add editor

Signed-off-by: Mattias Andrée <maandree@operamail.com>

1 files changed, 372 insertions, 0 deletions

diff --git a/src/editor.py b/src/editor.py
new file mode 100644
index 0000000..8709ccf
--- /dev/null
+++ b/src/editor.py
@@ -0,0 +1,372 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+'''
+featherweight – A lightweight terminal news feed reader
+
+Copyright © 2013  Mattias Andrée (maandree@member.fsf.org)
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+'''
+import sys
+from subprocess import Popen, PIPE
+
+
+'''
+GNU Emacs alike text area
+'''
+class TextArea(): # TODO support small screens
+    def __init__(self, fields, datamap, left, top, width, height, termsize):
+        '''
+        Constructor
+        
+        @param  fields:list<str>        Field names
+        @param  datamap:dist<str, str>  Data map
+        @param  left:int                Left position of the component
+        @param  top:int                 Top position of the component
+        @param  width:int               Width of the component
+        @param  height:int              Height of the component
+        @param  termsize:(int, int)     The height and width of the terminal
+        '''
+        self.fields, self.datamap, self.left, self.top, self.width, self.height, self.termsize = fields, datamap, left, top, width - 1, height, termsize
+    
+    
+    
+    def run(self, saver):
+        '''
+        Execute text reading
+        
+        @param  saver  Save method
+        '''
+        innerleft = len(max(self.fields, key = len)) + self.left + 3
+        
+        leftlines = []
+        datalines = []
+        
+        for key in self.fields:
+            for line in self.datamap[key].split('\n'):
+                leftlines.append(key)
+                datalines.append(line)
+        
+        (termh, termw) = self.termsize
+        (y, x) = (0, 0)
+        mark = None
+        
+        KILL_MAX = 50
+        killring = []
+        killptr = None
+        
+        def status(text):
+            print('\033[%i;%iH\033[7m%s\033[27m\033[%i;%iH' % (termh - 1, 1, ' (' + text + ') ' + '-' * (termw - len(' (' + text + ') ')), self.top + y, innerleft + x), end='')
+        
+        status('unmodified')
+        
+        print('\033[%i;%iH' % (self.top, innerleft), end='')
+        
+        def alert(text):
+            if text is None:
+                alert('')
+            else:
+                print('\033[%i;%iH\033[2K%s\033[%i;%iH' % (termh, 1, text, self.top + y, innerleft + x), end='')
+        
+        modified = False
+        override = False
+        
+        (oldy, oldx, oldmark) = (y, x, mark)
+        stored = chr(ord('L') - ord('@'))
+        alerted = False
+        edited = False
+        print('\033[%i;%iH' % (self.top + y, innerleft + x), end='')
+        while True:
+            if (oldmark is not None) and (oldmark >= 0):
+                if oldmark < oldx:
+                    print('\033[%i;%iH\033[49m%s\033[%i;%iH' % (self.top + oldy, innerleft + oldmark, datalines[oldy][oldmark : oldx], self.top + y, innerleft + x), end='')
+                elif oldmark > oldx:
+                    print('\033[%i;%iH\033[49m%s\033[%i;%iH' % (self.top + oldy, innerleft + oldx, datalines[oldy][oldx : oldmark], self.top + y, innerleft + x), end='')
+            if (mark is not None) and (mark >= 0):
+                if mark < x:
+                    print('\033[%i;%iH\033[44;37m%s\033[49;39m\033[%i;%iH' % (self.top + y, innerleft + mark, datalines[y][mark : x], self.top + y, innerleft + x), end='')
+                elif mark > x:
+                    print('\033[%i;%iH\033[44;37m%s\033[49;39m\033[%i;%iH' % (self.top + y, innerleft + x, datalines[y][x : mark], self.top + y, innerleft + x), end='')
+            if y != oldy:
+                if (oldy > 0) and (leftlines[oldy - 1] == leftlines[oldy]) and (leftlines[oldy] == leftlines[-1]):
+                    print('\033[%i;%iH\033[34m%s\033[39m' % (self.top + oldy, self.left, '>'), end='')
+                else:
+                    print('\033[%i;%iH\033[34m%s:\033[39m' % (self.top + oldy, self.left, leftlines[oldy]), end='')
+                if (y > 0) and (leftlines[y - 1] == leftlines[y]) and (leftlines[y] == leftlines[-1]):
+                    print('\033[%i;%iH\033[1;34m%s\033[21;39m' % (self.top + y, self.left, '>'), end='')
+                else:
+                    print('\033[%i;%iH\033[1;34m%s:\033[21;39m' % (self.top + y, self.left, leftlines[y]), end='')
+                print('\033[%i;%iH' % (self.top + y, innerleft + x), end='')
+            (oldy, oldx, oldmark) = (y, x, mark)
+            if edited:
+                edited = False
+                if not modified:
+                    modified = True
+                    status('modified' + (' override' if override else ''))
+            sys.stdout.flush()
+            if stored is None:
+                d = sys.stdin.read(1)
+            else:
+                d = stored
+                stored = None
+            if alerted:
+                alerted = False
+                alert(None)
+            if ord(d) == ord('@') - ord('@'):
+                if mark is None:
+                    mark = x
+                    alert('Mark set')
+                elif mark == ~x:
+                    mark = x
+                    alert('Mark activated')
+                elif mark == x:
+                    mark = ~x
+                    alert('Mark deactivated')
+                else:
+                    mark = x
+                    alert('Mark set')
+                alerted = True
+            elif ord(d) == ord('K') - ord('@'):
+                if x == len(datalines[y]):
+                    alert('At end')
+                    alerted = True
+                else:
