsKey(key))
+                return get(key);
+            else
+                return defaultValue;
+        }
+    }
+
+    static class CharDisplayMap extends CleverMap<String, String> {}
+
+    /**
+     * Keys are displayed in a natural looking way, like "→" for "RIGHT"
+     */
+    static final CharDisplayMap classicArrowsDisplay = new CharDisplayMap() {{
+        // classic arrow keys (for ◀ ▶ ▲ ▼ @see arrowVariationDisplay)
+        put("LEFT", "←"); // U+2190 ← LEFTWARDS ARROW
+        put("RIGHT", "→"); // U+2192 → RIGHTWARDS ARROW
+        put("UP", "↑"); // U+2191 ↑ UPWARDS ARROW
+        put("DOWN", "↓"); // U+2193 ↓ DOWNWARDS ARROW
+    }};
+
+    static final CharDisplayMap wellKnownCharactersDisplay = new CharDisplayMap() {{
+        // well known characters // https://en.wikipedia.org/wiki/{Enter_key, Tab_key, Delete_key}
+        put("ENTER", "↲"); // U+21B2 ↲ DOWNWARDS ARROW WITH TIP LEFTWARDS
+        put("TAB", "↹"); // U+21B9 ↹ LEFTWARDS ARROW TO BAR OVER RIGHTWARDS ARROW TO BAR
+        put("BKSP", "⌫"); // U+232B ⌫ ERASE TO THE LEFT sometimes seen and easy to understand
+        put("DEL", "⌦"); // U+2326 ⌦ ERASE TO THE RIGHT not well known but easy to understand
+        put("DRAWER", "☰"); // U+2630 ☰ TRIGRAM FOR HEAVEN not well known but easy to understand
+        put("KEYBOARD", "⌨"); // U+2328 ⌨ KEYBOARD not well known but easy to understand
+    }};
+
+    static final CharDisplayMap lessKnownCharactersDisplay = new CharDisplayMap() {{
+        // https://en.wikipedia.org/wiki/{Home_key, End_key, Page_Up_and_Page_Down_keys}
+        // home key can mean "goto the beginning of line" or "goto first page" depending on context, hence the diagonal
+        put("HOME", "⇱"); // from IEC 9995 // U+21F1 ⇱ NORTH WEST ARROW TO CORNER
+        put("END", "⇲"); // from IEC 9995 // ⇲ // U+21F2 ⇲ SOUTH EAST ARROW TO CORNER
+        put("PGUP", "⇑"); // no ISO character exists, U+21D1 ⇑ UPWARDS DOUBLE ARROW will do the trick
+        put("PGDN", "⇓"); // no ISO character exists, U+21D3 ⇓ DOWNWARDS DOUBLE ARROW will do the trick
+    }};
+
+    static final CharDisplayMap arrowTriangleVariationDisplay = new CharDisplayMap() {{
+        // alternative to classic arrow keys
+        put("LEFT", "◀"); // U+25C0 ◀ BLACK LEFT-POINTING TRIANGLE
+        put("RIGHT", "▶"); // U+25B6 ▶ BLACK RIGHT-POINTING TRIANGLE
+        put("UP", "▲"); // U+25B2 ▲ BLACK UP-POINTING TRIANGLE
+        put("DOWN", "▼"); // U+25BC ▼ BLACK DOWN-POINTING TRIANGLE
+    }};
+
+    static final CharDisplayMap notKnownIsoCharacters = new CharDisplayMap() {{
+        // Control chars that are more clear as text // https://en.wikipedia.org/wiki/{Function_key, Alt_key, Control_key, Esc_key}
+        // put("FN", "FN"); // no ISO character exists
+        put("CTRL", "⎈"); // ISO character "U+2388 ⎈ HELM SYMBOL" is unknown to people and never printed on computers, however "U+25C7 ◇ WHITE DIAMOND" is a nice presentation, and "^" for terminal app and mac is often used
+        put("ALT", "⎇"); // ISO character "U+2387 ⎇ ALTERNATIVE KEY SYMBOL'" is unknown to people and only printed as the Option key "⌥" on Mac computer
+        put("ESC", "⎋"); // ISO character "U+238B ⎋ BROKEN CIRCLE WITH NORTHWEST ARROW" is unknown to people and not often printed on computers
+    }};
+
+    static final CharDisplayMap nicerLookingDisplay = new CharDisplayMap() {{
+        // nicer looking for most cases
+        put("-", "―"); // U+2015 ― HORIZONTAL BAR
+    }};
+
+    /*
+     * Multiple maps are available to quickly change
+     * the style of the keys.
