2 Copyright (C) 2011 Paul Davis
3 Author: Carl Hetherington <cth@carlh.net>
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 2 of the License, or
8 (at your option) any later version.
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this program; if not, write to the Free Software
17 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
21 /** @file canvas/canvas.cc
22 * @brief Implementation of the main canvas classes.
27 #include <gtkmm/adjustment.h>
28 #include <gtkmm/label.h>
30 #include "pbd/compose.h"
31 #include "pbd/stacktrace.h"
33 #include "canvas/canvas.h"
34 #include "canvas/debug.h"
35 #include "canvas/line.h"
36 #include "canvas/scroll_group.h"
39 using namespace ArdourCanvas;
41 /** Construct a new Canvas */
49 Canvas::scroll_to (Coord x, Coord y)
51 /* We do things this way because we do not want to recurse through
52 the canvas for every scroll. In the presence of large MIDI
53 tracks this means traversing item lists that include
54 thousands of items (notes).
56 This design limits us to moving only those items (groups, typically)
57 that should move in certain ways as we scroll. In other terms, it
58 becomes O(1) rather than O(N).
61 for (list<ScrollGroup*>::iterator i = scrollers.begin(); i != scrollers.end(); ++i) {
62 (*i)->scroll_to (Duple (x, y));
65 pick_current_item (0); // no current mouse position
69 Canvas::add_scroller (ScrollGroup& i)
71 scrollers.push_back (&i);
77 pick_current_item (0); // no current mouse position
80 /** Render an area of the canvas.
81 * @param area Area in window coordinates.
82 * @param context Cairo context to render to.
85 Canvas::render (Rect const & area, Cairo::RefPtr<Cairo::Context> const & context) const
88 if (DEBUG_ENABLED(PBD::DEBUG::CanvasRender)) {
89 cerr << this << " RENDER: " << area << endl;
90 //cerr << "CANVAS @ " << this << endl;
92 //cerr << "-------------------------\n";
98 boost::optional<Rect> root_bbox = _root.bounding_box();
100 /* the root has no bounding box, so there's nothing to render */
104 boost::optional<Rect> draw = root_bbox->intersection (area);
107 /* there's a common area between the root and the requested
111 _root.render (*draw, context);
114 if (getenv ("CANVAS_HARLEQUIN_DEBUGGING")) {
115 // This transparently colors the rect being rendered, after it has been drawn.
116 double r = (random() % 65536) /65536.0;
117 double g = (random() % 65536) /65536.0;
118 double b = (random() % 65536) /65536.0;
119 context->rectangle (draw->x0, draw->y0, draw->x1 - draw->x0, draw->y1 - draw->y0);
120 context->set_source_rgba (r, g, b, 0.25);
129 operator<< (ostream& o, Canvas& c)
136 Canvas::indent() const
140 for (int n = 0; n < ArdourCanvas::dump_depth; ++n) {
148 Canvas::render_indent() const
152 for (int n = 0; n < ArdourCanvas::render_depth; ++n) {
160 Canvas::dump (ostream& o) const
166 /** Called when an item has been shown or hidden.
167 * @param item Item that has been shown or hidden.
170 Canvas::item_shown_or_hidden (Item* item)
172 boost::optional<Rect> bbox = item->bounding_box ();
174 if (item->item_to_window (*bbox).intersection (visible_area ())) {
175 queue_draw_item_area (item, bbox.get ());
180 /** Called when an item has a change to its visual properties
181 * that do NOT affect its bounding box.
182 * @param item Item that has been modified.
185 Canvas::item_visual_property_changed (Item* item)
187 boost::optional<Rect> bbox = item->bounding_box ();
189 if (item->item_to_window (*bbox).intersection (visible_area ())) {
190 queue_draw_item_area (item, bbox.get ());
195 /** Called when an item has changed, but not moved.
196 * @param item Item that has changed.
197 * @param pre_change_bounding_box The bounding box of item before the change,
198 * in the item's coordinates.
