[gthumb] grid view: use an array instead of a list to save the items

[Paolo Bacchilega <paobac src gnome org>]

commit 5dfbb9e7cb5e25d24c60ff6d72960d92d4360e59
Author: Paolo Bacchilega <paobac src gnome org>
Date:   Fri May 21 20:03:46 2021 +0200

    grid view: use an array instead of a list to save the items
    
    This speeds up navigation when a directory contains
    thousands of images.

 gthumb/gth-grid-view.c | 214 ++++++++++++++++---------------------------------
 1 file changed, 68 insertions(+), 146 deletions(-)
---
diff --git a/gthumb/gth-grid-view.c b/gthumb/gth-grid-view.c
index a10cc3e9..fc9e4cb8 100644
--- a/gthumb/gth-grid-view.c
+++ b/gthumb/gth-grid-view.c
@@ -131,7 +131,7 @@ typedef struct {
 
 struct _GthGridViewPrivate {
        GtkTreeModel          *model;
-       GList                 *items;
+       GPtrArray             *itemv;
        int                    n_items;
        GList                 *lines;
        GList                 *selection;
@@ -397,9 +397,9 @@ _gth_grid_view_free_lines (GthGridView *self)
 static void
 _gth_grid_view_free_items (GthGridView *self)
 {
-       g_list_foreach (self->priv->items, (GFunc) gth_grid_view_item_unref, NULL);
-       g_list_free (self->priv->items);
-       self->priv->items = NULL;
+       g_ptr_array_unref (self->priv->itemv);
+       self->priv->itemv = NULL;
+       self->priv->n_items = 0;
 
        g_list_free (self->priv->selection);
        self->priv->selection = NULL;
@@ -838,18 +838,14 @@ _gth_grid_view_relayout_at (GthGridView *self,
        int    items_per_line;
        GList *items;
        int    max_height;
-       GList *scan;
        int    n;
 
        new_lines = NULL;
        items_per_line = gth_grid_view_get_items_per_line (self);
        items = NULL;
        max_height = 0;
-       for (scan = g_list_nth (self->priv->items, pos), n = pos;
-            scan;
-            scan = scan->next, n++)
-       {
-               GthGridViewItem *item = scan->data;
+       for (n = pos; n < self->priv->n_items;  n++) {
+               GthGridViewItem *item = g_ptr_array_index (self->priv->itemv, n);
 
                if ((n % items_per_line) == 0) {
                        if (items != NULL) {
@@ -1660,7 +1656,7 @@ _gth_grid_view_draw_drop_target (GthGridView *self,
 
        style_context = gtk_widget_get_style_context (GTK_WIDGET (self));
 
-       item = g_list_nth (self->priv->items, self->priv->drop_item)->data;
+       item = g_ptr_array_index (self->priv->itemv, self->priv->drop_item);
 
        x = 0;
        if (self->priv->drop_pos == GTH_DROP_POSITION_LEFT)
@@ -1711,17 +1707,14 @@ gth_grid_view_draw (GtkWidget *widget,
 
        first_visible = gth_grid_view_get_first_visible (GTH_FILE_VIEW (self));
        if (first_visible >= 0) {
-               int    last_visible;
-               int    i;
-               GList *scan;
+               int last_visible;
+               int i;
 
                last_visible = gth_grid_view_get_last_visible (GTH_FILE_VIEW (self));
 
