libs/gtkmm2ext/pixscroller.cc

   1 /*
   2     Copyright (C) 2005 Paul Davis
   3
   4     This program is free software; you can redistribute it and/or modify
   5     it under the terms of the GNU General Public License as published by
   6     the Free Software Foundation; either version 2 of the License, or
   7     (at your option) any later version.
   8
   9     This program is distributed in the hope that it will be useful,
  10     but WITHOUT ANY WARRANTY; without even the implied warranty of
  11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12     GNU General Public License for more details.
  13
  14     You should have received a copy of the GNU General Public License
  15     along with this program; if not, write to the Free Software
  16     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  17
  18     $Id$
  19 */
  20 #include <iostream>
  21 #include <algorithm>
  22 #include <cmath>
  23
  24 #include <gtkmm.h>
  25
  26 #include "gtkmm2ext/pixscroller.h"
  27 #include "gtkmm2ext/keyboard.h"
  28
  29 using namespace std;
  30 using namespace Gtk;
  31 using namespace Gtkmm2ext;
  32
  33 PixScroller::PixScroller (Adjustment& a,
  34                           Glib::RefPtr<Gdk::Pixbuf> s,
  35                           Glib::RefPtr<Gdk::Pixbuf> r)
  36         : adj (a),
  37           rail (r),
  38           slider (s)
  39 {
  40         Cairo::Format format;
  41
  42         dragging = false;
  43         add_events (Gdk::BUTTON_PRESS_MASK|Gdk::BUTTON_RELEASE_MASK|Gdk::POINTER_MOTION_MASK|Gdk::SCROLL_MASK);
  44
  45         adj.signal_value_changed().connect (mem_fun (*this, &PixScroller::adjustment_changed));
  46         default_value = adj.get_value();
  47
  48         sliderrect.set_width(slider->get_width());
  49         sliderrect.set_height(slider->get_height());
  50         railrect.set_width(rail->get_width());
  51         railrect.set_height(rail->get_height());
  52
  53         railrect.set_y(sliderrect.get_height() / 2);
  54         sliderrect.set_x(0);
  55
  56         overall_height = railrect.get_height() + sliderrect.get_height();
  57
  58         sliderrect.set_y((int) rint ((overall_height - sliderrect.get_height()) * (adj.get_upper() - adj.get_value())));
  59         railrect.set_x((sliderrect.get_width() / 2) - 2);
  60
  61         if (rail->get_has_alpha()) {
  62                 format = Cairo::FORMAT_ARGB32;
  63         } else {
  64                 format = Cairo::FORMAT_RGB24;
  65         }
  66         rail_surface = Cairo::ImageSurface::create  (format, rail->get_width(), rail->get_height());
  67         rail_context = Cairo::Context::create (rail_surface);
  68         Gdk::Cairo::set_source_pixbuf (rail_context, rail, 0.0, 0.0);
  69         rail_context->paint();
  70
  71         if (slider->get_has_alpha()) {
  72                 format = Cairo::FORMAT_ARGB32;
  73         } else {
  74                 format = Cairo::FORMAT_RGB24;
  75         }
  76         slider_surface = Cairo::ImageSurface::create  (format, slider->get_width(), slider->get_height());
  77         slider_context = Cairo::Context::create (slider_surface);
  78         Gdk::Cairo::set_source_pixbuf (slider_context, slider, 0.0, 0.0);
  79         slider_context->paint();
  80 }
  81
  82 void
  83 PixScroller::on_size_request (GtkRequisition* requisition)
  84 {
  85         requisition->width = sliderrect.get_width();
  86         requisition->height = overall_height;
  87 }
  88
  89 bool
  90 PixScroller::on_expose_event (GdkEventExpose* ev)
  91 {
  92         GdkRectangle intersect;
  93         Glib::RefPtr<Gdk::Window> win (get_window());
  94         Cairo::RefPtr<Cairo::Context> context = get_window()->create_cairo_context();
  95
  96         if (gdk_rectangle_intersect (railrect.gobj(), &ev->area, &intersect)) {
  97
  98                 context->save();
  99                 context->rectangle (intersect.x, intersect.y, intersect.width, intersect.height);
 100                 context->clip();
 101                 context->set_source (rail_surface, intersect.x - railrect.get_x(), intersect.y - railrect.get_y());
 102                 context->rectangle (intersect.x, intersect.y, intersect.width, intersect.height);
 103                 context->clip();
 104                 context->paint();
 105                 context->restore();
 106         }
 107
 108         if (gdk_rectangle_intersect (sliderrect.gobj(), &ev->area, &intersect)) {
 109
 110                 context->save();
 111                 context->rectangle (intersect.x, intersect.y, intersect.width, intersect.height);
 112                 context->clip();
 113                 context->set_source (rail_surface, intersect.x - sliderrect.get_x(), intersect.y - sliderrect.get_y());
 114                 context->rectangle (intersect.x, intersect.y, intersect.width, intersect.height);
 115                 context->clip();
 116                 context->paint();
 117                 context->restore();
 118         }
 119
 120         return true;
 121 }
 122
 123 bool
 124 PixScroller::on_button_press_event (GdkEventButton* ev)