201 Canvas::item_changed (Item* item, boost::optional<Rect> pre_change_bounding_box)
204 Rect window_bbox = visible_area ();
206 if (pre_change_bounding_box) {
208 if (item->item_to_window (*pre_change_bounding_box).intersection (window_bbox)) {
209 /* request a redraw of the item's old bounding box */
210 queue_draw_item_area (item, pre_change_bounding_box.get ());
214 boost::optional<Rect> post_change_bounding_box = item->bounding_box ();
215 if (post_change_bounding_box) {
217 if (item->item_to_window (*post_change_bounding_box).intersection (window_bbox)) {
218 /* request a redraw of the item's new bounding box */
219 queue_draw_item_area (item, post_change_bounding_box.get ());
225 Canvas::window_to_canvas (Duple const & d) const
227 /* Find the scroll group that covers d (a window coordinate). Scroll groups are only allowed
228 * as children of the root group, so we just scan its first level
229 * children and see what we can find.
232 std::list<Item*> const& root_children (_root.items());
235 /* if the coordinates are negative, clamp to zero and find the item
236 * that covers that "edge" position.
241 if (in_window.x < 0) {
244 if (in_window.y < 0) {
248 for (std::list<Item*>::const_iterator i = root_children.begin(); i != root_children.end(); ++i) {
249 if (((sg = dynamic_cast<ScrollGroup*>(*i)) != 0) && sg->covers_window (in_window)) {
255 return d.translate (sg->scroll_offset());
262 Canvas::canvas_to_window (Duple const & d, bool rounded) const
264 /* Find the scroll group that covers d (a canvas coordinate). Scroll groups are only allowed
265 * as children of the root group, so we just scan its first level
266 * children and see what we can find.
269 std::list<Item*> const& root_children (_root.items());
273 for (std::list<Item*>::const_iterator i = root_children.begin(); i != root_children.end(); ++i) {
274 if (((sg = dynamic_cast<ScrollGroup*>(*i)) != 0) && sg->covers_canvas (d)) {
281 wd = d.translate (-sg->scroll_offset());
286 /* Note that this intentionally almost always returns integer coordinates */
296 /** Called when an item has moved.
297 * @param item Item that has moved.
298 * @param pre_change_parent_bounding_box The bounding box of the item before
299 * the move, in its parent's coordinates.
302 Canvas::item_moved (Item* item, boost::optional<Rect> pre_change_parent_bounding_box)
304 if (pre_change_parent_bounding_box) {
305 /* request a redraw of where the item used to be. The box has
306 * to be in parent coordinate space since the bounding box of
307 * an item does not change when moved. If we use
308 * item->item_to_canvas() on the old bounding box, we will be
310 * using the item's new position, and so will compute the wrong
311 * invalidation area. If we use the parent (which has not
312 * moved, then this will work.
314 queue_draw_item_area (item->parent(), pre_change_parent_bounding_box.get ());
317 boost::optional<Rect> post_change_bounding_box = item->bounding_box ();
318 if (post_change_bounding_box) {
319 /* request a redraw of where the item now is */
320 queue_draw_item_area (item, post_change_bounding_box.get ());
324 /** Request a redraw of a particular area in an item's coordinates.
326 * @param area Area to redraw in the item's coordinates.
329 Canvas::queue_draw_item_area (Item* item, Rect area)
331 request_redraw (item->item_to_window (area));
334 /** Construct a GtkCanvas */
335 GtkCanvas::GtkCanvas ()
337 , _new_current_item (0)
341 /* these are the events we want to know about */
342 add_events (Gdk::BUTTON_PRESS_MASK | Gdk::BUTTON_RELEASE_MASK | Gdk::POINTER_MOTION_MASK |
343 Gdk::SCROLL_MASK | Gdk::ENTER_NOTIFY_MASK | Gdk::LEAVE_NOTIFY_MASK);
347 GtkCanvas::pick_current_item (int state)
352 /* this version of ::pick_current_item() is called after an item is
353 * added or removed, so we have no coordinates to work from as is the
354 * case with a motion event. Find out where the mouse is and use that.
357 Glib::RefPtr<const Gdk::Window> pointer_window = Gdk::Display::get_default()->get_window_at_pointer (x, y);
359 if (pointer_window != get_window()) {
363 pick_current_item (Duple (x, y), state);
366 /** Given @param point (a position in window coordinates)
367 * and mouse state @param state, check to see if _current_item
368 * (which will be used to deliver events) should change.
