Optional prefetch with progress bar, post blacklist, theme template link

- Prefetch adjacent posts is now a toggle in Settings > General (off by default)
- Prefetch progress bar on thumbnails shows download state
- Blacklist Post: right-click to hide a specific post by URL
- "Create from Template" opens themes reference on git.pax.moe
  and spawns the default text editor with custom.qss

booru_viewer/core/db.py

@@ -54,6 +54,11 @@ CREATE TABLE IF NOT EXISTS blacklisted_tags (
     tag  TEXT NOT NULL UNIQUE
 );
 
+CREATE TABLE IF NOT EXISTS blacklisted_posts (
+    id   INTEGER PRIMARY KEY AUTOINCREMENT,
+    url  TEXT NOT NULL UNIQUE
+);
+
 CREATE TABLE IF NOT EXISTS settings (
     key   TEXT PRIMARY KEY,
     value TEXT NOT NULL
@@ -384,6 +389,20 @@ class Database:
         rows = self.conn.execute("SELECT tag FROM blacklisted_tags ORDER BY tag").fetchall()
         return [r["tag"] for r in rows]
 
+    # -- Blacklisted Posts --
+
+    def add_blacklisted_post(self, url: str) -> None:
+        self.conn.execute("INSERT OR IGNORE INTO blacklisted_posts (url) VALUES (?)", (url,))
+        self.conn.commit()
+
+    def remove_blacklisted_post(self, url: str) -> None:
+        self.conn.execute("DELETE FROM blacklisted_posts WHERE url = ?", (url,))
+        self.conn.commit()
+
+    def get_blacklisted_posts(self) -> set[str]:
+        rows = self.conn.execute("SELECT url FROM blacklisted_posts").fetchall()
+        return {r["url"] for r in rows}
+
     # -- Settings --
 
     def get_setting(self, key: str) -> str:

booru_viewer/gui/app.py

@@ -84,6 +84,7 @@ class AsyncSignals(QObject):
     batch_progress = Signal(int, int)      # current, total
     batch_done = Signal(str)
     download_progress = Signal(int, int)  # bytes_downloaded, total_bytes
+    prefetch_progress = Signal(int, float)  # index, progress (0-1 or -1 to hide)
 
 
 # -- Info Panel --
@@ -236,6 +237,11 @@ class BooruApp(QMainWindow):
         s.batch_progress.connect(self._on_batch_progress, Q)
         s.batch_done.connect(lambda m: self._status.showMessage(m), Q)
         s.download_progress.connect(self._on_download_progress, Q)
+        s.prefetch_progress.connect(self._on_prefetch_progress, Q)
+
+    def _on_prefetch_progress(self, index: int, progress: float) -> None:
+        if 0 <= index < len(self._grid._thumbs):
+            self._grid._thumbs[index].set_prefetch_progress(progress)
 
     def _clear_loading(self) -> None:
         self._loading = False
@@ -628,6 +634,10 @@ class BooruApp(QMainWindow):
             bl_tags = set(self._db.get_blacklisted_tags())
             if bl_tags:
                 posts = [p for p in posts if not bl_tags.intersection(p.tag_list)]
+        # Filter blacklisted posts by URL
+        bl_posts = self._db.get_blacklisted_posts()
+        if bl_posts:
+            posts = [p for p in posts if p.file_url not in bl_posts]
         self._posts = posts
         self._status.showMessage(f"{len(posts)} results")
         thumbs = self._grid.set_posts(len(posts))
@@ -762,7 +772,8 @@ class BooruApp(QMainWindow):
             self._run_async(_load)
 
             # Prefetch adjacent posts
-            self._prefetch_adjacent(index)
+            if self._db.get_setting_bool("prefetch_adjacent"):
+                self._prefetch_adjacent(index)
 
     def _prefetch_adjacent(self, index: int) -> None:
         """Prefetch posts in all 4 directions (left, right, up, down)."""
@@ -772,10 +783,15 @@ class BooruApp(QMainWindow):
             for offset in offsets:
                 adj = index + offset
                 if 0 <= adj < len(self._posts) and self._posts[adj].file_url:
+                    self._signals.prefetch_progress.emit(adj, 0.0)
                     try:
-                        await download_image(self._posts[adj].file_url)
+                        def _progress(dl, total, idx=adj):
+                            if total > 0:
+                                self._signals.prefetch_progress.emit(idx, dl / total)
+                        await download_image(self._posts[adj].file_url, progress_callback=_progress)
                     except Exception:
                         pass
+                    self._signals.prefetch_progress.emit(adj, -1)
         self._run_async(_prefetch_batch)
 
     def _on_download_progress(self, downloaded: int, total: int) -> None:
@@ -1054,6 +1070,7 @@ class BooruApp(QMainWindow):
         else:
             for tag in post.tag_list[:30]:
                 bl_menu.addAction(tag)
+        bl_post_action = menu.addAction("Blacklist Post")
 
         action = menu.exec(pos)
         if not action:
@@ -1105,6 +1122,10 @@ class BooruApp(QMainWindow):
             self._db.set_setting("blacklist_enabled", "1")
             self._status.showMessage(f"Blacklisted: {tag}")
             self._do_search()
+        elif action == bl_post_action:
+            self._db.add_blacklisted_post(post.file_url)
+            self._status.showMessage(f"Post #{post.id} blacklisted")
+            self._do_search()
 
