Implement a proper return key (fixes #689)

rtv/__main__.py

@@ -41,6 +41,7 @@
 from .terminal import Terminal
 from .content import RequestHeaderRateLimiter
 from .objects import curses_session, patch_webbrowser
+from .page import PageStack
 from .subreddit_page import SubredditPage
 from .submission_page import SubmissionPage
 from .exceptions import ConfigError, SubredditError, SubmissionError
@@ -233,8 +234,9 @@ def main():
                     except Exception as e:
                         _logger.exception(e)
                         raise SubmissionError('Unable to load {0}'.format(url))
-                while page:
-                    page = page.loop()
+                PageStack.add(page)
+                ps = PageStack()
+                ps.run()
 
             page = None
             name = config['subreddit']
@@ -251,8 +253,9 @@ def main():
                     raise SubredditError('Unable to load {0}'.format(name))
 
             # Launch the subreddit page
-            while page:
-                page = page.loop()
+            PageStack.add(page)
+            ps = PageStack()
+            ps.run()
 
     except ConfigError as e:
         _logger.exception(e)

rtv/inbox_page.py

@@ -25,22 +25,6 @@ def __init__(self, reddit, term, config, oauth, content_type='all'):
         self.nav = Navigator(self.content.get)
         self.content_type = content_type
 
-    def handle_selected_page(self):
-        """
-        Open the subscription and submission pages subwindows, but close the
-        current page if any other type of page is selected.
-        """
-        if not self.selected_page:
-            pass
-        if self.selected_page.name in ('subscription', 'submission'):
-            # Launch page in a subwindow
-            self.selected_page = self.selected_page.loop()
-        elif self.selected_page.name in ('subreddit', 'inbox'):
-            # Replace the current page
-            self.active = False
-        else:
-            raise RuntimeError(self.selected_page.name)
-
     @logged_in
     def refresh_content(self, order=None, name=None):
         """
@@ -108,13 +92,6 @@ def inbox_reply(self):
         """
         self.reply()
 
-    @InboxController.register(Command('INBOX_EXIT'))
-    def close_inbox(self):
-        """
-        Close inbox and return to the previous page.
-        """
-        self.active = False
-
     @InboxController.register(Command('INBOX_VIEW_CONTEXT'))
     @logged_in
     def view_context(self):
@@ -123,7 +100,7 @@ def view_context(self):
         """
         url = self.get_selected_item().get('context')
         if url:
-            self.selected_page = self.open_submission_page(url)
+            self.open_submission_page(url)
 
     @InboxController.register(Command('INBOX_OPEN_SUBMISSION'))
     @logged_in
@@ -133,7 +110,7 @@ def open_submission(self):
         """
         url = self.get_selected_item().get('submission_permalink')
         if url:
-            self.selected_page = self.open_submission_page(url)
+            self.open_submission_page(url)
 
     def _draw_item(self, win, data, inverted):
 

rtv/page.py

@@ -38,6 +38,51 @@ class PageController(Controller):
     character_map = {}
 
 
+class PageStack(object):
+    stack = []
+
+    def __init__(self, max_size=20):
+        self.max_size = max_size
+
+    @staticmethod
+    def add(page):
+        PageStack.stack.append(page)
+
+    @staticmethod
+    def init(page=None):
+        if page:
+            PageStack.stack = [page]
+        else:
+            PageStack.stack = []
+
+    @staticmethod
+    def pop():
+        return PageStack.stack.pop()
+
+    @staticmethod
+    def size():
+        return len(PageStack.stack)
+
+    @staticmethod
+    def current_page():
+        return PageStack.stack[-1]
+
+    def run(self):
+        """
+        Runs the PageStack. It takes the most recently added page and calls
+        the calls the pages' wait method to draw the page and wait for
+        user input.
+        """
+        while PageStack.stack:
+            self._stay_within_max_size()
+            page = PageStack.current_page()
+            page.wait()
+
+    def _stay_within_max_size(self):
+        if len(PageStack.stack) > self.max_size:
+            PageStack.stack = PageStack.stack[1:]
+
+
 class Page(object):
 
     BANNER = None
@@ -52,8 +97,6 @@ def __init__(self, reddit, term, config, oauth):
         self.nav = None
         self.controller = None
 