371 GtkCanvas::pick_current_item (Duple const & point, int state)
373 /* we do not enter/leave items during a drag/grab */
379 /* find the items at the given window position */
381 vector<Item const *> items;
382 _root.add_items_at_point (point, items);
384 DEBUG_TRACE (PBD::DEBUG::CanvasEnterLeave, string_compose ("%1 covers %2 items\n", point, items.size()));
387 if (DEBUG_ENABLED(PBD::DEBUG::CanvasEnterLeave)) {
388 for (vector<Item const*>::const_iterator it = items.begin(); it != items.end(); ++it) {
390 std::cerr << "\tItem " << (*it)->whatami() << '/' << (*it)->name << " ignore events ? " << (*it)->ignore_events() << " vis ? " << (*it)->visible() << std::endl;
392 std::cerr << "\tItem " << (*it)->whatami() << '/' << " ignore events ? " << (*it)->ignore_events() << " vis ? " << (*it)->visible() << std::endl;
398 /* put all items at point that are event-sensitive and visible and NOT
399 groups into within_items. Note that items is sorted from bottom to
400 top, but we're going to reverse that for within_items so that its
401 first item is the upper-most item that can be chosen as _current_item.
404 vector<Item const *>::const_iterator i;
405 list<Item const *> within_items;
407 for (i = items.begin(); i != items.end(); ++i) {
409 Item const * possible_item = *i;
411 /* We ignore invisible items, containers and items that ignore events */
413 if (!possible_item->visible() || possible_item->ignore_events() || dynamic_cast<ArdourCanvas::Container const *>(possible_item) != 0) {
416 within_items.push_front (possible_item);
419 DEBUG_TRACE (PBD::DEBUG::CanvasEnterLeave, string_compose ("after filtering insensitive + containers, we have %1 items\n", within_items.size()));
421 if (within_items.empty()) {
423 /* no items at point, just send leave event below */
424 _new_current_item = 0;
428 if (within_items.front() == _current_item) {
429 /* uppermost item at point is already _current_item */
433 _new_current_item = const_cast<Item*> (within_items.front());
436 if (_new_current_item != _current_item) {
437 deliver_enter_leave (point, state);
441 /** Deliver a series of enter & leave events based on the pointer position being at window
442 * coordinate @param point, and pointer @param state (modifier keys, etc)
445 GtkCanvas::deliver_enter_leave (Duple const & point, int state)
447 /* setup enter & leave event structures */
449 GdkEventCrossing enter_event;
450 enter_event.type = GDK_ENTER_NOTIFY;
451 enter_event.window = get_window()->gobj();
452 enter_event.send_event = 0;
453 enter_event.subwindow = 0;
454 enter_event.mode = GDK_CROSSING_NORMAL;
455 enter_event.focus = FALSE;
456 enter_event.state = state;
458 /* Events delivered to canvas items are expected to be in canvas
459 * coordinates but @param point is in window coordinates.
462 Duple c = window_to_canvas (point);
466 GdkEventCrossing leave_event = enter_event;
467 leave_event.type = GDK_LEAVE_NOTIFY;
470 GdkNotifyType enter_detail;
471 GdkNotifyType leave_detail;
472 vector<Item*> items_to_leave_virtual;
473 vector<Item*> items_to_enter_virtual;
475 if (_new_current_item == 0) {
477 leave_detail = GDK_NOTIFY_UNKNOWN;
481 /* no current item, so also send virtual leave events to the
482 * entire heirarchy for the current item
485 for (i = _current_item->parent(); i ; i = i->parent()) {
486 items_to_leave_virtual.push_back (i);
490 } else if (_current_item == 0) {
492 enter_detail = GDK_NOTIFY_UNKNOWN;
494 /* no current item, so also send virtual enter events to the
495 * entire heirarchy for the new item
498 for (i = _new_current_item->parent(); i ; i = i->parent()) {
499 items_to_enter_virtual.push_back (i);
502 } else if (_current_item->is_descendant_of (*_new_current_item)) {
504 /* move from descendant to ancestor (X: "_current_item is an
505 * inferior ("child") of _new_current_item")
507 * Deliver "virtual" leave notifications to all items in the
508 * heirarchy between current and new_current.
511 for (i = _current_item->parent(); i && i != _new_current_item; i = i->parent()) {
512 items_to_leave_virtual.push_back (i);
515 enter_detail = GDK_NOTIFY_INFERIOR;
516 leave_detail = GDK_NOTIFY_ANCESTOR;
518 } else if (_new_current_item->is_descendant_of (*_current_item)) {
519 /* move from ancestor to descendant (X: "_new_current_item is
520 * an inferior ("child") of _current_item")
522 * Deliver "virtual" enter notifications to all items in the
523 * heirarchy between current and new_current.
