From 93a7c3a099f10ce7ca86754cd9a1855c0d490e24 Mon Sep 17 00:00:00 2001
From: Michael Lazar <lazar.michael22@gmail.com>
Date: Mon, 26 Jan 2015 23:57:23 -0800
Subject: [PATCH] Submission view up and running.

---
 rtv/content_generators.py                 | 178 +++++++++++++++-------
 rtv/submission_viewer.py                  | 128 ++++++++++++++++
 rtv/{subreddit.py => subreddit_viewer.py} |  62 +-------
 rtv/viewer.py                             |  79 ++++++++--
 4 files changed, 331 insertions(+), 116 deletions(-)
 create mode 100644 rtv/submission_viewer.py
 rename rtv/{subreddit.py => subreddit_viewer.py} (52%)

diff --git a/rtv/content_generators.py b/rtv/content_generators.py
index 316d860..d352bc2 100644
--- a/rtv/content_generators.py
+++ b/rtv/content_generators.py
@@ -1,28 +1,70 @@
 import textwrap
+import praw
 
 from utils import clean, strip_subreddit_url, humanize_timestamp
 
-class SubmissionContent(object):
-    """
-    Facilitates navigating through the comments in a PRAW submission.
-    """
-
-    def __init__(self, submission):
-
-        self.submission = submission
-        self._comments = []
-
+class BaseContent(object):
 
     @staticmethod
-    def flatten_comments(submission):
+    def strip_praw_comment(comment):
+        """
+        Parse through a submission comment and return a dict with data ready to
+        be displayed through the terminal.
+        """
+
+        data = {}
+        data['object'] = comment
+        data['level'] = comment.nested_level
+
+
+        if isinstance(comment, praw.objects.MoreComments):
+            data['type'] = 'MoreComments'
+            data['body'] = 'More comments [{}]'.format(comment.count)
+        else:
+            data['type'] = 'Comment'
+            data['body'] = clean(comment.body)
+            data['created'] = humanize_timestamp(comment.created_utc)
+            data['score'] = '{} pts'.format(comment.score)
+            data['author'] = (clean(comment.author.name) if
+                              getattr(comment, 'author') else '[deleted]')
+
+        return data
+
+    @staticmethod
+    def strip_praw_submission(sub):
+        """
+        Parse through a submission and return a dict with data ready to be
+        displayed through the terminal.
+        """
+
+        is_selfpost = lambda s: s.startswith('http://www.reddit.com/r/')
+
+        data = {}
+        data['object'] = sub
+        data['type'] = 'Submission'
+        data['title'] = clean(sub.title)
+        data['text'] = clean(sub.selftext)
+        data['created'] = humanize_timestamp(sub.created_utc)
+        data['comments'] = '{} comments'.format(sub.num_comments)
+        data['score'] = '{} pts'.format(sub.score)
+        data['author'] = (clean(sub.author.name) if getattr(sub, 'author')
+                          else '[deleted]')
+        data['permalink'] = clean(sub.permalink)
+        data['subreddit'] = strip_subreddit_url(sub.permalink)
+        data['url'] = ('(selfpost)' if is_selfpost(sub.url) else clean(sub.url))
+
+        return data
+
+    @staticmethod
+    def flatten_comments(comments, initial_level=0):
         """
         Flatten a PRAW comment tree while preserving the nested level of each
         comment via the `nested_level` attribute.
         """
 
-        stack = submission[:]
+        stack = comments[:]
         for item in stack:
-            item.nested_level = 0
+            item.nested_level = initial_level
 
         retval = []
         while stack:
@@ -35,24 +77,8 @@ class SubmissionContent(object):
             retval.append(item)
         return retval
 
-    @staticmethod
-    def strip_praw_comment(comment):
-        """
-        Parse through a submission comment and return a dict with data ready to
-        be displayed through the terminal.
-        """
 
-        data = {}
-        data['body'] = clean(comment.body)
-        data['created'] = humanize_timestamp(comment.created_utc)
-        data['score'] = '{} pts'.format(comment.score)
-        data['author'] = (clean(comment.author.name) if
-                          getattr(comment, 'author') else '[deleted]')
-
-        return data
-
-
-class SubredditContent(object):
+class SubredditContent(BaseContent):
     """
     Grabs a subreddit from PRAW and lazily stores submissions to an internal
     list for repeat access.
@@ -74,28 +100,6 @@ class SubredditContent(object):
 
         self.reset(subreddit=subreddit)
 
