2 Copyright (C) 2009 Paul Davis
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 2 of the License, or
7 (at your option) any later version.
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, write to the Free Software
16 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20 #include <gtkmm/box.h>
22 #include "gtkmm2ext/visibility.h"
23 #include "gtkmm2ext/widget_state.h"
27 /** Parent class for children of a DnDVBox */
28 class /*LIBGTKMM2EXT_API*/ DnDVBoxChild
31 virtual ~DnDVBoxChild () {}
33 /** @return The widget that is to be put into the DnDVBox */
34 virtual Gtk::Widget& widget () = 0;
36 /** @return An EventBox containing the widget that should be used for selection, dragging etc. */
37 virtual Gtk::EventBox& action_widget () = 0;
39 /** @return Text to use in the icon that is dragged */
40 virtual std::string drag_text () const = 0;
42 /** Set the child's visual state */
43 virtual void set_visual_state (VisualState, bool onoff) = 0;
46 /** A VBox whose contents can be dragged and dropped */
48 class /*LIBGTKMM2EXT_API*/ DnDVBox : public Gtk::EventBox
51 DnDVBox () : _active (0), _drag_icon (0), _expecting_unwanted_button_event (false), _placeholder (0)
53 _targets.push_back (Gtk::TargetEntry ("processor"));
57 Gdk::KEY_PRESS_MASK | Gdk::KEY_RELEASE_MASK |
58 Gdk::ENTER_NOTIFY_MASK | Gdk::LEAVE_NOTIFY_MASK |
59 Gdk::BUTTON_PRESS_MASK | Gdk::BUTTON_RELEASE_MASK
62 signal_button_press_event().connect (sigc::bind (mem_fun (*this, &DnDVBox::button_press), (T *) 0));
63 signal_button_release_event().connect (sigc::bind (mem_fun (*this, &DnDVBox::button_release), (T *) 0));
64 signal_drag_motion().connect (mem_fun (*this, &DnDVBox::drag_motion));
65 signal_drag_leave().connect (mem_fun (*this, &DnDVBox::drag_leave));
67 _internal_vbox.show ();
69 drag_dest_set (_targets);
70 signal_drag_data_received().connect (mem_fun (*this, &DnDVBox::drag_data_received));
80 /** Add a child at the end of the widget. The DnDVBox will take responsibility for deleting the child */
81 void add_child (T* child)
83 child->action_widget().drag_source_set (_targets);
84 child->action_widget().signal_drag_begin().connect (sigc::bind (mem_fun (*this, &DnDVBox::drag_begin), child));
85 child->action_widget().signal_drag_data_get().connect (sigc::bind (mem_fun (*this, &DnDVBox::drag_data_get), child));
86 child->action_widget().signal_drag_end().connect (sigc::bind (mem_fun (*this, &DnDVBox::drag_end), child));
87 child->action_widget().signal_button_press_event().connect (sigc::bind (mem_fun (*this, &DnDVBox::button_press), child));
88 child->action_widget().signal_button_release_event().connect (sigc::bind (mem_fun (*this, &DnDVBox::button_release), child));
90 _internal_vbox.pack_start (child->widget(), false, false);
92 _children.push_back (child);
93 child->widget().show ();
96 /** @return Children, sorted into the order that they are currently being displayed in the widget */
97 std::list<T*> children ()
99 std::list<T*> sorted_children;
101 std::list<Gtk::Widget*> widget_children = _internal_vbox.get_children ();
102 for (std::list<Gtk::Widget*>::iterator i = widget_children.begin(); i != widget_children.end(); ++i) {
103 T* c = child_from_widget (*i);
106 sorted_children.push_back (c);
110 return sorted_children;
113 /** @return Selected children */
114 std::list<T*> selection () const {
118 /** Set the `active' child; this is simply a child which is set to have the
119 * visual state "active" for whatever purposes the client may have.
120 * @param c Child, or 0 for none.
