[syntax_highlight] Integrate with master branch

This commit contains all changes starting with the first integration of
the plugin into the gajim_1.1 branch (76dabe2e) until the current plugin
version V3 (42b9aeb8).
The manifest.ini is updated for compatibility with upcoming Gajim
versions.

syntax_highlight/README.md

+# Syntax Highlighting Plugin for Gajim
+
+[Gajim](https://gajim.org) Plugin that highlights source code blocks in chatbox.
+
+## Installation
+
+The recommended way of installing this plugin is to use
+Gajim's Plugin Installer.
+
+For more information and instruction on how to install plugins manually, please
+refer to the [Gajim Plugin Wiki seite](https://dev.gajim.org/gajim/gajim-plugins/wikis/home#how-to-install-plugins).
+
+
+## Usage
+
+This plugin uses markdown-style syntax to identify which parts of a message
+should be formatted as code in the chatbox.
+
+```
+Inline source code  will be highlighted when placed in between `two single
+back-ticks`.
+```
+
+The language used to highlight the syntax of inline code is selected as the
+default language in the plugin settings.
+
+
+Multi-line code blocks are started by three back-ticks followed by a newline.
+Optionally, a language can be specified directly after the opening back-ticks and
+before the line break:
+````
+```language
+Note, that the last line of a code block may only contain the closing back-ticks,
+i.e. there must be a newline here.
+```
+````
+
+In case no languge is specified with the opening tag or the specified language
+could not be identified, the default languge configured in the settings is
+used.
+
+You can test it by copying and sending the following text to one of your
+contacts:
+````
+```python
+def test():
+    print("Hello, world!")
+```
+````
+(**Note:** your contact will not receive highlighted text unless she is also
+using the plugin.)
+
+
+## Relation to XEP-0393 - 'Message Styling'
+
+
+https://xmpp.org/extensions/xep-0393.html#pre-block
+
+In [XEP-0393](https://xmpp.org/extensions/xep-0393.html),
+the back-tick based syntax is defined as markup for preformatted
+text blocks, respectively inline performatted text.
+Formatting of such text blocks with monospaced fonts is recommended by the XEP.
+
+By using the same syntax as defined in XEP-0393 XMPP clients with only XEP-0393
+support but without syntax highlighting can at least present their users blocks
+of pre-formatted text.
+
+Since text in between the back-tick markers is not further formatted by this
+plugin, it can be considered "pre-formatted".
+Hence, this plugin is compatible to the formatting options defined by XEP-0393,
+[section 5.1.2, "Preformatted Text"](https://xmpp.org/extensions/xep-0393.html#pre-block)
+and [section 5.2.5, "Preformatted Span"](https://xmpp.org/extensions/xep-0393.html#mono).
+
+Nevertheless, syntax highlighting for source code is not part of XEP but
+rather a non-standard extension introduced with this plugin.
+
+
+## Configuration
+
+The configuration can be found via 'Gajim' > 'Plugins', then select the
+'Source Code Syntax Highlight' Plugin and click the gears symbol.
+The configuration options let you specify many details how code is formatted,
+including default language, style, font settings, background color and formatting
+of the code markers.
+
+In the configuration window, the current settings are displayed in an
+interactive preview pannel. This allows you to directly check how code would
+look like in the message
+window.
+
+## Report Bugs and Feature Requests
+
+For bug reports, please report them to the [Gajim Plugin Issue tracker](https://dev.gajim.org/gajim/gajim-plugins/issues/new?issue[FlorianMuenchbach]=&issue[description]=Gajim%20Version%3A%20%0APlugin%20Version%3A%0AOperating%20System%3A&issue[title]=[syntax_highlight]).
+
+Please make sure that the issue you create contains `[syntax_highlight]` in the
+title and information such as Gajim version, Plugin version, Operating system,
+etc.
+
+## Debug
+
+The plugin adds its own logger. It can be used to set a specific debug level
+for this plugin and/or filter log messages.
+
+Run
+```
+gajim --loglevel gajim.plugin_system.syntax_highlight=DEBUG
+```
+in a terminal to display the debug messages.
+
+
+## Known Issues / ToDo
+
+ * ~~Gajim crashes when correcting a message containing highlighted code.~~
+   (fixed in version 1.1.0)
+
+
+## Credits
+
+Since I had no experience in writing Plugins for Gajim, I used the
+[Latex Plugin](https://trac-plugins.gajim.org/wiki/LatexPlugin)
+written by Yves Fischer and Yann Leboulanger as an example and copied a big
+portion of initial code. Therefore, credits go to the authors of the Latex
+Plugin for providing an example.
+
+The syntax highlighting itself is done by [pygments](http://pygments.org/).

