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Diffstat (limited to 'src/display/control/canvas-item.h')
| -rw-r--r-- | src/display/control/canvas-item.h | 175 |
1 files changed, 175 insertions, 0 deletions
diff --git a/src/display/control/canvas-item.h b/src/display/control/canvas-item.h new file mode 100644 index 0000000..37d5ec7 --- /dev/null +++ b/src/display/control/canvas-item.h @@ -0,0 +1,175 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +#ifndef SEEN_CANVAS_ITEM_H +#define SEEN_CANVAS_ITEM_H + +/** + * Abstract base class for on-canvas control items. + */ + +/* + * Author: + * Tavmjong Bah + * + * Copyright (C) 2020 Tavmjong Bah + * + * Rewrite of SPCanvasItem + * + * Released under GNU GPL v2+, read the file 'COPYING' for more information. + * + * A note about coordinates: + * + * 1. Canvas items are constructed using document (SVG) coordinates. + * 2. Calculations are made in canvas units, which is equivalent of SVG units multiplied by zoom factor. + * This is true for bounds and closest distance calculations. + * 3 Drawing is done in screen units which is the same as canvas units but translated. + * The document and canvas origins overlap. + * The affine contains only scaling and rotating components. + */ + +//#define CANVAS_ITEM_DEBUG + +#include <gdk/gdk.h> // GdkEvent +#include <gdkmm/device.h> // Gdk::EventMask +#include <glib.h> // guint32 +#include <sigc++/sigc++.h> + +#include <2geom/rect.h> + +#include <boost/intrusive/list.hpp> + +#include "canvas-item-buffer.h" +#include "canvas-item-enums.h" + +class SPItem; + +namespace Inkscape { + +static guint32 CANVAS_ITEM_COLORS[] = { 0x0000ff7f, 0xff00007f, 0xffff007f }; + +namespace UI::Widget { +class Canvas; +} + +class CanvasItemGroup; // A canvas control that contains other canvas controls. + +class CanvasItem { + +public: + CanvasItem(CanvasItemGroup* group); + virtual ~CanvasItem(); + + // Structure + void set_canvas(UI::Widget::Canvas *canvas) { _canvas = canvas; } + UI::Widget::Canvas* get_canvas() { return _canvas; } + + void set_parent(CanvasItemGroup *parent) { _parent = parent; } + CanvasItemGroup* get_parent() { return _parent; } + + void set_item(SPItem *item) { _item = item; } + SPItem* get_item() { return _item; } + + // Z Position + bool is_descendant_of(CanvasItem *ancestor); + void set_z_position(unsigned int n); + int get_z_position(); // z position in group. + // void raise_by(unsigned int n); + void raise_to_top(); // Move to top of group (last entry). + // void lower_by(unsigned int n); + void lower_to_bottom(); // Move to bottom of group (first entry). + + // Geometry + void request_update(); + virtual void update(Geom::Affine const &affine) = 0; + Geom::Affine get_affine() { return _affine; } + Geom::Rect get_bounds() { return _bounds; } + + // Selection + virtual bool contains(Geom::Point const &p, double tolerance = 0) { return _bounds.interiorContains(p); } + int grab(Gdk::EventMask event_mask, GdkCursor *cursor = nullptr); + int grab(Gdk::EventMask event_mask, Glib::RefPtr<Gdk::Cursor> cursor); + void ungrab(); + + // Display + virtual void render(Inkscape::CanvasItemBuffer *buf) = 0; + bool is_visible() { return _visible; } + virtual void hide(); + virtual void show(); + void request_redraw(); // queue redraw request + + // Properties + virtual void set_fill(guint32 rgba); + void set_fill(CanvasItemColor color) { set_fill(CANVAS_ITEM_COLORS[color]); } + virtual void set_stroke(guint32 rgba); + void set_stroke(CanvasItemColor color) { set_stroke(CANVAS_ITEM_COLORS[color]); } + void set_name(std::string const &name) { _name = name; } + std::string get_name() { return _name; } + + // Events + void set_pickable(bool pickable) { _pickable = pickable; } + bool is_pickable() { return _pickable; } + sigc::connection connect_event(sigc::slot<bool, GdkEvent*> slot) { + return _event_signal.connect(slot); + } + virtual bool handle_event(GdkEvent *event) { + return _event_signal.emit(event); // Default just emit event. + } + + // Boost linked list member hook, speeds deletion. + boost::intrusive::list_member_hook<> member_hook; + +protected: + + // Structure + CanvasItemGroup *_parent = nullptr; + Inkscape::UI::Widget::Canvas *_canvas = nullptr; + SPItem *_item; // The object this canvas item is linked to in some sense. Can be nullptr. + + // Geometry + Geom::Rect _bounds; + Geom::Affine _affine; + bool _need_update = true; // Need update after creation! + + // Display + bool _visible = true; + bool _align_to_drawing = false; // Rotate if drawing is rotated. TODO: Implement! + + // Selection + bool _pickable = false; // Most items are just for display and are not pickable! + + // Properties + guint32 _fill = CANVAS_ITEM_COLORS[CANVAS_ITEM_SECONDARY]; + guint32 _stroke = CANVAS_ITEM_COLORS[CANVAS_ITEM_PRIMARY]; + std::string _name; // For debugging + + // Events + sigc::signal<bool, GdkEvent*> _event_signal; +}; + + +} // namespace Inkscape + +/** Type for linked list storing CanvasItem's. + * + * Used to speed deletion when a group contains a large number of item's (as in nodes for a + * complex path). + */ +typedef boost::intrusive::list< + Inkscape::CanvasItem, + boost::intrusive::member_hook<Inkscape::CanvasItem, boost::intrusive::list_member_hook<>, + &Inkscape::CanvasItem::member_hook> > CanvasItemList; + +// Recursively print CanvasItem tree. +void canvas_item_print_tree(Inkscape::CanvasItem *item); + +#endif // SEEN_CANVAS_ITEM_H + +/* + Local Variables: + mode:c++ + c-file-style:"stroustrup" + c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +)) + indent-tabs-mode:nil + fill-column:99 + End: +*/ +// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 : |