canvas/canvas/item.h

Go to the documentation of this file.

/*
 * Copyright (C) 2012 Carl Hetherington <carl@carlh.net>
 * Copyright (C) 2013-2017 Paul Davis <paul@linuxaudiosystems.com>
 * Copyright (C) 2014-2015 Robin Gareus <robin@gareus.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
 
#ifndef __CANVAS_ITEM_H__
#define __CANVAS_ITEM_H__
 
#include <stdint.h>
 
#include <ydk/gdk.h>
 
#include <cairomm/context.h>
 
#include "pbd/signals.h"
 
#include "canvas/fill.h"
#include "canvas/lookup_table.h"
#include "canvas/outline.h"
#include "canvas/types.h"
#include "canvas/visibility.h"
 
namespace ArdourCanvas
{
 
class Canvas;
class ScrollGroup;
class ConstrainedItem;
 
class LIBCANVAS_API Item : public Fill, public Outline
{
public:
        Item (Canvas *);
        Item (Item *);
        Item (Item *, Duple const& p);
        virtual ~Item ();
 
        void redraw () const;
 
        virtual void render (Rect const & area, Cairo::RefPtr<Cairo::Context>) const = 0;
 
        virtual void prepare_for_render (Rect const & area) const { }
        virtual bool needs_prepare_for_render () const { return false; }
 
        virtual void add_items_at_point (Duple point, std::vector<Item const *>& items) const;
 
        virtual bool covers (Duple const& point) const;
 
        virtual void compute_bounding_box () const = 0;
 
        void grab ();
        void ungrab ();
 
        void unparent ();
        void reparent (Item *, bool already_added = false);
 
        Item* parent () const {
                return _parent;
        }
 
        uint32_t depth() const;
        const Item* closest_ancestor_with (const Item& other) const;
        bool common_ancestor_within (uint32_t, const Item& other) const;
 
        bool is_ancestor_of (const Item& candidate) const {
                return candidate.is_descendant_of (*this);
        }
 
        bool is_descendant_of (const Item& candidate) const;
 
        void set_position (Duple);
        void set_x_position (Coord);
        void set_y_position (Coord);
        void move (Duple);
 
        Duple position () const {
                return _position;
        }
 
        Duple window_origin() const;
        Duple canvas_origin() const;
 
        ScrollGroup* scroll_parent() const { return _scroll_parent; }
 
        /* layout-related methods */
 
        virtual void size_request (double& w, double& h) const;
        void set_size_request (double w, double h);
        void set_size_request_to_display_given_text (const std::vector<std::string>& strings, gint hpadding, gint vpadding);
 
        void size_allocate (Rect const&);
        virtual void _size_allocate (Rect const&);
        virtual void size_allocate_children (Rect const & r);
        Rect allocation() const { return _allocation; }
        void set_layout_sensitive (bool);
        bool layout_sensitive () const { return _layout_sensitive; }
 
        Rect bounding_box () const;
 
        Coord height() const;
        Coord width() const;
 
        Duple item_to_parent (Duple const &) const;
        Rect item_to_parent (Rect const &) const;
        Duple parent_to_item (Duple const &) const;
        Rect parent_to_item (Rect const &) const;
 
        /* XXX: it's a pity these two aren't the same form as item_to_parent etc.,
         * but it makes a bit of a mess in the rest of the code if they are not.
         */
        void canvas_to_item (Coord &, Coord &) const;
        void item_to_canvas (Coord &, Coord &) const;
 
        Duple canvas_to_item (Duple const&) const;
        Rect item_to_canvas (Rect const&) const;
        Duple item_to_canvas (Duple const&) const;
        Rect canvas_to_item (Rect const&) const;
 
        Duple item_to_window (Duple const&, bool rounded = true) const;
        Duple window_to_item (Duple const&) const;
        Rect item_to_window (Rect const&, bool rounded = true) const;
        Rect window_to_item (Rect const&) const;
 
        void raise_to_top ();
        void raise (int);
        void lower_to_bottom ();
 
        virtual void hide ();
        virtual void show ();
 
        void block_change_notifications ();
        void unblock_change_notifications ();
 
        bool self_visible () const {
                return _visible;
        }
 
        bool visible () const;
 