syntax_highlight/__init__.py

+from .syntax_highlight import SyntaxHighlighterPlugin

syntax_highlight/chat_syntax_highlighter.py

+import logging
+import re
+import pygments
+
+from gi.repository import Gtk
+
+from gajim.plugins.helpers import log
+
+
+from .gtkformatter import GTKFormatter
+from .types import MatchType, LineBreakOptions, CodeMarkerOptions
+
+
+log = logging.getLogger('gajim.plugin_system.syntax_highlight')
+
+class ChatSyntaxHighlighter:
+    def hide_code_markup(self, buf, start, end):
+        tag = buf.get_tag_table().lookup('hide_code_markup')
+        if tag is None:
+            tag = Gtk.TextTag.new('hide_code_markup')
+            tag.set_property('invisible', True)
+            buf.get_tag_table().add(tag)
+
+        buf.apply_tag_by_name('hide_code_markup', start, end)
+
+    def check_line_break(self, is_multiline):
+        line_break = self.config.get_line_break_action()
+
+        return (line_break == LineBreakOptions.ALWAYS) \
+                or (is_multiline and line_break == LineBreakOptions.MULTILINE)
+
+
+    def format_code(self, buf, s_tag, s_code, e_tag, e_code, language):
+        style = self.config.get_style_name()
+        if self.config.get_code_marker_setting() == CodeMarkerOptions.HIDE:
+            self.hide_code_markup(buf, s_tag, s_code)
+            self.hide_code_markup(buf, e_code, e_tag)
+        else:
+            comment_tag = GTKFormatter.create_tag_for_token(
+                    pygments.token.Comment,
+                    pygments.styles.get_style_by_name(style))
+            buf.get_tag_table().add(comment_tag)
+            buf.apply_tag(comment_tag, s_tag, s_code)
+            buf.apply_tag(comment_tag, e_tag, e_code)
+
+        code = s_code.get_text(e_code)
+        log.debug("full text to encode: %s.", code)
+
+
+        start_mark  = buf.create_mark(None, s_code, False)
+
+        lexer = None
+
+        if language is None:
+            lexer = self.config.get_default_lexer()
+            log.info("No Language specified. Falling back to default lexer: %s.",
+                    self.config.get_default_lexer_name())
+        else:
+            log.debug("Using lexer for %s.", str(language))
+            lexer = self.config.get_lexer_with_fallback(language)
+
+        if lexer is None:
+            iterator = buf.get_iter_at_mark(start_mark)
+            buf.insert(iterator, '\n')
+        elif not self.config.is_internal_none_lexer(lexer):
+            tokens = pygments.lex(code, lexer)
+
+            formatter = GTKFormatter(style=style, start_mark=start_mark)
+            pygments.format(tokens, formatter, buf)
+
+    def find_multiline_matches(self, text):
+        start = None
+        matches = []
+        #Less strict, allow prefixed whitespaces: for i in re.finditer(r'(?:^|\n)[ |\t]*(```)\S*[ |\t]*(?:\n|$)', text, re.DOTALL):
+        for i in re.finditer(r'(?:^|\n)(```)\S*(?:\n|$)', text, re.DOTALL):
+            if start is None:
+                start = i
+            elif re.match(r'^\n```', i.group(0)) is not None:
+                matches.append(
+                        (start.start(), i.end(), text[start.start():i.end()]))
+                start = None
+            else:
+                # not an end...
+                continue
+        return matches
+
+    def find_inline_matches(self, text):
+        """
+        Inline code is highlighted if the start marker is precedded by a start
+        of line, a whitespace character or either of the other span markers
+        defined in XEP-0393.
+        The same applies mirrored to the end marker.
+        """
+        return [(i.start(1), i.end(1), i.group(1)) for i in \
+                re.finditer(r'(?:^|\s|\*|~|_)(`((?!`).+?)`)(?:\s|\*|~|_|$)', text)]
+
+    def merge_match_groups(self, real_text, inline_matches, multiline_matches):
+        it_inline = iter(inline_matches)
+        it_multi  = iter(multiline_matches)
+        length    = len(real_text)
+
+        # Just to get cleaner code below...
+        def get_next(iterator):
+            return next(iterator, (length, length, ""))
+
+        # In order to simplify the process, we use the 'length' here.
+        cur_inline = get_next(it_inline)
+        cur_multi  = get_next(it_multi)
+
+        pos = 0
+
+        # This will contain tuples with parts of the input and its classification
+        parts  = []
+        while pos < length:
+            log.debug("-> in: %s", str(cur_inline))
+            log.debug("-> mu: %s", str(cur_multi))
+
+            # selected = (start, end, type)
+            selected = (cur_inline[0], cur_inline[1], MatchType.INLINE) \
+                    if cur_inline[0] < cur_multi[0] \
+                    else (cur_multi[0], cur_multi[1], MatchType.MULTILINE) \
+                        if cur_multi[0] < length \
+                        else (pos, length, MatchType.TEXT)
+            log.debug("--> select: %s", str(selected))
+
+            # Handle plain text string parts (and unforseen errors...)
+            if pos < selected[0]:
+                end = selected[0] if selected[0] != pos else selected[1]
+                parts.append((real_text[pos:end], MatchType.TEXT))
+                pos = selected[0]
+            elif pos > selected[0]:
+                log.error("Should not happen, position > found match.")
+
+            # Cut out and append selected text segment
+            parts.append((real_text[selected[0]:selected[1]], selected[2]))
+            pos = selected[1]
+
+            # Depending on the match type, we have to forward the iterators.
+            # Also, forward the other one, if regions overlap or we took over...
+            if selected[2] == MatchType.INLINE:
+                if cur_multi[0] < cur_inline[1]:
+                    cur_multi = get_next(it_multi)
+                cur_inline = get_next(it_inline)
+            elif selected[2] == MatchType.MULTILINE:
+                if cur_inline[0] < cur_multi[1]:
+                    cur_inline = get_next(it_inline)
+                cur_multi = get_next(it_multi)
+
+        return parts
+
+    def process_text(self, real_text, other_tags, _graphics, iter_,
+            _additional):
+        def fix_newline(char, marker_len_no_newline, force=False):
+            fixed = (marker_len_no_newline, '')
+            if char == '\n':
+                fixed = (marker_len_no_newline + 1, '')
+            elif force:
+                fixed = (marker_len_no_newline + 1, '\n')
+            return fixed
+
+
+        buf = self.textview.tv.get_buffer()
+
+        # first, try to find inline or multiline code snippets
+        inline_matches      = self.find_inline_matches(real_text)
+        multiline_matches   = self.find_multiline_matches(real_text)
+
+        if not inline_matches and not multiline_matches:
+            log.debug("Stopping early, since there is no code block in it....")
+            return
+
+        iterator   = iter_ if iter_ is not None else buf.get_end_iter()
+
+        # Create a start marker with left gravity before inserting text.
