More consistent icon placement (Bug #8814)

When the screen size changes, icons are loaded from the icon cache
if the position is available, then an attempt is made to re-locate
the icon at its original position before the change event, if that
is still available, and finally any leftover icons are appended to
any free position. This should help keep the icons where the user
would like them to be.

2 files changed, 118 insertions, 71 deletions

diff --git a/src/xfdesktop-file-icon-manager.c b/src/xfdesktop-file-icon-manager.c
index 8f4d72a8..ae4ffc20 100644
--- a/src/xfdesktop-file-icon-manager.c
+++ b/src/xfdesktop-file-icon-manager.c
@@ -1691,7 +1691,9 @@ xfdesktop_file_icon_manager_save_icons(gpointer user_data)
     path = xfce_resource_save_location(XFCE_RESOURCE_CONFIG, relpath, TRUE);
     if(!path)
         return FALSE;
-    
+
+    DBG("saving to: %s", path);
+
     tmppath = g_strconcat(path, ".new", NULL);
     
     rcfile = xfce_rc_simple_open(tmppath, FALSE);
@@ -1714,11 +1716,15 @@ xfdesktop_file_icon_manager_save_icons(gpointer user_data)
     
     xfce_rc_flush(rcfile);
     xfce_rc_close(rcfile);
-    
-    if(rename(tmppath, path)) {
-        g_warning("Unable to rename temp file to %s: %s", path,
-                  strerror(errno));
-        unlink(tmppath);
+
+    if(g_file_test(tmppath, G_FILE_TEST_EXISTS)) {
+        if(rename(tmppath, path)) {
+            g_warning("Unable to rename temp file to %s: %s", path,
+                      strerror(errno));
+            unlink(tmppath);
+        }
+    } else {
+        DBG("didn't write anything in the RC file, desktop is probably empty");
     }
     
     g_free(path);
diff --git a/src/xfdesktop-icon-view.c b/src/xfdesktop-icon-view.c
index cf034852..4ae5b53f 100644
--- a/src/xfdesktop-icon-view.c
+++ b/src/xfdesktop-icon-view.c
@@ -1682,20 +1682,6 @@ xfdesktop_icon_view_compare_icons(gconstpointer *a,
 }
 
 static void
-xfdesktop_move_icon_from_pending_list_to_icons_list(XfdesktopIconView *icon_view,
-                                                    XfdesktopIcon *icon)
-{
-    GList *pending_icons = icon_view->priv->pending_icons;
-    GList *icon_list = icon_view->priv->icons;
-
-    if(g_list_find(pending_icons, icon)) {
-        /* Add the icon to the icon list and remove from the pending list */
-        icon_list = g_list_append(icon_list, icon);
-        pending_icons = g_list_remove(pending_icons, icon);
-    }
-}
-
-static void
 xfdesktop_icon_view_append_icons(XfdesktopIconView *icon_view,
                                  GList *icon_list,
                                  guint16 *row,
@@ -1722,38 +1708,6 @@ xfdesktop_icon_view_append_icons(XfdesktopIconView *icon_view,
     }
 }
 