-               for (i = first_visible, scan = g_list_nth (self->priv->items, first_visible);
-                    (i <= last_visible) && scan;
-                    i++, scan = scan->next)
-               {
-                       _gth_grid_view_draw_item (self, GTH_GRID_VIEW_ITEM (scan->data), cr);
+               for (i = first_visible; i <= last_visible; i++) {
+                       GthGridViewItem *item = g_ptr_array_index (self->priv->itemv, i);
+                       _gth_grid_view_draw_item (self, item, cr);
                }
 
                if (self->priv->selecting || self->priv->multi_selecting_with_keyboard)
@@ -1856,7 +1849,6 @@ static void
 _gth_grid_view_select_item (GthGridView *self,
                            int          pos)
 {
-       GList           *link;
        GthGridViewItem *item;
 
        g_return_if_fail ((pos >= 0) && (pos < self->priv->n_items));
@@ -1864,10 +1856,7 @@ _gth_grid_view_select_item (GthGridView *self,
        if (self->priv->selection_mode == GTK_SELECTION_NONE)
                return;
 
-       link = g_list_nth (self->priv->items, pos);
-       g_return_if_fail (link != NULL);
-
-       item = link->data;
+       item = g_ptr_array_index (self->priv->itemv, pos);
        if (item->state & GTK_STATE_FLAG_SELECTED)
                return;
 
@@ -1883,7 +1872,6 @@ static void
 _gth_grid_view_unselect_item (GthGridView *self,
                              int          pos)
 {
-       GList           *link;
        GthGridViewItem *item;
 
        g_return_if_fail ((pos >= 0) && (pos < self->priv->n_items));
@@ -1891,11 +1879,7 @@ _gth_grid_view_unselect_item (GthGridView *self,
        if (self->priv->selection_mode == GTK_SELECTION_NONE)
                return;
 
-       link = g_list_nth (self->priv->items, pos);
-       g_return_if_fail (link != NULL);
-
-       item = link->data;
-
+       item = g_ptr_array_index (self->priv->itemv, pos);
        if (! (item->state & GTK_STATE_FLAG_SELECTED))
                return;
 
@@ -1943,17 +1927,12 @@ static int
 _gth_grid_view_unselect_all (GthGridView *self,
                             gpointer     keep_selected)
 {
-       GthGridViewPrivate *priv = self->priv;
-       int                 idx;
-       GList              *scan;
-       int                 i;
+       int idx;
+       int i;
 
        idx = 0;
-       for (scan = priv->items, i = 0;
-            scan != NULL;
-            scan = scan->next, i++)
-       {
-               GthGridViewItem *item = scan->data;
+       for (i = 0; i < self->priv->n_items; i++) {
+               GthGridViewItem *item = g_ptr_array_index (self->priv->itemv, i);
 
                if (item == keep_selected)
                        idx = i;
@@ -1970,16 +1949,12 @@ gth_grid_view_select (GthFileSelection *selection,
                      int               pos)
 {
        GthGridView *self = GTH_GRID_VIEW (selection);
-       GList       *list;
        int          i;
 
        switch (self->priv->selection_mode) {
        case GTK_SELECTION_SINGLE:
-               for (list = self->priv->items, i = 0;
-                    list != NULL;
-                    list = list->next, i++)
-               {
-                       GthGridViewItem *item = list->data;
+               for (i = 0; i < self->priv->n_items; i++) {
+                       GthGridViewItem *item = g_ptr_array_index (self->priv->itemv, i);
 
                        if ((i != pos) && (item->state & GTK_STATE_FLAG_SELECTED))
                                _gth_grid_view_set_item_selected (self, FALSE, i);
@@ -2012,14 +1987,10 @@ gth_grid_view_unselect (GthFileSelection *selection,
 static void
 _gth_grid_view_select_all (GthGridView *self)
 {
-       GList *scan;
-       int    i;
+       int i;
 
