GTK3 – Text editor multilinea

L’oggetto Gtk.TextView può essere utilizzato per visualizzare e modificare testo, anche in grande quantità, utilizzando Gtk.TextBuffer.
Serve? Probabilmente no. Almeno non a me, per quanto posso prevedere.
Però c’è. Allora facciamo come ho fatto per il visualizzatore di icone, anzi un ulteriore passo verso l’abisso e l’abominio. Riproduco solo l’esempio, preso da qui.

Dalla mia ho un paio di giustificazioni (quasi):

• problemi di salute (intesi come carenza della stessa);
• scadenze in arrivo (Lubit, Yupp (segretissimo questo, per adesso));
• il corso di Ruby, elementare ma il linguaggio comincia a piacermi;
• altre cose in sospeso.

#!/usr/bin/python3

# tem.py

from gi.repository import Gtk, Pango

class SearchDialog(Gtk.Dialog):

    def __init__(self, parent):
        Gtk.Dialog.__init__(self, "Search", parent,
            Gtk.DialogFlags.MODAL, buttons=(
            Gtk.STOCK_FIND, Gtk.ResponseType.OK,
            Gtk.STOCK_CANCEL, Gtk.ResponseType.CANCEL))

        box = self.get_content_area()

        label = Gtk.Label("Insert text you want to search for:")
        box.add(label)

        self.entry = Gtk.Entry()
        box.add(self.entry)

        self.show_all()

class TextViewWindow(Gtk.Window):

    def __init__(self):
        Gtk.Window.__init__(self, title="TextView Example")

        self.set_default_size(-1, 350)

        self.grid = Gtk.Grid()
        self.add(self.grid)

        self.create_textview()
        self.create_toolbar()
        self.create_buttons()

    def create_toolbar(self):
        toolbar = Gtk.Toolbar()
        self.grid.attach(toolbar, 0, 0, 3, 1)

        button_bold = Gtk.ToolButton.new_from_stock(Gtk.STOCK_BOLD)
        toolbar.insert(button_bold, 0)

        button_italic = Gtk.ToolButton.new_from_stock(Gtk.STOCK_ITALIC)
        toolbar.insert(button_italic, 1)

        button_underline = Gtk.ToolButton.new_from_stock(Gtk.STOCK_UNDERLINE)
        toolbar.insert(button_underline, 2)

        button_bold.connect("clicked", self.on_button_clicked, self.tag_bold)
        button_italic.connect("clicked", self.on_button_clicked,
            self.tag_italic)
        button_underline.connect("clicked", self.on_button_clicked,
            self.tag_underline)

        toolbar.insert(Gtk.SeparatorToolItem(), 3)

        radio_justifyleft = Gtk.RadioToolButton()
        radio_justifyleft.set_stock_id(Gtk.STOCK_JUSTIFY_LEFT)
        toolbar.insert(radio_justifyleft, 4)

        radio_justifycenter = Gtk.RadioToolButton.new_with_stock_from_widget(
            radio_justifyleft, Gtk.STOCK_JUSTIFY_CENTER)
        toolbar.insert(radio_justifycenter, 5)

        radio_justifyright = Gtk.RadioToolButton.new_with_stock_from_widget(
            radio_justifyleft, Gtk.STOCK_JUSTIFY_RIGHT)
        toolbar.insert(radio_justifyright, 6)

        radio_justifyfill = Gtk.RadioToolButton.new_with_stock_from_widget(
            radio_justifyleft, Gtk.STOCK_JUSTIFY_FILL)
        toolbar.insert(radio_justifyfill, 7)

        radio_justifyleft.connect("toggled", self.on_justify_toggled,
            Gtk.Justification.LEFT)
        radio_justifycenter.connect("toggled", self.on_justify_toggled,
            Gtk.Justification.CENTER)
        radio_justifyright.connect("toggled", self.on_justify_toggled,
            Gtk.Justification.RIGHT)
        radio_justifyfill.connect("toggled", self.on_justify_toggled,
            Gtk.Justification.FILL)

        toolbar.insert(Gtk.SeparatorToolItem(), 8)

        button_clear = Gtk.ToolButton.new_from_stock(Gtk.STOCK_CLEAR)
        button_clear.connect("clicked", self.on_clear_clicked)
        toolbar.insert(button_clear, 9)

        toolbar.insert(Gtk.SeparatorToolItem(), 10)

        button_search = Gtk.ToolButton.new_from_stock(Gtk.STOCK_FIND)
        button_search.connect("clicked", self.on_search_clicked)
        toolbar.insert(button_search, 11)

