bool
LargeTextWindow::OnKeyCheck(unsigned key_code) const
{
switch (key_code) {
case KEY_UP:
return origin > 0;
case KEY_DOWN:
return GetRowCount() > GetVisibleRows() &&
origin < GetRowCount() - GetVisibleRows();
}
return false;
}
void
LargeTextWindow::OnResize(PixelSize new_size)
{
Window::OnResize(new_size);
if (!value.empty()) {
/* revalidate the scroll position */
const unsigned visible_rows = GetVisibleRows();
const unsigned row_count = GetRowCount();
if (visible_rows >= row_count)
origin = 0;
else if (origin > row_count - visible_rows)
origin = row_count - visible_rows;
Invalidate();
}
}
void
LargeTextWindow::ScrollVertically(int delta_lines)
{
const unsigned visible_rows = GetVisibleRows();
const unsigned row_count = GetRowCount();
if (visible_rows >= row_count)
/* all rows are visible at a time, no scrolling needed/possible */
return;
unsigned new_origin = origin + delta_lines;
if ((int)new_origin < 0)
new_origin = 0;
else if (new_origin > row_count - visible_rows)
new_origin = row_count - visible_rows;
if (new_origin != origin) {
origin = new_origin;
Invalidate();
}
}
