recode group- and user-avatar to 192x192 pixel

src/blob.rs

@@ -6,9 +6,13 @@ use std::fs;
 use std::io::Write;
 use std::path::{Path, PathBuf};
 
+use self::image::GenericImageView;
+use crate::constants::AVATAR_SIZE;
 use crate::context::Context;
 use crate::events::Event;
 
+extern crate image;
+
 /// Represents a file in the blob directory.
 ///
 /// The object has a name, which will always be valid UTF-8.  Having a
@@ -349,6 +353,31 @@ impl<'a> BlobObject<'a> {
         }
         true
     }
+
+    pub fn recode_to_avatar_size(&self, context: &Context) -> Result<(), BlobError> {
+        let blob_abs = self.to_abs_path();
+        let img = image::open(&blob_abs).map_err(|err| BlobError::RecodeFailure {
+            blobdir: context.get_blobdir().to_path_buf(),
+            blobname: blob_abs.to_str().unwrap_or_default().to_string(),
+            cause: err,
+            backtrace: failure::Backtrace::new(),
+        })?;
+
+        if img.width() <= AVATAR_SIZE && img.height() <= AVATAR_SIZE {
+            return Ok(());
+        }
+
+        let img = img.thumbnail(AVATAR_SIZE, AVATAR_SIZE);
+
+        img.save(&blob_abs).map_err(|err| BlobError::WriteFailure {
+            blobdir: context.get_blobdir().to_path_buf(),
+            blobname: blob_abs.to_str().unwrap_or_default().to_string(),
+            cause: err,
+            backtrace: failure::Backtrace::new(),
+        })?;
+
+        Ok(())
+    }
 }
 
 impl<'a> fmt::Display for BlobObject<'a> {
@@ -382,6 +411,13 @@ pub enum BlobError {
         cause: std::io::Error,
         backtrace: failure::Backtrace,
     },
+    RecodeFailure {
+        blobdir: PathBuf,
+        blobname: String,
+        #[cause]
+        cause: image::ImageError,
+        backtrace: failure::Backtrace,
+    },
     WrongBlobdir {
         blobdir: PathBuf,
         src: PathBuf,
@@ -429,6 +465,9 @@ impl fmt::Display for BlobError {
                 blobname,
                 blobdir.display(),
             ),
+            BlobError::RecodeFailure {
+                blobdir, blobname, ..
+            } => write!(f, "Failed to recode {} in {}", blobname, blobdir.display(),),
             BlobError::WrongBlobdir { blobdir, src, .. } => write!(
                 f,
                 "File path {} is not in blobdir {}",

src/chat.rs

@@ -1883,6 +1883,7 @@ pub fn set_chat_profile_image(
                 _ => Err(err),
             },
         )?;
+        image_blob.recode_to_avatar_size(context)?;
         chat.param.set(Param::ProfileImage, image_blob.as_name());
         msg.param.set(Param::Arg, image_blob.as_name());
         msg.text = Some(context.stock_system_msg(

src/config.rs

@@ -136,6 +136,7 @@ impl Context {
                 match value {
                     Some(value) => {
                         let blob = BlobObject::new_from_path(&self, value)?;
+                        blob.recode_to_avatar_size(self)?;
                         self.sql.set_raw_config(self, key, Some(blob.as_name()))
                     }
                     None => self.sql.set_raw_config(self, key, None),

src/constants.rs

@@ -184,6 +184,9 @@ pub const DC_VC_CONTACT_CONFIRM: i32 = 6;
 pub const DC_BOB_ERROR: i32 = 0;
 pub const DC_BOB_SUCCESS: i32 = 1;
 
+// max. width/height of an avatar
+pub const AVATAR_SIZE: u32 = 192;
+
 #[derive(Debug, Display, Clone, Copy, PartialEq, Eq, FromPrimitive, ToPrimitive, FromSql, ToSql)]
 #[repr(i32)]
 pub enum Viewtype {