122 void set_active (T* c) {
123 T* old_active = _active;
126 setup_child_state (old_active);
129 setup_child_state (_active);
133 /** @param child Child
134 * @return true if the child is selected, otherwise false.
136 bool selected (T* child) const {
137 return (find (_selection.begin(), _selection.end(), child) != _selection.end());
140 /** Clear all children from the widget */
145 for (typename std::list<T*>::iterator i = _children.begin(); i != _children.end(); ++i) {
146 _internal_vbox.remove ((*i)->widget());
157 for (typename std::list<T*>::iterator i = _children.begin(); i != _children.end(); ++i) {
158 add_to_selection (*i);
161 SelectionChanged (); /* EMIT SIGNAL */
168 SelectionChanged (); /* EMIT SIGNAL */
171 /** @param y y coordinate.
172 * @return Pair consisting of the child under y (or 0) and the (fractional) index of the child under y (or -1)
174 std::pair<T*, double> get_child_at_position (int y) const
179 std::pair<T*, double> r;
181 r.second = get_children_around_position (y, &before, &r.first, &after);
186 void set_spacing (int s) {
187 _internal_vbox.set_spacing (s);
190 void remove_placeholder ()
193 _internal_vbox.remove (*_placeholder);
198 /** Add a placeholder where a child would be put if it were added at the given y position.
199 * @param y y position within the DnDVBox.
200 * @return index of child that the placeholder represents, or -1 if it is at the end of all children.
202 int add_placeholder (double y)
204 return create_or_update_placeholder (get_child_at_position (y).second);
207 /** Children have been reordered by a drag */
208 sigc::signal<void> Reordered;
210 /** A button has been pressed over the widget */
211 sigc::signal<bool, GdkEventButton*, T*> ButtonPress;
213 /** A button has been release over the widget */
214 sigc::signal<bool, GdkEventButton*, T*> ButtonRelease;
216 /** A child has been dropped onto this DnDVBox from another one;
217 * Parameters are the source DnDVBox, our child which the other one was dropped on (or 0) and the DragContext.
219 sigc::signal<void, DnDVBox*, T*, Glib::RefPtr<Gdk::DragContext> const & > DropFromAnotherBox;
220 sigc::signal<void> SelectionChanged;
224 /** @return the bottom y position of a child, pretending any placeholder
227 double bottom_of_child_ignoring_placeholder (T* child) const
229 Gtk::Allocation const a = child->widget().get_allocation ();
230 double bottom = a.get_y() + a.get_height();
233 Gtk::Allocation const b = _placeholder->get_allocation ();
234 if (b.get_y() < a.get_y()) {
235 bottom -= (b.get_height () + _internal_vbox.get_spacing ());
242 /** Look at a y coordinate and find the children below y, and the ones either side.
243 * @param y y position.
244 * @param before Filled in with the child before, or 0.
245 * @param at Filled in with the child under y, or 0.
246 * @param after Filled in with the child after, or 0.
247 * @return Fractional position in terms of child height, or -1 if not over a child.