+     */
+
+    /**
+     * Some classic symbols everybody knows
+     */
+    private static final CharDisplayMap defaultCharDisplay = new CharDisplayMap() {{
+        putAll(classicArrowsDisplay);
+        putAll(wellKnownCharactersDisplay);
+        putAll(nicerLookingDisplay);
+        // all other characters are displayed as themselves
+    }};
+
+    /**
+     * Classic symbols and less known symbols
+     */
+    private static final CharDisplayMap lotsOfArrowsCharDisplay = new CharDisplayMap() {{
+        putAll(classicArrowsDisplay);
+        putAll(wellKnownCharactersDisplay);
+        putAll(lessKnownCharactersDisplay); // NEW
+        putAll(nicerLookingDisplay);
+    }};
+
+    /**
+     * Only arrows
+     */
+    private static final CharDisplayMap arrowsOnlyCharDisplay = new CharDisplayMap() {{
+        putAll(classicArrowsDisplay);
+        // putAll(wellKnownCharactersDisplay); // REMOVED
+        // putAll(lessKnownCharactersDisplay); // REMOVED
+        putAll(nicerLookingDisplay);
+    }};
+
+    /**
+     * Full Iso
+     */
+    private static final CharDisplayMap fullIsoCharDisplay = new CharDisplayMap() {{
+        putAll(classicArrowsDisplay);
+        putAll(wellKnownCharactersDisplay);
+        putAll(lessKnownCharactersDisplay); // NEW
+        putAll(nicerLookingDisplay);
+        putAll(notKnownIsoCharacters); // NEW
+    }};
+
+    /**
+     * Some people might call our keys differently
+     */
+    static private final CharDisplayMap controlCharsAliases = new CharDisplayMap() {{
+        put("ESCAPE", "ESC");
+        put("CONTROL", "CTRL");
+        put("RETURN", "ENTER"); // Technically different keys, but most applications won't see the difference
+        put("FUNCTION", "FN");
+        // no alias for ALT
+
+        // Directions are sometimes written as first and last letter for brevety
+        put("LT", "LEFT");
+        put("RT", "RIGHT");
+        put("DN", "DOWN");
+        // put("UP", "UP"); well, "UP" is already two letters
+
+        put("PAGEUP", "PGUP");
+        put("PAGE_UP", "PGUP");
+        put("PAGE UP", "PGUP");
+        put("PAGE-UP", "PGUP");
+
+        // no alias for HOME
+        // no alias for END
+
+        put("PAGEDOWN", "PGDN");
+        put("PAGE_DOWN", "PGDN");
+        put("PAGE-DOWN", "PGDN");
+
+        put("DELETE", "DEL");
+        put("BACKSPACE", "BKSP");
+
+        // easier for writing in termux.properties
+        put("BACKSLASH", "\\");
+        put("QUOTE", "\"");
+        put("APOSTROPHE", "'");
+    }};
+
+    CharDisplayMap getSelectedCharMap() {
+        switch (style) {
+            case "arrows-only":
+                return arrowsOnlyCharDisplay;
+            case "arrows-all":
+                return lotsOfArrowsCharDisplay;
+            case "all":
+                return fullIsoCharDisplay;
+            case "none":
+                return new CharDisplayMap();
+            default:
+                return defaultCharDisplay;
+        }
+    }
+
+    /**
+     * Applies the 'controlCharsAliases' mapping to all the strings in *buttons*
+     * Modifies the array, doesn't return a new one.