     @staticmethod
     def _is_child_of_menu(action, menu) -> bool:

booru_viewer/gui/grid.py

@@ -38,6 +38,7 @@ class ThumbnailWidget(QWidget):
         self._hover = False
         self._drag_start: QPoint | None = None
         self._cached_path: str | None = None
+        self._prefetch_progress: float = -1  # -1 = not prefetching, 0-1 = progress
         self.setFixedSize(THUMB_SIZE, THUMB_SIZE)
         self.setCursor(Qt.CursorShape.PointingHandCursor)
         self.setMouseTracking(True)
@@ -66,6 +67,11 @@ class ThumbnailWidget(QWidget):
         self._saved_locally = saved
         self.update()
 
+    def set_prefetch_progress(self, progress: float) -> None:
+        """Set prefetch progress: -1 = hide, 0.0-1.0 = progress."""
+        self._prefetch_progress = progress
+        self.update()
+
     def paintEvent(self, event) -> None:
         # Ensure QSS is applied so palette picks up custom colors
         self.ensurePolished()
@@ -120,6 +126,17 @@ class ThumbnailWidget(QWidget):
             p.drawLine(7, 10, 9, 13)
             p.drawLine(9, 13, 14, 7)
 
+        # Prefetch progress bar
+        if self._prefetch_progress >= 0:
+            bar_h = 3
+            bar_y = self.height() - bar_h - 2
+            bar_w = int((self.width() - 8) * self._prefetch_progress)
+            p.setPen(Qt.PenStyle.NoPen)
+            p.setBrush(QColor(100, 100, 100, 120))
+            p.drawRect(4, bar_y, self.width() - 8, bar_h)
+            p.setBrush(highlight)
+            p.drawRect(4, bar_y, bar_w, bar_h)
+
         p.end()
 
     def enterEvent(self, event) -> None:

booru_viewer/gui/settings.py

@@ -110,6 +110,11 @@ class SettingsDialog(QDialog):
         self._preload.setChecked(self._db.get_setting_bool("preload_thumbnails"))
         form.addRow("", self._preload)
 
+        # Prefetch adjacent posts
+        self._prefetch = QCheckBox("Prefetch adjacent posts for faster navigation")
+        self._prefetch.setChecked(self._db.get_setting_bool("prefetch_adjacent"))
+        form.addRow("", self._prefetch)
+
         # File dialog platform (Linux only)
         self._file_dialog_combo = None
         if not IS_WINDOWS:
@@ -372,37 +377,14 @@ class SettingsDialog(QDialog):
         QDesktopServices.openUrl(QUrl.fromLocalFile(str(css_path)))
 
     def _create_css_template(self) -> None:
+        from PySide6.QtGui import QDesktopServices
+        from PySide6.QtCore import QUrl
+        # Open themes reference online and create a blank custom.qss for editing
+        QDesktopServices.openUrl(QUrl("https://git.pax.moe/pax/booru-viewer/src/branch/main/themes"))
         css_path = data_dir() / "custom.qss"
-        if css_path.exists():
+        if not css_path.exists():
-            reply = QMessageBox.question(
+            css_path.write_text("/* booru-viewer custom stylesheet */\n/* See themes reference for examples */\n\n")
-                self, "Confirm", "Overwrite existing custom.qss with template?",
+        QDesktopServices.openUrl(QUrl.fromLocalFile(str(css_path)))
-                QMessageBox.StandardButton.Yes | QMessageBox.StandardButton.No,
-            )
-            if reply != QMessageBox.StandardButton.Yes:
-                return
-        template = (
-            "/* booru-viewer custom stylesheet */\n"
-            "/* Edit and restart the app to apply changes */\n\n"
-            "/* -- Accent color -- */\n"
-            "/* QWidget { color: #00ff00; } */\n\n"
-            "/* -- Background -- */\n"
-            "/* QWidget { background-color: #000000; } */\n\n"
-            "/* -- Font -- */\n"
-            "/* QWidget { font-family: monospace; font-size: 13px; } */\n\n"
-            "/* -- Buttons -- */\n"
-            "/* QPushButton { padding: 6px 16px; border-radius: 4px; } */\n"
-            "/* QPushButton:hover { border-color: #00ff00; } */\n\n"
-            "/* -- Inputs -- */\n"
-            "/* QLineEdit { padding: 6px 10px; border-radius: 4px; } */\n"
-            "/* QLineEdit:focus { border-color: #00ff00; } */\n\n"
-            "/* -- Scrollbar -- */\n"
-            "/* QScrollBar:vertical { width: 10px; } */\n\n"
-            "/* -- Video seek bar -- */\n"
-            "/* QSlider::groove:horizontal { background: #333; height: 6px; } */\n"
-            "/* QSlider::handle:horizontal { background: #00ff00; width: 14px; } */\n"
-        )
-        css_path.write_text(template)
-        QMessageBox.information(self, "Done", f"Template created at:\n{css_path}")
 
     def _view_css_guide(self) -> None:
         from PySide6.QtGui import QDesktopServices
@@ -611,6 +593,7 @@ class SettingsDialog(QDialog):
         self._db.set_setting("default_rating", self._default_rating.currentText())
         self._db.set_setting("default_score", str(self._default_score.value()))
         self._db.set_setting("preload_thumbnails", "1" if self._preload.isChecked() else "0")
+        self._db.set_setting("prefetch_adjacent", "1" if self._prefetch.isChecked() else "0")
         self._db.set_setting("max_cache_mb", str(self._max_cache.value()))
         self._db.set_setting("auto_evict", "1" if self._auto_evict.isChecked() else "0")
         self._db.set_setting("clear_cache_on_exit", "1" if self._clear_on_exit.isChecked() else "0")