249 double get_children_around_position (int y, T** before, T** at, T** after) const
251 if (_children.empty()) {
252 *before = *at = *after = 0;
258 typename std::list<T*>::const_iterator j = _children.begin ();
260 /* index of current child */
262 /* top of current child */
264 /* bottom of current child */
265 double bottom = bottom_of_child_ignoring_placeholder (*j);
267 while (y >= bottom && j != _children.end()) {
275 if (j != _children.end()) {
276 bottom = bottom_of_child_ignoring_placeholder (*j);
280 if (j == _children.end()) {
289 *after = j != _children.end() ? *j : 0;
291 return i + ((y - top) / (bottom - top));
294 void drag_begin (Glib::RefPtr<Gdk::DragContext> const & context, T* child)
298 /* make up an icon for the drag */
299 _drag_icon = new Gtk::Window (Gtk::WINDOW_POPUP);
301 Gtk::Allocation a = child->widget().get_allocation ();
302 _drag_icon->set_size_request (a.get_width(), a.get_height());
304 _drag_icon->signal_expose_event().connect (sigc::mem_fun (*this, &DnDVBox::icon_expose));
305 _drag_icon->set_name (get_name ());
307 /* make the icon transparent if possible */
308 Glib::RefPtr<Gdk::Screen const> s = _drag_icon->get_screen ();
309 Glib::RefPtr<Gdk::Colormap const> c = s->get_rgba_colormap ();
311 _drag_icon->set_colormap (c);
315 _drag_icon->get_size (w, h);
316 _drag_icon->drag_set_as_icon (context, w / 2, h / 2);
321 /* Draw the drag icon */
322 bool icon_expose (GdkEventExpose*)
324 /* Just grab the child's widget and use that */
327 _drag_icon->get_size (w, h);
329 cairo_t* cr = gdk_cairo_create (_drag_icon->get_window()->gobj ());
331 Glib::RefPtr<Gdk::Pixmap> p = _drag_child->widget().get_snapshot();
332 gdk_cairo_set_source_pixmap (cr, p->gobj(), 0, 0);
333 cairo_rectangle (cr, 0, 0, w, h);
340 void drag_data_get (Glib::RefPtr<Gdk::DragContext> const &, Gtk::SelectionData & selection_data, guint, guint, T* child)
342 selection_data.set (selection_data.get_target(), 8, (const guchar *) &child, sizeof (&child));
345 void drag_data_received (
346 Glib::RefPtr<Gdk::DragContext> const & context, int /*x*/, int y, Gtk::SelectionData const & selection_data, guint /*info*/, guint time
349 /* work out where it was dropped */
350 std::pair<T*, double> const drop = get_child_at_position (y);
352 if (_drag_source == this) {
354 /* dropped from ourselves onto ourselves */
356 T* child = *((T * const *) selection_data.get_data());
358 if (drop.first == 0) {
359 _internal_vbox.reorder_child (child->widget(), -1);
362 /* where in the list this child should be dropped */
363 int target = drop.second + 0.5;
365 /* find out whether the child was `picked up' from before the drop position */
367 typename std::list<T*>::const_iterator i = _children.begin ();
368 while (i != _children.end() && *i != child && n < target) {
373 /* if so, adjust the drop position to account for this */
378 _internal_vbox.reorder_child (child->widget(), target);
383 /* drag started in another DnDVBox; raise a signal to say what happened */
385 std::list<T*> dropped = _drag_source->selection ();
386 DropFromAnotherBox (_drag_source, drop.first, context);
389 context->drag_finish (false, false, time);
392 void drag_end (Glib::RefPtr<Gdk::DragContext> const &, T *)
398 remove_placeholder ();
400 Reordered (); /* EMIT SIGNAL */
403 /** Insert a placeholder at a given fractional child position, creating it if necessary.
404 * @param c Fractional child position.
405 * @return index of child that the placeholder represents, or -1 if it is at the end of all children.
