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add a listbox::scroll() to scroll the view to the top or bottom

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This commit is contained in:
Jinhao
2015-11-04 01:21:35 +08:00
parent 29eddaa97f
commit 9844792c54
2 changed files with 85 additions and 3 deletions
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83
source/gui/widgets/listbox.cpp
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@@ -848,6 +848,8 @@ namespace nana
return sorted_reverse_;
}
void scroll(const index_pair& pos, bool to_bottom);
///Append a new category with a specified name and return a pointer to it.
category_t* create_cat(nana::string&& text)
{
@@ -2405,6 +2407,54 @@ namespace nana
std::vector<std::pair<index_type, essence_t::inline_pane*>> panes_;
};
void es_lister::scroll(const index_pair& pos, bool to_bottom)
{
auto& cat = *get(pos.cat);
if ((pos.item != ::nana::npos) && (pos.item >= cat.items.size()))
throw std::invalid_argument("listbox: invalid pos to scroll");
if (!cat.expand)
{
this->expand(pos.cat, true);
ess_->adjust_scroll_life();
}
//The number of items can be displayed on screen
auto view_items = ess_->number_of_lister_items(false) - 1;
index_pair start_pos;
if (to_bottom)
{
//start_pos will be (0,0) if backward fails
backward(pos, view_items, start_pos);
}
else
{
if (forward(pos, view_items, start_pos))
start_pos = pos;
else
{
index_pair last(list_.size() - 1);
if (list_.back().expand)
{
if (list_.back().items.empty())
last.item = npos;
else
last.item = list_.back().items.size() - 1;
}
else
last.item = ::nana::npos;
backward(last, view_items, start_pos);
}
}
ess_->set_scroll_y_dpl(start_pos);
ess_->adjust_scroll_value();
}
void es_lister::erase(const index_pair& pos)
{
auto & catobj = *get(pos.cat);
@@ -4180,12 +4230,41 @@ namespace nana
_m_ess().set_auto_draw(ad);
}
void listbox::scroll(size_type cat_pos, bool to_bottom)
{
auto & ess = _m_ess();
auto cats = ess.lister.size_categ();
if (::nana::npos != cat_pos)
{
if (cat_pos >= cats)
throw std::invalid_argument("listbox: invalid category");
}
else
cat_pos = cats - 1;
index_pair pos(cat_pos);
if (to_bottom)
{
auto items = ess.lister.size_item(cat_pos);
if (0 == items)
pos.item = ::nana::npos;
else
pos.item = items - 1;
}
else
pos.item = ess.lister.size_item(cat_pos) ? 0 : ::nana::npos;
ess.lister.scroll(pos, to_bottom);
ess.update();
}
listbox::size_type listbox::append_header(nana::string text, unsigned width)
{
auto & ess = _m_ess();
listbox::size_type index = ess.header.create(std::move(text), width);
auto pos = ess.header.create(std::move(text), width);
ess.update();
return index;
return pos;
}
listbox& listbox::header_width(size_type pos, unsigned pixels)