class DnDVBox : public Gtk::EventBox
{
public:
- DnDVBox () : _drag_icon (0), _expecting_unwanted_button_event (false)
+ DnDVBox () : _drag_icon (0), _expecting_unwanted_button_event (false), _drag_placeholder (0)
{
_targets.push_back (Gtk::TargetEntry ("processor"));
add (_internal_vbox);
- add_events (Gdk::KEY_PRESS_MASK | Gdk::KEY_RELEASE_MASK | Gdk::ENTER_NOTIFY_MASK | Gdk::LEAVE_NOTIFY_MASK | Gdk::BUTTON_PRESS_MASK | Gdk::BUTTON_RELEASE_MASK);
+ add_events (
+ Gdk::KEY_PRESS_MASK | Gdk::KEY_RELEASE_MASK |
+ Gdk::ENTER_NOTIFY_MASK | Gdk::LEAVE_NOTIFY_MASK |
+ Gdk::BUTTON_PRESS_MASK | Gdk::BUTTON_RELEASE_MASK
+ );
signal_button_press_event().connect (bind (mem_fun (*this, &DnDVBox::button_press), (T *) 0));
signal_button_release_event().connect (bind (mem_fun (*this, &DnDVBox::button_release), (T *) 0));
+ signal_drag_motion().connect (mem_fun (*this, &DnDVBox::drag_motion));
+ signal_drag_leave().connect (mem_fun (*this, &DnDVBox::drag_leave));
drag_dest_set (_targets);
signal_drag_data_received().connect (mem_fun (*this, &DnDVBox::drag_data_received));
}
/** @param Child
- * @return true if the child is selected, otherwise false */
+ * @return true if the child is selected, otherwise false.
+ */
bool selected (T* child) const {
return (find (_selection.begin(), _selection.end(), child) != _selection.end());
}
_children.clear ();
}
-
void select_all ()
{
clear_selection ();
SelectionChanged (); /* EMIT SIGNAL */
}
- /** @param x x coordinate.
- * @param y y coordinate.
- * @return Pair consisting of the child under (x, y) (or 0) and the index of the child under (x, y) (or -1)
+ /** Look at a y coordinate and find the children below y, and the ones either side.
+ * @param y y position.
+ * @param before Filled in with the child before, or 0.
+ * @param before Filled in with the child under y, or 0.
+ * @param after Filled in with the child after, or 0.
+ * @return Fractional position in terms of child height.
*/
- std::pair<T*, int> get_child_at_position (int /*x*/, int y) const
+ double get_children_around_position (int y, T** before, T** at, T** after) const
{
- std::list<Gtk::Widget const *> children = _internal_vbox.get_children ();
- std::list<Gtk::Widget const *>::iterator i = children.begin();
-
- int n = 0;
- while (i != children.end()) {
- Gdk::Rectangle const a = (*i)->get_allocation ();
- if (y >= a.get_y() && y <= (a.get_y() + a.get_height())) {
- break;
- }
+ if (_children.empty()) {
+ *before = *at = *after = 0;
+ return -1;
+ }
+
+ /* fractional position in terms of children */
+ double const nf = double (y) / _children.front()->widget().get_allocation().get_height ();
+
+ *before = 0;
+
+ int i = 0;
+ typename std::list<T*>::const_iterator j = _children.begin ();
+ while (i < int (nf) && j != _children.end()) {
+ *before = *j;
++i;
- ++n;
+ ++j;
}
-
- if (i == children.end()) {
- return std::make_pair ((T *) 0, -1);
+
+ if (j == _children.end()) {
+ *at = 0;
+ *after = 0;
+ return -1;
}
- return std::make_pair (child_from_widget (*i), n);
- }
+ *at = *j;
+
+ ++j;
+ *after = j != _children.end() ? *j : 0;
+
+ return nf;
+ }
+
+ /** @param y y coordinate.
+ * @return Pair consisting of the child under y (or 0) and the (fractional) index of the child under y (or -1)
+ */
+ std::pair<T*, double> get_child_at_position (int y) const
+ {
+ T* before;
+ T* after;
+
+ std::pair<T*, double> r;
+
+ r.second = get_children_around_position (y, &before, &r.first, &after);
+ return r;
+ }
+
/** Children have been reordered by a drag */
sigc::signal<void> Reordered;
private:
void drag_begin (Glib::RefPtr<Gdk::DragContext> const & context, T* child)
{
+ _drag_child = child;
+
/* make up an icon for the drag */
- Gtk::Window* _drag_icon = new Gtk::Window (Gtk::WINDOW_POPUP);
+ _drag_icon = new Gtk::Window (Gtk::WINDOW_POPUP);
+
+ Gtk::Allocation a = child->widget().get_allocation ();
+ _drag_icon->set_size_request (a.get_width(), a.get_height());
+
+ _drag_icon->signal_expose_event().connect (sigc::mem_fun (*this, &DnDVBox::icon_expose));
_drag_icon->set_name (get_name ());
- Gtk::Label* l = new Gtk::Label (child->drag_text ());
- l->set_padding (4, 4);
- _drag_icon->add (*Gtk::manage (l));
- _drag_icon->show_all_children ();
+
+ /* make the icon transparent if possible */
+ Glib::RefPtr<Gdk::Screen const> s = _drag_icon->get_screen ();
+ Glib::RefPtr<Gdk::Colormap const> c = s->get_rgba_colormap ();
+ if (c) {
+ _drag_icon->set_colormap (c);
+ _have_alpha = true;
+ } else {
+ _have_alpha = false;
+ }
+
int w, h;
_drag_icon->get_size (w, h);
- _drag_icon->drag_set_as_icon (context, w / 2, h);
+ _drag_icon->drag_set_as_icon (context, w / 2, h / 2);
_drag_source = this;
}
+
+ /* Draw the drag icon; we go to these lengths so that we can have the icon
+ * transparent if the window system supports it.
