core/boxes: Improve handling of pressing Esc during message compose.

Introduces variable MAX_MESSAGE_LENGTH_CONFIRMATION_POPUP to set
a threshold for maximum length of message in compose box beyond
which it prompts a confirmation popup instead of the current
instant exit when Esc is pressed.

Fixes zulip#1342.

tests/ui_tools/test_boxes.py

@@ -21,7 +21,12 @@
 )
 from zulipterminal.config.ui_mappings import StreamAccessType
 from zulipterminal.helper import Index, MinimalUserData
-from zulipterminal.ui_tools.boxes import PanelSearchBox, WriteBox, _MessageEditState
+from zulipterminal.ui_tools.boxes import (
+    MAX_MESSAGE_LENGTH_CONFIRMATION_POPUP,
+    PanelSearchBox,
+    WriteBox,
+    _MessageEditState,
+)
 from zulipterminal.urwid_types import urwid_Size
 
 
@@ -232,7 +237,7 @@ def test_not_calling_send_private_message_without_recipients(
         assert not write_box.model.send_private_message.called
 
     @pytest.mark.parametrize("key", keys_for_command("GO_BACK"))
-    def test__compose_attributes_reset_for_private_compose(
+    def test__compose_attributes_reset_for_private_compose__no_popup(
         self,
         key: str,
         mocker: MockerFixture,
@@ -243,17 +248,41 @@ def test__compose_attributes_reset_for_private_compose(
         mocker.patch("urwid.connect_signal")
         write_box.model.user_id_email_dict = user_id_email_dict
         write_box.private_box_view(recipient_user_ids=[11])
-        write_box.msg_write_box.edit_text = "random text"
+
+        write_box.msg_write_box.edit_text = "." * (
+            MAX_MESSAGE_LENGTH_CONFIRMATION_POPUP - 1
+        )
 
         size = widget_size(write_box)
         write_box.keypress(size, key)
 
+        write_box.view.controller.exit_compose_confirmation_popup.assert_not_called()
         assert write_box.to_write_box is None
         assert write_box.msg_write_box.edit_text == ""
         assert write_box.compose_box_status == "closed"
 
     @pytest.mark.parametrize("key", keys_for_command("GO_BACK"))
-    def test__compose_attributes_reset_for_stream_compose(
+    def test__compose_attributes_reset_for_private_compose__popup(
+        self,
+        key: str,
+        mocker: MockerFixture,
+        write_box: WriteBox,
+        widget_size: Callable[[Widget], urwid_Size],
+        user_id_email_dict: Dict[int, str],
+    ) -> None:
+        mocker.patch("urwid.connect_signal")
+        write_box.model.user_id_email_dict = user_id_email_dict
+        write_box.private_box_view(recipient_user_ids=[11])
+
+        write_box.msg_write_box.edit_text = "." * MAX_MESSAGE_LENGTH_CONFIRMATION_POPUP
+
+        size = widget_size(write_box)
+        write_box.keypress(size, key)
+
+        write_box.view.controller.exit_compose_confirmation_popup.assert_called_once()
+
+    @pytest.mark.parametrize("key", keys_for_command("GO_BACK"))
+    def test__compose_attributes_reset_for_stream_compose__no_popup(
         self,
         key: str,
         mocker: MockerFixture,
@@ -262,15 +291,37 @@ def test__compose_attributes_reset_for_stream_compose(
     ) -> None:
         mocker.patch(WRITEBOX + "._set_stream_write_box_style")
         write_box.stream_box_view(stream_id=1)
-        write_box.msg_write_box.edit_text = "random text"
+
+        write_box.msg_write_box.edit_text = "." * (
+            MAX_MESSAGE_LENGTH_CONFIRMATION_POPUP - 1
+        )
 
         size = widget_size(write_box)
         write_box.keypress(size, key)
 
+        write_box.view.controller.exit_compose_confirmation_popup.assert_not_called()
         assert write_box.stream_id is None
         assert write_box.msg_write_box.edit_text == ""
         assert write_box.compose_box_status == "closed"
 