+                    mark = len(datalines[y])
+                    stored = chr(ord('W') - ord('@'))
+            elif ord(d) == ord('W') - ord('@'):
+                if (mark is not None) and (mark >= 0) and (mark != x):
+                    selected = datalines[y][mark : x] if mark < x else datalines[y][x : mark]
+                    killring.append(selected)
+                    if len(killring) > KILL_MAX:
+                        killring = killring[1:]
+                    stored = chr(127)
+                else:
+                    alert('No text is selected')
+                    alerted = True
+            elif ord(d) == ord('Y') - ord('@'):
+                if len(killring) == 0:
+                    alert('Killring is empty')
+                    alerted = True
+                else:
+                    mark = None
+                    killptr = len(killring) - 1
+                    yanked = killring[killptr]
+                    print('\033[%i;%iH%s' % (self.top + y, innerleft + x, yanked + datalines[y][x:]), end='')
+                    datalines[y] = datalines[y][:x] + yanked + datalines[y][x:]
+                    x += len(yanked)
+                    print('\033[%i;%iH' % (self.top + y, innerleft + x), end='')
+            elif ord(d) == ord('X') - ord('@'):
+                alert('C-x')
+                alerted = True
+                sys.stdout.flush()
+                d = sys.stdin.read(1)
+                alert(str(ord(d)))
+                sys.stdout.flush()
+                if ord(d) == ord('X') - ord('@'):
+                    if (mark is not None) and (mark >= 0):
+                        x ^= mark; mark ^= x; x ^= mark
+                        alert('Mark swapped')
+                    else:
+                        alert('No mark is activated')
+                elif ord(d) == ord('S') - ord('@'):
+                    last = ''
+                    for row in range(0, len(datalines)):
+                        current = leftlines[row]
+                        if len(datalines[row].strip()) == 0:
+                            if current is not 'comment':
+                                if current != last:
+                                    self.datamap[current] = None
+                                continue
+                        if current == last:
+                            self.datamap[current] += '\n' + datalines[row]
+                        else:
+                            self.datamap[current] = datalines[row]
+                            last = current
+                    saver()
+                    status('unmodified' + (' override' if override else ''))
+                    alert('Saved')
+                elif ord(d) == ord('C') - ord('@'):
+                    break
+                else:
+                    stored = d
+                    alerted = False
+                    alert(None)
+            elif (ord(d) == 127) or (ord(d) == 8):
+                removed = 1
+                if (mark is not None) and (mark >= 0) and (mark != x):
+                    if mark > x:
+                        x ^= mark; mark ^= x; x ^= mark
+                    removed = x - mark
+                if x == 0:
+                    alert('At beginning')
+                    alerted = True
+                    continue
+                dataline = datalines[y]
+                datalines[y] = dataline = dataline[:x - removed] + dataline[x:]
+                x -= removed
+                mark = None
+                print('\033[%i;%iH%s%s\033[%i;%iH' % (self.top + y, innerleft, dataline, ' ' * removed, self.top + y, innerleft + x), end='')
+                edited = True
+            elif ord(d) < ord(' '):
+                if ord(d) == ord('P') - ord('@'):
+                    if y == 0:
+                        alert('At first line')
+                        alerted = True
+                    else:
+                        y -= 1
+                        mark = None
+                        x = 0
+                elif ord(d) == ord('N') - ord('@'):
+                    if y < len(datalines) - 1:
+                        y += 1
+                        mark = None
+                        x = 0
+                elif ord(d) == ord('F') - ord('@'):
+                    if x < len(datalines[y]):
+                        x += 1
+                        print('\033[C', end='')
+                    else:
+                        alert('At end')
+                        alerted = True
+                elif ord(d) == ord('B') - ord('@'):
+                    if x > 0:
+                        x -= 1
+                        print('\033[D', end='')
+                    else:
+                        alert('At beginning')
+                        alerted = True
+                elif ord(d) == ord('L') - ord('@'):
+                    empty = '\033[0m' + (' ' * self.width + '\n') * len(datalines)
+                    print('\033[%i;%iH%s' % (self.top, self.left, empty), end='')
+                    for row in range(0, len(leftlines)):
+                        leftline = leftlines[row] + ':'
+                        if (leftlines[row - 1] == leftlines[row]) and (leftlines[row] == leftlines[-1]):
+                            leftline = '>'
+                        print('\033[%i;%iH\033[%s34m%s\033[%s39m' % (self.top + row, self.left, '1;' if row == y else '', leftline, '21;' if row == y else ''), end='')
+                    for row in range(0, len(datalines)):
+                        print('\033[%i;%iH%s\033[49m' % (self.top + row, innerleft, datalines[row]), end='')
+                    print('\033[%i;%iH' % (self.top + y, innerleft + x), end='')
+                elif d == '\033':
+                    d = sys.stdin.read(1)
+                    if d == '[':
+                        d = sys.stdin.read(1)
