[PATCH 4/5] comctl32/listbox: Implement LBS_NODATA for single-selection listboxes

Gabriel Iv─âncescu gabrielopcode at gmail.com
Fri Feb 8 06:41:45 CST 2019


The LBS_NODATA style's purpose is to drastically improve performance and
memory usage on very large lists, since they should function as virtual
lists. Thus, don't store any data for single-selection listboxes (descr->items
always NULL).

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=32374
Signed-off-by: Gabriel Iv─âncescu <gabrielopcode at gmail.com>
---

Most of the changes are just indentation in InsertItem/RemoveItem.

 dlls/comctl32/listbox.c | 140 ++++++++++++++++++++++++++--------------
 1 file changed, 90 insertions(+), 50 deletions(-)

diff --git a/dlls/comctl32/listbox.c b/dlls/comctl32/listbox.c
index d115617..fd3bfa6 100644
--- a/dlls/comctl32/listbox.c
+++ b/dlls/comctl32/listbox.c
@@ -19,7 +19,7 @@
  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  *
  * TODO:
- *    - LBS_NODATA
+ *    - LBS_NODATA for multi-selection listboxes
  */
 
 #include <string.h>
@@ -154,6 +154,12 @@ static BOOL is_item_selected( const LB_DESCR *descr, UINT index )
     return descr->items[index].selected;
 }
 
+static BOOL is_singlesel_NODATA(const LB_DESCR *descr)
+{
+    return (descr->style & LBS_NODATA) &&
+           !(descr->style & (LBS_MULTIPLESEL | LBS_EXTENDEDSEL));
+}
+
 /***********************************************************************
  *           LISTBOX_GetCurrentPageSize
  *
@@ -547,6 +553,7 @@ static void LISTBOX_PaintItem( LB_DESCR *descr, HDC hdc, const RECT *rect,
         GetClientRect(descr->self, &r);
         hrgn = set_control_clipping( hdc, &r );
 
+        if (is_singlesel_NODATA(descr)) item = NULL;
         dis.CtlType      = ODT_LISTBOX;
         dis.CtlID        = GetWindowLongPtrW( descr->self, GWLP_ID );
         dis.hwndItem     = descr->self;
@@ -709,8 +716,15 @@ static LRESULT LISTBOX_InitStorage( LB_DESCR *descr, INT nb_items )
 {
     UINT new_size = descr->nb_items + nb_items;
 
-    if (new_size > descr->items_size && !resize_storage(descr, new_size))
-        return LB_ERRSPACE;
+    /* Windows keeps track of (unaligned) reserved space
+       for LBS_NODATA, despite the fact it is useless */
+    if (new_size > descr->items_size)
+    {
+        if (is_singlesel_NODATA(descr))
+            descr->items_size = new_size;
+        else if (!resize_storage(descr, new_size))
+            return LB_ERRSPACE;
+    }
     return descr->items_size;
 }
 
@@ -1460,10 +1474,13 @@ static LRESULT LISTBOX_SetSelection( LB_DESCR *descr, INT index,
     {
         INT oldsel = descr->selected_item;
         if (index == oldsel) return LB_OKAY;
-        if (oldsel != -1) descr->items[oldsel].selected = FALSE;
-        if (index != -1) descr->items[index].selected = TRUE;
-        if (oldsel != -1) LISTBOX_RepaintItem( descr, oldsel, ODA_SELECT );
+        if (!(descr->style & LBS_NODATA))
+        {
+            if (oldsel != -1) descr->items[oldsel].selected = FALSE;
+            if (index != -1) descr->items[index].selected = TRUE;
+        }
         descr->selected_item = index;
+        if (oldsel != -1) LISTBOX_RepaintItem( descr, oldsel, ODA_SELECT );
         if (index != -1) LISTBOX_RepaintItem( descr, index, ODA_SELECT );
         if (send_notify && descr->nb_items) SEND_NOTIFICATION( descr,
                                (index != -1) ? LBN_SELCHANGE : LBN_SELCANCEL );
@@ -1535,36 +1552,42 @@ static LRESULT LISTBOX_InsertItem( LB_DESCR *descr, INT index,
 
     if (index == -1) index = descr->nb_items;
     else if ((index < 0) || (index > descr->nb_items)) return LB_ERR;
-    if (!resize_storage(descr, descr->nb_items + 1)) return LB_ERR;
-
-    /* Insert the item structure */
-
-    item = &descr->items[index];
-    if (index < descr->nb_items)
-        RtlMoveMemory( item + 1, item,
-                       (descr->nb_items - index) * sizeof(LB_ITEMDATA) );
-    item->str      = str;
-    item->data     = HAS_STRINGS(descr) ? 0 : data;
-    item->height   = 0;
-    item->selected = FALSE;
-    descr->nb_items++;
-
-    /* Get item height */
-
-    if (descr->style & LBS_OWNERDRAWVARIABLE)
+    if (is_singlesel_NODATA(descr))
     {
-        MEASUREITEMSTRUCT mis;
-        UINT id = (UINT)GetWindowLongPtrW( descr->self, GWLP_ID );
+        descr->nb_items++;
+        descr->items_size = max(descr->items_size, descr->nb_items);
+    }
+    else
+    {
+        if (!resize_storage(descr, descr->nb_items + 1)) return LB_ERR;
+
+        /* Insert the item structure */
+        item = &descr->items[index];
+        if (index < descr->nb_items)
+            RtlMoveMemory( item + 1, item,
+                           (descr->nb_items - index) * sizeof(LB_ITEMDATA) );
+        item->str      = str;
+        item->data     = HAS_STRINGS(descr) ? 0 : data;
+        item->height   = 0;
+        item->selected = FALSE;
+        descr->nb_items++;
+
+        /* Get item height */
+        if (descr->style & LBS_OWNERDRAWVARIABLE)
+        {
+            MEASUREITEMSTRUCT mis;
+            UINT id = (UINT)GetWindowLongPtrW( descr->self, GWLP_ID );
 
