Allow users to disable terminal margin adjustment

The user can add `disable-terminal-margin-adjustment=true` entry to `termux.properties` file to disable terminal view margin adjustment that is done to prevent soft keyboard from covering bottom part of terminal view on some devices. Margin adjustment may cause screen flickering on some devices and so should be disabled. The default value is `false`. So adding the entry `disable-terminal-margin-adjustment=true` to `termux.properties` file will disable margin adjustment. Exit termux and restart for changes to take affect after updating value.

In case e5a9b99 did not fix screen flickering issues for #2127, then this can be used to disable it. Closes #2127.

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

@@ -259,7 +259,8 @@ public void onStart() {
         if (mTermuxTerminalViewClient != null)
             mTermuxTerminalViewClient.onStart();
 
-        addTermuxActivityRootViewGlobalLayoutListener();
+        if (!mProperties.isTerminalMarginAdjustmentDisabled())
+            addTermuxActivityRootViewGlobalLayoutListener();
 
         registerTermuxActivityBroadcastReceiver();
     }

termux-shared/src/main/java/com/termux/shared/settings/properties/TermuxPropertyConstants.java

@@ -72,6 +72,13 @@ public final class TermuxPropertyConstants {
 
     /* boolean */
 
+    /** Defines the key for whether terminal view margin adjustment that is done to prevent soft
+     * keyboard from covering bottom part of terminal view on some devices is disabled or not.
+     * Margin adjustment may cause screen flickering on some devices and so should be disabled. */
+    public static final String KEY_DISABLE_TERMINAL_MARGIN_ADJUSTMENT =  "disable-terminal-margin-adjustment"; // Default: "disable-terminal-margin-adjustment"
+
+
+
     /** Defines the key for whether a toast will be shown when user changes the terminal session */
     public static final String KEY_DISABLE_TERMINAL_SESSION_CHANGE_TOAST =  "disable-terminal-session-change-toast"; // Default: "disable-terminal-session-change-toast"
 
@@ -290,6 +297,7 @@ public final class TermuxPropertyConstants {
      * */
     public static final Set<String> TERMUX_PROPERTIES_LIST = new HashSet<>(Arrays.asList(
         /* boolean */
+        KEY_DISABLE_TERMINAL_MARGIN_ADJUSTMENT,
         KEY_DISABLE_TERMINAL_SESSION_CHANGE_TOAST,
         KEY_ENFORCE_CHAR_BASED_INPUT,
         KEY_HIDE_SOFT_KEYBOARD_ON_STARTUP,
@@ -329,6 +337,7 @@ public final class TermuxPropertyConstants {
      * default: false
      * */
     public static final Set<String> TERMUX_DEFAULT_BOOLEAN_BEHAVIOUR_PROPERTIES_LIST = new HashSet<>(Arrays.asList(
+        KEY_DISABLE_TERMINAL_MARGIN_ADJUSTMENT,
         KEY_DISABLE_TERMINAL_SESSION_CHANGE_TOAST,
         KEY_ENFORCE_CHAR_BASED_INPUT,
         KEY_HIDE_SOFT_KEYBOARD_ON_STARTUP,

termux-shared/src/main/java/com/termux/shared/settings/properties/TermuxSharedProperties.java

@@ -460,6 +460,10 @@ public static String getVolumeKeysBehaviourInternalPropertyValueFromValue(String
 
 
 
+    public boolean isTerminalMarginAdjustmentDisabled() {
+        return (boolean) getInternalPropertyValue(TermuxPropertyConstants.KEY_DISABLE_TERMINAL_MARGIN_ADJUSTMENT, true);
+    }
+
     public boolean areTerminalSessionChangeToastsDisabled() {
         return (boolean) getInternalPropertyValue(TermuxPropertyConstants.KEY_DISABLE_TERMINAL_SESSION_CHANGE_TOAST, true);
     }