-    @staticmethod
-    def strip_praw_submission(sub):
-        """
-        Parse through a submission and return a dict with data ready to be
-        displayed through the terminal.
-        """
-
-        is_selfpost = lambda s: s.startswith('http://www.reddit.com/r/')
-
-        data = {}
-        data['title'] = clean(sub.title)
-        data['text'] = clean(sub.selftext)
-        data['created'] = humanize_timestamp(sub.created_utc)
-        data['comments'] = '{} comments'.format(sub.num_comments)
-        data['score'] = '{} pts'.format(sub.score)
-        data['author'] = (clean(sub.author.name) if getattr(sub, 'author')
-                          else '[deleted]')
-        data['subreddit'] = strip_subreddit_url(sub.permalink)
-        data['url'] = ('(selfpost)' if is_selfpost(sub.url) else clean(sub.url))
-
-        return data
-
     def get(self, index, n_cols=70):
         """
         Grab the `i`th submission, with the title field formatted to fit inside
@@ -119,6 +123,7 @@ class SubredditContent(object):
         data = self._submission_data[index]
         data['split_title'] = textwrap.wrap(data['title'], width=n_cols)
         data['n_rows'] = len(data['split_title']) + 3
+        data['offset'] = 0
 
         return data
 
@@ -143,4 +148,71 @@ class SubredditContent(object):
             self.display_name = 'Front Page'
         else:
             self._submissions = self.r.get_subreddit(self.subreddit, limit=None)
-            self.display_name = self._submissions.display_name
\ No newline at end of file
+            self.display_name = self._submissions.display_name
+
+
+class SubmissionContent(BaseContent):
+    """
+    Grabs a submission from PRAW and lazily store comments to an internal
+    list for repeat access and to allow expanding and hiding comments.
+    """
+
+    def __init__(self, submission, indent_size=2, max_indent_level=4):
+
+        self.submission = submission
+        self.indent_size = indent_size
+        self.max_indent_level = max_indent_level
+
+        self.display_name = None
+        self._submission_data = None
+        self._comments = None
+        self._comment_data = None
+
+        self.reset()
+
+    def get(self, index, n_cols=70):
+        """
+        Grab the `i`th submission, with the title field formatted to fit inside
+        of a window of width `n`
+        """
+
+        if index < -1:
+            raise IndexError
+
+        elif index == -1:
+            data = self._submission_data
+            data['split_title'] = textwrap.wrap(data['title'], width=n_cols)
+            data['n_rows'] = len(data['split_title']) + 3
+            data['offset'] = 0
+
+        else:
+            data = self._comment_data[index]
+            indent_level = min(data['level'], self.max_indent_level)
+            data['offset'] = indent_level * self.indent_size
+
+            if data['type'] == 'Comment':
+                data['split_body'] = textwrap.wrap(
+                    data['body'], width=n_cols-data['offset'])
+                data['n_rows'] = len(data['split_body']) + 1
+            else:
+                data['n_rows'] = 1
+
+        return data
+
+    def iterate(self, index, step, n_cols):
+
+        while True:
+            yield self.get(index, n_cols)
+            index += step
+
+    def reset(self):
+        """
+        Fetch changes to the submission from PRAW and clear the internal list.
+        """
+
+        self.submission.refresh()
+        self._submission_data = self.strip_praw_submission(self.submission)
+
+        self.display_name = self._submission_data['permalink']
+        self._comments = self.flatten_comments(self.submission.comments)
+        self._comment_data = [self.strip_praw_comment(c) for c in self._comments]
\ No newline at end of file
diff --git a/rtv/submission_viewer.py b/rtv/submission_viewer.py
new file mode 100644
index 0000000..a151b7d
--- /dev/null
+++ b/rtv/submission_viewer.py