526 for (i = _new_current_item->parent(); i && i != _current_item; i = i->parent()) {
527 items_to_enter_virtual.push_back (i);
530 enter_detail = GDK_NOTIFY_ANCESTOR;
531 leave_detail = GDK_NOTIFY_INFERIOR;
535 Item const * common_ancestor = _current_item->closest_ancestor_with (*_new_current_item);
537 /* deliver virtual leave events to everything between _current
538 * and common_ancestor.
541 for (i = _current_item->parent(); i && i != common_ancestor; i = i->parent()) {
542 items_to_leave_virtual.push_back (i);
545 /* deliver virtual enter events to everything between
546 * _new_current and common_ancestor.
549 for (i = _new_current_item->parent(); i && i != common_ancestor; i = i->parent()) {
550 items_to_enter_virtual.push_back (i);
553 enter_detail = GDK_NOTIFY_NONLINEAR;
554 leave_detail = GDK_NOTIFY_NONLINEAR;
558 if (_current_item && !_current_item->ignore_events ()) {
559 leave_event.detail = leave_detail;
560 _current_item->Event ((GdkEvent*)&leave_event);
561 DEBUG_TRACE (PBD::DEBUG::CanvasEnterLeave, string_compose ("LEAVE %1/%2\n", _current_item->whatami(), _current_item->name));
564 leave_event.detail = GDK_NOTIFY_VIRTUAL;
565 enter_event.detail = GDK_NOTIFY_VIRTUAL;
567 for (vector<Item*>::iterator it = items_to_leave_virtual.begin(); it != items_to_leave_virtual.end(); ++it) {
568 if (!(*it)->ignore_events()) {
569 DEBUG_TRACE (PBD::DEBUG::CanvasEnterLeave, string_compose ("leave %1/%2\n", (*it)->whatami(), (*it)->name));
570 (*it)->Event ((GdkEvent*)&leave_event);
574 for (vector<Item*>::iterator it = items_to_enter_virtual.begin(); it != items_to_enter_virtual.end(); ++it) {
575 if (!(*it)->ignore_events()) {
576 DEBUG_TRACE (PBD::DEBUG::CanvasEnterLeave, string_compose ("enter %1/%2\n", (*it)->whatami(), (*it)->name));
577 (*it)->Event ((GdkEvent*)&enter_event);
578 // std::cerr << "enter " << (*it)->whatami() << '/' << (*it)->name << std::endl;
582 if (_new_current_item && !_new_current_item->ignore_events()) {
583 enter_event.detail = enter_detail;
584 DEBUG_TRACE (PBD::DEBUG::CanvasEnterLeave, string_compose ("ENTER %1/%2\n", _new_current_item->whatami(), _new_current_item->name));
585 _new_current_item->Event ((GdkEvent*)&enter_event);
588 _current_item = _new_current_item;
592 /** Deliver an event to the appropriate item; either the grabbed item, or
593 * one of the items underneath the event.
594 * @param point Position that the event has occurred at, in canvas coordinates.
595 * @param event The event.
598 GtkCanvas::deliver_event (GdkEvent* event)
600 /* Point in in canvas coordinate space */
602 const Item* event_item;
605 /* we have a grabbed item, so everything gets sent there */
606 DEBUG_TRACE (PBD::DEBUG::CanvasEvents, string_compose ("%1 %2 (%3) was grabbed, send event there\n",
607 _grabbed_item, _grabbed_item->whatami(), _grabbed_item->name));
608 event_item = _grabbed_item;
610 event_item = _current_item;
617 /* run through the items from child to parent, until one claims the event */
619 Item* item = const_cast<Item*> (event_item);
623 Item* parent = item->parent ();
625 if (!item->ignore_events () &&
626 item->Event (event)) {
627 /* this item has just handled the event */
629 PBD::DEBUG::CanvasEvents,
630 string_compose ("canvas event handled by %1 %2\n", item->whatami(), item->name.empty() ? "[unknown]" : item->name)
636 DEBUG_TRACE (PBD::DEBUG::CanvasEvents, string_compose ("canvas event %3 left unhandled by %1 %2\n", item->whatami(), item->name.empty() ? "[unknown]" : item->name, event_type_string (event->type)));
638 if ((item = parent) == 0) {
647 /** Called when an item is being destroyed.
648 * @param item Item being destroyed.
649 * @param bounding_box Last known bounding box of the item.