+                        if d == 'A':
+                            stored = chr(ord('P') - ord('@'))
+                        elif d == 'B':
+                            if y == len(datalines) - 1:
+                                alert('At last line')
+                                alerted = True
+                            else:
+                                stored = chr(ord('N') - ord('@'))
+                        elif d == 'C':
+                            stored = chr(ord('F') - ord('@'))
+                        elif d == 'D':
+                            stored = chr(ord('B') - ord('@'))
+                        elif d == '2':
+                            d = sys.stdin.read(1)
+                            if d == '~':
+                                override = not override
+                                status(('modified' if modified else 'unmodified') + (' override' if override else ''))
+                        elif d == '3':
+                            d = sys.stdin.read(1)
+                            if d == '~':
+                                removed = 1
+                                if (mark is not None) and (mark >= 0) and (mark != x):
+                                    if mark < x:
+                                        x ^= mark; mark ^= x; x ^= mark
+                                    removed = mark - x
+                                dataline = datalines[y]
+                                if x == len(dataline):
+                                    alert('At end')
+                                    alerted = True
+                                    continue
+                                datalines[y] = dataline = dataline[:x] + dataline[x + removed:]
+                                print('\033[%i;%iH%s%s\033[%i;%iH' % (self.top + y, innerleft, dataline, ' ' * removed, self.top + y, innerleft + x), end='')
+                                mark = None
+                                edited = True
+                        else:
+                            while True:
+                                d = sys.stdin.read(1)
+                                if (ord('a') <= ord(d)) and (ord(d) <= ord('z')): break
+                                if (ord('A') <= ord(d)) and (ord(d) <= ord('Z')): break
+                                if d == '~': break
+                    elif (d == 'w') or (d == 'W'):
+                        if (mark is not None) and (mark >= 0) and (mark != x):
+                            selected = datalines[y][mark : x] if mark < x else datalines[y][x : mark]
+                            killring.append(selected)
+                            mark = None
+                            if len(killring) > KILL_MAX:
+                                killring = killring[1:]
+                        else:
+                            alert('No text is selected')
+                            alerted = True
+                    elif (d == 'y') or (d == 'Y'):
+                        if killptr is not None:
+                            yanked = killring[killptr]
+                            dataline = datalines[y]
+                            if (len(yanked) <= x) and (dataline[x - len(yanked) : x] == yanked):
+                                killptr -= 1
+                                if killptr < 0:
+                                    killptr += len(killring)
+                                dataline = dataline[:x - len(yanked)] + killring[killptr] + dataline[x:]
+                                additional = len(killring[killptr]) - len(yanked)
+                                x += additional
+                                datalines[y] = dataline
+                                print('\033[%i;%iH%s%s\033[%i;%iH' % (self.top + y, innerleft, dataline, ' ' * max(0, -additional), self.top + y, innerleft + x), end='')
+                            else:
+                                stored = chr(ord('Y') - ord('@'))
+                        else:
+                            stored = chr(ord('Y') - ord('@'))
+                    elif d == 'O':
+                        d = sys.stdin.read(1)
+                        if d == 'H':
+                            x = 0
+                        elif d == 'F':
+                            x = len(datalines[y])
+                        print('\033[%i;%iH' % (self.top + y, innerleft + x), end='')
+                elif d == '\n':
+                    stored = chr(ord('N') - ord('@'))
+            else:
+                insert = d
+                if len(insert) == 0:
+                    continue
+                dataline = datalines[y]
+                if (not override) or (x == len(dataline)):
+                    print(insert + dataline[x:], end='')
+                    if len(dataline) - x > 0:
+                        print('\033[%iD' % (len(dataline) - x), end='')
+                    datalines[y] = dataline[:x] + insert + dataline[x:]
+                    if (mark is not None) and (mark >= 0):
+                        if mark >= x:
+                            mark += len(insert)
+                else:
+                    print(insert, end='')
+                    datalines[y] = dataline[:x] + insert + dataline[x + 1:]
+                x += len(insert)
+                edited = True
+
+
+def phonysaver():
+    pass
+print('\033[H\033[2J')
+old_stty = Popen('stty --save'.split(' '), stdout = PIPE).communicate()[0]
+old_stty = old_stty.decode('utf-8', 'error')[:-1]
+Popen('stty -icanon -echo -isig'.split(' '), stdout = PIPE).communicate()
+try:
+    TextArea(['alpha', 'beta'], {'alpha' : 'a', 'beta' : 'be'}, 1, 1, 20, 4, (4, 20)).run(phonysaver)
+finally:
+    print('\033[H\033[2J', end = '')
+    sys.stdout.flush()
+    Popen(['stty', old_stty], stdout = PIPE).communicate()
+