        Canvas* canvas () const {
                return _canvas;
        }
 
        void set_ignore_events (bool);
        bool ignore_events () const {
                return _ignore_events;
        }
 
        void set_data (std::string const &, void *);
        void* get_data (std::string const &) const;
 
        /* nested item ("grouping") API */
        virtual void add (Item *);
        virtual void add_front (Item *);
        virtual void remove (Item *);
        /* XXX this should become virtual also */
        void clear (bool with_delete = false);
 
        std::list<Item*> const & items () const {
                return _items;
        }
 
        void raise_child_to_top (Item *);
        void raise_child (Item *, int);
        void lower_child_to_bottom (Item *);
        virtual void child_changed (bool bbox_changed);
 
        PackOptions pack_options () const { return _pack_options; }
        void set_pack_options (PackOptions);
 
        static int default_items_per_cell;
 
 
        /* This is a sigc++ signal because it is solely
                 concerned with GUI stuff and is thus single-threaded
                 */
 
        template <class T>
                struct EventAccumulator {
                        typedef T result_type;
                        template <class U>
                                result_type operator () (U first, U last) {
                                        while (first != last) {
                                                if (*first) {
                                                        return true;
                                                }
                                                ++first;
                                        }
                                        return false;
                                }
                };
 
        sigc::signal1<bool, GdkEvent*, EventAccumulator<bool> > Event;
 
#ifdef CANVAS_DEBUG
        std::string name;
        std::string whoami() const { return whatami() + '/' + name; }
#else
        std::string whoami() const { return whatami(); }
#endif
 
        const std::string& tooltip () const { return _tooltip; }
        void set_tooltip (const std::string&);
 
        void start_tooltip_timeout ();
        void stop_tooltip_timeout ();
 
        virtual void dump (std::ostream&) const;
        std::string whatami() const;
 
        bool resize_queued() const { return _resize_queued; }
        void queue_resize();
 
        bool scroll_translation() const { return _scroll_translation; }
        void disable_scroll_translation ();
 
        /* only derived containers need to implement this, but this
           is where they compute the sizes and position and their
           children. A fixed-layout container (i.e. one where every child
           has just had its position fixed via ::set_position()) does not
           need to do anything here. Only box/table/grid style containers,
           where the position of one child depends on the position and size of
           other children, need to provide an implementation.
        */
        virtual void layout();
 
  protected:
        friend class Fill;
        friend class Outline;
 
        void begin_change ();
        void end_change ();
        void begin_visual_change ();
        void end_visual_change ();
 
        Canvas* _canvas;
        Item* _parent;
        ScrollGroup* _scroll_parent;
        Duple _position;
        bool _visible;
        Rect _pre_change_bounding_box;
 
        mutable Rect _bounding_box;
        PackOptions _pack_options;
 
        void set_bbox_clean () const;
        void set_bbox_dirty () const;
        bool bbox_dirty() const { return _bounding_box_dirty; }
 
        Rect _allocation;
        bool _layout_sensitive;
 
        /* XXX: this is a bit grubby */
        std::map<std::string, void *> _data;
 
        /* nesting ("grouping") API */
 
        void invalidate_lut () const;
        void clear_items (bool with_delete);
 
        void ensure_lut () const;
        mutable LookupTable* _lut;
        /* our items, from lowest to highest in the stack */
        std::list<Item*> _items;
 
        void add_child_bounding_boxes (bool include_hidden = false) const;
        void render_children (Rect const & area, Cairo::RefPtr<Cairo::Context> context) const;
        void prepare_for_render_children (Rect const & area) const;
 
        Duple scroll_offset() const;
  public:
        Duple position_offset() const;
 
        bool _resize_queued;
        double _requested_width;
        double _requested_height;
 
private:
        void init ();
 
        std::string _tooltip;
        bool _ignore_events;
        bool _scroll_translation;
        mutable bool _bounding_box_dirty;
 
        void find_scroll_parent ();
        void propagate_show_hide ();
 
        int change_blocked;
};
 
extern LIBCANVAS_API std::ostream& operator<< (std::ostream&, const ArdourCanvas::Item&);
 
/* RAII wrapper for blocking item change notifications */
 
class LIBCANVAS_API ItemChangeBlocker
{
  public:
        ItemChangeBlocker (Item& i) : item (i) { item.block_change_notifications (); }
        ~ItemChangeBlocker() { item.block_change_notifications (); }
  private:
        Item& item;
};
 
}
 
#endif