"""This script adds an incremental-search capability to GPS

This is similar to what Emacs does
When you select the menu /Navigate/Find Incremental (or bind a key
shortcut to it through the editor at /Edit/Key shortcuts), a temporary
window is open. From then on, any character you type is displayed in
this new window, and makes a search pattern. Whenever this pattern
is modified, GPS will search, starting at the current location, for its
next occurrence in the current file.
While you are editing the pattern, there are a number of special key
shortcuts that can be used:
   - control-w
     will copy the current word into the pattern, and moves the cursor
     to the next word, so that pressing control-w multiple times in
     a row allows you to easily copy part of a line into the pattern

   - control-y
     is similar to control-w but copies the end of the current line into
     the pattern. If the cursor is at the end of the current line, the
     whole next line is copied

   - Key that activates the isearch
     If you press the same key that was used to activate the incremental
     search, GPS will jump to the next occurrence. If you press the key
     to activate the backward incremental search, GPS will jump to the
     stack occurrence.
     If you press that key twice in a row when the pattern is empty, it
     will restart a search for the previous pattern

   - Backspace
     Goes back to the stack location or search pattern. If you have just
     added a character to the pattern, this character is removed. Otherwise
     the pattern is preserved and the editor is moved back to the stack
     location.

   - alt-c
     Toggles the case sensitivity of the search
     The prompt will include the status "[CS]" if the search is currently
     case sensitive. By default, searches are case insensitive, unless your
     pattern includes upper cased letters

   - Esc, movement keys, keys with control or alt
     cancels the current search, and unselect the last occurrence found

If you press <enter> while there is no search string, this module will
automatically open the advanced, non-incremental search dialog of GPS, to
match Emacs' behavior

If the variable highlight_next_matches is set to True, then whenever you
modify the current pattern, GPS will also highlight the next matches of
this pattern in the buffer. Such higlights will stay even when you cancel
the current search. To hide them, start a new search, and cancel it
immediately. The highlighting of the next matches is done in the background
if pygtk was installed along with GPS. Otherwise, it is done every time the
pattern is modified, and will slow things down a little
"""


#############################################################################
## No user customization below this line
#############################################################################

from GPS import *

Preference ("Plugins/isearch/highlightnext").create (
  "Highlight next matches", "boolean",
  """Whether GPS should highlight the next matches. This highlighting will be visible until the next isearch command. To cancel, start an isearch and press Esc immediately""",
  True)

Preference ("Plugins/isearch/nextmatchcolor").create (
  "Matches color", "color",
  """Color to use when highlighting the next matches""",
  "cyan")

Preference ("Plugins/isearch/bgcolor").create (
  "Background color", "color",
  "Background color to use for the search field",
  "yellow")

Preference ("Plugins/isearch/errcolor").create (
  "Error color", "color",
  "Background color to use for the search field when no match is found",
  "red")


isearch_action_name = 'isearch'
isearch_menu = '/Navigate/Find Incremental'
isearch_backward_action_name = 'isearch backward'
isearch_backward_menu = '/Navigate/Find Previous Incremental'
## Changing the name of menus should be reflected in emacs.xml

try:
   ## If we have PyGTK installed, we'll do the highlighting of the next
   ## matches in the background, which makes the interface more responsive
   import gobject
   has_pygtk = 1
except:
   has_pygtk = 0

def on_gps_started (hook_name):
  parse_xml ("""
  <action name='""" + isearch_action_name + """' category="Editor" output="none">
     <description>This action provides an incremental search facility: once activated, each character you type is added to the search pattern, and GPS jumps to the next occurrence of the pattern</description>
     <filter id="Source editor" />
     <shell lang="python">isearch.Isearch()</shell>
  </action>
  <action name='""" + isearch_backward_action_name + """' category="Editor"
          output="none">
     <description>This action provides a backward incremental search facility: once activated, each character you type is added to the search pattern, and GPS jumps to the stack occurrence of the pattern</description>
     <filter id="Source editor" />
     <shell lang="python">isearch.Isearch (backward=1)</shell>
  </action>

