internal void SetSelectionStartItem(Point p)
{
//清除其他的选择状态
this.Clear();
MessageListItem item = _owner.GetItemAtPosition(p) as MessageListItem;
if (item == null)
{
return;
}
//设定文本选中
if (item.Message.Type == MessageType.Text)
{
this._selectingTextItem = item;
Rectangle rect = item.Bounds;
for (int i = 0; i < this._selectingTextItem.DrawingObjects.Count; i++)
{
DrawingObject dobj = item.DrawingObjects[i];
if (dobj.Type == DrawingObjectType.TextBlock)
{
Rectangle bounds = dobj.Offset(rect.X, rect.Y);
if (bounds.Contains(p))
{
TextBlockObj tb = dobj.Tag as TextBlockObj;
StringPart sp = tb.StringPart;
using (Graphics g = _owner.CreateGraphics())
{
tb.SelectionStart = StringMeasurer.GetCharIndex(g, sp.Font, p.X - (int)dobj.X, sp.String);
this._selectStartDoIndex = i;
break;
}
}
}
}
}
}
internal void SetSelectionEndItem(Point location)
{
if (!this.HasSelection)
{
return;
}
MessageListItem hoverItem = _owner.GetItemAtPosition(location) as MessageListItem;
if (hoverItem == null)
{
//鼠标移动到其他地方了，算了，不选了
this.Clear();
return;
}
if (hoverItem != this._selectingTextItem)
{
//当前的选择的不是上面一个
this.Clear();
return;
}
Rectangle rect = this._selectingTextItem.Bounds;
for (int i = 0; i < this._selectingTextItem.DrawingObjects.Count; i++)
{
DrawingObject dobj = this._selectingTextItem.DrawingObjects[i];
if (dobj.Type == DrawingObjectType.TextBlock)
{
Rectangle bounds = dobj.Offset(rect.X, rect.Y);
TextBlockObj tb = dobj.Tag as TextBlockObj;
if (bounds.Contains(location))
{
StringPart sp = tb.StringPart;
using (Graphics g = _owner.CreateGraphics())
{
tb.SelectionEnd = StringMeasurer.GetCharIndex(g, sp.Font, location.X - (int)dobj.X, sp.String);
this._selectEndDoIndex = i;
break;
}
}
}
}
//开始与结束直接的所有TextBlock都设定为全选中
int startIndex = Math.Min(this._selectStartDoIndex, this._selectEndDoIndex);
int endIndex = Math.Max(this._selectStartDoIndex, this._selectEndDoIndex);
List <TextBlockObj> selObj = new List <TextBlockObj>();
for (int i = startIndex; i <= endIndex; i++)
{
DrawingObject dobj = this._selectingTextItem.DrawingObjects[i];
if (dobj.Type == DrawingObjectType.TextBlock)
{
TextBlockObj tbObj = dobj.Tag as TextBlockObj;
if (this._selectStartDoIndex < this._selectEndDoIndex)
{
//从上往下选择时
if (i == this._selectStartDoIndex)
{
tbObj.SelectionEnd = tbObj.Length - 1;
}
else if (i == this._selectEndDoIndex)
{
tbObj.SelectionStart = 0;
}
}
else if (this._selectStartDoIndex > this._selectEndDoIndex)
{
//从下往上选择时
if (i == this._selectStartDoIndex)
{
tbObj.SelectionEnd = 0;
}
else if (i == this._selectEndDoIndex)
{
tbObj.SelectionStart = tbObj.Length - 1;
}
}
if (i != this._selectStartDoIndex && i != this._selectEndDoIndex)
{
tbObj.SelectAll();
}
selObj.Add(tbObj);
this._prevSelection.Remove(tbObj);
}
}
//清除选择
foreach (TextBlockObj item in this._prevSelection)
{
item.ClearSelection();
}
this._prevSelection = selObj;
}