+        start_mark = buf.create_mark("SHP_start", iterator, True)
+        end_mark   = buf.create_mark("SHP_end", iterator, False)
+
+        insert_newline_for_multiline    = self.check_line_break(True)
+        insert_newline_for_inline       = self.check_line_break(False)
+
+        split_text = self.merge_match_groups(
+                real_text, inline_matches, multiline_matches)
+
+        buf.begin_user_action()
+
+        for num, (text_to_insert, match_type) in enumerate(split_text):
+            language        = None
+            end_of_message  = num == (len(split_text) - 1)
+
+            if match_type == MatchType.TEXT:
+                self.textview.detect_and_print_special_text(
+                        text_to_insert, other_tags, graphics=_graphics,
+                        iter_=iterator, additional_data=_additional)
+            else:
+                if match_type == MatchType.MULTILINE:
+                    language_match = re.search(
+                            '\n*```([^\n]*)\n', text_to_insert, re.DOTALL)
+                    language = None if language_match is None \
+                            else language_match.group(1)
+                    language_len = 0 if language is None else len(language)
+
+                    # We account the language word width for the front marker
+                    front = fix_newline(text_to_insert[0],  3 + language_len,
+                            insert_newline_for_multiline)
+                    back  = fix_newline(text_to_insert[-1], 3,
+                            insert_newline_for_multiline and not end_of_message)
+                else:
+                    front = fix_newline(text_to_insert[0],  1,
+                            insert_newline_for_inline)
+                    back  = fix_newline(text_to_insert[-1], 1,
+                            insert_newline_for_inline and not end_of_message)
+
+                marker_widths = (front[0], back[0])
+                text_to_insert = ''.join([front[1], text_to_insert, back[1]])
+
+                # insertion invalidates iterator, let's use our start mark...
+                self.insert_and_format_code(buf, text_to_insert, language,
+                        marker_widths, start_mark, end_mark, other_tags)
+
+            iterator = buf.get_iter_at_mark(end_mark)
+            # the current end of the buffer's contents is the start for the
+            # next iteration
+            buf.move_mark(start_mark, iterator)
+
+        buf.delete_mark(start_mark)
+        buf.delete_mark(end_mark)
+
+        buf.end_user_action()
+
+        # We have to make sure this is the last thing we do (i.e. no calls to
+        # the other textview methods no more from here on), because the
+        # print_special_text method is resetting the plugin_modified variable...
+        self.textview.plugin_modified = True
+
+    def insert_and_format_code(self, buf, insert_text, language, marker,
+            start_mark, end_mark, other_tags=None):
+
+        start_iter  = buf.get_iter_at_mark(start_mark)
+
+        if other_tags:
+            buf.insert_with_tags_by_name(start_iter, insert_text,
+                    *other_tags)
+        else:
+            buf.insert(start_iter, insert_text)
+
+        tag_start   = buf.get_iter_at_mark(start_mark)
+        tag_end     = buf.get_iter_at_mark(end_mark)
+        s_code      = tag_start.copy()
+        e_code      = tag_end.copy()
+        s_code.forward_chars(marker[0])
+        e_code.backward_chars(marker[1])
+
+        log.debug("full text between tags: %s.", tag_start.get_text(tag_end))
+
+        self.format_code(buf, tag_start, s_code, tag_end, e_code, language)
+
+        self.textview.plugin_modified = True
+
+        # Set general code block format
+        tag = Gtk.TextTag.new()
+        if self.config.is_bgcolor_override_enabled():
+            tag.set_property('background', self.config.get_bgcolor())
+            tag.set_property('paragraph-background', self.config.get_bgcolor())
+        tag.set_property('font', self.config.get_font())
+        buf.get_tag_table().add(tag)
+        buf.apply_tag(tag, tag_start, tag_end)
+
+    def __init__(self, config, textview):
+        self.last_end_mark  = None
+        self.config         = config
+        self.textview       = textview

syntax_highlight/config_dialog.ui

+<?xml version="1.0" encoding="UTF-8"?>
+<!-- Generated with glade 3.22.1 -->
+<interface>
+  <requires lib="gtk+" version="3.0"/>
+  <object class="GtkTextBuffer"/>
+  <object class="GtkListStore" id="code_marker_selection">
+    <columns>
+      <!-- column-name column1 -->
+      <column type="gchararray"/>
+    </columns>
+    <data>
+      <row>
+        <col id="0" translatable="yes">Treat as code comment</col>
+      </row>
+      <row>
+        <col id="0" translatable="yes">Hide code markers</col>
+      </row>
+    </data>
+  </object>
+  <object class="GtkListStore" id="line_break_selection">
+    <columns>
+      <!-- column-name Text -->
+      <column type="gchararray"/>
+    </columns>
+    <data>
+      <row>
+        <col id="0" translatable="yes">Never</col>
+      </row>
+      <row>
+        <col id="0" translatable="yes">Always</col>
+      </row>
+      <row>
+        <col id="0" translatable="yes">Only around multi-line code blocks</col>
+      </row>
+    </data>
+  </object>
+  <object class="GtkTextBuffer" id="preview_textbuffer">
+    <property name="text" translatable="yes">// Test your highlighting here
+# Test your highlighting here
+/* Test your highlighting here */
+% Test your highlighting here
+; Test your highlighting here
+&lt;!-- Test your highlighting here --&gt;</property>
+  </object>
+  <object class="GtkWindow" id="window1">
+    <property name="can_focus">False</property>
+    <child>
+      <placeholder/>
+    </child>
+    <child>
+      <object class="GtkBox" id="mainBox">
+        <property name="visible">True</property>
+        <property name="can_focus">False</property>
+        <property name="orientation">vertical</property>
+        <child>
+          <object class="GtkGrid">
+            <property name="visible">True</property>
+            <property name="can_focus">False</property>
+            <property name="margin_bottom">40</property>
+            <child>
+              <object class="GtkLabel" id="label1">
+                <property name="visible">True</property>
+                <property name="can_focus">False</property>
+                <property name="label" translatable="yes">Default Language for Syntax Highlighting</property>
+                <property name="xalign">0</property>
+              </object>
+              <packing>
+                <property name="left_attach">0</property>
+                <property name="top_attach">0</property>
+              </packing>
+            </child>
+            <child>
+              <object class="GtkLabel" id="label2">
+                <property name="visible">True</property>
+                <property name="can_focus">False</property>
+                <property name="label" translatable="yes">Insert Line breaks around Code Blocks</property>
+                <property name="xalign">0</property>
+              </object>