+    @pytest.mark.parametrize("key", keys_for_command("GO_BACK"))
+    def test__compose_attributes_reset_for_stream_compose__popup(
+        self,
+        key: str,
+        mocker: MockerFixture,
+        write_box: WriteBox,
+        widget_size: Callable[[Widget], urwid_Size],
+    ) -> None:
+        mocker.patch(WRITEBOX + "._set_stream_write_box_style")
+        write_box.stream_box_view(stream_id=1)
+
+        write_box.msg_write_box.edit_text = "." * MAX_MESSAGE_LENGTH_CONFIRMATION_POPUP
+
+        size = widget_size(write_box)
+        write_box.keypress(size, key)
+
+        write_box.view.controller.exit_compose_confirmation_popup.assert_called_once_with()
+
     @pytest.mark.parametrize(
         ["raw_recipients", "tidied_recipients"],
         [
@@ -1516,13 +1567,15 @@ def test_keypress_SEND_MESSAGE_no_topic(
     )
     def test_keypress_typeahead_mode_autocomplete_key(
         self,
+        mocker: MockerFixture,
         write_box: WriteBox,
         widget_size: Callable[[Widget], urwid_Size],
         current_typeahead_mode: bool,
         expected_typeahead_mode: bool,
         expect_footer_was_reset: bool,
         key: str,
     ) -> None:
+        write_box.msg_write_box = mocker.Mock(edit_text="")
         write_box.is_in_typeahead_mode = current_typeahead_mode
         size = widget_size(write_box)
 

zulipterminal/core.py

@@ -527,6 +527,21 @@ def stream_muting_confirmation_popup(
         mute_this_stream = partial(self.model.toggle_stream_muted_status, stream_id)
         self.loop.widget = PopUpConfirmationView(self, question, mute_this_stream)
 
+    def exit_compose_confirmation_popup(self) -> None:
+        question = urwid.Text(
+            (
+                "bold",
+                "Please confirm that you wish to exit the compose box.\n"
+                "(You can save the message as a draft upon returning to compose)",
+            ),
+            "center",
+        )
+        write_box = self.view.write_box
+        popup_view = PopUpConfirmationView(
+            self, question, write_box.exit_compose_box, location="center"
+        )
+        self.loop.widget = popup_view
+
     def copy_to_clipboard(self, text: str, text_category: str) -> None:
         try:
             pyperclip.copy(text)

zulipterminal/ui_tools/boxes.py

@@ -10,7 +10,7 @@
 from typing import Any, Callable, Dict, List, NamedTuple, Optional, Tuple
 
 import urwid
-from typing_extensions import Literal
+from typing_extensions import Final, Literal
 from urwid_readline import ReadlineEdit
 
 from zulipterminal.api_types import Composition, PrivateComposition, StreamComposition
@@ -48,6 +48,11 @@
 from zulipterminal.urwid_types import urwid_Size
 
 
+# This constant defines the maximum character length of a message
+# in the compose box that does not trigger a confirmation popup.
+MAX_MESSAGE_LENGTH_CONFIRMATION_POPUP: Final = 15
+
+
 class _MessageEditState(NamedTuple):
     message_id: int
     old_topic: str
@@ -708,10 +713,19 @@ def autocomplete_emojis(
 
         return emoji_typeahead, emojis
 
+    def exit_compose_box(self) -> None:
+        self.is_in_typeahead_mode = False
+        self.view.set_footer_text()
+        self._set_compose_attributes_to_defaults()
+        self.view.controller.exit_editor_mode()
+        self.main_view(False)
+        self.view.middle_column.set_focus("body")
+
     def keypress(self, size: urwid_Size, key: str) -> Optional[str]:
         if self.is_in_typeahead_mode and not (
             is_command_key("AUTOCOMPLETE", key)
             or is_command_key("AUTOCOMPLETE_REVERSE", key)
+            or is_command_key("GO_BACK", key)
         ):
             # set default footer when done with autocomplete
             self.is_in_typeahead_mode = False
@@ -798,11 +812,23 @@ def keypress(self, size: urwid_Size, key: str) -> Optional[str]:
                         "Cannot narrow to message without specifying recipients."
                     )
         elif is_command_key("GO_BACK", key):
+            saved_draft = self.model.session_draft_message()
             self.send_stop_typing_status()
-            self._set_compose_attributes_to_defaults()
-            self.view.controller.exit_editor_mode()
-            self.main_view(False)
-            self.view.middle_column.set_focus("body")
+
+            if (
+                self.msg_edit_state is None
+                and len(self.msg_write_box.edit_text)
+                >= MAX_MESSAGE_LENGTH_CONFIRMATION_POPUP
+            ):
+                if (
+                    saved_draft is None
+                    or self.msg_write_box.edit_text != saved_draft.get("content")
+                ):
+                    self.view.controller.exit_compose_confirmation_popup()
+                else:
+                    self.exit_compose_box()
+            else:
+                self.exit_compose_box()
         elif is_command_key("MARKDOWN_HELP", key):
             self.view.controller.show_markdown_help()
             return key