-        mis.CtlType    = ODT_LISTBOX;
-        mis.CtlID      = id;
-        mis.itemID     = index;
-        mis.itemData   = data;
-        mis.itemHeight = descr->item_height;
-        SendMessageW( descr->owner, WM_MEASUREITEM, id, (LPARAM)&mis );
-        item->height = mis.itemHeight ? mis.itemHeight : 1;
-        TRACE("[%p]: measure item %d (%s) = %d\n",
-              descr->self, index, str ? debugstr_w(str) : "", item->height );
+            mis.CtlType    = ODT_LISTBOX;
+            mis.CtlID      = id;
+            mis.itemID     = index;
+            mis.itemData   = data;
+            mis.itemHeight = descr->item_height;
+            SendMessageW( descr->owner, WM_MEASUREITEM, id, (LPARAM)&mis );
+            item->height = mis.itemHeight ? mis.itemHeight : 1;
+            TRACE("[%p]: measure item %d (%s) = %d\n",
+                  descr->self, index, str ? debugstr_w(str) : "", item->height );
+        }
     }
 
     /* Repaint the items */
@@ -1678,19 +1701,29 @@ static LRESULT LISTBOX_RemoveItem( LB_DESCR *descr, INT index )
     LISTBOX_InvalidateItems( descr, index );
 
     descr->nb_items--;
-    LISTBOX_DeleteItem( descr, index );
-
-    if (!descr->nb_items) return LB_OKAY;
+    if (is_singlesel_NODATA(descr))
+    {
+        if (!descr->nb_items)
+        {
+            SendMessageW(descr->self, LB_RESETCONTENT, 0, 0);
+            return LB_OKAY;
+        }
+    }
+    else
+    {
+        LISTBOX_DeleteItem( descr, index );
 
-    /* Remove the item */
+        if (!descr->nb_items) return LB_OKAY;
 
-    item = &descr->items[index];
-    if (index < descr->nb_items)
-        RtlMoveMemory( item, item + 1,
-                       (descr->nb_items - index) * sizeof(LB_ITEMDATA) );
-    if (descr->anchor_item == descr->nb_items) descr->anchor_item--;
+        /* Remove the item */
+        item = &descr->items[index];
+        if (index < descr->nb_items)
+            RtlMoveMemory( item, item + 1,
+                           (descr->nb_items - index) * sizeof(LB_ITEMDATA) );
 
-    resize_storage(descr, descr->nb_items);
+        resize_storage(descr, descr->nb_items);
+    }
+    descr->anchor_item = min(descr->anchor_item, descr->nb_items - 1);
 
     /* Repaint the items */
 
@@ -1729,7 +1762,8 @@ static void LISTBOX_ResetContent( LB_DESCR *descr )
 {
     INT i;
 
-    for(i = descr->nb_items - 1; i>=0; i--) LISTBOX_DeleteItem( descr, i);
+    if (descr->items)
+        for (i = descr->nb_items - 1; i >= 0; i--) LISTBOX_DeleteItem(descr, i);
     HeapFree( GetProcessHeap(), 0, descr->items );
     descr->nb_items      = 0;
     descr->top_item      = 0;
@@ -1752,9 +1786,14 @@ static LRESULT LISTBOX_SetCount( LB_DESCR *descr, UINT count )
 
     if (count > orig_num)
     {
-        if (!resize_storage(descr, count))
-            return LB_ERRSPACE;
-        memset(&descr->items[orig_num], 0, (count - orig_num) * sizeof(LB_ITEMDATA));
+        if (descr->style & (LBS_MULTIPLESEL | LBS_EXTENDEDSEL))
+        {
+            if (!resize_storage(descr, count))
+                return LB_ERRSPACE;
+            memset(&descr->items[orig_num], 0, (count - orig_num) * sizeof(LB_ITEMDATA));
+        }
+        else
+            descr->items_size = max(descr->items_size, count);
         descr->nb_items = count;
 
         LISTBOX_UpdateScroll(descr);
@@ -1773,8 +1812,9 @@ static LRESULT LISTBOX_SetCount( LB_DESCR *descr, UINT count )
         {
             descr->anchor_item = min(descr->anchor_item, count - 1);
 
-            resize_storage(descr, count);
-            if (descr->selected_item >= count)
+            if (descr->style & (LBS_MULTIPLESEL | LBS_EXTENDEDSEL))
+                resize_storage(descr, count);
+            else if (descr->selected_item >= descr->nb_items)
                 descr->selected_item = -1;
 
             LISTBOX_UpdateScroll(descr);
-- 
2.19.1




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