pcsx2/3rdparty/wxwidgets3.0/include/wx/generic/private/widthcalc.h

124 lines
4.2 KiB
C
Raw Normal View History

/////////////////////////////////////////////////////////////////////////////
// Name: wx/generic/private/widthcalc.h
// Purpose: wxMaxWidthCalculatorBase helper class.
// Author: Václav Slavík, Kinaou Hervé
// Copyright: (c) 2015 wxWidgets team
// Licence: wxWindows licence
/////////////////////////////////////////////////////////////////////////////
#ifndef _WX_GENERIC_PRIVATE_WIDTHCALC_H_
#define _WX_GENERIC_PRIVATE_WIDTHCALC_H_
#include "wx/defs.h"
#if wxUSE_DATAVIEWCTRL || wxUSE_LISTCTRL
#include "wx/log.h"
#include "wx/timer.h"
// ----------------------------------------------------------------------------
// wxMaxWidthCalculatorBase: base class for calculating max column width
// ----------------------------------------------------------------------------
class wxMaxWidthCalculatorBase
{
public:
// column of which calculate the width
explicit wxMaxWidthCalculatorBase(size_t column)
: m_column(column),
m_width(0)
{
}
void UpdateWithWidth(int width)
{
m_width = wxMax(m_width, width);
}
// Update the max with for the expected row
virtual void UpdateWithRow(int row) = 0;
int GetMaxWidth() const { return m_width; }
size_t GetColumn() const { return m_column; }
void
ComputeBestColumnWidth(size_t count,
size_t first_visible,
size_t last_visible)
{
// The code below deserves some explanation. For very large controls, we
// simply can't afford to calculate sizes for all items, it takes too
// long. So the best we can do is to check the first and the last N/2
// items in the control for some sufficiently large N and calculate best
// sizes from that. That can result in the calculated best width being too
// small for some outliers, but it's better to get slightly imperfect
// result than to wait several seconds after every update. To avoid highly
// visible miscalculations, we also include all currently visible items
// no matter what. Finally, the value of N is determined dynamically by
// measuring how much time we spent on the determining item widths so far.
#if wxUSE_STOPWATCH
size_t top_part_end = count;
static const long CALC_TIMEOUT = 20/*ms*/;
// don't call wxStopWatch::Time() too often
static const unsigned CALC_CHECK_FREQ = 100;
wxStopWatch timer;
#else
// use some hard-coded limit, that's the best we can do without timer
size_t top_part_end = wxMin(500, count);
#endif // wxUSE_STOPWATCH/!wxUSE_STOPWATCH
size_t row = 0;
for ( row = 0; row < top_part_end; row++ )
{
#if wxUSE_STOPWATCH
if ( row % CALC_CHECK_FREQ == CALC_CHECK_FREQ-1 &&
timer.Time() > CALC_TIMEOUT )
break;
#endif // wxUSE_STOPWATCH
UpdateWithRow(row);
}
// row is the first unmeasured item now; that's our value of N/2
if ( row < count )
{
top_part_end = row;
// add bottom N/2 items now:
const size_t bottom_part_start = wxMax(row, count - row);
for ( row = bottom_part_start; row < count; row++ )
{
UpdateWithRow(row);
}
// finally, include currently visible items in the calculation:
first_visible = wxMax(first_visible, top_part_end);
last_visible = wxMin(bottom_part_start, last_visible);
for ( row = first_visible; row < last_visible; row++ )
{
UpdateWithRow(row);
}
wxLogTrace("items container",
"determined best size from %zu top, %zu bottom "
"plus %zu more visible items out of %zu total",
top_part_end,
count - bottom_part_start,
wxMax(0, last_visible - first_visible),
count);
}
}
private:
const size_t m_column;
int m_width;
wxDECLARE_NO_COPY_CLASS(wxMaxWidthCalculatorBase);
};
#endif // wxUSE_DATAVIEWCTRL || wxUSE_LISTCTRL
#endif // _WX_GENERIC_PRIVATE_WIDTHCALC_H_