+              <packing>
+                <property name="left_attach">0</property>
+                <property name="top_attach">1</property>
+              </packing>
+            </child>
+            <child>
+              <object class="GtkComboBox" id="default_lexer_combobox">
+                <property name="visible">True</property>
+                <property name="can_focus">False</property>
+                <signal name="changed" handler="lexer_changed" swapped="no"/>
+                <child>
+                  <object class="GtkCellRendererText" id="cellrenderertext1"/>
+                  <attributes>
+                    <attribute name="text">0</attribute>
+                  </attributes>
+                </child>
+              </object>
+              <packing>
+                <property name="left_attach">1</property>
+                <property name="top_attach">0</property>
+              </packing>
+            </child>
+            <child>
+              <object class="GtkComboBox" id="line_break_combobox">
+                <property name="visible">True</property>
+                <property name="can_focus">False</property>
+                <property name="model">line_break_selection</property>
+                <signal name="changed" handler="line_break_changed" swapped="no"/>
+                <child>
+                  <object class="GtkCellRendererText" id="cellrenderertext2"/>
+                  <attributes>
+                    <attribute name="text">0</attribute>
+                  </attributes>
+                </child>
+              </object>
+              <packing>
+                <property name="left_attach">1</property>
+                <property name="top_attach">1</property>
+              </packing>
+            </child>
+            <child>
+              <object class="GtkComboBox" id="style_combobox">
+                <property name="visible">True</property>
+                <property name="can_focus">False</property>
+                <signal name="changed" handler="style_changed" swapped="no"/>
+                <child>
+                  <object class="GtkCellRendererText" id="cellrenderertext3"/>
+                  <attributes>
+                    <attribute name="text">0</attribute>
+                  </attributes>
+                </child>
+              </object>
+              <packing>
+                <property name="left_attach">1</property>
+                <property name="top_attach">2</property>
+              </packing>
+            </child>
+            <child>
+              <object class="GtkLabel" id="label3">
+                <property name="visible">True</property>
+                <property name="can_focus">False</property>
+                <property name="label" translatable="yes">Select Syntax Highlighting Style</property>
+                <property name="xalign">0</property>
+              </object>
+              <packing>
+                <property name="left_attach">0</property>
+                <property name="top_attach">2</property>
+              </packing>
+            </child>
+            <child>
+              <object class="GtkLabel">
+                <property name="visible">True</property>
+                <property name="can_focus">False</property>
+                <property name="label" translatable="yes">Select code marker (the backticks) formatting:</property>
+                <property name="xalign">0</property>
+              </object>
+              <packing>
+                <property name="left_attach">0</property>
+                <property name="top_attach">3</property>
+              </packing>
+            </child>
+            <child>
+              <object class="GtkComboBox" id="code_marker_combobox">
+                <property name="visible">True</property>
+                <property name="can_focus">False</property>
+                <property name="model">code_marker_selection</property>
+                <signal name="changed" handler="code_marker_changed" swapped="no"/>
+                <child>
+                  <object class="GtkCellRendererText" id="cellrenderertext4"/>
+                  <attributes>
+                    <attribute name="text">0</attribute>
+                  </attributes>
+                </child>
+              </object>
+              <packing>
+                <property name="left_attach">1</property>
+                <property name="top_attach">3</property>
+              </packing>
+            </child>
+            <child>
+              <object class="GtkLabel">
+                <property name="visible">True</property>
+                <property name="can_focus">False</property>
+                <property name="label" translatable="yes">Select Font for Code Snippets:</property>
+                <property name="xalign">0</property>
+              </object>
+              <packing>
+                <property name="left_attach">0</property>
+                <property name="top_attach">4</property>
+              </packing>
+            </child>
+            <child>
+              <object class="GtkFontButton" id="font_button">
+                <property name="visible">True</property>
+                <property name="can_focus">True</property>
+                <property name="receives_default">True</property>
+                <property name="font">Sans 12</property>
+                <property name="language">de-de</property>
+                <property name="preview_text"/>
+                <property name="use_font">True</property>
+                <signal name="font-set" handler="font_changed" swapped="no"/>
+              </object>
+              <packing>
+                <property name="left_attach">1</property>
+                <property name="top_attach">4</property>
+              </packing>
+            </child>
+            <child>
+              <object class="GtkCheckButton" id="bg_color_checkbutton">
+                <property name="label" translatable="yes">Set Background Color</property>
+                <property name="visible">True</property>
+                <property name="can_focus">True</property>
+                <property name="receives_default">False</property>
+                <property name="halign">start</property>
+                <property name="draw_indicator">True</property>
+                <signal name="toggled" handler="bg_color_enabled" swapped="no"/>
+              </object>
+              <packing>
+                <property name="left_attach">0</property>
+                <property name="top_attach">5</property>
+              </packing>
+            </child>
+            <child>
+              <object class="GtkColorButton" id="bg_color_colorbutton">
+                <property name="visible">True</property>
+                <property name="can_focus">True</property>
+                <property name="receives_default">True</property>
+                <property name="halign">center</property>
+                <property name="valign">center</property>
+                <property name="title" translatable="yes">Chose the background color for code blocks</property>
+                <property name="show_editor">True</property>