 125 {
 126         switch (ev->button) {
 127         case 1:
 128                 if (!(ev->state & Keyboard::TertiaryModifier)) {
 129                         add_modal_grab();
 130                         grab_y = ev->y;
 131                         grab_start = ev->y;
 132                         grab_window = ev->window;
 133                         dragging = true;
 134                 }
 135                 break;
 136         default:
 137                 break;
 138         }
 139
 140
 141         return false;
 142 }
 143
 144 bool
 145 PixScroller::on_button_release_event (GdkEventButton* ev)
 146 {
 147         double scale;
 148
 149         if (ev->state & Keyboard::PrimaryModifier) {
 150                 if (ev->state & Keyboard::SecondaryModifier) {
 151                         scale = 0.05;
 152                 } else {
 153                         scale = 0.1;
 154                 }
 155         } else {
 156                 scale = 1.0;
 157         }
 158
 159         switch (ev->button) {
 160         case 1:
 161                 if (dragging) {
 162                         remove_modal_grab();
 163                         dragging = false;
 164
 165                         if (ev->y == grab_start) {
 166                                 /* no motion - just a click */
 167                                 double fract;
 168
 169                                 if (ev->y < sliderrect.get_height()/2) {
 170                                         /* near the top */
 171                                         fract = 1.0;
 172                                 } else {
 173                                         fract = 1.0 - (ev->y - sliderrect.get_height()/2) / railrect.get_height();
 174                                 }
 175
 176                                 fract = min (1.0, fract);
 177                                 fract = max (0.0, fract);
 178
 179                                 adj.set_value (scale * fract * (adj.get_upper() - adj.get_lower()));
 180                         }
 181                 } else {
 182                         if (ev->state & Keyboard::TertiaryModifier) {
 183                                 adj.set_value (default_value);
 184                                 cerr << "default value = " << default_value << endl;
 185                         }
 186                 }
 187                 break;
 188         default:
 189                 break;
 190         }
 191         return false;
 192 }
 193
 194 bool
 195 PixScroller::on_scroll_event (GdkEventScroll* ev)
 196 {
 197         double scale;
 198
 199         if (ev->state & Keyboard::PrimaryModifier) {
 200                 if (ev->state & Keyboard::SecondaryModifier) {
 201                         scale = 0.05;
 202                 } else {
 203                         scale = 0.1;
 204                 }
 205         } else {
 206                 scale = 0.5;
 207         }
 208
 209         switch (ev->direction) {
 210
 211         case GDK_SCROLL_UP:
 212                 /* wheel up */
 213                 adj.set_value (adj.get_value() + (adj.get_page_increment() * scale));
 214                 break;
 215         case GDK_SCROLL_DOWN:
 216                 /* wheel down */
 217                 adj.set_value (adj.get_value() - (adj.get_page_increment() * scale));
 218                 break;
 219         default:
 220                 break;
 221         }
 222         return false;
 223 }
 224
 225 bool
 226 PixScroller::on_motion_notify_event (GdkEventMotion* ev)
 227 {
 228         if (dragging) {
 229                 double fract;
 230                 double delta;
 231                 double scale;
 232
 233                 if (ev->window != grab_window) {
 234                         grab_y = ev->y;
 235                         grab_window = ev->window;
 236                         return true;
 237                 }
 238
 239                 if (ev->state & Keyboard::PrimaryModifier) {
 240                         if (ev->state & Keyboard::SecondaryModifier) {
 241                                 scale = 0.05;
 242                         } else {
 243                                 scale = 0.1;
 244                         }
 245                 } else {
 246                         scale = 1.0;
 247                 }
 248
 249                 delta = ev->y - grab_y;
 250                 grab_y = ev->y;
 251
 252                 fract = (delta / railrect.get_height());
 253
 254                 fract = min (1.0, fract);
 255                 fract = max (-1.0, fract);
 256
 257                 fract = -fract;
 258
 259                 adj.set_value (adj.get_value() + scale * fract * (adj.get_upper() - adj.get_lower()));
 260         }
 261
 262         return true;
 263 }
 264
 265 void
 266 PixScroller::adjustment_changed ()
 267 {
 268         int y = (int) rint ((overall_height - sliderrect.get_height()) * (adj.get_upper() - adj.get_value()));
 269
 270         if (y != sliderrect.get_y()) {
 271                 sliderrect.set_y(y);
 272                 queue_draw ();
 273         }
 274 }