Render incoming typing notifications

We're not sending typing notification ourselves,
but at least now we can see them coming
from the good clients that do.

friend.c

@@ -107,6 +107,11 @@ void friend_addmessage(FRIEND *f, void *data)
     }
 }
 
+void friend_set_typing(FRIEND *f, int typing) {
+    f->typing = typing;
+    messages_set_typing(&messages_friend, &f->msg, typing);
+}
+
 void friend_addid(uint8_t *id, char_t *msg, uint16_t msg_length)
 {
     void *data = malloc(TOX_FRIEND_ADDRESS_SIZE + msg_length * sizeof(char_t));

messages.c

@@ -1,5 +1,22 @@
 #include "main.h"
 
+// Ideally this function would have returned an array of simultaneously
+// typing friends, e.g. in a groupchat. But since groupchats don't support
+// notifications, it simply returns the friend associated with
+// given MESSAGES, or NULL if he is not typing.
+static FRIEND* get_typers(MESSAGES *m) {
+    // Currently only friends support typing notifications
+    if(sitem->item == ITEM_FRIEND) {
+        FRIEND *f = sitem->data;
+        // check just in case that we're given the messages panel for
+        // the currently selected friend
+        if(&f->msg == m->data) {
+            if(f->typing) return f;
+        }
+    }
+    return NULL;
+}
+
 void messages_draw(MESSAGES *m, int x, int y, int width, int height)
 {
     setcolor(0);
@@ -192,6 +209,18 @@ void messages_draw(MESSAGES *m, int x, int y, int width, int height)
 
         y += MESSAGES_SPACING;
     }
+
+    if(i == n) {
+        // Last message is visible. Append typing notifications, if needed.
+        FRIEND *f = get_typers(m);
+        if(f) {
+            setfont(FONT_TEXT);
+            setcolor(C_GRAY2);
+            drawtextwidth_right(x, MESSAGES_X - NAME_OFFSET, y, f->name, f->name_length);
+            // TODO: i18n
+            drawtextwidth(x + MESSAGES_X, x + width, y, "is typing...", sizeof("is typing...") - 1);
+        }
+    }
 }
 
 _Bool messages_mmove(MESSAGES *m, int px, int py, int width, int height, int mx, int my, int dx, int dy)
@@ -765,6 +794,10 @@ void messages_updateheight(MESSAGES *m)
         height += msg->height;
         i++;
     }
+    if(get_typers(m)) {
+        // Add space for typing notification
+        height += font_small_lineheight + MESSAGES_SPACING;
+    }
 
     m->height = height;
     data->height = height;
@@ -837,6 +870,14 @@ void message_add(MESSAGES *m, MESSAGE *msg, MSG_DATA *p)
     message_setheight(m, msg, p);
 }
 
+void messages_set_typing(MESSAGES *m, MSG_DATA *p, int typing) {
+    if(m->data == p) {
+        // MSG_DATA associated with typing notification
+        // corresponds to given MESSAGES, so update their height.
+        messages_updateheight(m);
+    }
+}
+
 _Bool messages_char(uint32_t ch)
 {
     MESSAGES *m;

tox.c

@@ -1301,14 +1301,17 @@ void tox_message(uint8_t msg, uint16_t param1, uint16_t param2, void *data)
 
     case FRIEND_TYPING: {
         FRIEND *f = &friend[param1];
-        f->typing = param2;
+        friend_set_typing(f, param2);
         updatefriend(f);
         break;
     }
 
     case FRIEND_ONLINE: {
         FRIEND *f = &friend[param1];
         f->online = param2;
+        if(!f->online) {
+            friend_set_typing(f, 0);
+        }
         updatefriend(f);
         break;
     }