 <menu action='""" + isearch_backward_action_name + """' after="Find Or Replace...">
    <title>""" + isearch_backward_menu + """</title>
 </menu>
 <menu action='""" + isearch_action_name + """' after="Find Or Replace...">
    <title>""" + isearch_menu + """</title>
 </menu>
""")

class Isearch (CommandWindow):
   """This class provides an incremental search facility in GPS.
      When instanciated, it immediately starts executing"""

   last_search = ""
   last_case_sensitive = False

   def __init__ (self, case_sensitive=0, backward=0, regexp=0):
     try:
       self.editor   = EditorBuffer.get ()
       self.loc      = self.editor.current_view ().cursor ()
       self.end_loc  = self.loc
       self.regexp   = regexp
       self.case_sensitive = case_sensitive
       self.explicit_case_sensitive = False   ## Automatic or from alt-c ?
       self.backward = backward
       self.stack = [(self.loc, self.end_loc, "", 0)]
       self.locked = False
       self.overlay = self.editor.create_overlay ("isearch")
       self.overlay.set_property ("background", Preference ("Plugins/isearch/nextmatchcolor").get())
       self.insert_overlays_id = 0
       self.remove_overlays ()
       CommandWindow.__init__ (self,
                               prompt      = self.prompt(),
                               on_changed  = self.on_changed,
                               on_cancel   = self.on_cancel,
                               on_key      = self.on_key,
                               on_activate = self.on_activate)
       self.set_background (Preference ("Plugins/isearch/bgcolor").get())

     except:
       pass

   def prompt (self):
     """Return the prompt to use for the command window"""
     prompt = ""
     if self.case_sensitive:
        prompt = prompt + "[CS] "
     return prompt + "Pattern:"

   def cancel_idle_overlays (self):
     """Cancel the background loop that computes the next matches"""
     if self.insert_overlays_id != 0:
        gobject.source_remove (self.insert_overlays_id)
        self.insert_overlays_id = 0

   def remove_overlays (self):
     """Remove all isearch overlays in the current editor"""

     highlight_next_matches = Preference ("Plugins/isearch/highlightnext").get()

     self.cancel_idle_overlays ()

     if highlight_next_matches:
        loc   = self.editor.beginning_of_buffer ()
        is_on = loc.has_overlay (self.overlay)
        end   = self.editor.end_of_buffer ()
        while loc < end:
           loc2 = loc.forward_overlay (self.overlay)
           if is_on:
              self.editor.remove_overlay (self.overlay, loc, loc2)
           is_on = not is_on
           loc = loc2

   def insert_next_overlay (self, input):
        result = self.overlay_loc.search \
           (input, regexp = self.regexp,
                   case_sensitive = self.case_sensitive,
                   dialog_on_failure = False,
                   backward = self.backward)
        if result:
           (self.overlay_loc, end_loc) = result
           self.editor.apply_overlay (self.overlay, self.overlay_loc, end_loc - 1)
           self.overlay_loc = self.overlay_loc + 1
           return True
        else:
           self.insert_overlays_id = 0
           return False

   def insert_overlays (self):
     highlight_next_matches = Preference ("Plugins/isearch/highlightnext").get()
     if highlight_next_matches:
        input = self.read ()
        self.overlay_loc = self.loc
        if input != "":
           if has_pygtk:
              self.insert_overlays_id = \
                gobject.idle_add (self.insert_next_overlay, input)
           elif len (input) > 2:
              while self.insert_next_overlay (input): pass

   def highlight_match (self, save_in_stack=1):
     """Highlight the match at self.loc"""
     self.editor.current_view ().center(self.loc)
     self.editor.select (self.loc, self.end_loc)

     if save_in_stack:
        self.stack.append ((self.loc, self.end_loc, self.read (), 1))

   def on_key (self, input, key, cursor_pos):
     """The user has typed a new key.
        Return True if you have handled the key yourself, or if you want
        to prevent its insertion in the command line.
        Return False if the key should be processed as usual"""

     # ctrl-w copies the current word (do not change case sensitivity though)
     # ctrl-y copies the end of the current line
     if key == "control-w" or key == "control-y":
       start = self.editor.current_view().cursor()
       if key == "control-w":
          end = start.forward_word () - 1  ## Go to end of current word
       elif self.editor.get_chars (start, start) == "\n":
          end = (start + 1).forward_line () - 2  ## Go to end of next line
       else:
          end = start.forward_line () - 2  ## Go to end of this line

       self.locked = True
       case_sensitive = self.case_sensitive
       self.write (input[:cursor_pos + 1] + \
                   self.editor.get_chars (start, end) + \
                   input[cursor_pos + 1 :])
       self.locked = False
       self.editor.select (self.loc, end + 1)
       self.case_sensitive = case_sensitive
       return True

     # backspace goes back to stack location and pattern
     if key.lower() == "backspace" and self.stack != []:
        if self.stack != []:
           self.stack.pop ()
        if self.stack != []:
           self.locked = True
           (self.loc, self.end_loc, pattern, matched) = self.stack [-1]
           changed = pattern != input
           if changed: self.remove_overlays ()
           self.write (pattern)
           self.highlight_match (save_in_stack = 0)
           self.set_background (Preference ("Plugins/isearch/bgcolor").get())
           if changed: self.insert_overlays ()
           self.locked = False
           return True

