propertiesView: Use decoder format

Use the format that we actually used when decoding.
The mime type is usually derived from the file extension
which might not always be correct.

Issue #43

Part-of: <https://gitlab.gnome.org/Incubator/loupe/-/merge_requests/132>

src/decoder/formats/mod.rs

@@ -7,3 +7,29 @@ pub use image_rs_other::ImageRsOther;
 pub use svg::{Svg, RSVG_MAX_SIZE};
 
 use super::{Decoder, UpdateSender};
+
+#[derive(Clone, Copy, Debug)]
+pub enum ImageFormat {
+    ImageRs(image_rs::ImageFormat),
+    // TODO: Add details about contained format
+    Heif,
+    Svg,
+}
+
+impl std::fmt::Display for ImageFormat {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> Result<(), std::fmt::Error> {
+        match self {
+            Self::ImageRs(format) => {
+                let debug = format!("{:?}", format);
+                if debug.len() <= 4 {
+                    // uppercase abbreviations
+                    write!(f, "{}", debug.to_uppercase())
+                } else {
+                    write!(f, "{}", debug)
+                }
+            }
+            Self::Heif => write!(f, "HEIF Container"),
+            Self::Svg => write!(f, "SVG"),
+        }
+    }
+}

src/decoder/mod.rs

@@ -15,25 +15,7 @@ use gtk::graphene;
 use std::io::Read;
 use std::sync::Arc;
 
-pub use formats::RSVG_MAX_SIZE;
-
-#[derive(Clone, Copy, Debug)]
-pub enum ImageFormat {
-    ImageRs(image_rs::ImageFormat),
-    // TODO: Add details about contained format
-    Heif,
-    Svg,
-}
-
-impl std::fmt::Display for ImageFormat {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> Result<(), std::fmt::Error> {
-        match self {
-            Self::ImageRs(format) => write!(f, "{:?}", format),
-            Self::Heif => write!(f, "HEIF"),
-            Self::Svg => write!(f, "SVG"),
-        }
-    }
-}
+pub use formats::{ImageFormat, RSVG_MAX_SIZE};
 
 #[derive(Clone, Copy, Debug)]
 /// Renderer requests new tiles