gtk2_ardour/lineset.h

   1 /*
   2     Copyright (C) 2007 Paul Davis
   3     This program is free software; you can redistribute it and/or modify
   4     it under the terms of the GNU General Public License as published by
   5     the Free Software Foundation; either version 2 of the License, or
   6     (at your option) any later version.
   7
   8     This program is distributed in the hope that it will be useful,
   9     but WITHOUT ANY WARRANTY; without even the implied warranty of
  10     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11     GNU General Public License for more details.
  12
  13     You should have received a copy of the GNU General Public License
  14     along with this program; if not, write to the Free Software
  15     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  16 */
  17
  18 #ifndef __gnome_canvas_lineset_h__
  19 #define __gnome_canvas_lineset_h__
  20
  21 #include <stdint.h>
  22 #include <libgnomecanvasmm/item.h>
  23
  24 namespace Gnome {
  25 namespace Canvas {
  26
  27 class LineSetClass : public Glib::Class {
  28 public:
  29         const Glib::Class& init();
  30         static void class_init_function(void* g_class, void* class_data);
  31 };
  32
  33 /** A canvas item that displays a set of vertical or horizontal lines,
  34  * spanning the entire size of the item.
  35  */
  36 class LineSet : public Item {
  37 public:
  38         enum Orientation {
  39                 Vertical,
  40                 Horizontal
  41         };
  42
  43         LineSet(Group& parent, Orientation);
  44         virtual ~LineSet();
  45
  46         Glib::PropertyProxy<double> property_x1() { return x1.get_proxy(); }
  47         Glib::PropertyProxy<double> property_y1() { return y1.get_proxy(); }
  48         Glib::PropertyProxy<double> property_x2() { return x2.get_proxy(); }
  49         Glib::PropertyProxy<double> property_y2() { return y2.get_proxy(); }
  50
  51         /* Note: every line operation takes a coord parameter, as an index to
  52          * the line it modifies. The index will identify a line if it is between
  53          * line.coord and line.coord + line.width.
  54          */
  55
  56         /** Move a line to a new position.
  57          * For this to work (to move the desired line) it is important that
  58          * lines have unique coordinates. This also applies to every line
  59          * accessing functions below
  60          */
  61         void move_line(double coord, double dest);
  62
  63         /** Change the width of a line.
  64          * Only allow if the new width doesn't overlap the next line (see below)
  65          */
  66         void change_line_width(double coord, double width);
  67
  68         /** Change the color of a line.
  69          */
  70         void change_line_color(double coord, uint32_t color);
  71
  72         /** Add a line to draw.
  73          * width is an offset, so that coord + width specifies the end of the line.
  74          * lines should not overlap, as no layering information is provided.
  75          * however, line_coord[i] + line_width[i] == line_coord[i+1] is
  76          * be legal, as the coordinates are real numbers and represents
  77          * real world coordinates. Two real world object sharing coordinates for start
  78          * and end are not overlapping.
  79          */
  80         void add_line(double coord, double width, uint32_t color);
  81
  82         /** Remove the line at coord
  83          */
  84         void remove_line(double coord);
  85
  86         /** Remove all lines in a coordinate range
  87          */
  88         void remove_lines(double c1, double c2);
  89
  90         /** Remove all lines with a coordinate lower than coord
  91          */
  92         void remove_until(double coord);
  93
  94         /** Remove all lines with a coordinate equal to or higher than coord.
  95          */
  96         void remove_from(double coord);
  97
  98         /** Remove all lines.
  99          */
 100         void clear();
 101
 102         /** Add a set of lines in the given range.
 103          * For every line visible in the provided coordinate range, call add_line().
 104          * This is called when the area between c1 and c2 becomes visible, when
 105          * previously outside any possible view.
 106          * The number of calls to this function should be kept at a minimum.
 107          */
 108         virtual void request_lines(double c1, double c2);
 109
 110         /** Instead of overriding the update_lines function one can connect to this
 111          * and add lines externally instead.
 112          * If add_lines() is overrided, this signal will not be emitted.
 113          */
 114         sigc::signal<void, LineSet&, double, double> signal_request_lines;
 115
 116         /* overridden from Gnome::Canvas::Item */
 117         void update_vfunc(double* affine, ArtSVP* clip_path, int flags);
 118         void realize_vfunc();
 119         void unrealize_vfunc();
 120         void map_vfunc();
 121         void unmap_vfunc();
 122         void draw_vfunc(const Glib::RefPtr<Gdk::Drawable>& drawable, int x, int y, int width, int height);
 123         void render_vfunc(GnomeCanvasBuf* buf);
 124         double point_vfunc(double x, double y, int cx, int cy, GnomeCanvasItem** actual_item);
 125         void bounds_vfunc(double* x1, double* y1, double* x2, double* y2);
 126         bool on_event(GdkEvent* p1);
 127
 128         /* debug */
 129         void print_lines();
 130
 131 protected:
 132         struct Line {
 133                 Line(double c, double w, uint32_t color);
 134                 Line(double c);
 135
 136                 void set_color(uint32_t color);
 137
 138                 double coord;
 139                 double width;
 140                 unsigned char r;
 141                 unsigned char g;
 142                 unsigned char b;
 143                 unsigned char a;
 144         };
 145
 146         static inline void paint_vert(GnomeCanvasBuf* buf, LineSet::Line& line, int x1, int y1, int x2, int y2);
 147         static inline void paint_horiz(GnomeCanvasBuf* buf, LineSet::Line& line, int x1, int y1, int x2, int y2);
 148
 149         static bool line_compare(const Line& a, const Line& b);
 150
 151         typedef std::list<Line> Lines;
 152         void bounds_need_update();
 153         void region_needs_update(double coord1, double coord2);
 154         bool update_bounds();
 155         void update_lines(bool need_redraw);
 156         void redraw_request (ArtDRect const &);
 157
 158         Lines::iterator line_at(double coord);
 159
 160         /** Stores last accessed line so adjacent lines are found faster */
 161         Lines::iterator cached_pos;
 162
 163         static LineSetClass lineset_class;
 164         Orientation orientation;
 165         Lines lines;
 166
 167         /* properties */
 168         Glib::Property<double> x1;
 169         Glib::Property<double> y1;
 170         Glib::Property<double> x2;
 171         Glib::Property<double> y2;
 172
 173         /** Cached bounding box in canvas coordinates */
 174         ArtIRect bbox;
 175
 176 private:
 177         LineSet();
 178         LineSet(const LineSet&);
 179
 180         bool in_update;
 181
 182         /* a range that needs update update1 > update2 ==> no update needed */
 183         double update_region1;
 184         double update_region2;
 185         bool bounds_changed;
 186
 187         double covered1;
 188         double covered2;
 189 };
 190
 191 } /* namespace Canvas */
 192 } /* namespace Gnome */
 193
 194 #endif /* __gnome_canvas_lineset_h__ */