-       for (scan = self->priv->items, i = 0;
-            scan != NULL;
-            scan = scan->next, i++)
-       {
-               GthGridViewItem *item = scan->data;
+       for (i = 0; i < self->priv->n_items; i++) {
+               GthGridViewItem *item = g_ptr_array_index (self->priv->itemv, i);
 
                if (! (item->state & GTK_STATE_FLAG_SELECTED))
                        _gth_grid_view_set_item_selected (self, TRUE, i);
@@ -2118,7 +2089,6 @@ model_row_changed_cb (GtkTreeModel *tree_model,
 {
        GthGridView     *self = user_data;
        int              pos;
-       GList           *link;
        GthFileData     *file_data;
        cairo_surface_t *thumbnail;
        gboolean         is_icon;
@@ -2132,10 +2102,7 @@ model_row_changed_cb (GtkTreeModel *tree_model,
                            -1);
 
        pos = gtk_tree_path_get_indices (path)[0];
-       link = g_list_nth (self->priv->items, pos);
-       g_return_if_fail (link != NULL);
-
-       item = GTH_GRID_VIEW_ITEM (link->data);
+       item = g_ptr_array_index (self->priv->itemv, pos);
        gth_grid_view_item_set_file_data (item, file_data);
        gth_grid_view_item_set_thumbnail (item, thumbnail);
        item->is_icon = is_icon;
@@ -2155,14 +2122,12 @@ model_row_deleted_cb (GtkTreeModel *tree_model,
 {
        GthGridView *self = user_data;
        int          pos;
-       GList       *link;
        GList       *scan;
        GList       *selected_link;
 
        pos = gtk_tree_path_get_indices (path)[0];
-       link = g_list_nth (self->priv->items, pos);
-       self->priv->items = g_list_remove_link (self->priv->items, link);
-       self->priv->n_items--;
+       g_ptr_array_remove_index (self->priv->itemv, pos);
+       self->priv->n_items = (int) self->priv->itemv->len;
 
        /* update the selection */
 
@@ -2196,9 +2161,6 @@ model_row_deleted_cb (GtkTreeModel *tree_model,
        /* relayout from the minimum changed position */
 
        _gth_grid_view_queue_relayout_from_position (self, pos);
-
-       gth_grid_view_item_unref (GTH_GRID_VIEW_ITEM (link->data));
-       g_list_free (link);
 }
 
 
@@ -2228,8 +2190,8 @@ model_row_inserted_cb (GtkTreeModel *tree_model,
                                       is_icon,
                                       self->priv->caption_attributes_v);
        pos = gtk_tree_path_get_indices (path)[0];
-       self->priv->items = g_list_insert (self->priv->items, item, pos);
-       self->priv->n_items++;
+       g_ptr_array_insert (self->priv->itemv, pos, item);
+       self->priv->n_items = (int) self->priv->itemv->len;
 
        /* update the selection */
 
@@ -2266,7 +2228,7 @@ model_rows_reordered_cb (GtkTreeModel *tree_model,
                         gpointer      user_data)
 {
        GthGridView *self = user_data;
-       GList       *items;
+       GPtrArray   *itemv;
        int          i;
        int          min_changed_pos;
        gboolean     focused_updated = FALSE;
@@ -2275,10 +2237,10 @@ model_rows_reordered_cb (GtkTreeModel *tree_model,
        /* change the order of the items list */
 
        min_changed_pos = -1;
-       items = NULL;
+       itemv = g_ptr_array_new_full (self->priv->n_items, (GDestroyNotify) gth_grid_view_item_unref);
        for (i = 0; i < self->priv->n_items; i++) {
-               GList *link;
-               int    old_pos;
+               int              old_pos;
+               GthGridViewItem *item;
 
                old_pos = ((int *) new_order)[i];
                if ((min_changed_pos == -1) && (old_pos != i))
@@ -2291,14 +2253,13 @@ model_rows_reordered_cb (GtkTreeModel *tree_model,
                        focused_updated = TRUE;
                }
 
-               link = g_list_nth (self->priv->items, old_pos);
-               g_return_if_fail (link != NULL);
-               items = g_list_prepend (items, link->data);
+               item = g_ptr_array_index (self->priv->itemv, old_pos);
+               g_ptr_array_add (itemv, gth_grid_view_item_ref (item));
        }
-       items = g_list_reverse (items);
 