-static void
-xfdesktop_icon_view_append_pending_icons(XfdesktopIconView *icon_view)
-{
-    GList *l = NULL;
-    guint16 row = 0, col = 0;
-
-    for(l = icon_view->priv->pending_icons; l != NULL; l = g_list_next(l)) {
-
-        /* Find the next available spot for an icon */
-        do {
-            if(row + 1 >= icon_view->priv->nrows) {
-                ++col;
-                row = 0;
-            } else {
-                ++row;
-            }
-
-            /* Check that we haven't ran out of space */
-            if(col > icon_view->priv->ncols)
-                return;
-        } while(!xfdesktop_grid_is_free_position(icon_view, row, col));
-
-        /* set new position */
-        xfdesktop_icon_set_position(l->data, row, col);
-        xfdesktop_grid_unset_position_free(icon_view, l->data);
-
-        xfdesktop_move_icon_from_pending_list_to_icons_list(icon_view, l->data);
-
-        xfdesktop_icon_view_invalidate_icon(icon_view, l->data, TRUE);
-    }
-}
-
 void
 xfdesktop_icon_view_sort_icons(XfdesktopIconView *icon_view)
 {
@@ -3136,56 +3090,130 @@ xfdesktop_move_all_icons_to_pending_icons_list(XfdesktopIconView *icon_view)
     icon_view->priv->pending_icons = g_list_concat(icon_view->priv->icons,
                                                    icon_view->priv->pending_icons);
     icon_view->priv->icons = NULL;
-    
-    DUMP_GRID_LAYOUT(icon_view);
-    
+
     memset(icon_view->priv->grid_layout, 0,
            icon_view->priv->nrows * icon_view->priv->ncols
            * sizeof(XfdesktopIcon *));
     
     xfdesktop_setup_grids(icon_view);
-    
-    DUMP_GRID_LAYOUT(icon_view);
 }
 
+/* When changing resolutions this moves all the icons that are in the rc file
+ * for the new resolution to the desktop and removes them from the pending
+ * icons list */
 static void
-xfdesktop_move_all_pending_icons_to_desktop(XfdesktopIconView* icon_view)
+xfdesktop_move_all_cached_icons_to_desktop(XfdesktopIconView *icon_view)
 {
-    XfdesktopFileIconManager *fmanager;
+#ifdef ENABLE_FILE_ICONS
     GList *l, *leftovers = NULL;
+    XfdesktopFileIconManager *fmanager;
+
+    TRACE("entering");
 
-#ifdef ENABLE_FILE_ICONS
     if(XFDESKTOP_IS_FILE_ICON_MANAGER(icon_view->priv->manager))
         fmanager = XFDESKTOP_FILE_ICON_MANAGER(icon_view->priv->manager);
-#endif
 
-    /* add all icons back */
+    if(fmanager == NULL)
+        return;
+
+    /* add all cached icons back */
     for(l = icon_view->priv->pending_icons; l; l = l->next) {
         gint16 row, col;
         XfdesktopIcon *icon = XFDESKTOP_ICON(l->data);
 
-#ifdef ENABLE_FILE_ICONS
         /* Try to get the cached position for the new resolution */
-        if(fmanager != NULL &&
-           xfdesktop_file_icon_manager_get_cached_icon_position(
+        if(xfdesktop_file_icon_manager_get_cached_icon_position(
                                                             fmanager,
                                                             xfdesktop_icon_peek_label(icon),
                                                             &row,
                                                             &col))
         {
-            xfdesktop_icon_set_position(icon, row, col);
+            DBG("icon %s setting position row%dxcol%d",
+                xfdesktop_icon_peek_label(icon), row, col);
+
+            /* Make sure the spot is available */
+            if(xfdesktop_grid_is_free_position(icon_view, row, col)) {
+                xfdesktop_icon_set_position(icon, row, col);
+                xfdesktop_icon_view_add_item_internal(icon_view, icon);
+            } else {
+                leftovers = g_list_prepend(leftovers, icon);
+            }
+        } else {
+            leftovers = g_list_prepend(leftovers, icon);
         }
+    }
+
+    g_list_free(icon_view->priv->pending_icons);
+    icon_view->priv->pending_icons = g_list_reverse(leftovers);
 #endif
+}
 
