[geary] Tidy up Geary.Attachment API a bit.

[Michael Gratton <mjog src gnome org>]

commit 6257e05ad9c478cb2c2447e13fd8729046cbd0f8
Author: Michael James Gratton <mike vee net>
Date:   Sat Feb 11 09:52:23 2017 +1100

    Tidy up Geary.Attachment API a bit.
    
    * src/engine/api/geary-attachment.vala (Attachment): Allow direct access
      to MIME content-disposition filename if available. Make it obvious that
      the filename comes from content-disposition. Reorder attrs to reflect
      importance. Update subclasses and call sites.

 .../conversation-viewer/conversation-email.vala    |    2 +-
 src/engine/api/geary-attachment.vala               |   84 +++++++++++---------
 src/engine/imap-db/imap-db-attachment.vala         |   27 +++++--
 src/engine/imap-db/imap-db-folder.vala             |   21 ++++--
 4 files changed, 83 insertions(+), 51 deletions(-)
---
diff --git a/src/client/conversation-viewer/conversation-email.vala 
b/src/client/conversation-viewer/conversation-email.vala
index e24ff84..bd70da1 100644
--- a/src/client/conversation-viewer/conversation-email.vala
+++ b/src/client/conversation-viewer/conversation-email.vala
@@ -114,7 +114,7 @@ public class ConversationEmail : Gtk.Box {
             );
 
             string file_name = null;
-            if (attachment.has_supplied_filename) {
+            if (attachment.has_content_filename) {
                 file_name = attachment.file.get_basename();
             }
             string file_desc = ContentType.get_description(gio_content_type);
diff --git a/src/engine/api/geary-attachment.vala b/src/engine/api/geary-attachment.vala
index fd6624c..82e64cf 100644
--- a/src/engine/api/geary-attachment.vala
+++ b/src/engine/api/geary-attachment.vala
@@ -11,69 +11,81 @@
  */
 
 public abstract class Geary.Attachment : BaseObject {
+
     /**
      * An identifier that can be used to locate the {@link Attachment} in an {@link Email}.
      *
      * @see Email.get_attachment
      */
     public string id { get; private set; }
-    
-    /**
-     * Returns true if the originating {@link Email} supplied a filename for the {@link Attachment}.
-     *
-     * Since all files must have a name, one is supplied for the Attachment by Geary if this is
-     * false.  This is merely to indicate how the filename should be displayed, since Geary's will
-     * be an untranslated "none".
-     */
-    public bool has_supplied_filename { get; private set; }
-    
-    /**
-     * The on-disk File of the {@link Attachment}.
-     */
-    public File file { get; private set; }
-    
+
     /**
      * The {@link Mime.ContentType} of the {@link Attachment}.
      */
     public Mime.ContentType content_type { get; private set; }
-    
+
     /**
-     * The file size (in bytes) if the {@link file}.
+     * The Content-ID of the attachment.
+     *
+     * See [[https://tools.ietf.org/html/rfc2111]]
      */
-    public int64 filesize { get; private set; }
-    
+    public string? content_id { get; private set; }
+
+    /**
+     * The Content-Description of the attachment.
+     *
+     * See [[https://tools.ietf.org/html/rfc2045#section-8]]
+     */
+    public string? content_description { get; private set; }
+
     /**
      * The {@link Mime.ContentDisposition} of the attachment, as specified by the {@link Email}.
      *
      * See [[https://tools.ietf.org/html/rfc2183]]
      */
     public Mime.ContentDisposition content_disposition { get; private set; }
-    
+
     /**
-     * The Content-ID of the attachment.
+     * Returns true if a filename was supplied in {@link content_disposition}.
      *
-     * See [[https://tools.ietf.org/html/rfc2111]]
+     * Since all files must have a name, one is supplied for the
+     * Attachment by Geary if this is false.  This is merely to
+     * indicate how the filename should be displayed, since Geary's
+     * will be an untranslated "none".
      */
-    public string? content_id { get; private set; }
-    
+    public bool has_content_filename { get { return this.content_filename != null; } }
+
     /**
-     * The Content-Description of the attachment.
-     *
-     * See [[https://tools.ietf.org/html/rfc2045#section-8]]
+     * The filename supplied in {@link content_disposition}, if any.
      */
-    public string? content_description { get; private set; }
-    
-    protected Attachment(string id, File file, bool has_supplied_filename, Mime.ContentType content_type,
-        int64 filesize, Mime.ContentDisposition content_disposition, string? content_id,
-        string? content_description) {
+    public string? content_filename { get; private set; }
+
+    /**
+     * The on-disk File of the {@link Attachment}.
+     */
+    public File file { get; private set; }
+
+    /**
+     * The file size (in bytes) if the {@link file}.
+     */
+    public int64 filesize { get; private set; }
+
+    protected Attachment(string id,
+                         Mime.ContentType content_type,
+                         string? content_id,
+                         string? content_description,
+                         Mime.ContentDisposition content_disposition,
+                         string? content_filename,
+                         File file,
+                         int64 filesize) {
         this.id = id;
-        this.file = file;
-        this.has_supplied_filename = has_supplied_filename;
         this.content_type = content_type;
-        this.filesize = filesize;
-        this.content_disposition = content_disposition;
         this.content_id = content_id;
         this.content_description = content_description;
+        this.content_disposition = content_disposition;
+        this.content_filename = content_filename;
+        this.file = file;
+        this.filesize = filesize;
     }
 }
 