+     */
+    public static String replaceAlias(String key) {
+        return controlCharsAliases.get(key, key);
+    }
+}
+

app/src/main/java/com/termux/app/terminal/io/extrakeys/ExtraKeysView.java

@@ -0,0 +1,382 @@
+package com.termux.app.terminal.io.extrakeys;
+
+import android.annotation.SuppressLint;
+import android.content.Context;
+import android.os.Build;
+import android.provider.Settings;
+import android.util.AttributeSet;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Set;
+import java.util.concurrent.Executors;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.ScheduledExecutorService;
+
+import java.util.Map;
+import java.util.HashMap;
+import java.util.Arrays;
+import java.util.stream.Collectors;
+
+import android.view.Gravity;
+import android.view.HapticFeedbackConstants;
+import android.view.KeyEvent;
+import android.view.MotionEvent;
+import android.view.View;
+import android.view.inputmethod.InputMethodManager;
+import android.widget.Button;
+import android.widget.GridLayout;
+import android.widget.PopupWindow;
+
+import com.termux.R;
+import com.termux.view.TerminalView;
+
+import androidx.drawerlayout.widget.DrawerLayout;
+
+/**
+ * A view showing extra keys (such as Escape, Ctrl, Alt) not normally available on an Android soft
+ * keyboard.
+ */
+public final class ExtraKeysView extends GridLayout {
+
+    private static final int TEXT_COLOR = 0xFFFFFFFF;
+    private static final int BUTTON_COLOR = 0x00000000;
+    private static final int INTERESTING_COLOR = 0xFF80DEEA;
+    private static final int BUTTON_PRESSED_COLOR = 0xFF7F7F7F;
+
+    public ExtraKeysView(Context context, AttributeSet attrs) {
+        super(context, attrs);
+    }
+
+    static final Map<String, Integer> keyCodesForString = new HashMap<String, Integer>() {{
+        put("SPACE", KeyEvent.KEYCODE_SPACE);
+        put("ESC", KeyEvent.KEYCODE_ESCAPE);
+        put("TAB", KeyEvent.KEYCODE_TAB);
+        put("HOME", KeyEvent.KEYCODE_MOVE_HOME);
+        put("END", KeyEvent.KEYCODE_MOVE_END);
+        put("PGUP", KeyEvent.KEYCODE_PAGE_UP);
+        put("PGDN", KeyEvent.KEYCODE_PAGE_DOWN);
+        put("INS", KeyEvent.KEYCODE_INSERT);
+        put("DEL", KeyEvent.KEYCODE_FORWARD_DEL);
+        put("BKSP", KeyEvent.KEYCODE_DEL);
+        put("UP", KeyEvent.KEYCODE_DPAD_UP);
+        put("LEFT", KeyEvent.KEYCODE_DPAD_LEFT);
+        put("RIGHT", KeyEvent.KEYCODE_DPAD_RIGHT);
+        put("DOWN", KeyEvent.KEYCODE_DPAD_DOWN);
+        put("ENTER", KeyEvent.KEYCODE_ENTER);
+        put("F1", KeyEvent.KEYCODE_F1);
+        put("F2", KeyEvent.KEYCODE_F2);
+        put("F3", KeyEvent.KEYCODE_F3);
+        put("F4", KeyEvent.KEYCODE_F4);
+        put("F5", KeyEvent.KEYCODE_F5);
+        put("F6", KeyEvent.KEYCODE_F6);
+        put("F7", KeyEvent.KEYCODE_F7);
+        put("F8", KeyEvent.KEYCODE_F8);
+        put("F9", KeyEvent.KEYCODE_F9);
+        put("F10", KeyEvent.KEYCODE_F10);
+        put("F11", KeyEvent.KEYCODE_F11);
+        put("F12", KeyEvent.KEYCODE_F12);
+    }};
+
+    @SuppressLint("RtlHardcoded")
+    private void sendKey(View view, String keyName, boolean forceCtrlDown, boolean forceLeftAltDown) {
+        TerminalView terminalView = view.findViewById(R.id.terminal_view);
+        if ("KEYBOARD".equals(keyName)) {
+            InputMethodManager imm = (InputMethodManager) getContext().getSystemService(Context.INPUT_METHOD_SERVICE);
+            imm.toggleSoftInput(0, 0);
+        } else if ("DRAWER".equals(keyName)) {
+            DrawerLayout drawer = view.findViewById(R.id.drawer_layout);
+            drawer.openDrawer(Gravity.LEFT);
+        } else if (keyCodesForString.containsKey(keyName)) {
+            Integer keyCode = keyCodesForString.get(keyName);
