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>
21 #include "gtkmm2ext/widget_state.h"
25 /** Parent class for children of a DnDVBox */
29 virtual ~DnDVBoxChild () {}
31 /** @return The widget that is to be put into the DnDVBox */
32 virtual Gtk::Widget& widget () = 0;
34 /** @return An EventBox containing the widget that should be used for selection, dragging etc. */
35 virtual Gtk::EventBox& action_widget () = 0;
37 /** @return Text to use in the icon that is dragged */
38 virtual std::string drag_text () const = 0;
40 /** Set the child's visual state */
41 virtual void set_visual_state (VisualState, bool onoff) = 0;
44 /** A VBox whose contents can be dragged and dropped */
46 class DnDVBox : public Gtk::EventBox
49 DnDVBox () : _active (0), _drag_icon (0), _expecting_unwanted_button_event (false), _placeholder (0)
51 _targets.push_back (Gtk::TargetEntry ("processor"));
55 Gdk::KEY_PRESS_MASK | Gdk::KEY_RELEASE_MASK |
56 Gdk::ENTER_NOTIFY_MASK | Gdk::LEAVE_NOTIFY_MASK |
57 Gdk::BUTTON_PRESS_MASK | Gdk::BUTTON_RELEASE_MASK
60 signal_button_press_event().connect (sigc::bind (mem_fun (*this, &DnDVBox::button_press), (T *) 0));
61 signal_button_release_event().connect (sigc::bind (mem_fun (*this, &DnDVBox::button_release), (T *) 0));
62 signal_drag_motion().connect (mem_fun (*this, &DnDVBox::drag_motion));
63 signal_drag_leave().connect (mem_fun (*this, &DnDVBox::drag_leave));
65 _internal_vbox.show ();
67 drag_dest_set (_targets);
68 signal_drag_data_received().connect (mem_fun (*this, &DnDVBox::drag_data_received));
78 /** Add a child at the end of the widget. The DnDVBox will take responsibility for deleting the child */
79 void add_child (T* child)
81 child->action_widget().drag_source_set (_targets);
82 child->action_widget().signal_drag_begin().connect (sigc::bind (mem_fun (*this, &DnDVBox::drag_begin), child));
83 child->action_widget().signal_drag_data_get().connect (sigc::bind (mem_fun (*this, &DnDVBox::drag_data_get), child));
84 child->action_widget().signal_drag_end().connect (sigc::bind (mem_fun (*this, &DnDVBox::drag_end), child));
85 child->action_widget().signal_button_press_event().connect (sigc::bind (mem_fun (*this, &DnDVBox::button_press), child));
86 child->action_widget().signal_button_release_event().connect (sigc::bind (mem_fun (*this, &DnDVBox::button_release), child));
88 _internal_vbox.pack_start (child->widget(), false, false);
90 _children.push_back (child);
91 child->widget().show ();
94 /** @return Children, sorted into the order that they are currently being displayed in the widget */
95 std::list<T*> children ()
97 std::list<T*> sorted_children;
99 std::list<Gtk::Widget*> widget_children = _internal_vbox.get_children ();
100 for (std::list<Gtk::Widget*>::iterator i = widget_children.begin(); i != widget_children.end(); ++i) {
101 T* c = child_from_widget (*i);
104 sorted_children.push_back (c);
108 return sorted_children;
111 /** @return Selected children */
112 std::list<T*> selection () const {
116 /** Set the `active' child; this is simply a child which is set to have the
117 * visual state "active" for whatever purposes the client may have.
118 * @param c Child, or 0 for none.
120 void set_active (T* c) {
121 T* old_active = _active;
124 setup_child_state (old_active);
127 setup_child_state (_active);
131 /** @param child Child
132 * @return true if the child is selected, otherwise false.
134 bool selected (T* child) const {
135 return (find (_selection.begin(), _selection.end(), child) != _selection.end());
138 /** Clear all children from the widget */
143 for (typename std::list<T*>::iterator i = _children.begin(); i != _children.end(); ++i) {
144 _internal_vbox.remove ((*i)->widget());
155 for (typename std::list<T*>::iterator i = _children.begin(); i != _children.end(); ++i) {
156 add_to_selection (*i);
159 SelectionChanged (); /* EMIT SIGNAL */
166 SelectionChanged (); /* EMIT SIGNAL */
169 /** @param y y coordinate.
170 * @return Pair consisting of the child under y (or 0) and the (fractional) index of the child under y (or -1)
172 std::pair<T*, double> get_child_at_position (int y) const
177 std::pair<T*, double> r;
179 r.second = get_children_around_position (y, &before, &r.first, &after);
184 void set_spacing (int s) {
185 _internal_vbox.set_spacing (s);
188 void remove_placeholder ()
191 _internal_vbox.remove (*_placeholder);
196 /** Add a placeholder where a child would be put if it were added at the given y position.
197 * @param y y position within the DnDVBox.
198 * @return index of child that the placeholder represents, or -1 if it is at the end of all children.
