ladybird/LibGUI/GSortingProxyModel.cpp
Andreas Kling d02238af48 LibGUI: Expand GModelIndex a bit, adding internal data and model pointers.
This will be useful for implementing more complicated models.
2019-03-29 04:58:15 +01:00

108 lines
2.8 KiB
C++

#include <LibGUI/GSortingProxyModel.h>
#include <AK/QuickSort.h>
#include <stdlib.h>
#include <stdio.h>
GSortingProxyModel::GSortingProxyModel(Retained<GModel>&& target)
: m_target(move(target))
, m_key_column(-1)
{
m_target->on_model_update = [this] (GModel&) {
resort();
};
}
GSortingProxyModel::~GSortingProxyModel()
{
}
int GSortingProxyModel::row_count(const GModelIndex& index) const
{
return target().row_count(index);
}
int GSortingProxyModel::column_count(const GModelIndex& index) const
{
return target().column_count(index);
}
GModelIndex GSortingProxyModel::map_to_target(const GModelIndex& index) const
{
if (!index.is_valid())
return { };
if (index.row() >= row_count() || index.column() >= column_count())
return { };
return target().index(m_row_mappings[index.row()], index.column());
}
String GSortingProxyModel::row_name(int index) const
{
return target().row_name(index);
}
String GSortingProxyModel::column_name(int index) const
{
return target().column_name(index);
}
GModel::ColumnMetadata GSortingProxyModel::column_metadata(int index) const
{
return target().column_metadata(index);
}
GVariant GSortingProxyModel::data(const GModelIndex& index, Role role) const
{
return target().data(map_to_target(index), role);
}
void GSortingProxyModel::activate(const GModelIndex& index)
{
target().activate(map_to_target(index));
}
void GSortingProxyModel::update()
{
target().update();
}
void GSortingProxyModel::set_key_column_and_sort_order(int column, GSortOrder sort_order)
{
if (column == m_key_column && sort_order == m_sort_order)
return;
ASSERT(column >= 0 && column < column_count());
m_key_column = column;
m_sort_order = sort_order;
resort();
}
void GSortingProxyModel::resort()
{
int previously_selected_target_row = map_to_target(selected_index()).row();
int row_count = target().row_count();
m_row_mappings.resize(row_count);
for (int i = 0; i < row_count; ++i)
m_row_mappings[i] = i;
if (m_key_column == -1)
return;
quick_sort(m_row_mappings.begin(), m_row_mappings.end(), [&] (auto row1, auto row2) -> bool {
auto data1 = target().data(target().index(row1, m_key_column), GModel::Role::Sort);
auto data2 = target().data(target().index(row2, m_key_column), GModel::Role::Sort);
if (data1 == data2)
return 0;
bool is_less_than = data1 < data2;
return m_sort_order == GSortOrder::Ascending ? is_less_than : !is_less_than;
});
if (previously_selected_target_row != -1) {
// Preserve selection.
for (int i = 0; i < row_count; ++i) {
if (m_row_mappings[i] == previously_selected_target_row) {
set_selected_index(index(i, 0));
break;
}
}
}
did_update();
}