add: updatePreviewBox(panel, 1<<section);
context: textureDoubleClick(WMWidget *w, void *data){    _Panel *panel = (_Panel*)data;    int i, section;    WMListItem *item;    TextureListItem *titem;    char *str;    /* unselect old texture */    section = WMGetPopUpButtonSelectedItem(panel->secP);    item = WMGetListItem(panel->texLs, panel->textureIndex[section]);    titem = (TextureListItem*)item->clientData;    titem->selectedFor &= ~(1 << section);    /* select new texture */    i = WMGetListSelectedItemRow(panel->texLs);    item = WMGetListItem(panel->texLs, i);    titem = (TextureListItem*)item->clientData;    titem->selectedFor |= 1<<section;    panel->textureIndex[section] = i;    WMRedisplayWidget(panel->texLs);    str = wmalloc(strlen(titem->title) + strlen(titem->texture) + 4);    sprintf(str, "%s: %s", titem->title, titem->texture);    WMSetLabelText(panel->texsL, str);    free(str);}