diff --git a/src/engine/imap-db/imap-db-attachment.vala b/src/engine/imap-db/imap-db-attachment.vala
index c032a50..7ed57f3 100644
--- a/src/engine/imap-db/imap-db-attachment.vala
+++ b/src/engine/imap-db/imap-db-attachment.vala
@@ -8,15 +8,26 @@ private class Geary.ImapDB.Attachment : Geary.Attachment {
     public const Email.Field REQUIRED_FIELDS = Email.REQUIRED_FOR_MESSAGE;
     
     private const string ATTACHMENTS_DIR = "attachments";
-    
-    public Attachment(File data_dir, string? filename, Mime.ContentType content_type, int64 filesize,
-        int64 message_id, int64 attachment_id, Mime.ContentDisposition content_disposition,
-        string? content_id, string? content_description) {
-        base (generate_id(attachment_id),generate_file(data_dir, message_id, attachment_id, filename),
-            !String.is_empty(filename), content_type, filesize, content_disposition, content_id,
-            content_description);
+
+    public Attachment(int64 message_id,
+                      int64 attachment_id,
+                      Mime.ContentType content_type,
+                      string? content_id,
+                      string? content_description,
+                      Mime.ContentDisposition content_disposition,
+                      string? content_filename,
+                      File data_dir,
+                      int64 filesize) {
+        base (generate_id(attachment_id),
+              content_type,
+              content_id,
+              content_description,
+              content_disposition,
+              content_filename,
+              generate_file(data_dir, message_id, attachment_id, content_filename),
+              filesize);
     }
-    
+
     private static string generate_id(int64 attachment_id) {
         return "imap-db:%s".printf(attachment_id.to_string());
     }
diff --git a/src/engine/imap-db/imap-db-folder.vala b/src/engine/imap-db/imap-db-folder.vala
index 18d0123..f7d0d7a 100644
--- a/src/engine/imap-db/imap-db-folder.vala
+++ b/src/engine/imap-db/imap-db-folder.vala
@@ -2006,17 +2006,26 @@ private class Geary.ImapDB.Folder : BaseObject, Geary.ReferenceSemantics {
         Db.Result results = stmt.exec(cancellable);
         if (results.finished)
             return null;
-        
+
         Gee.List<Geary.Attachment> list = new Gee.ArrayList<Geary.Attachment>();
         do {
             Mime.ContentDisposition disposition = new Mime.ContentDisposition.simple(
                 Mime.DispositionType.from_int(results.int_at(4)));
-            list.add(new ImapDB.Attachment(cx.database.db_file.get_parent(), results.string_at(1),
-                Mime.ContentType.deserialize(results.nonnull_string_at(2)), results.int64_at(3),
-                message_id, results.rowid_at(0), disposition, results.string_at(5),
-                results.string_at(6)));
+            list.add(
+                new ImapDB.Attachment(
+                    message_id,
+                    results.rowid_at(0),
+                    Mime.ContentType.deserialize(results.nonnull_string_at(2)),
+                    results.string_at(5),
+                    results.string_at(6),
+                    disposition,
+                    results.string_at(1),
+                    cx.database.db_file.get_parent(),
+                    results.int64_at(3)
+                )
+            );
         } while (results.next(cancellable));
-        
+
         return list;
     }