-       g_list_free (self->priv->items);
-       self->priv->items = items;
+       g_ptr_array_unref (self->priv->itemv);
+       self->priv->itemv = itemv;
+       self->priv->n_items = (int) self->priv->itemv->len;
 
        /* update the selection */
 
@@ -2330,7 +2291,6 @@ model_thumbnail_changed_cb (GtkTreeModel *tree_model,
 {
        GthGridView     *self = user_data;
        int              pos;
-       GList           *link;
        cairo_surface_t *thumbnail;
        gboolean         is_icon;
        GthGridViewItem *item;
@@ -2342,10 +2302,7 @@ model_thumbnail_changed_cb (GtkTreeModel *tree_model,
                            -1);
 
        pos = gtk_tree_path_get_indices (path)[0];
-       link = g_list_nth (self->priv->items, pos);
-       g_return_if_fail (link != NULL);
-
-       item = GTH_GRID_VIEW_ITEM (link->data);
+       item = g_ptr_array_index (self->priv->itemv, pos);
        gth_grid_view_item_set_thumbnail (item, thumbnail);
        item->is_icon = is_icon;
 
@@ -2404,14 +2361,10 @@ _gth_grid_view_get_at_position (GthGridView      *self,
                                int               y,
                                GthGridViewItem **item_ref)
 {
-       GList *scan;
-       int    n;
+       int n;
 
-       for (scan = self->priv->items, n = 0;
-            scan != NULL;
-            scan = scan->next, n++)
-       {
-               GthGridViewItem *item = scan->data;
+       for (n = 0; n < self->priv->n_items; n++) {
+               GthGridViewItem *item = g_ptr_array_index (self->priv->itemv, n);
 
                if (_cairo_rectangle_contains_point (&item->thumbnail_area, x, y)
                    || _cairo_rectangle_contains_point (&item->caption_area, x, y))
@@ -2443,29 +2396,20 @@ gth_grid_view_cursor_changed (GthFileView *file_view,
                              int          pos)
 {
        GthGridView     *self = GTH_GRID_VIEW (file_view);
-       GList           *link;
        GthGridViewItem *new_item;
 
-       if (pos != self->priv->focused_item) {
+       if ((pos != self->priv->focused_item) && (self->priv->focused_item >= 0)) {
                GthGridViewItem *old_item = NULL;
 
-               if (self->priv->focused_item >= 0) {
-                       link = g_list_nth (self->priv->items, self->priv->focused_item);
-                       if (link != NULL)
-                               old_item = link->data;
-               }
+               old_item = g_ptr_array_index (self->priv->itemv, self->priv->focused_item);
                if (old_item != NULL) {
                        old_item->state ^= GTK_STATE_FLAG_FOCUSED | GTK_STATE_FLAG_ACTIVE;
                        _gth_grid_view_queue_draw_item (self, old_item);
                }
        }
 
-       link = g_list_nth (self->priv->items, pos);
-       g_return_if_fail (link != NULL);
-
        self->priv->focused_item = pos;
-
-       new_item = link->data;
+       new_item = g_ptr_array_index (self->priv->itemv, pos);
        new_item->state |= GTK_STATE_FLAG_FOCUSED | GTK_STATE_FLAG_ACTIVE;
        _gth_grid_view_queue_draw_item (self, new_item);
 
@@ -2603,7 +2547,7 @@ gth_grid_view_set_drag_dest_pos (GthFileView    *file_view,
                        drop_pos = GTH_DROP_POSITION_RIGHT;
                }
                else {
-                       GthGridViewItem *item = g_list_nth (self->priv->items, drop_image)->data;
+                       GthGridViewItem *item = g_ptr_array_index (self->priv->itemv, drop_image);
                        if (x - item->area.x > self->priv->cell_size / 2)
                                drop_pos = GTH_DROP_POSITION_RIGHT;
                        else
@@ -2661,8 +2605,7 @@ _gth_grid_view_select_range (GthGridView     *self,
                             GthGridViewItem *item,
                             int              pos)
 {
-       int    a, b;
-       GList *scan;
+       int a, b;
 
        if (self->priv->last_selected_pos == -1)
                self->priv->last_selected_pos = pos;
@@ -2676,11 +2619,8 @@ _gth_grid_view_select_range (GthGridView     *self,
                b = pos;
        }
 
