#!/usr/bin/env python # -*- Mode: Python; py-indent-offset: 4 -*- # vim: tabstop=4 shiftwidth=4 expandtab # # Copyright (C) 2013 Gian Mario Tagliaretti # # This library is free software; you can redistribute it and/or # modify it under the terms of the GNU Lesser General Public # License as published by the Free Software Foundation; either # version 2.1 of the License, or (at your option) any later version. # # This library 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 # Lesser General Public License for more details. # # You should have received a copy of the GNU Lesser General Public # License along with this library; if not, write to the Free Software # Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 # USA title = "CSS Theming/Multiple Backgrounds" description = """ Gtk themes are written using CSS. Every widget is build of multiple items that you can style very similarly to a regular website. """ from gi.repository import Gtk, Gdk, Pango, Gio, GLib class CSSMultiplebgsApp: def __init__(self, demoapp): self.demoapp = demoapp #: Store the last successful parsing of the css so we can revert #: this in case of an error. self.last_good_text = '' #: Set when we receive a parsing-error callback. This is needed #: to handle logic after a parsing-error callback which does not raise #: an exception with provider.load_from_data() self.last_error_code = 0 self.window = Gtk.Window() self.window.set_title('CSS Multiplebgs') self.window.set_default_size(400, 300) self.window.set_border_width(10) self.window.connect('destroy', lambda w: Gtk.main_quit()) overlay = Gtk.Overlay() overlay.add_events(Gdk.EventMask.ENTER_NOTIFY_MASK | Gdk.EventMask.LEAVE_NOTIFY_MASK | Gdk.EventMask.POINTER_MOTION_MASK) self.infobar = Gtk.InfoBar() self.infolabel = Gtk.Label() self.infobar.get_content_area().pack_start(self.infolabel, False, False, 0) self.infobar.set_message_type(Gtk.MessageType.WARNING) box = Gtk.Box(orientation=Gtk.Orientation.VERTICAL) box.pack_start(overlay, expand=True, fill=True, padding=0) box.pack_start(self.infobar, expand=False, fill=True, padding=0) self.window.add(box) canvas = Gtk.DrawingArea() canvas.set_name("canvas") canvas.connect("draw", self.drawing_area_draw) overlay.add(canvas) button = Gtk.Button() button.add_events(Gdk.EventMask.ENTER_NOTIFY_MASK | Gdk.EventMask.LEAVE_NOTIFY_MASK | Gdk.EventMask.POINTER_MOTION_MASK) button.set_name("bricks-button") button.set_halign(Gtk.Align.CENTER) button.set_valign(Gtk.Align.CENTER) button.set_size_request(250, 84) overlay.add_overlay(button) paned = Gtk.Paned(orientation=Gtk.Orientation.VERTICAL) overlay.add_overlay(paned) # We need a filler so we get a handle box = Gtk.Box(orientation=Gtk.Orientation.VERTICAL) paned.add(box) buffer = Gtk.TextBuffer() buffer.create_tag(tag_name="warning", underline=Pango.Underline.SINGLE) buffer.create_tag(tag_name="error", underline=Pango.Underline.ERROR) provider = Gtk.CssProvider() buffer.connect("changed", self.css_text_changed, provider) provider.connect("parsing-error", self.show_parsing_error, buffer) textview = Gtk.TextView() textview.set_buffer(buffer) scrolled = Gtk.ScrolledWindow() scrolled.add(textview) paned.add(scrolled) bytes = Gio.resources_lookup_data("/css_multiplebgs/css_multiplebgs.css", 0) buffer.set_text(bytes.get_data().decode('utf-8')) self.apply_css(self.window, provider) self.window.show_all() self.infobar.hide() def drawing_area_draw(self, widget, cairo_t): context = widget.get_style_context() Gtk.render_background(context, cairo_t, 0, 0, widget.get_allocated_width(), widget.get_allocated_height()) Gtk.render_frame(context, cairo_t, 0, 0, widget.get_allocated_width(), widget.get_allocated_height()) def apply_css(self, widget, provider): Gtk.StyleContext.add_provider(widget.get_style_context(), provider, Gtk.STYLE_PROVIDER_PRIORITY_APPLICATION) if isinstance(widget, Gtk.Container): widget.forall(self.apply_css, provider) def show_parsing_error(self, provider, section, error, buffer): start = buffer.get_iter_at_line_index(section.get_start_line(), section.get_start_position()) end = buffer.get_iter_at_line_index(section.get_end_line(), section.get_end_position()) if error.code == Gtk.CssProviderError.DEPRECATED: tag_name = "warning" else: tag_name = "error" self.last_error_code = error.code self.infolabel.set_text(error.message) self.infobar.show_all() buffer.apply_tag_by_name(tag_name, start, end) def css_text_changed(self, buffer, provider): start = buffer.get_start_iter() end = buffer.get_end_iter() buffer.remove_all_tags(start, end) text = buffer.get_text(start, end, False).encode('utf-8') # Ignore CSS errors as they are shown by highlighting try: provider.load_from_data(text) except GLib.GError as e: if e.domain != 'gtk-css-provider-error-quark': raise e # If the parsing-error callback is ever run (even in the case of warnings) # load the last good css text that ran without any warnings. Otherwise # we may have a discrepancy in "last_good_text" vs the current buffer # causing section.get_start_position() to give back an invalid position # for the editor buffer. if self.last_error_code: provider.load_from_data(self.last_good_text) self.last_error_code = 0 else: self.last_good_text = text self.infobar.hide() Gtk.StyleContext.reset_widgets(Gdk.Screen.get_default()) def main(demoapp=None): CSSMultiplebgsApp(demoapp) Gtk.main() if __name__ == '__main__': import os base_path = os.path.abspath(os.path.dirname(__file__)) resource_path = os.path.join(base_path, '../data/demo.gresource') resource = Gio.Resource.load(resource_path) # FIXME: method register() should be without the underscore # FIXME: see https://bugzilla.gnome.org/show_bug.cgi?id=684319 resource._register() main()