@@ -0,0 +1,128 @@
+import praw
+import curses
+
+from content_generators import SubmissionContent, SubredditContent
+from utils import curses_session
+from viewer import BaseViewer
+
+class SubmissionViewer(BaseViewer):
+
+    def __init__(self, stdscr, content):
+
+        page_index, cursor_index = -1, 1
+        super(SubmissionViewer, self).__init__(
+            stdscr, content,
+            page_index=page_index, cursor_index=cursor_index)
+
+    def loop(self):
+
+        self.draw()
+        while True:
+            cmd = self.stdscr.getch()
+
+            if cmd == curses.KEY_UP:
+                self.move_cursor_up()
+                self.clear_input_queue()
+
+            elif cmd == curses.KEY_DOWN:
+                self.move_cursor_down()
+                self.clear_input_queue()
+
+            # Refresh page
+            elif cmd in (curses.KEY_F5, ord('r')):
+                self.content.reset()
+                self.stdscr.clear()
+                self.draw()
+
+            elif cmd == curses.KEY_RESIZE:
+                self.draw()
+
+            # Quit
+            elif cmd == ord('q'):
+                break
+
+            else:
+                curses.beep()
+
+    def draw(self):
+
+        n_rows, n_cols = self.stdscr.getmaxyx()
+        self._header_window = self.stdscr.derwin(1, n_cols, 0, 0)
+        self._content_window = self.stdscr.derwin(1, 0)
+
+        self.draw_header()
+        self.draw_content()
+        self.add_cursor()
+
+    def draw_item(self, win, data, inverted=False):
+
+        if data['type'] == 'MoreComments':
+            self.draw_more_comments(win, data)
+
+        elif data['type'] == 'Comment':
+            self.draw_comment(win, data, inverted=inverted)
+
+        else:
+            self.draw_submission(win, data)
+
+    @staticmethod
+    def draw_comment(win, data, inverted=False):
+
+        n_rows, n_cols = win.getmaxyx()
+        n_cols -= 2
+
+        # Handle the case where the window is not large enough to fit the data.
+        valid_rows = range(0, n_rows)
+        offset = 0 if not inverted else -(data['n_rows'] - n_rows)
+
+        row = offset
+        text = '{} {} {}'.format(data['author'], data['score'], data['created'])
+        if row in valid_rows:
+            win.addnstr(row, 1, text, n_cols)
+
+        n_body = len(data['split_body'])
+        for row, text in enumerate(data['split_body'], start=offset+1):
+            if row in valid_rows:
+                win.addnstr(row, 1, text, n_cols)
+
+        # Vertical line, unfortunately vline() doesn't support custom color so
+        # we have to build it one chr at a time.
+        for y in xrange(n_rows):
+            win.addch(y, 0, curses.ACS_VLINE)
+
+    @staticmethod
+    def draw_more_comments(win, data):
+
+        n_rows, n_cols = win.getmaxyx()
+        n_cols -= 2
+        win.addnstr(0, 1, data['body'], n_cols)
+
+        for y in xrange(n_rows):
+            win.addch(y, 0, curses.ACS_VLINE)
+
+    @staticmethod
+    def draw_submission(win, data):
+
+        n_rows, n_cols = win.getmaxyx()
+        n_cols -= 1
+
+        # Don't print anything if there is not enough room
+        if data['n_rows'] > n_rows:
+            return
+
+        win.border()
+
+
+def main():
+
+    with curses_session() as stdscr:
+        r = praw.Reddit(user_agent='reddit terminal viewer (rtv) v0.0')
+        submission = SubredditContent(r).get(0)['object']
+        generator = SubmissionContent(submission)
+
+        viewer = SubmissionViewer(stdscr, generator)
+        viewer.loop()
+
+if __name__ == '__main__':
+
+    main()
\ No newline at end of file
diff --git a/rtv/subreddit.py b/rtv/subreddit_viewer.py
similarity index 52%
rename from rtv/subreddit.py
rename to rtv/subreddit_viewer.py
index dd48c16..3c1b648 100644
--- a/rtv/subreddit.py
+++ b/rtv/subreddit_viewer.py
@@ -8,14 +8,6 @@ from viewer import BaseViewer
 
 class SubredditViewer(BaseViewer):
 
