[latex] Fix plugin, cleanup code

latex/latex_renderer.py

@@ -0,0 +1,175 @@
+# Copyright (C) 2010-2011 Yves Fischer <yvesf AT xapek.org>
+# Copyright (C) 2011 Yann Leboulanger <asterix AT lagaule.org>
+#
+# This file is part of Gajim.
+#
+# Gajim 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; version 3 only.
+#
+# Gajim 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 Gajim.  If not, see <http://www.gnu.org/licenses/>.
+
+import random
+import os
+import logging
+from tempfile import mkstemp
+from tempfile import mkdtemp
+
+from gi.repository import Gtk
+from gi.repository import GdkPixbuf
+from gi.repository import GLib
+
+from gajim.common import app
+
+from gajim.plugins.plugins_i18n import _
+
+from latex.util import try_run
+from latex.util import write_latex
+from latex.util import BLACKLIST
+
+log = logging.getLogger('gajim.p.latex')
+
+
+class LatexRenderer:
+    def __init__(self, iter_start, iter_end, widget, png_dpi):
+        self.widget = widget
+        self.buffer = widget.get_buffer()
+        self.code = iter_start.get_text(iter_end)
+        self.mark_name = 'LatexRendererMark%s' % str(random.randint(0, 1000))
+        self.mark = self.buffer.create_mark(self.mark_name, iter_start, True)
+        self.png_dpi = str(png_dpi)
+
+        # delete code and show message 'processing'
+        self.buffer.delete(iter_start, iter_end)
+        self.buffer.insert(iter_start, _('Processing LaTeX'))
+        self._start_processing()
+
+    def _start_processing(self):
+        try:
+            if self._check_code():
+                self._show_image()
+            else:
+                self._show_error(_('There are bad commands!'))
+        except Exception as err:
+            self._show_error(_('Error processing LaTeX: %s' % err))
+        finally:
+            self.buffer.delete_mark(self.mark)
+
+    def _check_code(self):
+        for bad_cmd in BLACKLIST:
+            if self.code.find(bad_cmd) != -1:
+                # Found bad command
+                return False
+        return True
+
+    def _show_error(self, message):
+        """
+        String -> TextBuffer
+        """
+        iter_mark = self.buffer.get_iter_at_mark(self.mark)
+        iter_end = iter_mark.copy().forward_search(
+            _('Processing LaTeX'),
+            Gtk.TextSearchFlags.TEXT_ONLY, None)[1]
+        self.buffer.delete(iter_mark, iter_end)
+        self.buffer.insert(iter_end, message)
+
+    def _show_image(self):
+        """
+        Latex -> PNG -> TextBuffer
+        """
+
+        def _fg_str(fmt):
+            try:
+                return [
+                    {'hex' : '+level-colors', 'tex' : '-fg'}[fmt],
+                    app.interface.get_fg_color(fmt)]
+            except KeyError:
+                # interface may not be available when we test latex at startup
+                return []
+            except AttributeError:
+                # interface may not be available when we test latext at startup
+                return {'hex': ['+level-colors', '0x000000'],
+                        'tex': ['-fg', 'rgb 0.0 0.0 0.0']}[fmt]
+
+        try:
+            tmpdir = mkdtemp(prefix='gajim_tex')
+            tmpfd, tmppng = mkstemp(prefix='gajim_tex', suffix='.png')
+            os.close(tmpfd)
+        except Exception:
+            msg = 'Could not create temporary files for Latex plugin'
+            log.debug(msg)
+            self._show_error(
+                _('latex error: %(error)s\n===ORIGINAL CODE====\n'
+                  '%(code)s') % {
+                      'error': msg,
+                      'code': self.code[2:len(self.code)-2]})
+            return False
+
+        tmpfile = os.path.join(tmpdir, 'gajim_tex')
+
+        # build latex string
+        write_latex(tmpfile + '.tex', self.code[2:len(self.code)-2])
+
+        # convert TeX to dvi
+        exitcode = try_run(
+            ['latex', '--interaction=nonstopmode', tmpfile + '.tex'], tmpdir)
+
+        if exitcode == 0:
+            # convert dvi to png
+            log.debug('DVI OK')
+            exitcode = try_run(
+                ['dvipng', '-bg', 'Transparent'] + _fg_str('tex') + \
+                ['-T', 'tight', '-D', self.png_dpi, tmpfile + '.dvi', '-o',
+                 tmpfile + '.png'], tmpdir)
+
+            if exitcode:
+                # dvipng failed, try convert
+                log.debug('dvipng failed, try convert')
+                exitcode = try_run(
+                    ['convert'] + _fg_str('hex') + \
+                    ['-trim', '-density', self.png_dpi,
+                     tmpfile + '.dvi', tmpfile + '.png'], tmpdir)
+
+        # remove temp files created by us and TeX
+        extensions = ['.tex', '.log', '.aux', '.dvi']
+        for ext in extensions:
+            try:
+                os.remove(tmpfile + ext)
+            except Exception:
+                pass
+
+        if exitcode == 0:
+            log.debug('PNG OK')
+            os.rename(tmpfile + '.png', tmppng)
+        else:
+            log.debug('PNG FAILED')
+            os.remove(tmppng)
+            os.rmdir(tmpdir)
+            self._show_error(
+                _('Convertion to image failed\n===ORIGINAL CODE===='
+                  '\n%s') % self.code[2:len(self.code)-2])
+            return False
+
+        log.debug('Loading PNG %s', tmppng)
+        try:
+            pixbuf = GdkPixbuf.Pixbuf.new_from_file(tmppng)
+            log.debug('png loaded')
+            iter_mark = self.buffer.get_iter_at_mark(self.mark)
+            iter_end = iter_mark.copy().forward_search(
+                _('Processing LaTeX'),
+                Gtk.TextSearchFlags.TEXT_ONLY, None)[1]
+            log.debug('Delete old Text')
+            self.buffer.delete(iter_mark, iter_end)
+            log.debug('Insert pixbuf')
+            self.buffer.insert_pixbuf(iter_end, pixbuf)
+        except GLib.GError:
+            self._show_error(_('Cannot open %s for reading') % tmppng)
+            log.debug('Cant open %s for reading', tmppng)
+        finally:
+            os.remove(tmppng)