+            if (keyCode == null) return;
+            int metaState = 0;
+            if (forceCtrlDown) {
+                metaState |= KeyEvent.META_CTRL_ON | KeyEvent.META_CTRL_LEFT_ON;
+            }
+            if (forceLeftAltDown) {
+                metaState |= KeyEvent.META_ALT_ON | KeyEvent.META_ALT_LEFT_ON;
+            }
+            KeyEvent keyEvent = new KeyEvent(0, 0, KeyEvent.ACTION_UP, keyCode, 0, metaState);
+            terminalView.onKeyDown(keyCode, keyEvent);
+        } else {
+            // not a control char
+            keyName.codePoints().forEach(codePoint -> {
+                terminalView.inputCodePoint(codePoint, forceCtrlDown, forceLeftAltDown);
+            });
+        }
+    }
+
+    private void sendKey(View view, ExtraKeyButton buttonInfo) {
+        if (buttonInfo.isMacro()) {
+            String[] keys = buttonInfo.getKey().split(" ");
+            boolean ctrlDown = false;
+            boolean altDown = false;
+            for (String key : keys) {
+                if ("CTRL".equals(key)) {
+                    ctrlDown = true;
+                } else if ("ALT".equals(key)) {
+                    altDown = true;
+                } else {
+                    sendKey(view, key, ctrlDown, altDown);
+                    ctrlDown = false;
+                    altDown = false;
+                }
+            }
+        } else {
+            sendKey(view, buttonInfo.getKey(), false, false);
+        }
+    }
+
+    public enum SpecialButton {
+        CTRL, ALT, FN
+    }
+
+    private static class SpecialButtonState {
+        boolean isOn = false;
+        boolean isActive = false;
+        List<Button> buttons = new ArrayList<>();
+
+        void setIsActive(boolean value) {
+            isActive = value;
+            buttons.forEach(button -> button.setTextColor(value ? INTERESTING_COLOR : TEXT_COLOR));
+        }
+    }
+
+    private final Map<SpecialButton, SpecialButtonState> specialButtons = new HashMap<SpecialButton, SpecialButtonState>() {{
+        put(SpecialButton.CTRL, new SpecialButtonState());
+        put(SpecialButton.ALT, new SpecialButtonState());
+        put(SpecialButton.FN, new SpecialButtonState());
+    }};
+
+    private final Set<String> specialButtonsKeys = specialButtons.keySet().stream().map(Enum::name).collect(Collectors.toSet());
+
+    private boolean isSpecialButton(ExtraKeyButton button) {
+        return specialButtonsKeys.contains(button.getKey());
+    }
+
+    private ScheduledExecutorService scheduledExecutor;
+    private PopupWindow popupWindow;
+    private int longPressCount;
+
+    public boolean readSpecialButton(SpecialButton name) {
+        SpecialButtonState state = specialButtons.get(name);
+        if (state == null)
+            throw new RuntimeException("Must be a valid special button (see source)");
+
+        if (!state.isOn || !state.isActive)
+            return false;
+
+        state.setIsActive(false);
+
+        return true;
+    }
+
+    private Button createSpecialButton(String buttonKey, boolean needUpdate) {
+        SpecialButtonState state = specialButtons.get(SpecialButton.valueOf(buttonKey));
+        if (state == null) return null;
+        state.isOn = true;
+        Button button = new Button(getContext(), null, android.R.attr.buttonBarButtonStyle);
+        button.setTextColor(state.isActive ? INTERESTING_COLOR : TEXT_COLOR);
+        if (needUpdate) {
+            state.buttons.add(button);
+        }
+        return button;
+    }
+
+    void popup(View view, ExtraKeyButton extraButton) {
+        int width = view.getMeasuredWidth();
+        int height = view.getMeasuredHeight();
+        Button button;
