Use thumbnails for big images

matrix-api.c

@@ -846,6 +846,48 @@ MatrixApiRequestData *matrix_api_download_file(MatrixConnectionData *conn,
     return fetch_data;
 }
 
+/**
+ * Download a thumbnail for a file
+ * @param uri       URI string in the form mxc://example.com/unique
+ */
+MatrixApiRequestData *matrix_api_download_thumb(MatrixConnectionData *conn,
+        const gchar *uri,
+        gsize max_size,
+        unsigned int width, unsigned int height, gboolean scale,
+        MatrixApiCallback callback,
+        MatrixApiErrorCallback error_callback,
+        MatrixApiBadResponseCallback bad_response_callback,
+        gpointer user_data)
+{
+    GString *url;
+    MatrixApiRequestData *fetch_data;
+    char tmp[64];
+
+    /* Sanity check the uri - TODO: Add more sanity */
+    if (strncmp(uri, "mxc://", 6)) {
+        error_callback(conn, user_data, "bad media uri");
+        return NULL;
+    }
+    url = g_string_new(conn->homeserver);
+    g_string_append(url, "_matrix/media/r0/thumbnail/");
+    g_string_append(url, uri + 6); /* i.e. after the mxc:// */
+    sprintf(tmp, "?width=%u", width);
+    g_string_append(url, tmp);
+    sprintf(tmp, "&height=%u", height);
+    g_string_append(url, tmp);
+    g_string_append(url, scale ? "&method=scale": "&method=crop");
+
+    /* I'd like to validate the headers etc a bit before downloading the
+     * data (maybe using _handle_header_completed), also I'm not convinced
+     * purple always does sane things on over-size.
+     */
+    fetch_data = matrix_api_start(url->str, "GET", NULL, conn, callback,
+            error_callback, bad_response_callback, user_data, max_size);
+    g_string_free(url, TRUE);
+
+    return fetch_data;
+}
+
 #if 0
 MatrixApiRequestData *matrix_api_get_room_state(MatrixConnectionData *conn,
         const gchar *room_id,

matrix-api.h

@@ -277,6 +277,34 @@ MatrixApiRequestData *matrix_api_download_file(MatrixConnectionData *conn,
         MatrixApiBadResponseCallback bad_response_callback,
         gpointer user_data);
 
+/**
+ * Download a thumbnail for a file
+ *
+ * @param conn             The connection with which to make the request
+ * @param uri              The Matrix uri to fetch starting mxc://
+ * @param max_size         A maximum size of file to receive.
+ * @param width            Desired width; the server might not obey
+ * @param height           Desired height; the server might not obey
+ * @param scale            True to scale, false to crop
+ * @param callback         Function to be called when the request completes
+ * @param error_callback   Function to be called if there is an error making
+ *                             the request. If NULL, matrix_api_error will be
+ *                             used.
+ * @param bad_response_callback Function to be called if the API gives a non-200
+ *                            response. If NULL, matrix_api_bad_response will be
+ *                            used.
+ * @param user_data        Opaque data to be passed to the callbacks
+ *
+ */
+MatrixApiRequestData *matrix_api_download_thumb(MatrixConnectionData *conn,
+        const gchar *uri,
+        gsize max_size,
+        unsigned int width, unsigned int height, gboolean scale,
+        MatrixApiCallback callback,
+        MatrixApiErrorCallback error_callback,
+        MatrixApiBadResponseCallback bad_response_callback,
+        gpointer user_data);
+
 #if 0
 /**
  * Get the current state of a room

matrix-room.c

@@ -600,6 +600,7 @@ static gboolean _handle_incoming_image(PurpleConversation *conv,
     MatrixConnectionData *conn = _get_connection_data_from_conversation(conv);
     MatrixApiRequestData *fetch_data = NULL;
     struct ReceiveImageData *rid;
+    gboolean use_thumb = FALSE;
 
     const gchar *url;
     JsonObject *json_info_object;
@@ -625,9 +626,7 @@ static gboolean _handle_incoming_image(PurpleConversation *conv,
         /* OK, we've got some (optional) info on the image */
         size = matrix_json_object_get_int_member(json_info_object, "size");
         if (size > purple_max_image_size) {
-            purple_debug_info("matrixprpl", "image too large %" PRId64 "\n", size);
-            /* TODO: Switch to a thumbnail */
-            return FALSE;
+            use_thumb = TRUE;
         }
         mime_type = matrix_json_object_get_string_member(json_info_object,
                         "mimetype");
@@ -649,10 +648,26 @@ static gboolean _handle_incoming_image(PurpleConversation *conv,
     rid->room_id = room_id;
     rid->original_body = g_strdup(msg_body);
 
-    fetch_data = matrix_api_download_file(conn, url, purple_max_image_size,
-            _image_download_complete,
-            _image_download_error,
-            _image_download_bad_response, rid);
+    if (!use_thumb) {
+            fetch_data = matrix_api_download_file(conn, url,
+                    purple_max_image_size,
+                    _image_download_complete,
+                    _image_download_error,
+                    _image_download_bad_response, rid);
+    } else {
+            /* TODO: Configure the size of thumbnails, and provide
+             * a way for the user to get the full image if they want.
+             * 640x480 is a good a width as any and reasonably likely to
+             * fit in the byte size limit unless someone has a big long
+             * tall png.
+             */
+            fetch_data = matrix_api_download_thumb(conn, url,
+                    purple_max_image_size,
+                    640, 480, TRUE, /* Scaled */
+                    _image_download_complete,
+                    _image_download_error,
+                    _image_download_bad_response, rid);
+    }
 
     purple_conversation_set_data(conv, PURPLE_CONV_DATA_ACTIVE_SEND,
             fetch_data);