-        if(xfdesktop_icon_view_icon_find_position(icon_view, icon))
+/* Takes any icons in the pending icons list that has their original spot open.
+ * This way icons stay somewhat stable during minor resolution changes */
+static void
+xfdesktop_move_all_previous_icons_to_desktop(XfdesktopIconView *icon_view)
+{
+    GList *l, *leftovers = NULL;
+
+    TRACE("entering");
+
+    /* add all pending icons back if their space is still available */
+    for(l = icon_view->priv->pending_icons; l; l = l->next) {
+        guint16 row, col;
+        XfdesktopIcon *icon = XFDESKTOP_ICON(l->data);
+
+        xfdesktop_icon_get_position(icon, &row, &col);
+
+        if(xfdesktop_grid_is_free_position(icon_view, row, col)) {
+            DBG("adding icon %s position row %d x col %d",
+                xfdesktop_icon_peek_label(icon), row, col);
             xfdesktop_icon_view_add_item_internal(icon_view, icon);
-        else
+        } else {
             leftovers = g_list_prepend(leftovers, icon);
+        }
     }
+
     g_list_free(icon_view->priv->pending_icons);
     icon_view->priv->pending_icons = g_list_reverse(leftovers);
+}
 
-    xfdesktop_icon_view_append_pending_icons(icon_view);
+/* Takes any icons in the pending icons list and adds them where there is space */
+static void
+xfdesktop_append_all_pending_icons(XfdesktopIconView *icon_view)
+{
+    GList *l, *leftovers = NULL;
+
+    TRACE("entering");
+
+    /* add all pending icons back if space is available */
+    for(l = icon_view->priv->pending_icons; l; l = l->next) {
+        guint16 row, col;
+        XfdesktopIcon *icon = XFDESKTOP_ICON(l->data);
+
+        if(xfdesktop_grid_get_next_free_position(icon_view, &row, &col)) {
+            xfdesktop_icon_set_position(icon, row, col);
+            xfdesktop_icon_view_add_item_internal(icon_view, icon);
+        } else {
+            leftovers = g_list_prepend(leftovers, icon);
+        }
+    }
+
+    g_list_free(icon_view->priv->pending_icons);
+    icon_view->priv->pending_icons = g_list_reverse(leftovers);
+}
+
+static void
+xfdesktop_move_all_pending_icons_to_desktop(XfdesktopIconView *icon_view)
+{
+    if(!XFDESKTOP_IS_ICON_VIEW(icon_view))
+        return;
+
+    if(icon_view->priv->grid_layout == NULL)
+        return;
+
+    xfdesktop_move_all_cached_icons_to_desktop(icon_view);
+    xfdesktop_move_all_previous_icons_to_desktop(icon_view);
+    xfdesktop_append_all_pending_icons(icon_view);
 }
 
 static void
@@ -3299,6 +3327,8 @@ xfdesktop_grid_is_free_position(XfdesktopIconView *icon_view,
                                 guint16 row,
                                 guint16 col)
 {
+    g_return_val_if_fail(icon_view->priv->grid_layout != NULL, FALSE);
+
     if(row >= icon_view->priv->nrows
        || col >= icon_view->priv->ncols)
     {
@@ -3358,11 +3388,17 @@ xfdesktop_grid_unset_position_free_raw(XfdesktopIconView *icon_view,
     idx = col * icon_view->priv->nrows + row;
     if(icon_view->priv->grid_layout[idx])
         return FALSE;
-    
+
+#if 0 /*def DEBUG*/
     DUMP_GRID_LAYOUT(icon_view);
+#endif
+
     icon_view->priv->grid_layout[idx] = data;
+
+#if 0 /*def DEBUG*/
     DUMP_GRID_LAYOUT(icon_view);
-    
+#endif
+
     return TRUE;
 }
 
@@ -3632,6 +3668,11 @@ xfdesktop_icon_view_remove_item(XfdesktopIconView *icon_view,
     
     g_object_set_data(G_OBJECT(icon), "--xfdesktop-icon-view", NULL);
     g_object_unref(G_OBJECT(icon));
+
+    if(icon_view->priv->pending_icons != NULL) {
+        /* Move in any pending icons to the space available */
+        xfdesktop_move_all_pending_icons_to_desktop(icon_view);
+    }
 }
 
 void