Fix issue where terminal cursor blinking would not automatically start again if termux activity was restarted after exiting it with double back press

app/src/main/java/com/termux/app/terminal/TermuxTerminalViewClient.java

@@ -60,6 +60,8 @@ public class TermuxTerminalViewClient extends TermuxTerminalViewClientBase {
     private boolean mShowSoftKeyboardIgnoreOnce;
     private boolean mShowSoftKeyboardWithDelayOnce;
 
+    private boolean mTerminalCursorBlinkerStateAlreadySet;
+
     private static final String LOG_TAG = "TermuxTerminalViewClient";
 
     public TermuxTerminalViewClient(TermuxActivity activity, TermuxTerminalSessionClient termuxTerminalSessionClient) {
@@ -95,8 +97,7 @@ public class TermuxTerminalViewClient extends TermuxTerminalViewClientBase {
         // Show the soft keyboard if required
         setSoftKeyboardState(true, false);
 
-        // Start terminal cursor blinking if enabled
-        setTerminalCursorBlinkerState(true);
+        mTerminalCursorBlinkerStateAlreadySet = false;
     }
 
     /**
@@ -118,6 +119,23 @@ public class TermuxTerminalViewClient extends TermuxTerminalViewClientBase {
         setTerminalCursorBlinkerState(true);
     }
 
+    /**
+     * Should be called when {@link com.termux.view.TerminalView#mEmulator}
+     */
+    @Override
+    public void onEmulatorSet() {
+        if (!mTerminalCursorBlinkerStateAlreadySet) {
+            // Start terminal cursor blinking if enabled
+            // We need to wait for the first session to be attached that's set in
+            // TermuxActivity.onServiceConnected() and then the multiple calls to TerminalView.updateSize()
+            // where the final one eventually sets the mEmulator when width/height is not 0. Otherwise
+            // blinker will not start again if TermuxActivity is started again after exiting it with
+            // double back press. Check TerminalView.setTerminalCursorBlinkerState().
+            setTerminalCursorBlinkerState(true);
+            mTerminalCursorBlinkerStateAlreadySet = true;
+        }
+    }
+
 
 
     @Override

terminal-emulator/src/main/java/com/termux/terminal/TerminalEmulator.java

@@ -322,6 +322,7 @@ public final class TerminalEmulator {
     public void updateTerminalSessionClient(TerminalSessionClient client) {
         mClient = client;
         setCursorStyle();
+        setCursorBlinkState(true);
     }
 
     public TerminalBuffer getScreen() {

terminal-view/src/main/java/com/termux/view/TerminalView.java

@@ -755,6 +755,7 @@ public final class TerminalView extends View {
         if (mEmulator == null || (newColumns != mEmulator.mColumns || newRows != mEmulator.mRows)) {
             mTermSession.updateSize(newColumns, newRows);
             mEmulator = mTermSession.getEmulator();
+            mClient.onEmulatorSet();
 
             mTopRow = 0;
             scrollTo(0, 0);
@@ -880,7 +881,13 @@ public final class TerminalView extends View {
      * {@link #TERMINAL_CURSOR_BLINK_RATE_MIN} and {@link #TERMINAL_CURSOR_BLINK_RATE_MAX}.
      *
      * This should be called when the view holding this activity is resumed or stopped so that
-     * cursor blinker does not run when activity is not visible.
+     * cursor blinker does not run when activity is not visible. Ensure that {@link #mEmulator}
+     * is set when you call this to start cursor blinking by waiting for {@link TerminalViewClient#onEmulatorSet()}
+     * event after calling {@link #attachSession(TerminalSession)} for the first session added in the
+     * activity, otherwise blinking will not start. Do not call this directly after
+     * {@link #attachSession(TerminalSession)} since {@link #updateSize()} may return without
+     * setting {@link #mEmulator} since width/height may be 0. Its called again in
+     * {@link #onSizeChanged(int, int, int, int)}.
      *
      * It should also be called on the
      * {@link com.termux.terminal.TerminalSessionClient#onTerminalCursorStateChange(boolean)}

terminal-view/src/main/java/com/termux/view/TerminalViewClient.java

@@ -56,6 +56,8 @@ public interface TerminalViewClient {
     boolean onCodePoint(int codePoint, boolean ctrlDown, TerminalSession session);
 
 
+    void onEmulatorSet();
+
 
     void logError(String tag, String message);
 

termux-shared/src/main/java/com/termux/shared/terminal/TermuxTerminalViewClientBase.java

@@ -67,6 +67,11 @@ public class TermuxTerminalViewClientBase implements TerminalViewClient {
         return false;
     }
 
+    @Override
+    public void onEmulatorSet() {
+
+    }
+
     @Override
     public void logError(String tag, String message) {
         Logger.logError(tag, message);