-       for (scan = g_list_nth (self->priv->items, a);
-            (a <= b) && (scan != NULL);
-            a++, scan = scan->next)
-       {
-               GthGridViewItem *item = scan->data;
+       for (/* void */; a <= b; a++) {
+               GthGridViewItem *item = g_ptr_array_index (self->priv->itemv, a);
 
                if (! (item->state & GTK_STATE_FLAG_SELECTED))
                        _gth_grid_view_set_item_selected (self, TRUE, a);
@@ -2751,10 +2691,10 @@ _gth_grid_view_select_multiple (GthGridView     *self,
 static void
 gth_grid_view_store_items_state (GthGridView *self)
 {
-       GList *scan;
+       int i;
 
-       for (scan = self->priv->items; scan; scan = scan->next) {
-               GthGridViewItem *item = scan->data;
+       for (i = 0; i < self->priv->n_items; i++) {
+               GthGridViewItem *item = g_ptr_array_index (self->priv->itemv, i);
                item->tmp_state = item->state;
        }
 }
@@ -2898,7 +2838,6 @@ _gth_grid_view_update_mouse_selection (GthGridView *self,
        gboolean               additive;
        gboolean               invert;
        int                    min_y, max_y;
-       GList                 *l, *begin, *end;
        int                    i, begin_idx, end_idx;
 
        old_selection_area = self->priv->selection_area;
@@ -2973,13 +2912,9 @@ _gth_grid_view_update_mouse_selection (GthGridView *self,
        max_y = self->priv->selection_area.y + self->priv->selection_area.height;
 
        begin_idx = get_first_visible_at_offset (self, min_y);
-       begin = g_list_nth (self->priv->items, begin_idx);
-
        end_idx = get_last_visible_at_offset (self, max_y);
-       end = g_list_nth (self->priv->items, end_idx);
-
-       if (end != NULL)
-               end = end->next;
+       if ((begin_idx == -1) || (end_idx == -1))
+               return;
 
        gdk_window_freeze_updates (self->priv->bin_window);
 
@@ -2988,8 +2923,8 @@ _gth_grid_view_update_mouse_selection (GthGridView *self,
        x2 = x1 + self->priv->selection_area.width;
        y2 = y1 + self->priv->selection_area.height;
 
-       for (l = begin, i = begin_idx; l != end; l = l->next, i++) {
-               GthGridViewItem *item = l->data;
+       for (i = begin_idx; i <= end_idx; i++) {
+               GthGridViewItem *item = g_ptr_array_index (self->priv->itemv, i);
                gboolean         selection_changed;
 
                selection_changed = (item->state & GTK_STATE_FLAG_SELECTED) != (item->tmp_state & 
GTK_STATE_FLAG_SELECTED);
@@ -3226,26 +3161,19 @@ static void
 select_range_with_keyboard (GthGridView *self,
                            int          next_focused_item)
 {
-       int    begin_idx;
-       int    end_idx;
-       GList *begin;
-       GList *end;
-       int    i;
-       GList *link;
+       int begin_idx;
+       int end_idx;
+       int i;
 
        if (self->priv->focused_item == -1)
                return;
 
        begin_idx = MIN (MIN (self->priv->first_focused_item, self->priv->focused_item), next_focused_item);
        end_idx = MAX (MAX (self->priv->first_focused_item, self->priv->focused_item), next_focused_item);
-       begin = g_list_nth (self->priv->items, begin_idx);
-       end = g_list_nth (self->priv->items, end_idx);
-       if (end != NULL)
-               end = end->next;
 
        gdk_window_freeze_updates (self->priv->bin_window);
 