+                <signal name="color-set" handler="bg_color_changed" swapped="no"/>
+              </object>
+              <packing>
+                <property name="left_attach">1</property>
+                <property name="top_attach">5</property>
+              </packing>
+            </child>
+          </object>
+          <packing>
+            <property name="expand">False</property>
+            <property name="fill">False</property>
+            <property name="position">0</property>
+          </packing>
+        </child>
+        <child>
+          <object class="GtkSeparator">
+            <property name="visible">True</property>
+            <property name="can_focus">False</property>
+          </object>
+          <packing>
+            <property name="expand">False</property>
+            <property name="fill">True</property>
+            <property name="position">1</property>
+          </packing>
+        </child>
+        <child>
+          <object class="GtkLabel">
+            <property name="visible">True</property>
+            <property name="can_focus">False</property>
+            <property name="margin_top">20</property>
+            <property name="margin_bottom">5</property>
+            <property name="label" translatable="yes">Test how code blocks will look like in the chat window:</property>
+            <property name="xalign">0</property>
+          </object>
+          <packing>
+            <property name="expand">False</property>
+            <property name="fill">True</property>
+            <property name="position">2</property>
+          </packing>
+        </child>
+        <child>
+          <object class="GtkTextView" id="preview_textview">
+            <property name="visible">True</property>
+            <property name="can_focus">True</property>
+            <property name="wrap_mode">word-char</property>
+            <property name="buffer">preview_textbuffer</property>
+          </object>
+          <packing>
+            <property name="expand">True</property>
+            <property name="fill">True</property>
+            <property name="position">3</property>
+          </packing>
+        </child>
+        <child>
+          <object class="GtkSeparator">
+            <property name="visible">True</property>
+            <property name="can_focus">False</property>
+            <property name="margin_top">20</property>
+          </object>
+          <packing>
+            <property name="expand">False</property>
+            <property name="fill">True</property>
+            <property name="position">4</property>
+          </packing>
+        </child>
+        <child>
+          <placeholder/>
+        </child>
+      </object>
+    </child>
+  </object>
+  <object class="GtkTextBuffer" id="textbuffer1">
+    <property name="text">Plug-in decription should be displayed here. This text will be erased during PluginsWindow initialization.</property>
+  </object>
+</interface>

syntax_highlight/gtkformatter.py

+import logging
+
+from gi.repository import Gtk as gtk
+from gi.repository import Pango
+
+from pygments.formatter import Formatter
+from gajim.plugins.helpers import log
+log = logging.getLogger('gajim.plugin_system.syntax_highlight')
+
+class GTKFormatter(Formatter):
+    name = 'GTK Formatter'
+    aliases = ['textbuffer', 'gtk']
+    filenames = []
+
+    def __init__(self, **options):
+        super(GTKFormatter, self).__init__(**options)
+        #Formatter.__init__(self, **options)
+        self.tags = {}
+        self.mark = options.get('start_mark', None)
+
+    @staticmethod
+    def create_tag_for_token(ttype, highlighting_style):
+        style = highlighting_style.style_for_token(ttype)
+        tag = gtk.TextTag.new()
+        if 'bgcolor' in style and not style['bgcolor'] is None:
+            tag.set_property('background', '#%s' % style['bgcolor'])
+        if 'bold' in style and style['bold']:
+            tag.set_property('weight', Pango.Weight.BOLD)
+        if 'border' in style and not style['border'] is None:
+            pass
+        if 'color' in style and not style['color'] is None:
+            tag.set_property('foreground', '#%s' % style['color'])
+        if 'italic' in style and style['italic']:
+            tag.set_property('style', Pango.Style.ITALIC)
+        if 'mono' in style and not style['mono'] is None:
+            tag.set_property('family', 'Monospace')
+            tag.set_property('family-set', True)
+        if 'roman' in style and not style['roman'] is None:
+            pass
+        if 'sans' in style and not style['sans'] is None:
+            tag.set_property('family', 'Sans')
+            tag.set_property('family-set', True)
+        if 'underline' in style and style['underline']:
+            tag.set_property('underline', 'single')
+        return tag
+
+
+    def get_tag(self, ttype, buf):
+        """
+        Creates, stores and returs a tag for a given token type.
+
+        This method ensures that a tag style is created only once.
+        Furthermore, the tag will be added to the given Gtk.TextBuffer's tag table.
+        """
+        tag = None
+        if ttype in self.tags:
+            tag = self.tags[ttype]
+        else:
+            tag = GTKFormatter.create_tag_for_token(ttype, self.style)
+            self.tags[ttype] = tag
+            buf.get_tag_table().add(tag)
+        return tag
+
+    def set_insert_pos_mark(self, mark):
+        self.mark = mark
+
+    def format(self, tokensource, outfile):
+        if not isinstance(outfile, gtk.TextBuffer) or outfile is None:
+            log.warn("Did not get a buffer to format...")
+            return
+        buf = outfile
+
+        end_iter    = buf.get_end_iter()
+
+        start_mark  = self.mark
+        start_iter  = buf.get_iter_at_mark(start_mark) if not start_mark is None \
+                else end_iter
+
+        last_ttype  = None
+        last_start  = start_iter
+        last_end    = buf.get_end_iter()
+        last_fixed_start = last_start
+
+        reset       = True
+
+        for ttype, value in tokensource:
+            search = None
+            if last_ttype is not None and ttype != last_ttype:
+                tag = self.get_tag(last_ttype, buf)
+
+                buf.apply_tag(tag, last_fixed_start, last_end)
+
+                search = last_end.forward_search(value, gtk.TextSearchFlags.TEXT_ONLY, end_iter)
+                reset = True
+            else:
+                # in case last_ttype is None, i.e. first loop walkthrough:
+                # last_start to end_iter is the full code block.
+                search = last_start.forward_search(value, gtk.TextSearchFlags.TEXT_ONLY, end_iter)
+
+            # Prepare for next iteration
+            last_ttype = ttype
+            if search is not None:
+                (last_start, last_end) = search
+
+                # If we've found the end of a sequence of similar type tokens or if
+                # we are in the first loop iteration, set the fixed point
+                if reset:
+                    last_fixed_start = last_start
+                    reset = False
+            else:
+                # Hm... Nothing found, but tags left? Seams there's nothing we
+                # can do now.
