chiark - git - mdw - disorder/blob - disobedience/multidrag.c

   1 /*
   2  * This file is part of DisOrder
   3  * Copyright (C) 2009 Richard Kettlewell
   4  *
   5  * This program is free software: you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation, either version 3 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18 /** @file disobedience/multidrag.c
  19  * @brief Drag multiple rows of a GtkTreeView
  20  */
  21 #include "disobedience.h"
  22
  23 static gboolean multidrag_selection_block(GtkTreeSelection attribute((unused)) *selection,
  24                                           GtkTreeModel attribute((unused)) *model,
  25                                           GtkTreePath attribute((unused)) *path,
  26                                           gboolean attribute((unused)) path_currently_selected,
  27                                           gpointer data) {
  28   return *(gboolean *)data;
  29 }
  30
  31 static void block_selection(GtkWidget *w, gboolean block,
  32                             int x, int y) {
  33   static gboolean which[] = { FALSE, TRUE };
  34   GtkTreeSelection *s = gtk_tree_view_get_selection(GTK_TREE_VIEW(w));
  35   gtk_tree_selection_set_select_function(s,
  36                                          multidrag_selection_block,
  37                                          &which[!!block],
  38                                          NULL);
  39   // Remember the pointer location
  40   int *where = g_object_get_data(G_OBJECT(w), "multidrag-where");
  41   if(!where) {
  42     where = g_malloc(2 * sizeof (int));
  43     g_object_set_data(G_OBJECT(w), "multidrag-where", where);
  44   }
  45   where[0] = x;
  46   where[1] = y;
  47 }
  48
  49 static gboolean multidrag_button_press_event(GtkWidget *w,
  50                                              GdkEventButton *event,
  51                                              gpointer attribute((unused)) user_data) {
  52   /* By default we assume that anything this button press does should
  53    * act as normal */
  54   block_selection(w, TRUE, -1, -1);
  55   /* We are only interested in left-button behavior */
  56   if(event->button != 1)
  57     return FALSE;
  58   /* We are only interested in unmodified clicks (not SHIFT etc) */
  59   if(event->state & GDK_MODIFIER_MASK)
  60     return FALSE;
  61   /* We are only interested if a well-defined path is clicked */
  62   GtkTreePath *path;
  63   if(!gtk_tree_view_get_path_at_pos(GTK_TREE_VIEW(w),
  64                                     event->x, event->y,
  65                                     &path,
  66                                     NULL,
  67                                     NULL, NULL))
  68     return FALSE;
  69   //gtk_widget_grab_focus(w);    // TODO why??
  70   /* We are only interested if a selected row is clicked */
  71   GtkTreeSelection *s = gtk_tree_view_get_selection(GTK_TREE_VIEW(w));
  72   if(!gtk_tree_selection_path_is_selected(s, path))
  73     return FALSE;
  74   /* We block subsequent selection changes and remember where the
  75    * click was */
  76   block_selection(w, FALSE, event->x, event->y);
  77   return FALSE;                 /* propagate */
  78 }
  79
  80 static gboolean multidrag_button_release_event(GtkWidget *w,
  81                                                GdkEventButton *event,
  82                                                gpointer attribute((unused)) user_data) {
  83   int *where = g_object_get_data(G_OBJECT(w), "multidrag-where");
  84
  85   if(where && where[0] != -1) {
  86     // Remember where the down-click was
  87     const int x = where[0], y = where[1];
  88     // Re-allow selections
  89     block_selection(w, TRUE, -1, -1);
  90     if(x == event->x && y == event->y) {
  91       // If the up-click is at the same location as the down-click,
  92       // it's not a drag.
  93       GtkTreePath *path;
  94       GtkTreeViewColumn *col;
  95       if(gtk_tree_view_get_path_at_pos(GTK_TREE_VIEW(w),
  96                                        event->x, event->y,
  97                                        &path,
  98                                        &col,
  99                                        NULL, NULL)) {
 100         gtk_tree_view_set_cursor(GTK_TREE_VIEW(w), path, col, FALSE);
 101       }
 102     }
 103   }
 104   return FALSE;                 /* propagate */
 105 }
 106
 107 void make_treeview_multidrag(GtkWidget *w) {
 108   g_signal_connect(w, "button-press-event",
 109                    G_CALLBACK(multidrag_button_press_event), NULL);
 110   g_signal_connect(w, "button-release-event",
 111                    G_CALLBACK(multidrag_button_release_event), NULL);
 112 }
 113
 114 /*
 115 Local Variables:
 116 c-basic-offset:2
 117 comment-column:40
 118 fill-column:79
 119 indent-tabs-mode:nil
 120 End:
 121 */