200 int add_placeholder (double y)
202 return create_or_update_placeholder (get_child_at_position (y).second);
205 /** Children have been reordered by a drag */
206 sigc::signal<void> Reordered;
208 /** A button has been pressed over the widget */
209 sigc::signal<bool, GdkEventButton*, T*> ButtonPress;
211 /** A button has been release over the widget */
212 sigc::signal<bool, GdkEventButton*, T*> ButtonRelease;
214 /** A child has been dropped onto this DnDVBox from another one;
215 * Parameters are the source DnDVBox, our child which the other one was dropped on (or 0) and the DragContext.
217 sigc::signal<void, DnDVBox*, T*, Glib::RefPtr<Gdk::DragContext> const & > DropFromAnotherBox;
218 sigc::signal<void> SelectionChanged;
222 /** @return the bottom y position of a child, pretending any placeholder
225 double bottom_of_child_ignoring_placeholder (T* child) const
227 Gtk::Allocation const a = child->widget().get_allocation ();
228 double bottom = a.get_y() + a.get_height();
231 Gtk::Allocation const b = _placeholder->get_allocation ();
232 if (b.get_y() < a.get_y()) {
233 bottom -= (b.get_height () + _internal_vbox.get_spacing ());
240 /** Look at a y coordinate and find the children below y, and the ones either side.
241 * @param y y position.
242 * @param before Filled in with the child before, or 0.
243 * @param at Filled in with the child under y, or 0.
244 * @param after Filled in with the child after, or 0.
245 * @return Fractional position in terms of child height, or -1 if not over a child.
247 double get_children_around_position (int y, T** before, T** at, T** after) const
249 if (_children.empty()) {
250 *before = *at = *after = 0;
256 typename std::list<T*>::const_iterator j = _children.begin ();
258 /* index of current child */
260 /* top of current child */
262 /* bottom of current child */
263 double bottom = bottom_of_child_ignoring_placeholder (*j);
265 while (y >= bottom && j != _children.end()) {
273 if (j != _children.end()) {
274 bottom = bottom_of_child_ignoring_placeholder (*j);
278 if (j == _children.end()) {
287 *after = j != _children.end() ? *j : 0;
289 return i + ((y - top) / (bottom - top));
292 void drag_begin (Glib::RefPtr<Gdk::DragContext> const & context, T* child)
296 /* make up an icon for the drag */
297 _drag_icon = new Gtk::Window (Gtk::WINDOW_POPUP);
299 Gtk::Allocation a = child->widget().get_allocation ();
300 _drag_icon->set_size_request (a.get_width(), a.get_height());
302 _drag_icon->signal_expose_event().connect (sigc::mem_fun (*this, &DnDVBox::icon_expose));
303 _drag_icon->set_name (get_name ());
305 /* make the icon transparent if possible */
306 Glib::RefPtr<Gdk::Screen const> s = _drag_icon->get_screen ();
307 Glib::RefPtr<Gdk::Colormap const> c = s->get_rgba_colormap ();
309 _drag_icon->set_colormap (c);
313 _drag_icon->get_size (w, h);
314 _drag_icon->drag_set_as_icon (context, w / 2, h / 2);
319 /* Draw the drag icon */
320 bool icon_expose (GdkEventExpose*)
322 /* Just grab the child's widget and use that */
325 _drag_icon->get_size (w, h);
327 cairo_t* cr = gdk_cairo_create (_drag_icon->get_window()->gobj ());
329 Glib::RefPtr<Gdk::Pixmap> p = _drag_child->widget().get_snapshot();
330 gdk_cairo_set_source_pixmap (cr, p->gobj(), 0, 0);
331 cairo_rectangle (cr, 0, 0, w, h);
338 void drag_data_get (Glib::RefPtr<Gdk::DragContext> const &, Gtk::SelectionData & selection_data, guint, guint, T* child)
340 selection_data.set (selection_data.get_target(), 8, (const guchar *) &child, sizeof (&child));
343 void drag_data_received (
344 Glib::RefPtr<Gdk::DragContext> const & context, int /*x*/, int y, Gtk::SelectionData const & selection_data, guint /*info*/, guint time
347 /* work out where it was dropped */
348 std::pair<T*, double> const drop = get_child_at_position (y);
350 if (_drag_source == this) {
352 /* dropped from ourselves onto ourselves */
354 T* child = *((T **) selection_data.get_data());
356 if (drop.first == 0) {
357 _internal_vbox.reorder_child (child->widget(), -1);
360 /* where in the list this child should be dropped */
361 int target = drop.second + 0.5;
363 /* find out whether the child was `picked up' from before the drop position */
365 typename std::list<T*>::const_iterator i = _children.begin ();
366 while (i != _children.end() && *i != child && n < target) {
371 /* if so, adjust the drop position to account for this */
376 _internal_vbox.reorder_child (child->widget(), target);
381 /* drag started in another DnDVBox; raise a signal to say what happened */
383 std::list<T*> dropped = _drag_source->selection ();
384 DropFromAnotherBox (_drag_source, drop.first, context);
387 context->drag_finish (false, false, time);
390 void drag_end (Glib::RefPtr<Gdk::DragContext> const &, T *)
396 remove_placeholder ();
398 Reordered (); /* EMIT SIGNAL */
401 /** Insert a placeholder at a given fractional child position, creating it if necessary.