-    def __init__(self, stdscr, subreddit_content):
-
-        self.stdscr = stdscr
-        self._title_window = None
-        self._content_window = None
-
-        super(SubredditViewer, self).__init__(subreddit_content)
-
     def loop(self):
 
         self.draw()
@@ -24,9 +16,11 @@ class SubredditViewer(BaseViewer):
 
             if cmd == curses.KEY_UP:
                 self.move_cursor_up()
+                self.clear_input_queue()
 
             elif cmd == curses.KEY_DOWN:
                 self.move_cursor_down()
+                self.clear_input_queue()
 
             # View submission
             elif cmd in (curses.KEY_RIGHT, ord(' ')):
@@ -54,59 +48,19 @@ class SubredditViewer(BaseViewer):
 
     def draw(self):
 
-        # Refresh window bounds incase the screen has been resized
         n_rows, n_cols = self.stdscr.getmaxyx()
-        self._title_window = self.stdscr.derwin(1, n_cols, 0, 0)
+        self._header_window = self.stdscr.derwin(1, n_cols, 0, 0)
         self._content_window = self.stdscr.derwin(1, 0)
 
         self.draw_header()
         self.draw_content()
         self.add_cursor()
 
-    def draw_content(self):
-        """
-        Loop through submissions and fill up the content page.
-        """
-
-        n_rows, n_cols = self._content_window.getmaxyx()
-        self._content_window.erase()
-        self._subwindows = []
-
-        page_index, cursor_index, inverted = self.nav.position
-        step = self.nav.step
-
-        # If not inverted, align the first submission with the top and draw
-        # downwards. If inverted, align the first submission with the bottom
-        # and draw upwards.
-        current_row = n_rows if inverted else 0
-        available_rows = n_rows
-        for data in self.content.iterate(page_index, step, n_cols-2):
-            window_rows = min(available_rows, data['n_rows'])
-            start = current_row - window_rows if inverted else current_row
-            window = self._content_window.derwin(window_rows, n_cols, start, 0)
-            self.draw_submission(window, data, inverted)
-            self._subwindows.append(window)
-            available_rows -= (window_rows + 1)  # Add one for the blank line
-            current_row += step * (window_rows + 1)
-            if available_rows <= 0:
-                break
-
-        self._content_window.refresh()
-
-    def draw_header(self):
-
-        n_rows, n_cols = self._title_window.getmaxyx()
-        sub_name = self.content.display_name
-
-        self._title_window.erase()
-        self._title_window.addnstr(0, 0, sub_name, n_cols)
-        self._title_window.refresh()
-
     @staticmethod
-    def draw_submission(win, data, inverted=False):
+    def draw_item(win, data, inverted=False):
 
         n_rows, n_cols = win.getmaxyx()
-        n_cols -= 1  # Leave space for the cursor in the first column
+        n_cols -= 2  # Leave space for the cursor in the first column
 
         # Handle the case where the window is not large enough to fit the data.
         valid_rows = range(0, n_rows)
@@ -119,15 +73,15 @@ class SubredditViewer(BaseViewer):
 
         row = n_title + offset
         if row in valid_rows:
-            win.addnstr(row, 1, '{url}'.format(**data), n_cols-1)
+            win.addnstr(row, 1, '{url}'.format(**data), n_cols)
 
         row = n_title + offset + 1
         if row in valid_rows:
-            win.addnstr(row, 1, '{created} {comments} {score}'.format(**data), n_cols-1)
+            win.addnstr(row, 1, '{created} {comments} {score}'.format(**data), n_cols)
 
         row = n_title + offset + 2
         if row in valid_rows:
-            win.addnstr(row, 1, '{author} {subreddit}'.format(**data), n_cols-1)
+            win.addnstr(row, 1, '{author} {subreddit}'.format(**data), n_cols)
 
 def main():
 
diff --git a/rtv/viewer.py b/rtv/viewer.py
index 6ce56a6..2ed517d 100644
--- a/rtv/viewer.py
+++ b/rtv/viewer.py
@@ -12,11 +12,12 @@ class Navigator(object):
             cursor_index=0,
             inverted=False):
 