+ */
+ bool icon_expose (GdkEventExpose *)
+ {
+ cairo_t* cr = gdk_cairo_create (_drag_icon->get_window()->gobj());
+
+ if (_have_alpha) {
+ cairo_set_source_rgba (cr, 0.2, 0.2, 0.2, 0.5);
+ } else {
+ cairo_set_source_rgba (cr, 0, 0, 0, 1);
+ }
+
+ cairo_set_operator (cr, CAIRO_OPERATOR_SOURCE);
+ cairo_paint (cr);
+ cairo_set_source_rgba (cr, 1, 1, 1, 0.8);
+
+ cairo_text_extents_t ext;
+ cairo_text_extents (cr, _drag_child->drag_text().c_str(), &ext);
+
+ cairo_move_to (cr, 0, ext.height);
+ cairo_show_text (cr, _drag_child->drag_text().c_str ());
+ cairo_restore (cr);
+ cairo_destroy (cr);
+
+ return false;
+ }
+
void drag_data_get (Glib::RefPtr<Gdk::DragContext> const &, Gtk::SelectionData & selection_data, guint, guint, T* child)
{
)
{
/* work out where it was dropped */
- std::pair<T*, int> const drop = get_child_at_position (x, y);
+ std::pair<T*, double> const drop = get_child_at_position (y);
if (_drag_source == this) {
if (drop.first == 0) {
_internal_vbox.reorder_child (child->widget(), -1);
} else {
- _internal_vbox.reorder_child (child->widget(), drop.second);
+ _internal_vbox.reorder_child (child->widget(), int (drop.second));
}
} else {
{
delete _drag_icon;
_drag_icon = 0;
+
+ _drag_child = 0;
+ remove_drag_placeholder ();
Reordered (); /* EMIT SIGNAL */
}
-
+
+ void remove_drag_placeholder ()
+ {
+ if (_drag_placeholder) {
+ _internal_vbox.remove (*_drag_placeholder);
+ _drag_placeholder = 0;
+ }
+ }
+
+ bool drag_motion (Glib::RefPtr<Gdk::DragContext> const &, int x, int y, guint)
+ {
+ if (_children.empty ()) {
+ return false;
+ }
+
+ T* before;
+ T* at;
+ T* after;
+
+ /* decide where we currently are */
+ double const c = get_children_around_position (y, &before, &at, &after);
+
+ /* whether we're in the top or bottom half of the child that we're over */
+ bool top_half = (c - int (c)) < 0.5;
+
+ if (top_half && (before == _drag_child || at == _drag_child)) {
+ /* dropping here would have no effect, so remove the visual cue */
+ remove_drag_placeholder ();
+ return false;
+ }
+
+ if (!top_half && (at == _drag_child || after == _drag_child)) {
+ /* dropping here would have no effect, so remove the visual cue */
+ remove_drag_placeholder ();
+ return false;
+ }
+
+ /* the index that the placeholder should be put at */
+ int const n = int (c + 0.5);
+
+ if (_drag_placeholder == 0) {
+ _drag_placeholder = manage (new Gtk::Label (""));
+ _internal_vbox.pack_start (*_drag_placeholder, false, false);
+ _drag_placeholder->show ();
+ }
+
+ if (c < 0) {
+ _internal_vbox.reorder_child (*_drag_placeholder, -1);
+ } else {
+ _internal_vbox.reorder_child (*_drag_placeholder, n);
+ }
+
+ return false;
+ }
+
+ void drag_leave (Glib::RefPtr<Gdk::DragContext> const &, guint)
+ {
+ remove_drag_placeholder ();
+ }
+
bool button_press (GdkEventButton* ev, T* child)
{
if (_expecting_unwanted_button_event == true && child == 0) {
std::list<T*> _selection;
Gtk::Window* _drag_icon;
bool _expecting_unwanted_button_event;
-
+ /** A blank label used as a placeholder to indicate where a dragged item would
+ * go if it were dropped now.
+ */
+ Gtk::Label* _drag_placeholder;
+ /** Our child being dragged, or 0 */
+ T* _drag_child;
+ /** true if we can have an alpha-blended drag icon */
+ bool _have_alpha;
+
static DnDVBox* _drag_source;
+
};
template <class T>
projects / ardour.git / commitdiff