+                break

syntax_highlight/manifest.ini

+[info]
+# Don't forget to point to the correct README.md file when switching to another
+# branch or so...
+name: Source Code Syntax Highlight
+short_name: syntax_highlight
+version: 1.2.3
+description: Source Code Syntax Highlighting in the chatbox.
+
+	It uses markdown-style syntax, i.e. text in between `single backticks` is
+	rendered as inline code, ```language
+	selection is possible in multi-line code snippets in between triple-backticks
+	Note the newlines in this case...
+	```
+
+	*Note:* You need to have pygments installed.
+	Please refer to the plugin's Wiki page for more information.
+
+	Changing settings will take effect after closing and opening the message
+	tab/window again.
+authors = Florian Muenchbach
+homepage = https://dev.gajim.org/gajim/gajim-plugins/blob/master/syntax_highlight/README.md
+min_gajim_version: 1.1.91
+max_gajim_version: 1.2.90

syntax_highlight/plugin_config.py

+from gajim.plugins.helpers import log
+
+from gi.repository import Gdk
+
+from pygments.lexers import get_lexer_by_name, get_all_lexers
+from pygments.styles import get_all_styles
+
+from .types import LineBreakOptions, CodeMarkerOptions, \
+                    PLUGIN_INTERNAL_NONE_LEXER_ID
+
+class SyntaxHighlighterConfig:
+    PLUGIN_INTERNAL_NONE_LEXER=('None (monospace only)', PLUGIN_INTERNAL_NONE_LEXER_ID)
+
+    def _create_lexer_list(self):
+        # The list we create here contains the plain text name and the lexer's
+        # id string
+        lexers = []
+
+        # Iteration over get_all_lexers() seems to be broken somehow. Workarround
+        all_lexers = get_all_lexers()
+        for lexer in all_lexers:
+            # We don't want to add lexers that we cant identify by name later
+            if lexer[1] is not None and lexer[1]:
+                lexers.append((lexer[0], lexer[1][0]))
+        lexers.sort()
+
+        # Insert our internal "none" type at top of the list.
+        lexers.insert(0, self.PLUGIN_INTERNAL_NONE_LEXER)
+        return lexers
+
+    def is_internal_none_lexer(self, lexer):
+        return lexer == PLUGIN_INTERNAL_NONE_LEXER_ID
+
+    def get_internal_none_lexer(self):
+        return self.PLUGIN_INTERNAL_NONE_LEXER
+
+    def get_lexer_by_name(self, name):
+        lexer = None
+        try:
+            lexer = get_lexer_by_name(name)
+        except:
+            pass
+        return lexer
+
+    def get_lexer_with_fallback(self, language):
+        lexer = self.get_lexer_by_name(language)
+        if lexer is None:
+            log.info("Falling back to default lexer for %s.",
+                    self.get_default_lexer_name())
+            lexer = self.default_lexer[1]
+        return lexer
+
+    def set_font(self, font):
+        if font is not None and font != "":
+            self.config['font'] = font
+
+    def set_style(self, style):
+        if style is not None and style != "":
+            self.config['style'] = style
+
+    def set_line_break_action(self, option):
+        if isinstance(option, int):
+            option = LineBreakOptions(option)
+        self.config['line_break'] = option
+
+    def set_default_lexer(self, name):
+        if not self.is_internal_none_lexer(name):
+            lexer = get_lexer_by_name(name)
+
+            if lexer is None and self.default_lexer is None:
+                log.error("Failed to get default lexer by name."\
+                        "Falling back to simply using the first in the list.")
+                lexer = self.lexer_list[0]
+                name  = lexer[0]
+                self.default_lexer = (name, lexer)
+            if lexer is None and self.default_lexer is not None:
+                log.info("Failed to get default lexer by name, keeping previous"\
+                        "setting (lexer = %s).", self.default_lexer[0])
+                name = self.default_lexer[0]
+            else:
+                self.default_lexer = (name, lexer)
+        else:
+            self.default_lexer = self.PLUGIN_INTERNAL_NONE_LEXER
+
+        self.config['default_lexer'] = name
+
+    def set_bgcolor_override_enabled(self, state):
+        self.config['bgcolor_override'] = state
+
+    def set_bgcolor(self, color):
+        if isinstance(color, Gdk.Color):
+            color = color.to_string()
+        self.config['bgcolor'] = color
+
+    def set_code_marker_setting(self, option):
+        if isinstance(option, int):
+            option = CodeMarkerOptions(option)
+        self.config['code_marker'] = option
+
+    def set_pygments_path(self, path):
+        self.config['pygments_path'] = path
+
+    def get_default_lexer(self):
+        return self.default_lexer[1]
+
+    def get_default_lexer_name(self):
+        return self.default_lexer[0]
+
+    def get_lexer_list(self):
+        return self.lexer_list
+
+    def get_line_break_action(self):
+        # return int only
+        if isinstance(self.config['line_break'], int):
+            # in case of legacy settings, convert.
+            action = self.config['line_break']
+            self.set_line_break_action(action)
+        else:
+            action = self.config['line_break'].value
+
+        return action
+
+    def get_pygments_path(self):
+        return self.config['pygments_path']
+
+    def get_font(self):
+        return self.config['font']
+
+    def get_style_name(self):
+        return self.config['style']
+
+    def is_bgcolor_override_enabled(self):
+        return self.config['bgcolor_override']
+
+    def get_bgcolor(self):
+        return self.config['bgcolor']
+
+    def get_code_marker_setting(self):
+        return self.config['code_marker']
+
+    def get_styles_list(self):
+        return self.style_list
+
+    def init_pygments(self):
+        """
+        Initialize all config variables that depend directly on pygments being
+        available.
