Add paste-mode to allow multiline text pasting

Ctrl-T toggles paste mode.
Useful when pasting multiline text because it avoids triggering an
enter keypress after linebreaks.
Instead, every \r is translated to \n which is again translated to a
pilcrow (see previous commit).
The pasted text can then be sent as a whole instead of splitting up in
multiple messages.

src/chat.c

@@ -892,6 +892,9 @@ static void chat_onKey(ToxWindow *self, Tox *m, wint_t key, bool ltr)
     if (y2 <= 0 || x2 <= 0)
         return;
 
+    if (ctx->pastemode && key == '\r')
+        key = '\n';
+
     if (self->help->active) {
         help_onKey(self, key);
         return;

src/groupchat.c

@@ -571,6 +571,9 @@ static void groupchat_onKey(ToxWindow *self, Tox *m, wint_t key, bool ltr)
         return;
     }
 
+    if (ctx->pastemode && key == '\r')
+        key = '\n';
+
     if (ltr || key == '\n') {    /* char is printable */
         input_new_char(self, key, x, y, x2, y2);
         return;

src/input.c

@@ -262,6 +262,10 @@ bool input_handle(ToxWindow *self, wint_t key, int x, int y, int mx_x, int mx_y)
             force_refresh(self->chatwin->history);
             break;
 
+        case T_KEY_C_T:
+            self->chatwin->pastemode ^= 1;
+            break;
+
         default:
             match = false;
             break;
@@ -278,6 +282,5 @@ bool input_handle(ToxWindow *self, wint_t key, int x, int y, int mx_x, int mx_y)
         match = true;
     }
 
-
     return match;
 }

src/prompt.c

@@ -189,6 +189,9 @@ static void prompt_onKey(ToxWindow *self, Tox *m, wint_t key, bool ltr)
     if (x2 <= 0 || y2 <= 0)
         return;
 
+    if (ctx->pastemode && key == '\r')
+        key = '\n';
+
     /* ignore non-menu related input if active */
     if (self->help->active) {
         help_onKey(self, key);

src/toxic.h

@@ -70,6 +70,7 @@
 #define T_KEY_C_L        0x0C     /* ctrl-l */
 #define T_KEY_C_W        0x17     /* ctrl-w */
 #define T_KEY_C_B        0x02     /* ctrl-b */
+#define T_KEY_C_T        0x14     /* ctrl-t */
 #define T_KEY_TAB        0x09     /* TAB key */
 
 #define ONLINE_CHAR "*"

src/windows.h

@@ -237,6 +237,7 @@ struct ChatContext {
 #endif
 
     uint8_t self_is_typing;
+    uint8_t pastemode; /* whether to translate \r to \n */
 
     WINDOW *history;
     WINDOW *linewin;