-       for (link = begin, i = begin_idx; link != end; link = link->next, i++) {
+       for (i = begin_idx; i <= end_idx; i++) {
                if (next_focused_item > self->priv->first_focused_item) {
                        if ((i >= self->priv->first_focused_item) && (i <= next_focused_item))
                                _gth_grid_view_select_item (self, i);
@@ -3270,14 +3198,10 @@ static GList *
 _gth_grid_view_get_line_at_position (GthGridView *self,
                                     int          pos)
 {
-       GList           *link;
        GthGridViewItem *item;
        GList           *scan;
 
-       link = g_list_nth (self->priv->items, pos);
-       g_return_val_if_fail (link != NULL, NULL);
-
-       item = link->data;
+       item = g_ptr_array_index (self->priv->itemv, pos);
        for (scan = self->priv->lines; scan; scan = scan->next) {
                GthGridViewLine *line = scan->data;
 
@@ -3420,7 +3344,7 @@ gth_grid_view_select_cursor_item (GthGridView *self)
        if (self->priv->focused_item == -1)
                return FALSE;
 
-       item = g_list_nth (self->priv->items, self->priv->focused_item)->data;
+       item = g_ptr_array_index (self->priv->itemv, self->priv->focused_item);
        g_return_val_if_fail (item != NULL, FALSE);
 
        _gth_grid_view_unselect_all (self, item);
@@ -3435,16 +3359,12 @@ gth_grid_view_select_cursor_item (GthGridView *self)
 static gboolean
 gth_grid_view_toggle_cursor_item (GthGridView *self)
 {
-       GList           *link;
        GthGridViewItem *item;
 
        if (self->priv->focused_item == -1)
                return FALSE;
 
-       link = g_list_nth (self->priv->items, self->priv->focused_item);
-       g_return_val_if_fail (link != NULL, FALSE);
-
-       item = link->data;
+       item = g_ptr_array_index (self->priv->itemv, self->priv->focused_item);
        if (item->state & GTK_STATE_FLAG_SELECTED)
                _gth_grid_view_unselect_item (self, self->priv->focused_item);
        else
@@ -3558,7 +3478,7 @@ static void
 _gth_grid_view_set_caption (GthGridView *self,
                            const char  *attributes)
 {
-       GList *scan;
+       int i;
 
        g_free (self->priv->caption_attributes);
        self->priv->caption_attributes = g_strdup (attributes);
@@ -3572,8 +3492,10 @@ _gth_grid_view_set_caption (GthGridView *self,
 
        self->priv->no_caption = (self->priv->caption_attributes_v == NULL) || 
(self->priv->caption_attributes_v[0] == NULL) || (g_strcmp0 (self->priv->caption_attributes_v[0], "none") == 
0);
 
-       for (scan = self->priv->items; scan; scan = scan->next)
-               gth_grid_view_item_update_caption (GTH_GRID_VIEW_ITEM (scan->data), 
self->priv->caption_attributes_v);
+       for (i = 0; i < self->priv->n_items; i++) {
+               GthGridViewItem *item = g_ptr_array_index (self->priv->itemv, i);
+               gth_grid_view_item_update_caption (item, self->priv->caption_attributes_v);
+       }
        self->priv->update_caption_height = TRUE;
 
        g_object_notify (G_OBJECT (self), "caption");
@@ -3908,7 +3830,7 @@ gth_grid_view_init (GthGridView *self)
        self->priv = gth_grid_view_get_instance_private (self);
 
        /* self->priv->model = NULL; */
-       self->priv->items = NULL;
+       self->priv->itemv = g_ptr_array_new_with_free_func ((GDestroyNotify) gth_grid_view_item_unref);
        self->priv->n_items = 0;
        self->priv->lines = NULL;
        self->priv->selection = NULL;