+        """
+        self.lexer_list     = self._create_lexer_list()
+        self.style_list     = [s for s in get_all_styles()]
+        self.style_list.sort()
+        self.set_default_lexer(self.config['default_lexer'])
+
+    def __init__(self, config):
+        self.lexer_list     = []
+        self.style_list     = []
+        self.config         = config
+        self.default_lexer  = None

syntax_highlight/plugin_config_dialog.py

+import re
+import pygments
+
+from gi.repository import Gtk, Gdk
+from gi.repository.Pango import FontDescription
+
+
+from gajim.plugins.gui import GajimPluginConfigDialog
+from gajim.plugins.helpers import log_calls
+
+
+from .gtkformatter import GTKFormatter
+from .types import LineBreakOptions, CodeMarkerOptions
+
+class SyntaxHighlighterPluginConfiguration(GajimPluginConfigDialog):
+    @log_calls('SyntaxHighlighterPluginConfiguration')
+    def init(self):
+        self.GTK_BUILDER_FILE_PATH = self.plugin.local_file_path(
+            'config_dialog.ui')
+        self.xml = Gtk.Builder()
+        self.xml.set_translation_domain('gajim_plugins')
+        self.xml.add_objects_from_file(self.GTK_BUILDER_FILE_PATH,
+                ['mainBox', 'line_break_selection', 'code_marker_selection',
+                    'preview_textbuffer'])
+        box = self.xml.get_object('mainBox')
+        self.get_child().pack_start(box, False, False, 0)
+        self.result_label = self.xml.get_object('result_label')
+
+        self.liststore = Gtk.ListStore(str)
+
+        self.default_lexer_combobox = self.xml.get_object('default_lexer_combobox')
+        self.default_lexer_combobox.set_property("model", self.liststore)
+
+        self.style_liststore = Gtk.ListStore(str)
+        self.style_combobox = self.xml.get_object('style_combobox')
+        self.style_combobox.set_property("model", self.style_liststore)
+
+        self.bg_color_checkbox    = self.xml.get_object('bg_color_checkbutton')
+        self.bg_color_colorbutton = self.xml.get_object('bg_color_colorbutton')
+
+        self.line_break_combobox  = self.xml.get_object('line_break_combobox')
+
+        self.code_marker_combobox = self.xml.get_object('code_marker_combobox')
+
+        self.preview_textview     = self.xml.get_object('preview_textview')
+        self.preview_textview.get_buffer().connect("insert-text", self.on_preview_text_inserted)
+        self.preview_textview.set_size_request(-1, 130)
+
+        self.font_button          = self.xml.get_object('font_button')
+
+        self.xml.connect_signals(self)
+        self.default_lexer_id   = 0
+        self.style_id           = 0
+
+    def set_config(self, config):
+        self.config     = config
+        self.lexers     = self.config.get_lexer_list()
+        self.styles     = self.config.get_styles_list()
+        default_lexer   = self.config.get_default_lexer_name()
+        default_style   = self.config.get_style_name()
+
+        for i, lexer in enumerate(self.lexers):
+            self.liststore.append([lexer[0]])
+            if lexer[1] == default_lexer:
+                self.default_lexer_id = i
+
+        for i, style in enumerate(self.styles):
+            self.style_liststore.append([style])
+            if style == default_style:
+                self.style_id = i
+        self.update_preview()
+
+    def lexer_changed(self, _widget):
+        new = self.default_lexer_combobox.get_active()
+        if new != self.default_lexer_id:
+            self.default_lexer_id = new
+            self.config.set_default_lexer(self.lexers[self.default_lexer_id][1])
+            self.update_preview()
+
+    def line_break_changed(self, _widget):
+        new = LineBreakOptions(self.line_break_combobox.get_active())
+        if new != self.config.get_line_break_action():
+            self.config.set_line_break_action(new)
+            self.update_preview()
+
+    def code_marker_changed(self, _widget):
+        new = CodeMarkerOptions(self.code_marker_combobox.get_active())
+        if new != self.config.get_code_marker_setting():
+            self.config.set_code_marker_setting(new)
+
+    def bg_color_enabled(self, _widget):
+        new = self.bg_color_checkbox.get_active()
+        if new != self.config.is_bgcolor_override_enabled():
+            bg_override_enabled = new
+            self.config.set_bgcolor_override_enabled(bg_override_enabled)
+            self.bg_color_colorbutton.set_sensitive(bg_override_enabled)
+            self.update_preview()
+
+    def bg_color_changed(self, _widget):
+        new = self.bg_color_colorbutton.get_color()
+        if new != self.config.get_bgcolor():
+            self.config.set_bgcolor(new)
+            self.update_preview()
+
+    def style_changed(self, _widget):
+        new = self.style_combobox.get_active()
+        if new != self.style_id:
+            self.style_id = new
+            self.config.set_style(self.styles[self.style_id])
+            self.update_preview()
+
+    def font_changed(self, _widget):
+        new = self.font_button.get_font()
+        if new != self.config.get_font():
+            self.config.set_font(new)
+            self.update_preview()
+
+    def update_preview(self):
+        self.format_preview_text()
+
+    def on_preview_text_inserted(self, _buf, _iterator, text, length, *_args):
+        if (length == 1 and re.match(r'\s', text)) or length > 1:
+            self.format_preview_text()
+
+    def format_preview_text(self):
+        buf = self.preview_textview.get_buffer()
+        start_iter = buf.get_start_iter()
+        start_mark = buf.create_mark(None, start_iter, True)
+        buf.remove_all_tags(start_iter, buf.get_end_iter())
+
+        formatter = GTKFormatter(
+                style=self.config.get_style_name(),
+                start_mark=start_mark)
+
+        code    = start_iter.get_text(buf.get_end_iter())
+        lexer   = self.config.get_default_lexer()
+        if not self.config.is_internal_none_lexer(lexer):
+            tokens  = pygments.lex(code, lexer)
+
