improved library screen, fixed issues with image rendering and navigation

tests/test_library_interaction.py

@@ -7,6 +7,7 @@ and verify that tap detection works correctly.
 
 import unittest
 from pathlib import Path
+from unittest.mock import MagicMock
 from dreader import LibraryManager
 
 
@@ -46,9 +47,12 @@ class TestLibraryInteraction(unittest.TestCase):
         # Table should exist
         self.assertIsNotNone(table)
 
-        # Table should have body rows matching book count
+        # Table should have body rows for 2-column grid layout
+        # Each pair of books gets 2 rows (cover row + detail row)
+        # So N books = ceil(N/2) * 2 rows
         body_rows = list(table.body_rows())
-        self.assertEqual(len(body_rows), len(books))
+        expected_rows = ((len(books) + 1) // 2) * 2  # Round up to nearest even number, then double
+        self.assertEqual(len(body_rows), expected_rows)
 
     def test_library_rendering(self):
         """Test that library can be rendered to image"""
@@ -136,7 +140,7 @@ class TestLibraryInteraction(unittest.TestCase):
         self.assertIsNone(selected_path, "Tap below last book should not select anything")
 
     def test_multiple_taps(self):
-        """Test that multiple taps work correctly"""
+        """Test that multiple taps work correctly with 2-column grid layout"""
         books = self.library.scan_library()
 
         if len(books) < 3:
@@ -145,16 +149,20 @@ class TestLibraryInteraction(unittest.TestCase):
         self.library.create_library_table()
         self.library.render_library()
 
-        # Tap first book (row 0: y=60-180)
+        # In 2-column layout:
+        # Books 0 and 1 are in the first pair (rows 0-1: cover and detail)
+        # Books 2 and 3 are in the second pair (rows 2-3: cover and detail)
+
+        # Tap first book (left column, first pair cover row)
         path1 = self.library.handle_library_tap(x=100, y=100)
         self.assertEqual(path1, books[0]['path'])
 
-        # Tap second book (row 1: y=181-301)
-        path2 = self.library.handle_library_tap(x=400, y=250)
+        # Tap second book (right column, first pair cover row)
+        path2 = self.library.handle_library_tap(x=500, y=100)
         self.assertEqual(path2, books[1]['path'])
 
-        # Tap third book (row 2: y=302-422)
-        path3 = self.library.handle_library_tap(x=400, y=360)
+        # Tap third book (left column, second pair cover row)
+        path3 = self.library.handle_library_tap(x=100, y=360)
         self.assertEqual(path3, books[2]['path'])
 
         # All should be different
@@ -162,6 +170,79 @@ class TestLibraryInteraction(unittest.TestCase):
         self.assertNotEqual(path2, path3)
         self.assertNotEqual(path1, path3)
 
+    def test_pagination(self):
+        """Test library pagination with fake book data"""
+        # Create fake books (20 books to ensure multiple pages)
+        fake_books = []
+        for i in range(20):
+            fake_books.append({
+                'path': f'/fake/path/book_{i}.epub',
+                'title': f'Book Title {i}',
+                'author': f'Author {i}',
+                'filename': f'book_{i}.epub',
+                'cover_data': None,
+                'cover_path': None
+            })
+
+        # Create library with 6 books per page
+        library = LibraryManager(
+            library_path=str(self.library_path),
+            page_size=(800, 1200),
+            books_per_page=6
+        )
+        library.books = fake_books
+
+        # Test initial state
+        self.assertEqual(library.current_page, 0)
+        self.assertEqual(library.get_total_pages(), 4)  # 20 books / 6 per page = 4 pages
+
+        # Test creating table for first page
+        table = library.create_library_table()
+        self.assertIsNotNone(table)
+        # 6 books = 3 pairs = 6 rows (3 cover rows + 3 detail rows)
+        body_rows = list(table.body_rows())
+        self.assertEqual(len(body_rows), 6)
+
+        # Test navigation to next page
+        self.assertTrue(library.next_page())
+        self.assertEqual(library.current_page, 1)
+
+        # Create table for second page
+        table = library.create_library_table()
+        body_rows = list(table.body_rows())
+        self.assertEqual(len(body_rows), 6)  # Still 6 books on page 2
+
+        # Test navigation to last page
+        library.set_page(3)
+        self.assertEqual(library.current_page, 3)
+        table = library.create_library_table()
+        body_rows = list(table.body_rows())
+        # Page 4 has 2 books (20 - 18 = 2) = 1 pair = 2 rows
+        self.assertEqual(len(body_rows), 2)
+
+        # Test can't go beyond last page
+        self.assertFalse(library.next_page())
+        self.assertEqual(library.current_page, 3)
+
+        # Test navigation to previous page
+        self.assertTrue(library.previous_page())
+        self.assertEqual(library.current_page, 2)
+
+        # Test navigation to first page
+        library.set_page(0)
+        self.assertEqual(library.current_page, 0)
+
+        # Test can't go before first page
+        self.assertFalse(library.previous_page())
+        self.assertEqual(library.current_page, 0)
+
+        # Test invalid page number
+        self.assertFalse(library.set_page(-1))
+        self.assertFalse(library.set_page(100))
+        self.assertEqual(library.current_page, 0)  # Should stay on current page
+
+        library.cleanup()
+
 
 if __name__ == '__main__':
     unittest.main()