Keep changes on switching from/to signature HTML

app/src/main/java/eu/faircode/email/ActivitySignature.java

@@ -26,9 +26,11 @@ import android.content.Intent;
 import android.graphics.drawable.Drawable;
 import android.net.Uri;
 import android.os.Bundle;
+import android.text.Editable;
 import android.text.Html;
 import android.text.SpannableStringBuilder;
 import android.text.Spanned;
+import android.text.TextWatcher;
 import android.text.style.ImageSpan;
 import android.view.LayoutInflater;
 import android.view.Menu;
@@ -53,6 +55,7 @@ public class ActivitySignature extends ActivityBase {
     private BottomNavigationView bottom_navigation;
 
     private boolean raw = false;
+    private boolean dirty = false;
 
     private static final int REQUEST_IMAGE = 1;
 
@@ -77,6 +80,23 @@ public class ActivitySignature extends ActivityBase {
             }
         });
 
+        etText.addTextChangedListener(new TextWatcher() {
+            @Override
+            public void beforeTextChanged(CharSequence s, int start, int count, int after) {
+                // Do nothing
+            }
+
+            @Override
+            public void onTextChanged(CharSequence s, int start, int before, int count) {
+                dirty = true;
+            }
+
+            @Override
+            public void afterTextChanged(Editable s) {
+                // Do nothing
+            }
+        });
+
         style_bar.setOnNavigationItemSelectedListener(new BottomNavigationView.OnNavigationItemSelectedListener() {
             @Override
             public boolean onNavigationItemSelected(@NonNull MenuItem item) {
@@ -136,8 +156,7 @@ public class ActivitySignature extends ActivityBase {
         switch (item.getItemId()) {
             case R.id.menu_edit_html:
                 item.setChecked(!item.isChecked());
-                raw = item.isChecked();
-                load();
+                html(item.isChecked());
                 return true;
             default:
                 return super.onOptionsItemSelected(item);
@@ -173,6 +192,7 @@ public class ActivitySignature extends ActivityBase {
                     return getDrawableByUri(ActivitySignature.this, Uri.parse(source));
                 }
             }, null));
+        dirty = false;
     }
 
     private void delete() {
@@ -191,6 +211,17 @@ public class ActivitySignature extends ActivityBase {
         finish();
     }
 
+    private void html(boolean raw) {
+        this.raw = raw;
+
+        if (!raw || dirty) {
+            String html = (raw ? HtmlHelper.toHtml(etText.getText()) : etText.getText().toString());
+            getIntent().putExtra("html", html);
+        }
+
+        load();
+    }
+
     private void insertImage() {
         Intent intent = new Intent(Intent.ACTION_OPEN_DOCUMENT);
         intent.addCategory(Intent.CATEGORY_OPENABLE);