     # Toggle case sensitivity
     if key.lower() == "alt-c":
       self.case_sensitive = not self.case_sensitive
       self.explicit_case_sensitive = True
       self.set_prompt (self.prompt())
       self.on_changed (input, len (input), redo_overlays=1)
       return True

     # doing another isearch just searches for the next occurrence
     # Since we do not know which key binding is bound to this action, we test
     # for the name of the action directly. Note that if the user has defined
     # another action wrapping this function, this will fail when he starts
     # using the other action
     actions = lookup_actions_from_key (key)
     if isearch_action_name in actions or isearch_menu.lower() in actions:
        self.backward = False
        if input == "":
           self.case_sensitive = Isearch.last_case_sensitive
           self.explicit_case_sensitive = True
           self.write (Isearch.last_search)
        else:
           self.loc = self.loc + 1
           self.search_next (input, len (input), redo_overlays=0)
        return True

     if isearch_backward_action_name in actions \
       or isearch_backward_menu.lower() in actions:
        self.backward = True
        if input == "":
           self.case_sensitive = Isearch.last_case_sensitive
           self.explicit_case_sensitive = True
           self.write (Isearch.last_search)
        else:
           self.loc = self.loc - 1
           self.search_next (input, len (input), redo_overlays=0)
        return True

     # Cancel the search on any special key. Currently, the key is lost, not
     # sent to the parent window
     if "control-" in key \
        or "alt-" in key:
        self.destroy()
        return True

     if key.lower() == "left" \
        or key.lower() == "right" \
        or key.lower() == "up" \
        or key.lower() == "down":

        self.destroy ()
        return True

     return False

   def on_changed (self, input, cursor_pos, redo_overlays=1):
     """The user has modified the command line.
        cursor_pos can be used to find where on the line the cursor is located,
        in case we need to change the command line.
        input [:cursor_pos + 1]  is before the cursor
        input [cursor_pos + 1:]  is after the cursor"""

     if not self.locked and input != "":
        # Automatic case sensitivity: when we have an upper case, switch to
        # case sensitive
        if not self.explicit_case_sensitive \
         and not self.case_sensitive \
         and input.lower () != input:
           self.case_sensitive = True
           self.set_prompt (self.prompt ())
        Isearch.last_case_sensitive = self.case_sensitive
        self.search_next (input, cursor_pos, redo_overlays)

   def search_next (self, input, cursor_pos, redo_overlays):
     """Same as a on_changed, but doesn't change case sensitivity"""
     if redo_overlays: self.remove_overlays ()

     Isearch.last_search = input

     # Special case for backward search: if the current location matches,
     # no need to do anything else. This is so that when the user keeps
     # adding characters to the pattern, we correctly highlight them at
     # the current location
     if self.backward:
        result = self.loc.search \
           (input, regexp = self.regexp,
            case_sensitive = self.case_sensitive,
            dialog_on_failure = False,
            backward = False)
        if result and result[0] == self.loc:
           self.set_background (Preference ("Plugins/isearch/bgcolor").get())
           (match_from, match_to) = result
           self.end_loc = match_to
           self.highlight_match ()
           self.insert_overlays ()
           return

     result = self.loc.search \
         (input, regexp = self.regexp,
                 case_sensitive = self.case_sensitive,
                 dialog_on_failure = False,
                 backward = self.backward)
     if result:
        self.set_background (Preference ("Plugins/isearch/bgcolor").get())
        (self.loc, self.end_loc) = result
        self.highlight_match ()
        if redo_overlays: self.insert_overlays ()
     else:
        # If the last entry in the stack was a match, add a new one
        if self.stack != [] and self.stack [-1][3]:
           self.stack.append ((self.loc, self.end_loc, self.read (), 0))

        # Loop around, so that next search matches
        if self.backward:
          self.loc = self.loc.buffer().end_of_buffer()
        else:
          self.loc = self.loc.buffer().beginning_of_buffer()
        self.end_loc = self.loc
        self.set_background (Preference ("Plugins/isearch/errcolor").get())
        Hook ("stop_macro_action_hook").run()

   def on_activate (self, input):
     """The user has pressed enter"""
     if input == "":
        execute_action ("/Navigate/Find or Replace...")

   def on_cancel (self, input):
     """The user has cancelled the search"""
     self.cancel_idle_overlays ()
     self.editor.unselect ()

Hook ("gps_started").add (on_gps_started)