+        if(isSpecialButton(extraButton)) {
+            button = createSpecialButton(extraButton.getKey(), false);
+            if (button == null) return;
+        } else {
+            button = new Button(getContext(), null, android.R.attr.buttonBarButtonStyle);
+            button.setTextColor(TEXT_COLOR);
+        }
+        button.setText(extraButton.getDisplay());
+        button.setPadding(0, 0, 0, 0);
+        button.setMinHeight(0);
+        button.setMinWidth(0);
+        button.setMinimumWidth(0);
+        button.setMinimumHeight(0);
+        button.setWidth(width);
+        button.setHeight(height);
+        button.setBackgroundColor(BUTTON_PRESSED_COLOR);
+        popupWindow = new PopupWindow(this);
+        popupWindow.setWidth(LayoutParams.WRAP_CONTENT);
+        popupWindow.setHeight(LayoutParams.WRAP_CONTENT);
+        popupWindow.setContentView(button);
+        popupWindow.setOutsideTouchable(true);
+        popupWindow.setFocusable(false);
+        popupWindow.showAsDropDown(view, 0, -2 * height);
+    }
+
+    /**
+     * General util function to compute the longest column length in a matrix.
+     */
+    static int maximumLength(Object[][] matrix) {
+        int m = 0;
+        for (Object[] row : matrix)
+            m = Math.max(m, row.length);
+        return m;
+    }
+
+    /**
+     * Reload the view given parameters in termux.properties
+     *
+     * @param infos matrix as defined in termux.properties extrakeys
+     * Can Contain The Strings CTRL ALT TAB FN ENTER LEFT RIGHT UP DOWN or normal strings
+     * Some aliases are possible like RETURN for ENTER, LT for LEFT and more (@see controlCharsAliases for the whole list).
+     * Any string of length > 1 in total Uppercase will print a warning
+     *
+     * Examples:
+     * "ENTER" will trigger the ENTER keycode
+     * "LEFT" will trigger the LEFT keycode and be displayed as "←"
+     * "→" will input a "→" character
+     * "−" will input a "−" character
+     * "-_-" will input the string "-_-"
+     */
+    @SuppressLint("ClickableViewAccessibility")
+    public void reload(ExtraKeysInfo infos) {
+        if(infos == null)
+            return;
+
+        for(SpecialButtonState state : specialButtons.values())
+            state.buttons = new ArrayList<>();
+
+        removeAllViews();
+
+        ExtraKeyButton[][] buttons = infos.getMatrix();
+
+        setRowCount(buttons.length);
+        setColumnCount(maximumLength(buttons));
+
+        for (int row = 0; row < buttons.length; row++) {
+            for (int col = 0; col < buttons[row].length; col++) {
+                final ExtraKeyButton buttonInfo = buttons[row][col];
+
+                Button button;
+                if(isSpecialButton(buttonInfo)) {
+                    button = createSpecialButton(buttonInfo.getKey(), true);
+                    if (button == null) return;
+                } else {
+                    button = new Button(getContext(), null, android.R.attr.buttonBarButtonStyle);
+                }
+
+                button.setText(buttonInfo.getDisplay());
+                button.setTextColor(TEXT_COLOR);
+                button.setPadding(0, 0, 0, 0);
+
+                final Button finalButton = button;
+                button.setOnClickListener(v -> {
+                    if (Settings.System.getInt(getContext().getContentResolver(),
+                        Settings.System.HAPTIC_FEEDBACK_ENABLED, 0) != 0) {
+
+                        if (Build.VERSION.SDK_INT >= 28) {
+                            finalButton.performHapticFeedback(HapticFeedbackConstants.KEYBOARD_TAP);
+                        } else {
+                            // Perform haptic feedback only if no total silence mode enabled.
