Allow users to adjust terminal transcript rows with termux.properties

This `terminal-transcript-rows` key can be used to adjust the terminal transcript rows. The user can set an integer value between `100` and `50000`. The default value is still `2000`. So adding an entry like `terminal-transcript-rows=10000` to `termux.properties` file will allow users to scroll back ~10000 lines of command output. After updating the value, termux must be restarted. You can also run `termux-reload-settings` command so that termux loads the updated value, but only new sessions will use the updated value, existing sessions will not be affected.

You can test this with the following, where `70` is number of `x` characters per line and `10001` is the number of lines to print.
`x="$(printf 'x%.0s' {1..70})"; for i in {1..10001}; do echo "$i:$x"; done`

Be advised that using large values may have a performance impact depending on your device capabilities, so use at your own risk.

Closes #2071

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

@@ -846,6 +846,9 @@ public final class TermuxActivity extends Activity implements ServiceConnection
         if (mTermuxTerminalViewClient != null)
             mTermuxTerminalViewClient.onReload();
 
+        if (mTermuxService != null)
+            mTermuxService.setTerminalTranscriptRows();
+
         // To change the activity and drawer theme, activity needs to be recreated.
         // But this will destroy the activity, and will call the onCreate() again.
         // We need to investigate if enabling this is wise, since all stored variables and

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

@@ -20,6 +20,7 @@ import android.provider.Settings;
 import android.widget.ArrayAdapter;
 
 import com.termux.R;
+import com.termux.app.settings.properties.TermuxAppSharedProperties;
 import com.termux.app.terminal.TermuxTerminalSessionClient;
 import com.termux.app.utils.PluginUtils;
 import com.termux.shared.termux.TermuxConstants;
@@ -106,6 +107,8 @@ public final class TermuxService extends Service implements TermuxTask.TermuxTas
     /** If the user has executed the {@link TERMUX_SERVICE#ACTION_STOP_SERVICE} intent. */
     boolean mWantsToStop = false;
 
+    public Integer mTerminalTranscriptRows;
+
     private static final String LOG_TAG = "TermuxService";
 
     @Override
@@ -503,6 +506,7 @@ public final class TermuxService extends Service implements TermuxTask.TermuxTas
         // If the execution command was started for a plugin, only then will the stdout be set
         // Otherwise if command was manually started by the user like by adding a new terminal session,
         // then no need to set stdout
+        executionCommand.terminalTranscriptRows = getTerminalTranscriptRows();
         TermuxSession newTermuxSession = TermuxSession.execute(this, executionCommand, getTermuxTerminalSessionClient(), this, sessionName, executionCommand.isPluginExecutionCommand);
         if (newTermuxSession == null) {
             Logger.logError(LOG_TAG, "Failed to execute new TermuxSession command for:\n" + executionCommand.getCommandIdAndLabelLogString());
@@ -560,6 +564,19 @@ public final class TermuxService extends Service implements TermuxTask.TermuxTas
         updateNotification();
     }
 
+    /** Get the terminal transcript rows to be used for new {@link TermuxSession}. */
+    public Integer getTerminalTranscriptRows() {
+        if (mTerminalTranscriptRows == null)
+            setTerminalTranscriptRows();
+        return mTerminalTranscriptRows;
+    }
+
+    public void setTerminalTranscriptRows() {
+        // TermuxService only uses this termux property currently, so no need to load them all into
+        // an internal values map like TermuxActivity does
+        mTerminalTranscriptRows = TermuxAppSharedProperties.getTerminalTranscriptRows(this);
+    }
+
 
 
 

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

@@ -5,7 +5,6 @@ import android.content.Context;
 import com.termux.app.terminal.io.KeyboardShortcut;
 import com.termux.app.terminal.io.extrakeys.ExtraKeysInfo;
 import com.termux.shared.logger.Logger;
-import com.termux.shared.settings.properties.SharedPropertiesParser;
 import com.termux.shared.settings.properties.TermuxPropertyConstants;
 import com.termux.shared.settings.properties.TermuxSharedProperties;
 
@@ -17,7 +16,7 @@ import java.util.Map;
 
 import javax.annotation.Nonnull;
 
-public class TermuxAppSharedProperties extends TermuxSharedProperties implements SharedPropertiesParser {
+public class TermuxAppSharedProperties extends TermuxSharedProperties {
 
     private ExtraKeysInfo mExtraKeysInfo;
     private List<KeyboardShortcut> mSessionShortcuts = new ArrayList<>();
@@ -96,4 +95,13 @@ public class TermuxAppSharedProperties extends TermuxSharedProperties implements
         return mExtraKeysInfo;
     }
 
+
+
+    /**
+     * Load the {@link TermuxPropertyConstants#KEY_TERMINAL_TRANSCRIPT_ROWS} value from termux properties file on disk.
+     */
+    public static int getTerminalTranscriptRows(Context context) {
+        return  (int) TermuxSharedProperties.getInternalPropertyValue(context, TermuxPropertyConstants.KEY_TERMINAL_TRANSCRIPT_ROWS);
+    }
+
 }