chiark / gitweb /
Merge drag+drop rewrite. It's now possible to drag multiple rows in
authorRichard Kettlewell <rjk@greenend.org.uk>
Sat, 14 Nov 2009 11:39:38 +0000 (11:39 +0000)
committerRichard Kettlewell <rjk@greenend.org.uk>
Sat, 14 Nov 2009 11:39:38 +0000 (11:39 +0000)
one operation in the queue.

1  2 
disobedience/queue-generic.c

@@@ -1,6 -1,6 +1,6 @@@
  /*
   * This file is part of DisOrder
-  * Copyright (C) 2006-2008 Richard Kettlewell
+  * Copyright (C) 2006-2009 Richard Kettlewell
   *
   * 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
  #include "popup.h"
  #include "queue-generic.h"
  
 -static struct queuelike *const queuelikes[] = {
 -  &ql_queue, &ql_recent, &ql_added
 -};
 -#define NQUEUELIKES (sizeof queuelikes / sizeof *queuelikes)
+ static const GtkTargetEntry queuelike_targets[] = {
+   {
+     (char *)"text/x-disorder-track-data", /* drag type */
+     GTK_TARGET_SAME_WIDGET,             /* rearrangement only for now */
+     0                                   /* ID value */
+   },
+ };
  /* Track detail lookup ----------------------------------------------------- */
  
  static void queue_lookups_completed(const char attribute((unused)) *event,
@@@ -152,6 -165,19 +161,19 @@@ struct queue_entry *ql_iter_to_q(GtkTre
    return q;
  }
  
+ /** @brief Return the @ref queue_entry corresponding to @p path
+  * @param model Model to query
+  * @param path Path into tree
+  * @return Pointer to queue entry or NULL
+  */
+ struct queue_entry *ql_path_to_q(GtkTreeModel *model,
+                                  GtkTreePath *path) {
+   GtkTreeIter iter[1];
+   if(!gtk_tree_model_get_iter(model, iter, path))
+     return NULL;
+   return ql_iter_to_q(model, iter);
+ }
  /** @brief Update one row of a list store
   * @param q Queue entry
   * @param iter Iterator referring to row or NULL to work it out
@@@ -397,118 -423,308 +419,308 @@@ void ql_new_queue(struct queuelike *ql
    --suppress_actions;
  }
  
- /* Drag and drop has to be figured out experimentally, because it is not well
-  * documented.
-  *
-  * First you get a row-inserted.  The path argument points to the destination
-  * row but this will not yet have had its values set.  The source row is still
-  * present.  AFAICT the iter argument points to the same place.
-  *
-  * Then you get a row-deleted.  The path argument identifies the row that was
-  * deleted.  By this stage the row inserted above has acquired its values.
-  *
-  * A complication is that the deletion will move the inserted row.  For
-  * instance, if you do a drag that moves row 1 down to after the track that was
-  * formerly on row 9, in the row-inserted call it will show up as row 10, but
-  * in the row-deleted call, row 1 will have been deleted thus making the
-  * inserted row be row 9.
-  *
-  * So when we see the row-inserted we have no idea what track to move.
-  * Therefore we stash it until we see a row-deleted.
-  */
+ /** @brief State for ql_drag_begin() and its callbacks */
+ struct ql_drag_begin_state {
+   struct queuelike *ql;
+   int rows;
+   int index;
+   GdkPixmap **pixmaps;
+ };
  