+                            if (Settings.Global.getInt(getContext().getContentResolver(), "zen_mode", 0) != 2) {
+                                finalButton.performHapticFeedback(HapticFeedbackConstants.KEYBOARD_TAP);
+                            }
+                        }
+                    }
+
+                    View root = getRootView();
+                    if (isSpecialButton(buttonInfo)) {
+                        SpecialButtonState state = specialButtons.get(SpecialButton.valueOf(buttonInfo.getKey()));
+                        if (state == null) return;
+                        state.setIsActive(!state.isActive);
+                    } else {
+                        sendKey(root, buttonInfo);
+                    }
+                });
+
+                button.setOnTouchListener((v, event) -> {
+                    final View root = getRootView();
+                    switch (event.getAction()) {
+                        case MotionEvent.ACTION_DOWN:
+                            longPressCount = 0;
+                            v.setBackgroundColor(BUTTON_PRESSED_COLOR);
+                            if (Arrays.asList("UP", "DOWN", "LEFT", "RIGHT", "BKSP", "DEL").contains(buttonInfo.getKey())) {
+                                // autorepeat
+                                scheduledExecutor = Executors.newSingleThreadScheduledExecutor();
+                                scheduledExecutor.scheduleWithFixedDelay(() -> {
+                                    longPressCount++;
+                                    sendKey(root, buttonInfo);
+                                }, 400, 80, TimeUnit.MILLISECONDS);
+                            }
+                            return true;
+
+                        case MotionEvent.ACTION_MOVE:
+                            if (buttonInfo.getPopup() != null) {
+                                if (popupWindow == null && event.getY() < 0) {
+                                    if (scheduledExecutor != null) {
+                                        scheduledExecutor.shutdownNow();
+                                        scheduledExecutor = null;
+                                    }
+                                    v.setBackgroundColor(BUTTON_COLOR);
+                                    popup(v, buttonInfo.getPopup());
+                                }
+                                if (popupWindow != null && event.getY() > 0) {
+                                    v.setBackgroundColor(BUTTON_PRESSED_COLOR);
+                                    popupWindow.dismiss();
+                                    popupWindow = null;
+                                }
+                            }
+                            return true;
+
+                        case MotionEvent.ACTION_CANCEL:
+                            v.setBackgroundColor(BUTTON_COLOR);
+                            if (scheduledExecutor != null) {
+                                scheduledExecutor.shutdownNow();
+                                scheduledExecutor = null;
+                            }
+                            return true;
+                        case MotionEvent.ACTION_UP:
+                            v.setBackgroundColor(BUTTON_COLOR);
+                            if (scheduledExecutor != null) {
+                                scheduledExecutor.shutdownNow();
+                                scheduledExecutor = null;
+                            }
+                            if (longPressCount == 0 || popupWindow != null) {
+                                if (popupWindow != null) {
+                                    popupWindow.setContentView(null);
+                                    popupWindow.dismiss();
+                                    popupWindow = null;
+                                    if (buttonInfo.getPopup() != null) {
+                                        if (isSpecialButton(buttonInfo.getPopup())) {
+                                            SpecialButtonState state = specialButtons.get(SpecialButton.valueOf(buttonInfo.getPopup().getKey()));
+                                            if (state == null) return true;
+                                            state.setIsActive(!state.isActive);
+                                        } else {
+                                            sendKey(root, buttonInfo.getPopup());
+                                        }
+                                    }
+                                } else {
+                                    v.performClick();
+                                }
+                            }
+                            return true;
+
+                        default:
+                            return true;
+                    }
+                });
+
+                LayoutParams param = new GridLayout.LayoutParams();
+                param.width = 0;
+                param.height = 0;
+                param.setMargins(0, 0, 0, 0);
+                param.columnSpec = GridLayout.spec(col, GridLayout.FILL, 1.f);
+                param.rowSpec = GridLayout.spec(row, GridLayout.FILL, 1.f);
+                button.setLayoutParams(param);
+
+                addView(button);
+            }
+        }
+    }
+
+}