/// <summary>
/// Raises the Layout event.
/// </summary>
/// <param name="e">A LayoutEventArgs that contains the event data.</param>
protected override void OnLayout(LayoutEventArgs e)
{
// Call the base class's method so that registered delegates receive the event.
base.OnLayout(e);
// If we have no parent, no layout is required.
if (Parent == null)
{
return;
}
// Layout the command bar lightweight controls. The return is the column layout rectangle.
Rectangle columnLayoutRectangle = LayoutCommandBars();
// Set the initial (to be adjusted below) column widths.
int leftColumnWidth = LeftColumnPreferredWidth;
int centerColumnWidth = CenterColumnMinimumWidth;
int rightColumnWidth = RightColumnPreferredWidth;
// Adjust the column widths as needed for the layout width.
if (leftColumnWidth + centerColumnWidth + rightColumnWidth > columnLayoutRectangle.Width)
{
// Calculate the width that is available to the left and right columns.
int availableWidth = columnLayoutRectangle.Width - centerColumnWidth;
// Adjust the left and right column widths.
if (LeftColumnVisible && RightColumnVisible)
{
// Calculate the relative width of the left column.
double leftColumnRelativeWidth = ((double)leftColumnWidth) / (leftColumnWidth + rightColumnWidth);
// Adjust the left and right column widths.
leftColumnWidth = Math.Max((int)(leftColumnRelativeWidth * availableWidth), LeftColumnMinimumWidth);
rightColumnWidth = Math.Max(availableWidth - leftColumnWidth, RightColumnMinimumWidth);
}
else if (LeftColumnVisible)
{
// Only the left column is visible, so it gets all the available width.
leftColumnWidth = Math.Max(availableWidth, LeftColumnMinimumWidth);
}
else if (RightColumnVisible)
{
// Only the right column is visible, so it gets all the available width.
rightColumnWidth = Math.Max(availableWidth, RightColumnMinimumWidth);
}
}
else
{
// We have a surplus of room. Allocate additional space to the center column, if
// if is visible, or the left column if it is not.
if (CenterColumnVisible)
{
centerColumnWidth = columnLayoutRectangle.Width - (leftColumnWidth + rightColumnWidth);
}
else
{
leftColumnWidth = columnLayoutRectangle.Width - rightColumnWidth;
}
}
// Set the layout X offset.
int layoutX = columnLayoutRectangle.X;
// Layout the left column, if it is visible.
if (LeftColumnVisible)
{
// Set the virtual bounds of the left column.
leftColumn.VirtualBounds = new Rectangle(layoutX,
columnLayoutRectangle.Y,
leftColumnWidth,
columnLayoutRectangle.Height);
leftColumn.PerformLayout();
// Adjust the layout X to account for the left column.
layoutX += leftColumnWidth;
// Update the left column vertical splitter and maximum column width.
if (CenterColumnVisible)
{
// Turn on the left column vertical splitter on the right side.
leftColumn.VerticalSplitterStyle = VerticalSplitterStyle.Right;
// Set the left column's maximum width.
leftColumn.MaximumColumnWidth = columnLayoutRectangle.Width -
(CenterColumnMinimumWidth + this.RightColumnPreferredWidth);
}
else
{
leftColumn.VerticalSplitterStyle = VerticalSplitterStyle.None;
leftColumn.MaximumColumnWidth = 0;
}
}
// Layout the center column.
if (CenterColumnVisible)
{
// Set the virtual bounds of the center column.
centerColumn.VirtualBounds = new Rectangle(layoutX,
columnLayoutRectangle.Y,
centerColumnWidth,
columnLayoutRectangle.Height);
centerColumn.PerformLayout();
// Adjust the layout X to account for the center column.
layoutX += centerColumnWidth;
// The center column never has a vertical splitter or a maximum column width.
centerColumn.VerticalSplitterStyle = VerticalSplitterStyle.None;
centerColumn.MaximumColumnWidth = 0;
}
// Layout the right column.
if (RightColumnVisible)
{
// Set the virtual bounds of the right column.
rightColumn.VirtualBounds = new Rectangle(layoutX,
columnLayoutRectangle.Y,
rightColumnWidth,
columnLayoutRectangle.Height);
rightColumn.PerformLayout();
// Update the right column vertical splitter and maximum column width.
if (CenterColumnVisible || LeftColumnVisible)
{
// Turn on the right column's vertical splitter on the left side.
rightColumn.VerticalSplitterStyle = VerticalSplitterStyle.Left;
// Set the right column's maximum width.
rightColumn.MaximumColumnWidth = columnLayoutRectangle.Width -
(LeftColumnPreferredWidth + CenterColumnMinimumWidth);
}
else
{
rightColumn.VerticalSplitterStyle = VerticalSplitterStyle.None;
rightColumn.MaximumColumnWidth = 0;
}
}
}