- /** @brief row-inserted callback */
- static void ql_row_inserted(GtkTreeModel attribute((unused)) *treemodel,
-                             GtkTreePath *path,
-                             GtkTreeIter attribute((unused)) *iter,
-                             gpointer user_data) {
-   struct queuelike *const ql = user_data;
-   if(!suppress_actions) {
- #if 0
-     char *ps = gtk_tree_path_to_string(path);
-     GtkTreeIter piter[1];
-     gboolean pi = gtk_tree_model_get_iter(treemodel, piter, path);
-     struct queue_entry *pq = pi ? ql_iter_to_q(treemodel, piter) : 0;
-     struct queue_entry *iq = ql_iter_to_q(treemodel, iter);
-     fprintf(stderr, "row-inserted %s path=%s pi=%d pq=%p path=%s iq=%p iter=%s\n",
-             ql->name,
-             ps,
-             pi,
-             pq,
-             (pi
-              ? (pq ? pq->track : "(pq=0)")
-              : "(pi=FALSE)"),
-             iq,
-             iq ? iq->track : "(iq=0)");
-     GtkTreeIter j[1];
-     gboolean jt = gtk_tree_model_get_iter_first(treemodel, j);
-     int row = 0;
-     while(jt) {
-       struct queue_entry *q = ql_iter_to_q(treemodel, j);
-       fprintf(stderr, " %2d %s\n", row++, q ? q->track : "(no q)");
-       jt = gtk_tree_model_iter_next(GTK_TREE_MODEL(ql->store), j);
-     }
-     g_free(ps);
- #endif
-     /* Remember an iterator pointing at the insertion target */
-     if(ql->drag_target)
-       gtk_tree_path_free(ql->drag_target);
-     ql->drag_target = gtk_tree_path_copy(path);
-   }
+ /** @brief Callback to construct a row pixmap */
+ static void ql_drag_make_row_pixmaps(GtkTreeModel attribute((unused)) *model,
+                                      GtkTreePath *path,
+                                      GtkTreeIter attribute((unused)) *iter,
+                                      gpointer data) {
+   struct ql_drag_begin_state *qdbs = data;
+   qdbs->pixmaps[qdbs->index++]
+     = gtk_tree_view_create_row_drag_icon(GTK_TREE_VIEW(qdbs->ql->view),
+                                          path);
  }
  
- /** @brief row-deleted callback */
- static void ql_row_deleted(GtkTreeModel attribute((unused)) *treemodel,
-                            GtkTreePath *path,
-                            gpointer user_data) {
+ /** @brief Called when a drag operation from this queuelike begins
+  * @param w Source widget (the tree view)
+  * @param dc Drag context
+  * @param user_data The queuelike
+  */
+ static void ql_drag_begin(GtkWidget attribute((unused)) *w,
+                           GdkDragContext attribute((unused)) *dc,
+                           gpointer user_data) {
    struct queuelike *const ql = user_data;
+   struct ql_drag_begin_state qdbs[1];
+   GdkPixmap *icon;
+   //fprintf(stderr, "drag-begin\n");
+   memset(qdbs, 0, sizeof *qdbs);
+   qdbs->ql = ql;
+   /* Find out how many rows there are */
+   if(!(qdbs->rows = gtk_tree_selection_count_selected_rows(ql->selection)))
+     return;                             /* doesn't make sense */
+   /* Generate a pixmap for each row */
+   qdbs->pixmaps = xcalloc(qdbs->rows, sizeof *qdbs->pixmaps);
+   gtk_tree_selection_selected_foreach(ql->selection,
+                                       ql_drag_make_row_pixmaps,
+                                       qdbs);
+   /* Determine the size of the final icon */
+   int height = 0, width = 0;
+   for(int n = 0; n < qdbs->rows; ++n) {
+     int pxw, pxh;
+     gdk_drawable_get_size(qdbs->pixmaps[n], &pxw, &pxh);
+     if(pxw > width)
+       width = pxw;
+     height += pxh;
+   }
+   if(!width || !height)
+     return;                             /* doesn't make sense */
+   /* Construct the icon */
+   icon = gdk_pixmap_new(qdbs->pixmaps[0], width, height, -1);
+   GdkGC *gc = gdk_gc_new(icon);
+   gdk_gc_set_colormap(gc, gtk_widget_get_colormap(ql->view));
+   int y = 0;
+   for(int n = 0; n < qdbs->rows; ++n) {
+     int pxw, pxh;
+     gdk_drawable_get_size(qdbs->pixmaps[n], &pxw, &pxh);
+     gdk_draw_drawable(icon,
+                       gc,
+                       qdbs->pixmaps[n],
+                       0, 0,             /* source coords */
+                       0, y,             /* dest coords */
+                       pxw, pxh);        /* size */
+     y += pxh;
+   }
+   // TODO scale down a bit, the resulting icons are currently a bit on the
+   // large side.
+   gtk_drag_source_set_icon(ql->view,
+                            gtk_widget_get_colormap(ql->view),
+                            icon,
+                            NULL);
+ }
  