652 GtkCanvas::item_going_away (Item* item, boost::optional<Rect> bounding_box)
655 queue_draw_item_area (item, bounding_box.get ());
658 if (_new_current_item == item) {
659 _new_current_item = 0;
662 if (_grabbed_item == item) {
666 if (_focused_item == item) {
670 ScrollGroup* sg = dynamic_cast<ScrollGroup*>(item);
672 scrollers.remove (sg);
675 if (_current_item == item) {
676 /* no need to send a leave event to this item, since it is going away
679 pick_current_item (0); // no mouse state
684 /** Handler for GDK expose events.
686 * @return true if the event was handled.
689 GtkCanvas::on_expose_event (GdkEventExpose* ev)
691 Cairo::RefPtr<Cairo::Context> cairo_context = get_window()->create_cairo_context ();
692 render (Rect (ev->area.x, ev->area.y, ev->area.x + ev->area.width, ev->area.y + ev->area.height), cairo_context);
696 /** @return Our Cairo context, or 0 if we don't have one */
697 Cairo::RefPtr<Cairo::Context>
698 GtkCanvas::context ()
700 Glib::RefPtr<Gdk::Window> w = get_window ();
702 return Cairo::RefPtr<Cairo::Context> ();
705 return w->create_cairo_context ();
708 /** Handler for GDK scroll events.
710 * @return true if the event was handled.
713 GtkCanvas::on_scroll_event (GdkEventScroll* ev)
715 /* translate event coordinates from window to canvas */
717 GdkEvent copy = *((GdkEvent*)ev);
718 Duple winpos = Duple (ev->x, ev->y);
719 Duple where = window_to_canvas (winpos);
721 pick_current_item (winpos, ev->state);
723 copy.button.x = where.x;
724 copy.button.y = where.y;
726 /* Coordinates in the event will be canvas coordinates, correctly adjusted
727 for scroll if this GtkCanvas is in a GtkCanvasViewport.
730 DEBUG_TRACE (PBD::DEBUG::CanvasEvents, string_compose ("canvas scroll @ %1, %2 => %3\n", ev->x, ev->y, where));
731 return deliver_event (reinterpret_cast<GdkEvent*>(©));
734 /** Handler for GDK button press events.
736 * @return true if the event was handled.
739 GtkCanvas::on_button_press_event (GdkEventButton* ev)
741 /* translate event coordinates from window to canvas */
743 GdkEvent copy = *((GdkEvent*)ev);
744 Duple winpos = Duple (ev->x, ev->y);
745 Duple where = window_to_canvas (winpos);
747 pick_current_item (winpos, ev->state);
749 copy.button.x = where.x;
750 copy.button.y = where.y;
752 /* Coordinates in the event will be canvas coordinates, correctly adjusted
753 for scroll if this GtkCanvas is in a GtkCanvasViewport.
756 DEBUG_TRACE (PBD::DEBUG::CanvasEvents, string_compose ("canvas button press @ %1, %2 => %3\n", ev->x, ev->y, where));
757 return deliver_event (reinterpret_cast<GdkEvent*>(©));
760 /** Handler for GDK button release events.
762 * @return true if the event was handled.
765 GtkCanvas::on_button_release_event (GdkEventButton* ev)
767 /* translate event coordinates from window to canvas */
769 GdkEvent copy = *((GdkEvent*)ev);
770 Duple winpos = Duple (ev->x, ev->y);
771 Duple where = window_to_canvas (winpos);
773 pick_current_item (winpos, ev->state);
775 copy.button.x = where.x;
776 copy.button.y = where.y;
778 /* Coordinates in the event will be canvas coordinates, correctly adjusted
779 for scroll if this GtkCanvas is in a GtkCanvasViewport.
782 DEBUG_TRACE (PBD::DEBUG::CanvasEvents, string_compose ("canvas button release @ %1, %2 => %3\n", ev->x, ev->y, where));
783 return deliver_event (reinterpret_cast<GdkEvent*>(©));
787 GtkCanvas::get_mouse_position (Duple& winpos) const
791 Gdk::ModifierType mask;
792 Glib::RefPtr<Gdk::Window> self = Glib::RefPtr<Gdk::Window>::cast_const (get_window ());
795 std::cerr << " no self window\n";
796 winpos = Duple (0, 0);
800 Glib::RefPtr<Gdk::Window> win = self->get_pointer (x, y, mask);
808 /** Handler for GDK motion events.
810 * @return true if the event was handled.