-        self.active = True
-        self.selected_page = None
         self._row = 0
         self._subwindows = None
 
@@ -69,68 +112,13 @@ def get_selected_item(self):
         """
         return self.content.get(self.nav.absolute_index)
 
-    def loop(self):
+    def wait(self):
         """
-        Main control loop runs the following steps:
-            1. Re-draw the screen
-            2. Wait for user to press a key (includes terminal resizing)
-            3. Trigger the method registered to the input key
-            4. Check if there are any nested pages that need to be looped over
-
-        The loop will run until self.active is set to False from within one of
-        the methods.
+        Draw the page and wait for user input.
         """
-        self.active = True
-
-        # This needs to be called once before the main loop, in case a subpage
-        # was pre-selected before the loop started. This happens in __main__.py
-        # with ``page.open_submission(url=url)``
-        while self.selected_page and self.active:
-            self.handle_selected_page()
-
-        while self.active:
-            self.draw()
-            ch = self.term.stdscr.getch()
-            self.controller.trigger(ch)
-
-            while self.selected_page and self.active:
-                self.handle_selected_page()
-
-        return self.selected_page
-
-    def handle_selected_page(self):
-        """
-        Some commands will result in an action that causes a new page to open.
-        Examples include selecting a submission, viewing subscribed subreddits,
-        or opening the user's inbox. With these commands, the newly selected
-        page will be pre-loaded and stored in ``self.selected_page`` variable.
-        It's up to each page type to determine what to do when another page is
-        selected.
-
-          - It can start a nested page.loop(). This would allow the user to
-            return to their previous screen after exiting the sub-page. For
-            example, this is what happens when opening an individual submission
-            from within a subreddit page. When the submission is closed, the
-            user resumes the subreddit that they were previously viewing.
-
-          - It can close the current self.loop() and bubble the selected page up
-            one level in the loop stack. For example, this is what happens when
-            the user opens their subscriptions and selects a subreddit. The
-            subscription page loop is closed and the selected subreddit is
-            bubbled up to the root level loop.
-
-        Care should be taken to ensure the user can never enter an infinite
-        nested loop, as this could lead to memory leaks and recursion errors.
-
-            # Example of an unsafe nested loop
-            subreddit_page.loop()
-                -> submission_page.loop()
-                    -> subreddit_page.loop()
-                        -> submission_page.loop()
-                            ...
-
-        """
-        raise NotImplementedError
+        self.draw()
+        ch = self.term.stdscr.getch()
+        self.controller.trigger(ch)
 
     @PageController.register(Command('REFRESH'))
     def reload_page(self):
@@ -240,6 +228,13 @@ def move_page_bottom(self):
         self.nav.cursor_index = 0
         self.nav.inverted = True
 
+    @PageController.register(Command('RETURN'))
+    def page_return(self):
+        if PageStack.size() == 1:
+            self.term.flash()
+        else:
+            PageStack.pop()
+
     @PageController.register(Command('UPVOTE'))
     @logged_in
     def upvote(self):
@@ -476,7 +471,7 @@ def send_private_message(self):
                 raise TemporaryFileError()
             else:
                 self.term.show_notification('Message sent!')
-                self.selected_page = self.open_inbox_page('sent')
+                self.open_inbox_page('sent')
 
     def prompt_and_select_link(self):
         """
@@ -551,15 +546,15 @@ def subscriptions(self):
         """
         View a list of the user's subscribed subreddits
         """
-        self.selected_page = self.open_subscription_page('subreddit')
+        self.open_subscription_page('subreddit')
 
     @PageController.register(Command('MULTIREDDITS'))
     @logged_in
     def multireddits(self):
         """
         View a list of the user's subscribed multireddits
         """
-        self.selected_page = self.open_subscription_page('multireddit')
+        self.open_subscription_page('multireddit')
 