-        self._page_cb = valid_page_cb
-
         self.page_index = page_index
         self.cursor_index = cursor_index
         self.inverted = inverted
+        self._page_cb = valid_page_cb
+        self._header_window = None
+        self._content_window = None
 
     @property
     def step(self):
@@ -26,6 +27,10 @@ class Navigator(object):
     def position(self):
         return (self.page_index, self.cursor_index, self.inverted)
 
+    @property
+    def absolute_index(self):
+        return self.page_index + (self.step * self.cursor_index)
+
     def move(self, direction, n_windows):
         "Move the cursor down (positive direction) or up (negative direction)"
 
@@ -70,10 +75,12 @@ class BaseViewer(object):
     Base terminal viewer incorperates a cursor to navigate content
     """
 
-    def __init__(self, content):
+    def __init__(self, stdscr, content, **kwargs):
 
+        self.stdscr = stdscr
         self.content = content
-        self.nav = Navigator(self.content.get)
+
+        self.nav = Navigator(self.content.get, **kwargs)
 
         self._subwindows = None
 
@@ -87,13 +94,61 @@ class BaseViewer(object):
         self._move_cursor(1)
 
     def add_cursor(self):
-        curses.curs_set(2)
         self._edit_cursor(curses.A_REVERSE)
 
     def remove_cursor(self):
-        curses.curs_set(0)
         self._edit_cursor(curses.A_NORMAL)
 
+    def clear_input_queue(self):
+        "Clear excessive input caused by the scroll wheel or holding down a key"
+        self.stdscr.nodelay(1)
+        while self.stdscr.getch() != -1:
+            continue
+        self.stdscr.nodelay(0)
+
+    def draw_header(self):
+
+        n_rows, n_cols = self._header_window.getmaxyx()
+
+        self._header_window.erase()
+        self._header_window.addnstr(0, 0, self.content.display_name, n_cols-1)
+        self._header_window.refresh()
+
+    def draw_content(self):
+        """
+        Loop through submissions and fill up the content page.
+        """
+
+        n_rows, n_cols = self._content_window.getmaxyx()
+        self._content_window.erase()
+        self._subwindows = []
+
+        page_index, cursor_index, inverted = self.nav.position
+        step = self.nav.step
+
+        # If not inverted, align the first submission with the top and draw
+        # downwards. If inverted, align the first submission with the bottom
+        # and draw upwards.
+        current_row = n_rows if inverted else 0
+        available_rows = n_rows
+        for data in self.content.iterate(page_index, step, n_cols-2):
+            window_rows = min(available_rows, data['n_rows'])
+            window_cols = n_cols - data['offset']
+            start = current_row - window_rows if inverted else current_row
+            subwindow = self._content_window.derwin(
+                window_rows, window_cols, start, data['offset'])
+            self.draw_item(subwindow, data, inverted)
+            self._subwindows.append(subwindow)
+            available_rows -= (window_rows + 1)  # Add one for the blank line
+            current_row += step * (window_rows + 1)
+            if available_rows <= 0:
+                break
+
+        self._content_window.refresh()
+
+    def draw_item(self, window, data, inverted):
+        raise NotImplementedError
+
     def _move_cursor(self, direction):
 
         self.remove_cursor()
@@ -101,18 +156,24 @@ class BaseViewer(object):
         valid, redraw = self.nav.move(direction, len(self._subwindows))
         if not valid:
             curses.flash()
-        if redraw:
+
+        # If we don't redraw, ACS_VLINE gets screwed up when changing the
+        # attr back to normal. There may be a way around this.
+        if True: #if redraw
             self.draw_content()
 
         self.add_cursor()
 
     def _edit_cursor(self, attribute):
 
-        window = self._subwindows[self.nav.cursor_index]
+        # Don't alow the cursor to go below page index 0
+        if self.nav.absolute_index == -1:
+            window = self._subwindows[self.nav.cursor_index + 1]
+        else:
+            window = self._subwindows[self.nav.cursor_index]
 
         n_rows, _ = window.getmaxyx()
         for row in xrange(n_rows):
             window.chgat(row, 0, 1, attribute)
-        window.move(0, 0)
 
         window.refresh()
\ No newline at end of file