813 GtkCanvas::on_motion_notify_event (GdkEventMotion* ev)
815 /* translate event coordinates from window to canvas */
817 GdkEvent copy = *((GdkEvent*)ev);
818 Duple point (ev->x, ev->y);
819 Duple where = window_to_canvas (point);
821 copy.motion.x = where.x;
822 copy.motion.y = where.y;
824 /* Coordinates in "copy" will be canvas coordinates,
827 DEBUG_TRACE (PBD::DEBUG::CanvasEvents, string_compose ("canvas motion @ %1, %2 canvas @ %3, %4\n", ev->x, ev->y, copy.motion.x, copy.motion.y));
829 MouseMotion (point); /* EMIT SIGNAL */
831 pick_current_item (point, ev->state);
833 /* Now deliver the motion event. It may seem a little inefficient
834 to recompute the items under the event, but the enter notify/leave
835 events may have deleted canvas items so it is important to
836 recompute the list in deliver_event.
839 return deliver_event (reinterpret_cast<GdkEvent*> (©));
843 GtkCanvas::on_enter_notify_event (GdkEventCrossing* ev)
845 pick_current_item (Duple (ev->x, ev->y), ev->state);
850 GtkCanvas::on_leave_notify_event (GdkEventCrossing* ev)
852 _new_current_item = 0;
853 deliver_enter_leave (Duple (ev->x, ev->y), ev->state);
857 /** Called to request a redraw of our canvas.
858 * @param area Area to redraw, in window coordinates.
861 GtkCanvas::request_redraw (Rect const & request)
865 Coord const w = width ();
866 Coord const h = height ();
868 /* clamp area requested to actual visible window */
870 real_area.x0 = max (0.0, min (w, request.x0));
871 real_area.x1 = max (0.0, min (w, request.x1));
872 real_area.y0 = max (0.0, min (h, request.y0));
873 real_area.y1 = max (0.0, min (h, request.y1));
875 queue_draw_area (real_area.x0, real_area.y0, real_area.width(), real_area.height());
878 /** Called to request that we try to get a particular size for ourselves.
879 * @param size Size to request, in pixels.
882 GtkCanvas::request_size (Duple size)
886 if (req.x > INT_MAX) {
890 if (req.y > INT_MAX) {
894 set_size_request (req.x, req.y);
897 /** `Grab' an item, so that all events are sent to that item until it is `ungrabbed'.
898 * This is typically used for dragging items around, so that they are grabbed during
900 * @param item Item to grab.
903 GtkCanvas::grab (Item* item)
905 /* XXX: should this be doing gdk_pointer_grab? */
906 _grabbed_item = item;
910 /** `Ungrab' any item that was previously grabbed */
914 /* XXX: should this be doing gdk_pointer_ungrab? */
918 /** Set keyboard focus on an item, so that all keyboard events are sent to that item until the focus
920 * @param item Item to grab.
923 GtkCanvas::focus (Item* item)
925 _focused_item = item;
929 GtkCanvas::unfocus (Item* item)
931 if (item == _focused_item) {
936 /** @return The visible area of the canvas, in window coordinates */
938 GtkCanvas::visible_area () const
940 return Rect (0, 0, get_allocation().get_width (), get_allocation().get_height ());
944 GtkCanvas::width() const
946 return get_allocation().get_width();
950 GtkCanvas::height() const
952 return get_allocation().get_height();
955 /** Create a GtkCanvaSViewport.
956 * @param hadj Adjustment to use for horizontal scrolling.
957 * @param vadj Adjustment to use for vertica scrolling.
959 GtkCanvasViewport::GtkCanvasViewport (Gtk::Adjustment& hadj, Gtk::Adjustment& vadj)
960 : Alignment (0, 0, 1.0, 1.0)
966 hadj.signal_value_changed().connect (sigc::mem_fun (*this, &GtkCanvasViewport::scrolled));
967 vadj.signal_value_changed().connect (sigc::mem_fun (*this, &GtkCanvasViewport::scrolled));
971 GtkCanvasViewport::scrolled ()
973 _canvas.scroll_to (hadjustment.get_value(), vadjustment.get_value());
977 /** Handler for when GTK asks us what minimum size we want.
978 * @param req Requsition to fill in.
981 GtkCanvasViewport::on_size_request (Gtk::Requisition* req)
983 /* force the canvas to size itself */
984 // _canvas.root()->bounding_box();