diff --git a/ComposeWindow.java b/ComposeWindow.java
index dba0eb9..2858fc0 100644
--- a/ComposeWindow.java
+++ b/ComposeWindow.java
@@ -102,19 +102,84 @@ ComposeWindow extends JFrame {
         if (composition.contentWarning != null)
             assert !composition.contentWarning.trim().isEmpty();
 
-		// Oh, this is gonna be hell.
+		//tabs.setCursor(new Cursor(Cursor.WAIT_CURSOR));
 		/*
-		* (未) For every attachment in composition,
-		* attempt to upload it, then fill the media ID.
-		* Then change MastodonApi#submit to accept an
-		* array of media IDs. If any upload fails,
-		* show an error message then return.
+		* setCursor only works for components that are enabled.
+		* I don't think there's any technical reason for this,
+		* but it's what it is.. rely on the enablement visuals
+		* or a statusbar to indicate to user.
+		*
+		* If we really wanted it, I suspect we could use a glass
+		* pane (or a scroll pane with no scrolling) to have an
+		* enabled pass-through on top.
+		*
+		* Technically contentsDisplay and attachmentsDisplay
+		* themselves aren't disabled. But disabling the tab pane
+		* covers both the tab area and content area. We can't
+		* just the tab area, except maybe by disabling the
+		* individual tabs.
 		*/
+		tabs.setEnabled(false);
+		tabs.setSelectedComponent(contentsDisplay);
+		contentsDisplay.setSubmitting(true);
+		tabs.paintImmediately(tabs.getBounds());
 
-        contentsDisplay.setSubmitting(true);
-        api.submit(
+		boolean uploadsOkay = true;
+		for (Attachment a: composition.attachments)
+		{ 
+			if (a.id != null) continue;
+			// Assume it had already been uploaded.
+
+			api.uploadFile(a.uploadee, new RequestListener() {
+
+				public void
+				connectionFailed(IOException eIo)
+				{
+					JOptionPane.showMessageDialog(
+                        ComposeWindow.this,
+                        "Tried to upload attachment, failed..."
+                        + "\n" + eIo.getMessage()
+                    );
+				}
+
+				public void
+				requestFailed(int httpCode, Tree<String> json)
+				{
+					JOptionPane.showMessageDialog(
+                        ComposeWindow.this,
+                        "Tried to upload attachment, failed..."
+						+ "\n" + json.get("error").value
+                        + "\n(HTTP code: " + httpCode + ")"
+                    );
+				}
+
+				public void
+				requestSucceeded(Tree<String> json)
+				{
+					a.id = json.get("id").value;
+				}
+
+			});
+			uploadsOkay &= a.id != null;
+		}
+
+		if (!uploadsOkay)
+		{
+			contentsDisplay.setSubmitting(false);
+			tabs.setEnabled(true);
+			//tabs.setCursor(null);
+			return;
+		}
+
+		int amt = composition.attachments.length;
+		String[] mediaIDs = new String[amt];
+		for (int o = 0; o < mediaIDs.length; ++o)
+			mediaIDs[o] = composition.attachments[o].id;
+
+		api.submit(
             composition.text, composition.visibility,
             composition.replyToPostId, composition.contentWarning,
+			mediaIDs,
             new RequestListener() {
 
                 public void
@@ -146,7 +211,10 @@ ComposeWindow extends JFrame {
 
             }
         );
+
         contentsDisplay.setSubmitting(false);
+		tabs.setEnabled(true);
+		tabs.setCursor(null);
     }
 
 //   -  -%-  -
@@ -339,14 +407,12 @@ implements ActionListener, CaretListener, KeyListener {
             text.setEnabled(false);
             visibility.setEnabled(false);
             submit.setEnabled(false);
-            setCursor(new Cursor(Cursor.WAIT_CURSOR));
         }
         else
         {
             text.setEnabled(true);
             visibility.setEnabled(true);
             submit.setEnabled(true);
-            setCursor(null);
         }
     }
 
diff --git a/MastodonApi.java b/MastodonApi.java
index 360fb42..4624b18 100644
--- a/MastodonApi.java
+++ b/MastodonApi.java
@@ -276,6 +276,7 @@ MastodonApi {
     submit(
         String text, PostVisibility visibility,
         String replyTo, String contentWarning,
+		String[] mediaIDs,
         RequestListener handler)
     {
         String token = accessToken.get("access_token").value;
@@ -315,6 +316,10 @@ MastodonApi {
             if (contentWarning != null) {
                 output.write("&spoiler_text=" + contentWarning);
             }
+			for (String mediaID: mediaIDs) {
+				output.write("&media_ids[]=" + mediaID);
+			}
+
             output.close();
 
             doStandardJsonReturn(conn, handler);
@@ -516,7 +521,7 @@ MastodonApi {
 			istream.close();
 			ostream.close();
 
-            wrapResponseInTree(conn, handler);
+            doStandardJsonReturn(conn, handler);
         }
         catch (IOException eIo) { handler.connectionFailed(eIo); }
     }
diff --git a/PostWindow.java b/PostWindow.java
index d9b2ef8..bfd42e4 100644
--- a/PostWindow.java
+++ b/PostWindow.java
@@ -469,6 +469,11 @@ implements ActionListener {
 		* this, using MediaTracker. That assumes what I'm doing
 		* right now definitely works.
 		*/
+		/*
+		* (悪) It doesn't work. I might be forced to use
+		* BufferedImage with ImageIO. Or have
+		* ImageApi#getScaledInstance spam until it works.
+		*/
 
 		profile.setImage(n);
 	}