-   if(!suppress_actions) {
- #if 0
-     char *ps = gtk_tree_path_to_string(path);
-     fprintf(stderr, "row-deleted %s path=%s ql->drag_target=%s\n",
-             ql->name, ps, gtk_tree_path_to_string(ql->drag_target));
-     GtkTreeIter j[1];
-     gboolean jt = gtk_tree_model_get_iter_first(treemodel, j);
-     int row = 0;
-     while(jt) {
-       struct queue_entry *q = ql_iter_to_q(treemodel, j);
-       fprintf(stderr, " %2d %s\n", row++, q ? q->track : "(no q)");
-       jt = gtk_tree_model_iter_next(GTK_TREE_MODEL(ql->store), j);
-     }
-     g_free(ps);
- #endif
-     if(!ql->drag_target) {
-       error(0, "%s: unsuppressed row-deleted with no row-inserted",
-             ql->name);
-       return;
+ /** @brief Called when a drag moves within a candidate destination
+  * @param w Destination widget
+  * @param dc Drag context
+  * @param x Current pointer location
+  * @param y Current pointer location
+  * @param time_ Current time
+  * @param user_data Pointer to queuelike
+  * @return TRUE in a dropzone, otherwise FALSE
+  */
+ static gboolean ql_drag_motion(GtkWidget *w,
+                                GdkDragContext *dc,
+                                gint x,
+                                gint y,
+                                guint time_,
+                                gpointer attribute((unused)) user_data) {
+   //struct queuelike *const ql = user_data;
+   GdkDragAction action = 0;
+   
+   // GTK_DEST_DEFAULT_MOTION vets actions as follows:
+   // 1) if dc->suggested_action is in the gtk_drag_dest_set actions
+   //    then dc->suggested_action is taken as the action.
+   // 2) otherwise if dc->actions intersects the gtk_drag_dest_set actions
+   //    then the lowest-numbered member of the intersection is chosen.
+   // 3) otherwise no member is chosen and gdk_drag_status() is called
+   //    with action=0 to refuse the drop.
+   // Currently we can only accept _MOVE.  But in the future we will
+   // need to accept _COPY in some cases.
+   if(dc->suggested_action) {
+     if(dc->suggested_action == GDK_ACTION_MOVE)
+       action = dc->suggested_action;
+   } else if(dc->actions & GDK_ACTION_MOVE)
+     action = dc->actions;
+   /*fprintf(stderr, "suggested %#x actions %#x result %#x\n",
+     dc->suggested_action, dc->actions, action);*/
+   if(action) {
+     // If the action is acceptable then we see if this widget is acceptable
+     if(!gtk_drag_dest_find_target(w, dc, NULL))
+       action = 0;
+   }
+   // Report the status
+   gdk_drag_status(dc, action, time_);
+   if(action) {
+     // Highlight the drop area
+     GtkTreePath *path;
+     GtkTreeViewDropPosition pos;
+     if(gtk_tree_view_get_dest_row_at_pos(GTK_TREE_VIEW(w),
+                                          x, y,
+                                          &path,
+                                          &pos)) {
+       //fprintf(stderr, "gtk_tree_view_get_dest_row_at_pos() -> TRUE\n");
+       // Normalize drop position
+       switch(pos) {
+       case GTK_TREE_VIEW_DROP_INTO_OR_BEFORE:
+         pos = GTK_TREE_VIEW_DROP_BEFORE;
+         break;
+       case GTK_TREE_VIEW_DROP_INTO_OR_AFTER:
+         pos = GTK_TREE_VIEW_DROP_AFTER;
+         break;
+       default: break;
+       }
+       // Highlight drop target
+       gtk_tree_view_set_drag_dest_row(GTK_TREE_VIEW(w), path, pos);
+     } else {
+       //fprintf(stderr, "gtk_tree_view_get_dest_row_at_pos() -> FALSE\n");
+       gtk_tree_view_set_drag_dest_row(GTK_TREE_VIEW(w), NULL, 0);
      }
+   }
+   return TRUE;
+ }
  
-     /* Get the source and destination row numbers. */
-     int srcrow = gtk_tree_path_get_indices(path)[0];
-     int dstrow = gtk_tree_path_get_indices(ql->drag_target)[0];
-     //fprintf(stderr, "srcrow=%d dstrow=%d\n", srcrow, dstrow);
+ /** @brief Called when a drag moves leaves a candidate destination
+  * @param w Destination widget
+  * @param dc Drag context
+  * @param time_ Current time
+  * @param user_data Pointer to queuelike
+  */
+ static void ql_drag_leave(GtkWidget *w,
+                           GdkDragContext attribute((unused)) *dc,
+                           guint attribute((unused)) time_,
+                           gpointer attribute((unused)) user_data) {
+   //struct queuelike *const ql = user_data;
  
