+unsigned int wxDataViewCtrl::GetBestColumnWidth(int idx) const
+{
+ if ( m_colsBestWidths[idx] != 0 )
+ return m_colsBestWidths[idx];
+
+ const int count = m_clientArea->GetRowCount();
+ wxDataViewColumn *column = GetColumn(idx);
+ wxDataViewRenderer *renderer =
+ const_cast<wxDataViewRenderer*>(column->GetRenderer());
+
+ class MaxWidthCalculator
+ {
+ public:
+ MaxWidthCalculator(wxDataViewMainWindow *clientArea,
+ wxDataViewRenderer *renderer,
+ const wxDataViewModel *model,
+ unsigned column)
+ : m_width(0),
+ m_clientArea(clientArea),
+ m_renderer(renderer),
+ m_model(model),
+ m_column(column)
+ {
+ }
+
+ void UpdateWithWidth(int width)
+ {
+ m_width = wxMax(m_width, width);
+ }
+
+ void UpdateWithRow(int row)
+ {
+ wxDataViewItem item = m_clientArea->GetItemByRow(row);
+ m_renderer->PrepareForItem(m_model, item, m_column);
+ m_width = wxMax(m_width, m_renderer->GetSize().x);
+ }
+
+ int GetMaxWidth() const { return m_width; }
+
+ private:
+ int m_width;
+ wxDataViewMainWindow *m_clientArea;
+ wxDataViewRenderer *m_renderer;
+ const wxDataViewModel *m_model;
+ unsigned m_column;
+ };
+
+ MaxWidthCalculator calculator(m_clientArea, renderer,
+ GetModel(), column->GetModelColumn());
+
+ if ( m_headerArea )
+ {
+ int header_width = m_headerArea->GetTextExtent(column->GetTitle()).x;
+ // Labels on native MSW header are indented on both sides
+ header_width +=
+ wxRendererNative::Get().GetHeaderButtonMargin(m_headerArea);
+ calculator.UpdateWithWidth(header_width);
+ }
+
+ // 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
+ int 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
+ int top_part_end = wxMin(500, count);
+#endif // wxUSE_STOPWATCH/!wxUSE_STOPWATCH
+
+ int 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
+ calculator.UpdateWithRow(row);
+ }
+
+ // row is the first unmeasured item now; that's out value of N/2
+
+ if ( row < count )
+ {
+ top_part_end = row;
+
+ // add bottom N/2 items now:
+ const int bottom_part_start = wxMax(row, count - row);
+ for ( row = bottom_part_start; row < count; row++ )
+ {
+ calculator.UpdateWithRow(row);
+ }
+
+ // finally, include currently visible items in the calculation:
+ const wxPoint origin = CalcUnscrolledPosition(wxPoint(0, 0));
+ int first_visible = m_clientArea->GetLineAt(origin.y);
+ int last_visible = m_clientArea->GetLineAt(origin.y + GetClientSize().y);
+
+ first_visible = wxMax(first_visible, top_part_end);
+ last_visible = wxMin(bottom_part_start, last_visible);
+
+ for ( row = first_visible; row < last_visible; row++ )
+ {
+ calculator.UpdateWithRow(row);
+ }
+
+ wxLogTrace("dataview",
+ "determined best size from %d top, %d bottom plus %d more visible items out of %d total",
+ top_part_end,
+ count - bottom_part_start,
+ wxMax(0, last_visible - first_visible),
+ count);
+ }
+
+ int max_width = calculator.GetMaxWidth();
+ if ( max_width > 0 )
+ max_width += 2 * PADDING_RIGHTLEFT;
+
+ const_cast<wxDataViewCtrl*>(this)->m_colsBestWidths[idx] = max_width;
+ return max_width;
+
+ #undef MEASURE_ITEM
+}
+
projects / wxWidgets.git / blobdiff