402 * @param c Fractional child position.
403 * @return index of child that the placeholder represents, or -1 if it is at the end of all children.
405 int create_or_update_placeholder (double c)
407 if (_placeholder == 0) {
408 _placeholder = manage (new Gtk::Label (""));
409 _internal_vbox.pack_start (*_placeholder, false, false);
410 _placeholder->show ();
413 /* round up the index, unless we're off the end of the children */
414 int const n = c < 0 ? -1 : int (c + 0.5);
415 _internal_vbox.reorder_child (*_placeholder, n);
419 bool drag_motion (Glib::RefPtr<Gdk::DragContext> const &, int /*x*/, int y, guint)
421 if (_children.empty ()) {
429 /* decide where we currently are */
430 double const c = get_children_around_position (y, &before, &at, &after);
432 /* whether we're in the top or bottom half of the child that we're over */
433 bool top_half = (c - int (c)) < 0.5;
435 /* Note that when checking on whether to remove a placeholder, we never do
436 so if _drag_child is 0 as this means that the child being dragged is
437 coming from a different DnDVBox, so it will never be the same as any
441 if (top_half && _drag_child && (before == _drag_child || at == _drag_child)) {
442 /* dropping here would have no effect, so remove the visual cue */
443 remove_placeholder ();
447 if (!top_half && _drag_child && (at == _drag_child || after == _drag_child)) {
448 /* dropping here would have no effect, so remove the visual cue */
449 remove_placeholder ();
453 create_or_update_placeholder (c);
457 void drag_leave (Glib::RefPtr<Gdk::DragContext> const &, guint)
459 remove_placeholder ();
462 bool button_press (GdkEventButton* ev, T* child)
464 if (_expecting_unwanted_button_event == true && child == 0) {
465 _expecting_unwanted_button_event = false;
470 _expecting_unwanted_button_event = true;
473 if (ev->button == 1 || ev->button == 3) {
475 if (!selected (child)) {
477 if ((ev->state & Gdk::SHIFT_MASK) && !_selection.empty()) {
479 /* Shift-click; select all between the clicked child and any existing selections */
481 bool selecting = false;
483 for (typename std::list<T*>::const_iterator i = _children.begin(); i != _children.end(); ++i) {
485 bool const was_selected = selected (*i);
487 if (selecting && !was_selected) {
488 add_to_selection (*i);
491 if (!selecting && !done) {
494 } else if (*i == child) {
496 add_to_selection (child);
498 } else if (selecting) {
499 if (was_selected || *i == child) {
508 if ((ev->state & Gdk::CONTROL_MASK) == 0) {
513 add_to_selection (child);
518 SelectionChanged (); /* EMIT SIGNAL */
521 /* XXX THIS NEEDS GENERALIZING FOR OS X */
522 if (ev->button == 1 && (ev->state & Gdk::CONTROL_MASK)) {
523 if (child && selected (child)) {
524 remove_from_selection (child);
525 SelectionChanged (); /* EMIT SIGNAL */
531 return ButtonPress (ev, child); /* EMIT SIGNAL */
534 bool button_release (GdkEventButton* ev, T* child)
536 if (_expecting_unwanted_button_event == true && child == 0) {
537 _expecting_unwanted_button_event = false;
542 _expecting_unwanted_button_event = true;
545 return ButtonRelease (ev, child); /* EMIT SIGNAL */
548 /** Setup a child's visual state correctly */
549 void setup_child_state (T* c)
552 c->set_visual_state (Selected, (selected (c) || (_active == c)));
555 void clear_selection ()
557 std::list<T*> old_selection = _selection;
559 for (typename std::list<T*>::iterator i = old_selection.begin(); i != old_selection.end(); ++i) {
560 setup_child_state (*i);
564 void add_to_selection (T* child)
566 _selection.push_back (child);
567 setup_child_state (child);
570 void remove_from_selection (T* child)
572 typename std::list<T*>::iterator x = find (_selection.begin(), _selection.end(), child);
573 if (x != _selection.end()) {
575 _selection.erase (x);
576 setup_child_state (c);
580 T* child_from_widget (Gtk::Widget const * w) const
582 typename std::list<T*>::const_iterator i = _children.begin();
583 while (i != _children.end() && &(*i)->widget() != w) {
587 if (i == _children.end()) {
594 Gtk::VBox _internal_vbox;
595 std::list<Gtk::TargetEntry> _targets;
596 std::list<T*> _children;
597 std::list<T*> _selection;
599 Gtk::Window* _drag_icon;
600 bool _expecting_unwanted_button_event;
601 /** A blank label used as a placeholder to indicate where an item would
602 * go if it were dropped or inserted "now".
604 Gtk::Label* _placeholder;
605 /** Our child being dragged, or 0 */
608 static DnDVBox* _drag_source;
613 DnDVBox<T>* DnDVBox<T>::_drag_source = 0;