[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 (76dabe2) until the current plugin
version V3 (42b9aeb).
The manifest.ini is updated for compatibility with upcoming Gajim
versions.

syntax_highlight/syntax_highlight.py

@@ -0,0 +1,117 @@
+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