    def create_textview(self):
        scrolledwindow = Gtk.ScrolledWindow()
        scrolledwindow.set_hexpand(True)
        scrolledwindow.set_vexpand(True)
        self.grid.attach(scrolledwindow, 0, 1, 3, 1)

        self.textview = Gtk.TextView()
        self.textbuffer = self.textview.get_buffer()
        self.textbuffer.set_text("This is some text inside of a Gtk.TextView. "
            + "Select text and click one of the buttons 'bold', 'italic', "
            + "or 'underline' to modify the text accordingly.")
        scrolledwindow.add(self.textview)

        self.tag_bold = self.textbuffer.create_tag("bold",
            weight=Pango.Weight.BOLD)
        self.tag_italic = self.textbuffer.create_tag("italic",
            style=Pango.Style.ITALIC)
        self.tag_underline = self.textbuffer.create_tag("underline",
            underline=Pango.Underline.SINGLE)
        self.tag_found = self.textbuffer.create_tag("found",
            background="yellow")

    def create_buttons(self):
        check_editable = Gtk.CheckButton("Editable")
        check_editable.set_active(True)
        check_editable.connect("toggled", self.on_editable_toggled)
        self.grid.attach(check_editable, 0, 2, 1, 1)

        check_cursor = Gtk.CheckButton("Cursor Visible")
        check_cursor.set_active(True)
        check_editable.connect("toggled", self.on_cursor_toggled)
        self.grid.attach_next_to(check_cursor, check_editable,
            Gtk.PositionType.RIGHT, 1, 1)

        radio_wrapnone = Gtk.RadioButton.new_with_label_from_widget(None,
            "No Wrapping")
        self.grid.attach(radio_wrapnone, 0, 3, 1, 1)

        radio_wrapchar = Gtk.RadioButton.new_with_label_from_widget(
            radio_wrapnone, "Character Wrapping")
        self.grid.attach_next_to(radio_wrapchar, radio_wrapnone,
            Gtk.PositionType.RIGHT, 1, 1)

        radio_wrapword = Gtk.RadioButton.new_with_label_from_widget(
            radio_wrapnone, "Word Wrapping")
        self.grid.attach_next_to(radio_wrapword, radio_wrapchar,
            Gtk.PositionType.RIGHT, 1, 1)

        radio_wrapnone.connect("toggled", self.on_wrap_toggled,
            Gtk.WrapMode.NONE)
        radio_wrapchar.connect("toggled", self.on_wrap_toggled,
            Gtk.WrapMode.CHAR)
        radio_wrapword.connect("toggled", self.on_wrap_toggled,
            Gtk.WrapMode.WORD)

    def on_button_clicked(self, widget, tag):
        bounds = self.textbuffer.get_selection_bounds()
        if len(bounds) != 0:
            start, end = bounds
            self.textbuffer.apply_tag(tag, start, end)

    def on_clear_clicked(self, widget):
        start = self.textbuffer.get_start_iter()
        end = self.textbuffer.get_end_iter()
        self.textbuffer.remove_all_tags(start, end)

    def on_editable_toggled(self, widget):
        self.textview.set_editable(widget.get_active())

    def on_cursor_toggled(self, widget):
        self.textview.set_cursor_visible(widget.get_active())

    def on_wrap_toggled(self, widget, mode):
        self.textview.set_wrap_mode(mode)

    def on_justify_toggled(self, widget, justification):
        self.textview.set_justification(justification)

    def on_search_clicked(self, widget):
        dialog = SearchDialog(self)
        response = dialog.run()
        if response == Gtk.ResponseType.OK:
            cursor_mark = self.textbuffer.get_insert()
            start = self.textbuffer.get_iter_at_mark(cursor_mark)
            if start.get_offset() == self.textbuffer.get_char_count():
                start = self.textbuffer.get_start_iter()

            self.search_and_mark(dialog.entry.get_text(), start)

        dialog.destroy()

    def search_and_mark(self, text, start):
        end = self.textbuffer.get_end_iter()
        match = start.forward_search(text, 0, end)

        if match != None:
            match_start, match_end = match
            self.textbuffer.apply_tag(self.tag_found, match_start, match_end)
            self.search_and_mark(text, match_end)

win = TextViewWindow()
win.connect("delete-event", Gtk.main_quit)
win.show_all()
Gtk.main()

Dal prossimo post si torna alla normalità, sono cose che mi serviranno. Forse 🙄

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