-     /* Note that the source row is computed AFTER the destination has been
-      * inserted, since GTK+ does the insert before the delete.  Therefore if
-      * the source row is south (higher row number) of the destination, it will
-      * be one higher than expected.
-      *
-      * For instance if we drag row 1 to before row 0 we will see row-inserted
-      * for row 0 but then a row-deleted for row 2.
-      */
-     if(srcrow > dstrow)
-       --srcrow;
+   gtk_tree_view_set_drag_dest_row(GTK_TREE_VIEW(w), NULL, 0);
+ }
  
-     /* Tell the queue implementation */
-     ql->drop(ql, srcrow, dstrow);
+ /** @brief Callback to add selected tracks to the selection data
+  *
+  * Called from ql_drag_data_get().
+  */
+ static void ql_drag_data_get_collect(GtkTreeModel *model,
+                                      GtkTreePath attribute((unused)) *path,
+                                      GtkTreeIter *iter,
+                                      gpointer data) {
+   struct dynstr *const result = data;
+   struct queue_entry *const q = ql_iter_to_q(model, iter);
+   dynstr_append_string(result, q->id);
+   dynstr_append(result, '\n');
+   dynstr_append_string(result, q->track);
+   dynstr_append(result, '\n');
+ }
  
-     /* Dispose of stashed data */
-     gtk_tree_path_free(ql->drag_target);
-     ql->drag_target = 0;
+ /** @brief Called to extract the dragged data from the source queuelike
+  * @param w Source widget (the tree view)
+  * @param dc Drag context
+  * @param data Where to put the answer
+  * @param info_ Target @c info parameter
+  * @param time_ Time data requested (for some reason not a @c time_t)
+  * @param user_data The queuelike
+  */
+ static void ql_drag_data_get(GtkWidget attribute((unused)) *w,
+                              GdkDragContext attribute((unused)) *dc,
+                              GtkSelectionData *data,
+                              guint attribute((unused)) info_,
+                              guint attribute((unused)) time_,
+                              gpointer user_data) {
+   struct queuelike *const ql = user_data;
+   struct dynstr result[1];
+   /* The list of tracks is converted into a single string, consisting of IDs
+    * and track names.  Each is terminated by a newline.  Including both ID and
+    * track name means that the receiver can use whichever happens to be more
+    * convenient. */
+   dynstr_init(result);
+   gtk_tree_selection_selected_foreach(ql->selection,
+                                       ql_drag_data_get_collect,
+                                       result);
+   //fprintf(stderr, "drag-data-get: %.*s\n",
+   //        result->nvec, result->vec);
+   /* gtk_selection_data_set_text() insists that data->target is one of a
+    * variety of stringy atoms.  TODO: where does this value actually come
+    * from?  */
+   gtk_selection_data_set(data,
+                          GDK_TARGET_STRING,
+                          8, (guchar *)result->vec, result->nvec);
+ }
+ /** @brief Called when drag data is received
+  * @param w Target widget (the tree view)
+  * @param dc Drag context
+  * @param x The drop location
+  * @param y The drop location
+  * @param data The selection data
+  * @param info_ The target type that was chosen
+  * @param time_ Time data received (for some reason not a @c time_t)
+  * @param user_data The queuelike
+  */
+ static void ql_drag_data_received(GtkWidget attribute((unused)) *w,
+                                   GdkDragContext attribute((unused)) *dc,
+                                   gint x,
+                                   gint y,
+                                   GtkSelectionData *data,
+                                   guint attribute((unused)) info_,
+                                   guint attribute((unused)) time_,
+                                   gpointer user_data) {
+   struct queuelike *const ql = user_data;
+   char *result, *p;
+   struct vector ids[1], tracks[1];
+   int parity = 0;
+   //fprintf(stderr, "drag-data-received: %d,%d\n", x, y);
+   /* Get the selection string */
+   p = result = (char *)gtk_selection_data_get_text(data);
+   if(!result) {
+     //fprintf(stderr, "gtk_selection_data_get_text() returned NULL\n");
+     return;
+   }
+   //fprintf(stderr, "%s--\n", result);
+   /* Parse it back into IDs and track names */
+   vector_init(ids);
+   vector_init(tracks);
+   while(*p) {
+     char *nl = strchr(p, '\n');
+     if(!nl)
+       break;
+     *nl = 0;
+     //fprintf(stderr, "  %s\n", p);
+     vector_append(parity++ & 1 ? tracks : ids, xstrdup(p));
+     p = nl + 1;
+   }
+   g_free(result);
+   if(ids->nvec != tracks->nvec) {
+     //fprintf(stderr, "  inconsistent drag data!\n");
+     return;
+   }
+   vector_terminate(ids);
+   vector_terminate(tracks);
+   /* Figure out which row the drop precedes (if any) */
+   GtkTreePath *path;
+   GtkTreeViewDropPosition pos;
+   struct queue_entry *q;
+   if(!gtk_tree_view_get_dest_row_at_pos(GTK_TREE_VIEW(ql->view), x, y,
+                                         &path, &pos)) {
+     //fprintf(stderr, "gtk_tree_view_get_dest_row_at_pos returned FALSE\n");
+     /* This generally means a drop past the end of the queue.  We find the last
+      * element in the queue and ask to move after that. */
+     for(q = ql->q; q && q->next; q = q->next)
+       ;
+   } else {
+     /* Convert the path to a queue entry pointer. */
+     q = ql_path_to_q(GTK_TREE_MODEL(ql->store), path);
+     //fprintf(stderr, "  tree view likes to drop near %s\n",
+     //        q->id ? q->id : "NULL");
+     /* TODO interpretation of q=NULL */
+     /* Q should point to the entry just before the insertion point, so that
+      * moveafter works, or NULL to insert right at the start.  We don't support
+      * dropping into a row, since that doesn't make sense for us. */
+     switch(pos) {
+     case GTK_TREE_VIEW_DROP_BEFORE:
+     case GTK_TREE_VIEW_DROP_INTO_OR_BEFORE:
+       if(q) {
+         q = q->prev;
+         //fprintf(stderr, "  ...but we like to drop near %s\n",
+         //        q ? q->id : "NULL");
+       }
+       break;
+     default:
+       break;
+     }
    }
+   /* Note that q->id can match one of ids[].  This doesn't matter for
+    * moveafter but TODO may matter for playlist support. */
+   ql->drop(ql, tracks->nvec, tracks->vec, ids->vec, q);
  }
  