407 int create_or_update_placeholder (double c)
409 if (_placeholder == 0) {
410 _placeholder = manage (new Gtk::Label (""));
411 _internal_vbox.pack_start (*_placeholder, false, false);
412 _placeholder->show ();
415 /* round up the index, unless we're off the end of the children */
416 int const n = c < 0 ? -1 : int (c + 0.5);
417 _internal_vbox.reorder_child (*_placeholder, n);
421 bool drag_motion (Glib::RefPtr<Gdk::DragContext> const &, int /*x*/, int y, guint)
423 if (_children.empty ()) {
431 /* decide where we currently are */
432 double const c = get_children_around_position (y, &before, &at, &after);
434 /* whether we're in the top or bottom half of the child that we're over */
435 bool top_half = (c - int (c)) < 0.5;
437 /* Note that when checking on whether to remove a placeholder, we never do
438 so if _drag_child is 0 as this means that the child being dragged is
439 coming from a different DnDVBox, so it will never be the same as any
443 if (top_half && _drag_child && (before == _drag_child || at == _drag_child)) {
444 /* dropping here would have no effect, so remove the visual cue */
445 remove_placeholder ();
449 if (!top_half && _drag_child && (at == _drag_child || after == _drag_child)) {
450 /* dropping here would have no effect, so remove the visual cue */
451 remove_placeholder ();
455 create_or_update_placeholder (c);
459 void drag_leave (Glib::RefPtr<Gdk::DragContext> const &, guint)
461 remove_placeholder ();
464 bool button_press (GdkEventButton* ev, T* child)
466 if (_expecting_unwanted_button_event == true && child == 0) {
467 _expecting_unwanted_button_event = false;
472 _expecting_unwanted_button_event = true;
475 if (ev->button == 1 || ev->button == 3) {
477 if (!selected (child)) {
479 if ((ev->state & Gdk::SHIFT_MASK) && !_selection.empty()) {
481 /* Shift-click; select all between the clicked child and any existing selections */
483 bool selecting = false;
485 for (typename std::list<T*>::const_iterator i = _children.begin(); i != _children.end(); ++i) {
487 bool const was_selected = selected (*i);
489 if (selecting && !was_selected) {
490 add_to_selection (*i);
493 if (!selecting && !done) {
496 } else if (*i == child) {
498 add_to_selection (child);
500 } else if (selecting) {
501 if (was_selected || *i == child) {
510 if ((ev->state & Gdk::CONTROL_MASK) == 0) {
515 add_to_selection (child);
520 SelectionChanged (); /* EMIT SIGNAL */
523 /* XXX THIS NEEDS GENERALIZING FOR OS X */
524 if (ev->button == 1 && (ev->state & Gdk::CONTROL_MASK)) {
525 if (child && selected (child)) {
526 remove_from_selection (child);
527 SelectionChanged (); /* EMIT SIGNAL */
533 return ButtonPress (ev, child); /* EMIT SIGNAL */
536 bool button_release (GdkEventButton* ev, T* child)
538 if (_expecting_unwanted_button_event == true && child == 0) {
539 _expecting_unwanted_button_event = false;
544 _expecting_unwanted_button_event = true;
547 return ButtonRelease (ev, child); /* EMIT SIGNAL */
550 /** Setup a child's visual state correctly */
551 void setup_child_state (T* c)
554 c->set_visual_state (Selected, (selected (c) || (_active == c)));
557 void clear_selection ()
559 std::list<T*> old_selection = _selection;
561 for (typename std::list<T*>::iterator i = old_selection.begin(); i != old_selection.end(); ++i) {
562 setup_child_state (*i);
566 void add_to_selection (T* child)
568 _selection.push_back (child);
569 setup_child_state (child);
572 void remove_from_selection (T* child)
574 typename std::list<T*>::iterator x = find (_selection.begin(), _selection.end(), child);
575 if (x != _selection.end()) {
577 _selection.erase (x);
578 setup_child_state (c);
582 T* child_from_widget (Gtk::Widget const * w) const
584 typename std::list<T*>::const_iterator i = _children.begin();
585 while (i != _children.end() && &(*i)->widget() != w) {
589 if (i == _children.end()) {
596 Gtk::VBox _internal_vbox;
597 std::list<Gtk::TargetEntry> _targets;
598 std::list<T*> _children;
599 std::list<T*> _selection;
601 Gtk::Window* _drag_icon;
602 bool _expecting_unwanted_button_event;
603 /** A blank label used as a placeholder to indicate where an item would
604 * go if it were dropped or inserted "now".
606 Gtk::Label* _placeholder;
607 /** Our child being dragged, or 0 */
610 static DnDVBox* _drag_source;
615 DnDVBox<T>* DnDVBox<T>::_drag_source = 0;