     @PageController.register(Command('PROMPT'))
     def prompt(self):
@@ -589,7 +584,7 @@ def inbox(self):
         """
         View the user's inbox.
         """
-        self.selected_page = self.open_inbox_page('all')
+        self.open_inbox_page('all')
 
     def open_inbox_page(self, content_type):
         """
@@ -601,6 +596,7 @@ def open_inbox_page(self, content_type):
             page = InboxPage(self.reddit, self.term, self.config, self.oauth,
                              content_type=content_type)
         if not self.term.loader.exception:
+            PageStack.add(page)
             return page
 
     def open_subscription_page(self, content_type):
@@ -613,6 +609,7 @@ def open_subscription_page(self, content_type):
             page = SubscriptionPage(self.reddit, self.term, self.config,
                                     self.oauth, content_type=content_type)
         if not self.term.loader.exception:
+            PageStack.add(page)
             return page
 
     def open_submission_page(self, url=None, submission=None):
@@ -625,6 +622,7 @@ def open_submission_page(self, url=None, submission=None):
             page = SubmissionPage(self.reddit, self.term, self.config,
                                   self.oauth, url=url, submission=submission)
         if not self.term.loader.exception:
+            PageStack.add(page)
             return page
 
     def open_subreddit_page(self, name):
@@ -637,6 +635,7 @@ def open_subreddit_page(self, name):
             page = SubredditPage(self.reddit, self.term, self.config,
                                  self.oauth, name)
         if not self.term.loader.exception:
+            PageStack.add(page)
             return page
 
     def clear_input_queue(self):

rtv/submission_page.py

@@ -34,22 +34,6 @@ def __init__(self, reddit, term, config, oauth, url=None, submission=None):
         # Start at the submission post, which is indexed as -1
         self.nav = Navigator(self.content.get, page_index=-1)
 
-    def handle_selected_page(self):
-        """
-        Open the subscription page in a subwindow, but close the current page
-        if any other type of page is selected.
-        """
-        if not self.selected_page:
-            pass
-        elif self.selected_page.name == 'subscription':
-            # Launch page in a subwindow
-            self.selected_page = self.selected_page.loop()
-        elif self.selected_page.name in ('subreddit', 'submission', 'inbox'):
-            # Replace the current page
-            self.active = False
-        else:
-            raise RuntimeError(self.selected_page.name)
-
     def refresh_content(self, order=None, name=None):
         """
         Re-download comments and reset the page index
@@ -110,13 +94,6 @@ def toggle_comment(self):
                 self.nav.flip(len(self._subwindows) - 1)
                 self.nav.top_item_height = n_rows
 
-    @SubmissionController.register(Command('SUBMISSION_EXIT'))
-    def exit_submission(self):
-        """
-        Close the submission and return to the subreddit page
-        """
-        self.active = False
-
     @SubmissionController.register(Command('SUBMISSION_OPEN_IN_BROWSER'))
     def open_link(self):
         """

rtv/subreddit_page.py

@@ -32,21 +32,6 @@ def __init__(self, reddit, term, config, oauth, name):
         self.nav = Navigator(self.content.get)
         self.toggled_subreddit = None
 
-    def handle_selected_page(self):
-        """
-        Open all selected pages in subwindows except other subreddit pages.
-        """
-        if not self.selected_page:
-            pass
-        elif self.selected_page.name in ('subscription', 'submission', 'inbox'):
-            # Launch page in a subwindow
-            self.selected_page = self.selected_page.loop()
-        elif self.selected_page.name == 'subreddit':
-            # Replace the current page
-            self.active = False
-        else:
-            raise RuntimeError(self.selected_page.name)
-
     def refresh_content(self, order=None, name=None):
         """
         Re-download all submissions and reset the page index
@@ -165,7 +150,7 @@ def open_submission(self, url=None):
             if data.get('url_type') == 'selfpost':
                 self.config.history.add(data['url_full'])
 
-        self.selected_page = self.open_submission_page(url)
+        self.open_submission_page(url)
 
     @SubredditController.register(Command('SUBREDDIT_OPEN_IN_BROWSER'))
     def open_link(self):
@@ -217,7 +202,7 @@ def post_submission(self):
 
         if not self.term.loader.exception:
             # Open the newly created submission
-            self.selected_page = self.open_submission_page(submission=submission)
+            self.open_submission_page(submission=submission)
 
     @SubredditController.register(Command('SUBREDDIT_HIDE'))
     @logged_in
@@ -233,7 +218,7 @@ def hide(self):
             with self.term.loader('Hiding'):
                 data['object'].hide()
                 data['hidden'] = True
-    
+
     def _draw_item(self, win, data, inverted):
 
         n_rows, n_cols = win.getmaxyx()