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using System;
using System.Collections.Generic;
using System.Text;
using System.Drawing;
using Aga.Controls.Tree.NodeControls;
namespace Aga.Controls.Tree
{
public class AutoRowHeightLayout: IRowLayout
{
private DrawContext _measureContext;
private TreeViewAdv _treeView;
private List<Rectangle> _rowCache;
public AutoRowHeightLayout(TreeViewAdv treeView, int rowHeight)
{
_rowCache = new List<Rectangle>();
_treeView = treeView;
PreferredRowHeight = rowHeight;
_measureContext = new DrawContext();
_measureContext.Graphics = Graphics.FromImage(new Bitmap(1, 1));
}
private int _rowHeight;
public int PreferredRowHeight
{
get { return _rowHeight; }
set { _rowHeight = value; }
}
public int PageRowCount
{
get
{
if (_treeView.RowCount == 0)
return 0;
else
{
int pageHeight = _treeView.DisplayRectangle.Height - _treeView.ColumnHeaderHeight;
int y = 0;
for (int i = _treeView.RowCount - 1; i >= 0; i--)
{
y += GetRowHeight(i);
if (y > pageHeight)
return Math.Max(0, _treeView.RowCount - 1 - i);
}
return _treeView.RowCount;
}
}
}
public int CurrentPageSize
{
get
{
if (_treeView.RowCount == 0)
return 0;
else
{
int pageHeight = _treeView.DisplayRectangle.Height - _treeView.ColumnHeaderHeight;
int y = 0;
for (int i = _treeView.FirstVisibleRow; i < _treeView.RowCount; i++)
{
y += GetRowHeight(i);
if (y > pageHeight)
return Math.Max(0, i - _treeView.FirstVisibleRow);
}
return Math.Max(0, _treeView.RowCount - _treeView.FirstVisibleRow);
}
}
}
public Rectangle GetRowBounds(int rowNo)
{
if (rowNo >= _rowCache.Count)
{
int count = _rowCache.Count;
int y = count > 0 ? _rowCache[count - 1].Bottom : 0;
for (int i = count; i <= rowNo; i++)
{
int height = GetRowHeight(i);
_rowCache.Add(new Rectangle(0, y, 0, height));
y += height;
}
if (rowNo < _rowCache.Count - 1)
return Rectangle.Empty;
}
if (rowNo >= 0 && rowNo < _rowCache.Count)
return _rowCache[rowNo];
else
return Rectangle.Empty;
}
private int GetRowHeight(int rowNo)
{
if (rowNo < _treeView.RowMap.Count)
{
TreeNodeAdv node = _treeView.RowMap[rowNo];
if (node.Height == null)
{
int res = 0;
_measureContext.Font = _treeView.Font;
foreach (NodeControl nc in _treeView.NodeControls)
{
int h = nc.GetActualSize(node, _measureContext).Height;
if (h > res)
res = h;
}
node.Height = res;
}
return node.Height.Value;
}
else
return 0;
}
public int GetRowAt(Point point)
{
int py = point.Y - _treeView.ColumnHeaderHeight;
int y = 0;
for (int i = _treeView.FirstVisibleRow; i < _treeView.RowCount; i++)
{
int h = GetRowHeight(i);
if (py >= y && py < y + h)
return i;
else
y += h;
}
return -1;
}
public int GetFirstRow(int lastPageRow)
{
int pageHeight = _treeView.DisplayRectangle.Height - _treeView.ColumnHeaderHeight;
int y = 0;
for (int i = lastPageRow; i >= 0; i--)
{
y += GetRowHeight(i);
if (y > pageHeight)
return Math.Max(0, i + 1);
}
return 0;
}
public void ClearCache()
{
_rowCache.Clear();
}
}
}
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Philip is a Software Architect with severaly years of experience. He studied business IT in the University of Wedel, Germany, and has reached his Masters degree in 2010. Back in 2002, he started his so far best-known software PDFCreator. The second developer joined two years later and since then, both constantly improve this piece of open source software.