add support of configurable extra keys

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

@@ -33,8 +33,6 @@ public final class ExtraKeysView extends GridLayout {
 
     public ExtraKeysView(Context context, AttributeSet attrs) {
         super(context, attrs);
-
-        reload();
     }
 
     static void sendKey(View view, String keyName) {
@@ -148,24 +146,24 @@ public final class ExtraKeysView extends GridLayout {
         popupWindow.showAsDropDown(view, 0, -2 * height);
     }
 
-    void reload() {
+    void reload(final String[][] buttons) {
         altButton = controlButton = null;
         removeAllViews();
 
-        String[][] buttons = {
+        int mx = 0;
-            {"ESC", "/", "―", "HOME", "↑", "END", "PGUP"},
+        for (int row = 0; row < rows; row++) {
-            {"TAB", "CTRL", "ALT", "←", "↓", "→", "PGDN"}
+            if(buttons[row].length > mx) mx = buttons[row].length;
-        };
+        }
-
         final int rows = buttons.length;
-        final int[] cols = {buttons[0].length, buttons[1].length};
+        final int cols = mx;
 
         setRowCount(rows);
         setColumnCount(cols[0]);
 
         for (int row = 0; row < rows; row++) {
-            for (int col = 0; col < cols[row]; col++) {
+            for (int col = 0; col < cols; col++) {
-                final String buttonText = buttons[row][col];
+                final String buttonText = (buttons[row][col] == null ? " " : buttons[row][col]);
+
                 Button button;
                 switch (buttonText) {
                     case "CTRL":

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

@@ -218,6 +218,11 @@ public final class TermuxActivity extends Activity implements ServiceConnection
         final ViewPager viewPager = findViewById(R.id.viewpager);
         if (mSettings.isShowExtraKeys()) viewPager.setVisibility(View.VISIBLE);
         
+        
+        ViewGroup.LayoutParams layoutParams = viewPager.getLayoutParams();
+        layoutParams.height = layoutParams.height * mSettings.mExtraKeys.length;
+        viewPager.setLayoutParams(layoutParams);
+
         viewPager.setAdapter(new PagerAdapter() {
             @Override
             public int getCount() {
@@ -236,6 +241,7 @@ public final class TermuxActivity extends Activity implements ServiceConnection
                 View layout;
                 if (position == 0) {
                     layout = mExtraKeysView = (ExtraKeysView) inflater.inflate(R.layout.extra_keys_main, collection, false);
+                    mExtraKeysView.reload(mSettings.mExtraKeys);
                 } else {
                     layout = inflater.inflate(R.layout.extra_keys_right, collection, false);
                     final EditText editText = layout.findViewById(R.id.text_input);

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

@@ -17,6 +17,7 @@ import java.lang.annotation.RetentionPolicy;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Properties;
+import org.json.JSONArray;
 
 final class TermuxPreferences {
 
@@ -104,6 +105,8 @@ final class TermuxPreferences {
         return null;
     }
     
+    public String[][] mExtraKeys;
+
     public void reloadFromProperties(Context context) {
         try {
             File propsFile = new File(TermuxService.HOME_PATH + "/.termux/termux.properties");
@@ -129,6 +132,16 @@ final class TermuxPreferences {
                     break;
             }
             
+            JSONArray arr = new JSONArray(props.getProperty("extrakeys", "[[\"ESC\",\"CTRL\",\"ALT\",\"TAB\",\"―\",\"/\",\"|\"]]"));
+            mExtraKeys = new String[arr.length()][];
+            for(int i = 0; i < arr.length(); i++) {
+                JSONArray line = arr.getJSONArray(i);
+                mExtraKeys[i] = new String[line.length()];
+                for(int j = 0; j < line.length(); j++) {
+                    mExtraKeys[i][j] = line.getString(j);
+                }
+            }
+
             mBackIsEscape = "escape".equals(props.getProperty("back-key", "back"));
 
             shortcuts.clear();