+            pygments.format(tokens, formatter, buf)
+
+        buf.delete_mark(start_mark)
+
+        self.preview_textview.override_font(
+                FontDescription.from_string(self.config.get_font()))
+
+        color = Gdk.RGBA()
+        if color.parse(self.config.get_bgcolor()):
+            self.preview_textview.override_background_color(
+                    Gtk.StateFlags.NORMAL, color)
+
+    def on_run(self):
+        self.default_lexer_combobox.set_active(self.default_lexer_id)
+        self.line_break_combobox.set_active(self.config.get_line_break_action())
+        self.code_marker_combobox.set_active(self.config.get_code_marker_setting())
+        self.style_combobox.set_active(self.style_id)
+
+        self.font_button.set_font(self.config.get_font())
+
+        bg_override_enabled = self.config.is_bgcolor_override_enabled()
+        self.bg_color_checkbox.set_active(bg_override_enabled)
+
+        self.bg_color_colorbutton.set_sensitive(bg_override_enabled)
+
+        parsed, color = Gdk.Color.parse(self.config.get_bgcolor())
+        if parsed:
+            self.bg_color_colorbutton.set_color(color)
+
+

syntax_highlight/syntax_highlight.py

+import logging
+import sys
+
+if sys.version_info >= (3, 4):
+    from importlib.util import find_spec as find_module
+else:
+    from importlib import find_loader as find_module
+
+
+from gajim.plugins.helpers import log_calls, log
+from gajim.plugins import GajimPlugin
+
+from .types import MatchType, LineBreakOptions, CodeMarkerOptions, \
+                    PLUGIN_INTERNAL_NONE_LEXER_ID
+
+log = logging.getLogger('gajim.plugin_system.syntax_highlight')
+
+def try_loading_pygments():
+    success = find_module('pygments') is not None
+    if success:
+        try:
+            from .chat_syntax_highlighter import ChatSyntaxHighlighter
+            from .plugin_config_dialog import SyntaxHighlighterPluginConfiguration
+            from .plugin_config import SyntaxHighlighterConfig
+            global SyntaxHighlighterPluginConfiguration, ChatSyntaxHighlighter, \
+                SyntaxHighlighterConfig
+            success = True
+            log.debug("pygments loaded.")
+        except Exception as exception:
+            log.error("Import Error: %s.", exception)
+            success = False
+
+    return success
+
+PYGMENTS_MISSING = 'You are missing Python-Pygments.'
+
+
+
+class SyntaxHighlighterPlugin(GajimPlugin):
+    @log_calls('SyntaxHighlighterPlugin')
+    def on_connect_with_chat_control(self, chat_control):
+        account = chat_control.contact.account.name
+        jid     = chat_control.contact.jid
+        if account not in self.ccontrol:
+            self.ccontrol[account] = {}
+        self.ccontrol[account][jid] = ChatSyntaxHighlighter(
+                self.conf, chat_control.conv_textview)
+
+    @log_calls('SyntaxHighlighterPlugin')
+    def on_disconnect_from_chat_control(self, chat_control):
+        account = chat_control.contact.account.name
+        jid = chat_control.contact.jid
+        del self.ccontrol[account][jid]
+
+    @log_calls('SyntaxHighlighterPlugin')
+    def on_print_real_text(self, text_view, real_text, other_tags, graphics,
+            iterator, additional):
+        account = text_view.account
+        for jid in self.ccontrol[account]:
+            if self.ccontrol[account][jid].textview != text_view:
+                continue
+            self.ccontrol[account][jid].process_text(
+                real_text, other_tags, graphics, iterator, additional)
+            return
+
+    def try_init(self):
+        """
+        Separating this part of the initialization from the init() method
+        allows repeating this step again, without reloading the plugin,
+        i.e. restarting Gajim for instance.
+        Doing so allows resolving the dependency issues without restart :)
+        """
+        pygments_loaded = try_loading_pygments()
+        if not pygments_loaded:
+            return False
+
+        self.activatable = True
+        self.available_text = None
+        self.config_dialog = SyntaxHighlighterPluginConfiguration(self)
+
+        self.conf   = SyntaxHighlighterConfig(self.config)
+        # The following initialization requires pygments to be available.
+        self.conf.init_pygments()
+
+        self.config_dialog  = SyntaxHighlighterPluginConfiguration(self)
+        self.config_dialog.set_config(self.conf)
+
+        self.gui_extension_points = {
+                'chat_control_base': (
+                        self.on_connect_with_chat_control,
+                        self.on_disconnect_from_chat_control
+                   ),
+                'print_real_text': (self.on_print_real_text, None),
+        }
+        return True
+
+    @log_calls('SyntaxHighlighterPlugin')
+    def init(self):
+        self.ccontrol       = {}
+
+        self.config_default_values = {
+                'default_lexer'     : (PLUGIN_INTERNAL_NONE_LEXER_ID, ''),
+                'line_break'        : (LineBreakOptions.MULTILINE, ''),
+                'style'             : ('default', ''),
+                'font'              : ('Monospace 10', ''),
+                'bgcolor'           : ('#ccc', ''),
+                'bgcolor_override'  : (True, ''),
+                'code_marker'       : (CodeMarkerOptions.AS_COMMENT, ''),
+                'pygments_path'     : (None, ''),
+                }
+
+        is_initialized = self.try_init()
+
+        if not is_initialized:
+            self.activatable = False
+            self.available_text = PYGMENTS_MISSING
+            self.config_dialog = None

syntax_highlight/types.py

+from enum import Enum, IntEnum, unique
+
+PLUGIN_INTERNAL_NONE_LEXER_ID='_syntax_highlight_internal_none_type'
+
+class MatchType(Enum):
+    INLINE      = 0
+    MULTILINE   = 1
+    TEXT        = 2
+
+@unique
+class LineBreakOptions(IntEnum):
+    NEVER       = 0
+    ALWAYS      = 1
+    MULTILINE   = 2
+
+@unique
+class CodeMarkerOptions(IntEnum):
+    AS_COMMENT  = 0
+    HIDE        = 1
+
+