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livetrax/libs/canvas/canvas/item.h
2020-02-24 23:01:15 +01:00

341 lines
9.8 KiB
C++

/*
* 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 <gdk/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;
/** The parent class for anything that goes on the canvas.
*
* Items have a position, which is expressed in the coordinates of the parent.
* They also have a bounding box, which describes the area in which they have
* drawable content, which is expressed in their own coordinates (whose origin
* is at the item position).
*
* Any item that is being displayed on a canvas has a pointer to that canvas,
* and all except the `root group' have a pointer to their parent group.
*/
class LIBCANVAS_API Item : public Fill, public Outline
{
public:
Item (Canvas *);
Item (Item *);
Item (Item *, Duple const& p);
virtual ~Item ();
void redraw () const;
/** Render this item to a Cairo context.
* @param area Area to draw, in **window** coordinates
*
* Items must convert their own coordinates into window coordinates
* because Cairo is limited to a fixed point coordinate space that
* does not extend as far as the Ardour timeline. All rendering must
* be done using coordinates that do not exceed the (rough) limits
* of the canvas' window, to avoid odd errors within Cairo as it
* converts doubles into its fixed point format and then tesselates
* the results.
*/
virtual void render (Rect const & area, Cairo::RefPtr<Cairo::Context>) const = 0;
/** Item has changed will be rendered in next render pass so give item a
* chance to perhaps schedule work in another thread etc.
*
* @param area Area to draw, in **window** coordinates
*/
virtual void prepare_for_render (Rect const & area) const { }
/** Adds one or more items to the vector \p items based on their
* covering \p point which is in window coordinates
*
* Note that Item::add_items_at_window_point() is only intended to be
* called on items already looked up in a LookupTable (i.e. by a
* parent) and thus known to cover \p point already.
*
* Derived classes may add more items than themselves (e.g. containers).
*/
virtual void add_items_at_point (Duple point, std::vector<Item const *>& items) const;
/** Test if point is inside the item
*
* @param point The point is in window coordinates
* @return true if the item covers \p point , false otherwise.
*/
virtual bool covers (Duple const& point) const;
/** Update _bounding_box and _bounding_box_dirty */
virtual void compute_bounding_box () const = 0;
void grab ();
void ungrab ();
void unparent ();
void reparent (Item *, bool already_added = false);
/** @return Parent group, or 0 if this is the root group */
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;
/** returns true if this item is an ancestor of \p candidate ,
* and false otherwise.
*/
bool is_ancestor_of (const Item& candidate) const {
return candidate.is_descendant_of (*this);
}
/** returns true if this Item is a descendant of \p candidate ,
* and false otherwise.
*/
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);
/** @return Position of this item in the parent's coordinates */
Duple position () const {
return _position;
}
Duple window_origin() const;
Duple canvas_origin() const;
ScrollGroup* scroll_parent() const { return _scroll_parent; }
/* item implementations can override this if they need to */
virtual Rect size_request() const { return bounding_box (true); }
void size_allocate (Rect const&);
/** bounding box is the public API to get the size of the item.
* If @param for_own_purposes is false, then it will return the
* allocated bounding box (if there is one) in preference to the
* one that would naturally be computed by the item.
*/
Rect bounding_box (bool for_own_purposes = false) const;
Rect allocation() const { return _allocation; }
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 ();
/** @return true if this item is visible (ie it will be rendered),
* otherwise false
*/
bool self_visible () const {
return _visible;
}
bool visible () const;
/** @return Our canvas, or 0 if we are not attached to one */
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 */
void add (Item *);
void add_front (Item *);
void remove (Item *);
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 ();
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;
#endif
#ifdef CANVAS_COMPATIBILITY
void grab_focus ();
#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;
protected:
friend class Fill;
friend class Outline;
/** To be called at the beginning of any property change that
* may alter the bounding box of this item
*/
void begin_change ();
/** To be called at the endof any property change that
* may alter the bounding box of this item
*/
void end_change ();
/** To be called at the beginning of any property change that
* does NOT alter the bounding box of this item
*/
void begin_visual_change ();
/** To be called at the endof any property change that
* does NOT alter the bounding box of this item
*/
void end_visual_change ();
Canvas* _canvas;
/** parent group; may be 0 if we are the root group or if we have been unparent()ed */
Item* _parent;
/** scroll parent group; may be 0 if we are the root group or if we have been unparent()ed */
ScrollGroup* _scroll_parent;
/** position of this item in parent coordinates */
Duple _position;
/** true if this item is visible (ie to be drawn), otherwise false */
bool _visible;
/** our bounding box before any change that is currently in progress */
Rect _pre_change_bounding_box;
/** our bounding box; may be out of date if _bounding_box_dirty is true */
mutable Rect _bounding_box;
/** true if _bounding_box might be out of date, false if its definitely not */
mutable bool _bounding_box_dirty;
Rect _allocation;
/* 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;
Duple position_offset() const;
private:
void init ();
std::string _tooltip;
bool _ignore_events;
void find_scroll_parent ();
void propagate_show_hide ();
};
extern LIBCANVAS_API std::ostream& operator<< (std::ostream&, const ArdourCanvas::Item&);
}
#endif