  /** @brief Initialize a @ref queuelike */
@@@ -558,13 -774,49 +770,49 @@@ GtkWidget *init_queuelike(struct queuel
  
    /* Drag+drop*/
    if(ql->drop) {
-     gtk_tree_view_set_reorderable(GTK_TREE_VIEW(ql->view), TRUE);
-     g_signal_connect(ql->store,
-                      "row-inserted",
-                      G_CALLBACK(ql_row_inserted), ql);
-     g_signal_connect(ql->store,
-                      "row-deleted",
-                      G_CALLBACK(ql_row_deleted), ql);
+     /* Originally this was:
+      *
+      *   gtk_tree_view_set_reorderable(GTK_TREE_VIEW(ql->view), TRUE);
+      *
+      * However this has a two deficiencies:
+      *
+      *   1) Only one row can be dragged at once.  It would be nice
+      *      to be able to do bulk rearrangements since the server
+      *      can cope with that well.
+      *   2) Dragging between windows is not possible.  When playlist
+      *      support appears, it should be possible to drag tracks
+      *      from the choose tag into the playlist.
+      *
+      * At the time of writing neither of these problems are fully solved, the
+      * code as it stands is just a stepping stone in that direction.
+      */
+     /* This view will act as a drag source */
+     gtk_drag_source_set(ql->view,
+                         GDK_BUTTON1_MASK,
+                         queuelike_targets,
+                         sizeof queuelike_targets / sizeof *queuelike_targets,
+                         GDK_ACTION_MOVE);
+     /* This view will act as a drag destination */
+     gtk_drag_dest_set(ql->view,
+                       GTK_DEST_DEFAULT_HIGHLIGHT|GTK_DEST_DEFAULT_DROP,
+                       queuelike_targets,
+                       sizeof queuelike_targets / sizeof *queuelike_targets,
+                       GDK_ACTION_MOVE);
+     g_signal_connect(ql->view, "drag-begin",
+                      G_CALLBACK(ql_drag_begin), ql);
+     g_signal_connect(ql->view, "drag-motion",
+                      G_CALLBACK(ql_drag_motion), ql);
+     g_signal_connect(ql->view, "drag-leave",
+                      G_CALLBACK(ql_drag_leave), ql);
+     g_signal_connect(ql->view, "drag-data-get",
+                      G_CALLBACK(ql_drag_data_get), ql);
+     g_signal_connect(ql->view, "drag-data-received",
+                      G_CALLBACK(ql_drag_data_received), ql);
+     make_treeview_multidrag(ql->view);
+   } else {
+     /* TODO: support copy-dragging out of non-rearrangeable queues.  Will need
+      * to support copy dropping into the rearrangeable ones. */
    }
    
    /* TODO style? */