image: Reorganize into several sub-modules

src/widgets/image/drag.rs

@@ -0,0 +1,57 @@
+// Copyright (c) 2023 Sophie Herold
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+use super::*;
+
+impl LpImage {
+    /// Drag and drop content provider
+    pub fn content_provider(&self) -> Option<gdk::ContentProvider> {
+        let file = self.file()?;
+        let list = gdk::FileList::from_array(&[file]);
+        Some(gdk::ContentProvider::for_value(&list.to_value()))
+    }
+
+    /// Returns a thumbnail of the displated image
+    pub fn thumbnail(&self) -> Option<gdk::Paintable> {
+        let (width, height) = self.image_size();
+        let long_side = i32::max(width, height);
+        let orientation = self.metadata().orientation();
+
+        let scale = f32::min(1., THUMBNAIL_SIZE / long_side as f32);
+        let render_options = tiling::RenderOptions {
+            scaling_filter: gsk::ScalingFilter::Trilinear,
+            scale_factor: self.scale_factor(),
+            background_color: Some(self.background_color()),
+        };
+
+        let snapshot = gtk::Snapshot::new();
+
+        self.snapshot_rotate_mirror(
+            &snapshot,
+            -orientation.rotation as f32,
+            orientation.mirrored,
+            scale as f64,
+        );
+
+        self.imp()
+            .frame_buffer
+            .load()
+            .add_to_snapshot(&snapshot, scale as f64, &render_options);
+
+        snapshot.to_paintable(None)
+    }
+}