From 02f50bf6ce2fe3cf2c67838810b3c653bdc07c08 Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Sun, 2 Apr 2023 11:24:27 +0530
Subject: [PATCH] Use both a colored border and an icon to indicate errors in
 line edits. Fixes #2007764 [Enhancement Request: Valid/invalid metadata
 display options](https://bugs.launchpad.net/calibre/+bug/2007764)

---
 src/calibre/gui2/search_box.py | 12 ++++++++----
 src/calibre/gui2/widgets.py    | 10 ++++++++++
 2 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/src/calibre/gui2/search_box.py b/src/calibre/gui2/search_box.py
index b2c148f49c..4f1fd86d0a 100644
--- a/src/calibre/gui2/search_box.py
+++ b/src/calibre/gui2/search_box.py
@@ -15,6 +15,7 @@ from qt.core import (
     QIcon, QApplication, QKeyEvent)
 
 from calibre.gui2 import config, question_dialog, gprefs, QT_HIDDEN_CLEAR_ACTION
+from calibre.gui2.widgets import stylesheet_for_lineedit
 from calibre.gui2.dialogs.saved_search_editor import SavedSearchEditor
 from calibre.gui2.dialogs.search import SearchDialog
 from calibre.utils.icu import primary_sort_key
@@ -174,7 +175,7 @@ class SearchBox2(QComboBox):  # {{{
 
     def normalize_state(self):
         self.setToolTip(self.tool_tip_text)
-        self.line_edit.setStyleSheet('')
+        self.setStyleSheet('')
         self.show_parse_error_action(False)
 
     def text(self):
@@ -194,11 +195,9 @@ class SearchBox2(QComboBox):  # {{{
         self.setFocus(Qt.FocusReason.OtherFocusReason)
 
     def show_parse_error_action(self, to_show, tooltip=''):
-        try:
+        if self.parse_error_action is not None:
             self.parse_error_action.setVisible(to_show)
             self.parse_error_action.setToolTip(tooltip)
-        except Exception:
-            pass
 
     def search_done(self, ok):
         if isinstance(ok, string_or_bytes):
@@ -206,9 +205,14 @@ class SearchBox2(QComboBox):  # {{{
             self.show_parse_error_action(True, tooltip=ok)
             ok = False
         if not str(self.currentText()).strip():
+            self.setStyleSheet('')
             self.clear(emit_search=False)
             return
         self._in_a_search = ok
+        if self.parse_error_action is not None and not ok:
+            self.setStyleSheet(stylesheet_for_lineedit(bool(ok), 'QComboBox'))
+        else:
+            self.setStyleSheet('')
 
     # Comes from the lineEdit control
     def key_pressed(self, event):
diff --git a/src/calibre/gui2/widgets.py b/src/calibre/gui2/widgets.py
index aff4faf2df..e3242feec5 100644
--- a/src/calibre/gui2/widgets.py
+++ b/src/calibre/gui2/widgets.py
@@ -555,6 +555,14 @@ def setup_status_actions(self: QLineEdit):
     self.status_actions[0].setVisible(False)
     self.status_actions[1].setVisible(False)
 
+
+def stylesheet_for_lineedit(ok, selector='QLineEdit') -> str:
+    if ok is None:
+        return ''
+    col = '#50c878' if ok else '#FF2400'
+    return f'{selector} {{ border: 2px solid {col}; border-radius: 3px }}'
+
+
 def update_status_actions(self: QLineEdit, ok, tooltip: str = ''):
     self.status_actions[0].setVisible(bool(ok))
     self.status_actions[1].setVisible(not ok)
@@ -564,6 +572,8 @@ def update_status_actions(self: QLineEdit, ok, tooltip: str = ''):
         self.status_actions[1].setVisible(False)
     else:
         self.status_actions[1].setToolTip(tooltip)
+    self.setStyleSheet(stylesheet_for_lineedit(ok))
+
 
 class LineEditIndicators: