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// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
using System.Collections.Generic; // List<T>
using System.Collections.Specialized; // NotifyCollectionChangedAction
using System.ComponentModel; // DesignerSerializationVisibility
using System.Windows.Automation.Peers; // AutomationPeer
using System.Windows.Controls.Primitives; // GridViewRowPresenterBase
using System.Windows.Data; // Binding
using System.Windows.Input; // MouseEventArgs
using System.Windows.Media; // SolidColorBrush
using System.Diagnostics;
using MS.Internal; // Helper
namespace System.Windows.Controls
{
/// <summary>
/// GridViewHeaderRowPresenter is used within the style to denote the headers place
/// in GridView's visual tree
/// </summary>
[StyleTypedProperty(Property = "ColumnHeaderContainerStyle", StyleTargetType = typeof(GridViewColumnHeader))]
public class GridViewHeaderRowPresenter : GridViewRowPresenterBase
{
//-------------------------------------------------------------------
//
// Constructors
//
//-------------------------------------------------------------------
//-------------------------------------------------------------------
//
// Public Methods
//
//-------------------------------------------------------------------
//-------------------------------------------------------------------
//
// Public Properties
//
//-------------------------------------------------------------------
#region Public Properties
#region ColumnHeaderContainerStyle
/// <summary>
/// ColumnHeaderContainerStyleProperty DependencyProperty
/// </summary>
public static readonly DependencyProperty ColumnHeaderContainerStyleProperty =
GridView.ColumnHeaderContainerStyleProperty.AddOwner(
typeof(GridViewHeaderRowPresenter),
new FrameworkPropertyMetadata(
new PropertyChangedCallback(PropertyChanged))
);
/// <summary>
/// header container's style
/// </summary>
public Style ColumnHeaderContainerStyle
{
get { return (Style)GetValue(ColumnHeaderContainerStyleProperty); }
set { SetValue(ColumnHeaderContainerStyleProperty, value); }
}
#endregion // ColumnHeaderContainerStyle
#region ColumnHeaderTemplate
/// <summary>
/// ColumnHeaderTemplate DependencyProperty
/// </summary>
public static readonly DependencyProperty ColumnHeaderTemplateProperty =
GridView.ColumnHeaderTemplateProperty.AddOwner(
typeof(GridViewHeaderRowPresenter),
new FrameworkPropertyMetadata(
new PropertyChangedCallback(PropertyChanged))
);
/// <summary>
/// column header template
/// </summary>
public DataTemplate ColumnHeaderTemplate
{
get { return (DataTemplate)GetValue(ColumnHeaderTemplateProperty); }
set { SetValue(ColumnHeaderTemplateProperty, value); }
}
#endregion ColumnHeaderTemplate
#region ColumnHeaderTemplateSelector
/// <summary>
/// ColumnHeaderTemplateSelector DependencyProperty
/// </summary>
public static readonly DependencyProperty ColumnHeaderTemplateSelectorProperty =
GridView.ColumnHeaderTemplateSelectorProperty.AddOwner(
typeof(GridViewHeaderRowPresenter),
new FrameworkPropertyMetadata(
new PropertyChangedCallback(PropertyChanged))
);
/// <summary>
/// header template selector
/// </summary>
/// <remarks>
/// This property is ignored if <seealso cref="ColumnHeaderTemplate"/> is set.
/// </remarks>
[DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)]
public DataTemplateSelector ColumnHeaderTemplateSelector
{
get { return (DataTemplateSelector)GetValue(ColumnHeaderTemplateSelectorProperty); }
set { SetValue(ColumnHeaderTemplateSelectorProperty, value); }
}
#endregion ColumnHeaderTemplateSelector
#region ColumnHeaderStringFormat
/// <summary>
/// ColumnHeaderStringFormat DependencyProperty
/// </summary>
public static readonly DependencyProperty ColumnHeaderStringFormatProperty =
GridView.ColumnHeaderStringFormatProperty.AddOwner(
typeof(GridViewHeaderRowPresenter),
new FrameworkPropertyMetadata(
new PropertyChangedCallback(PropertyChanged))
);
/// <summary>
/// header template selector
/// </summary>
/// <remarks>
/// This property is ignored if <seealso cref="ColumnHeaderTemplate"/> is set.
/// </remarks>
[DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)]
public String ColumnHeaderStringFormat
{
get { return (String)GetValue(ColumnHeaderStringFormatProperty); }
set { SetValue(ColumnHeaderStringFormatProperty, value); }
}
#endregion ColumnHeaderStringFormat
#region AllowsColumnReorder
/// <summary>
/// AllowsColumnReorder DependencyProperty
/// </summary>
public static readonly DependencyProperty AllowsColumnReorderProperty =
GridView.AllowsColumnReorderProperty.AddOwner(
typeof(GridViewHeaderRowPresenter)
);
/// <summary>
/// Allow column re-order or not
/// </summary>
public bool AllowsColumnReorder
{
get { return (bool)GetValue(AllowsColumnReorderProperty); }
set { SetValue(AllowsColumnReorderProperty, value); }
}
#endregion AllowsColumnReorder
#region ColumnHeaderContextMenu
/// <summary>
/// ColumnHeaderContextMenu DependencyProperty
/// </summary>
public static readonly DependencyProperty ColumnHeaderContextMenuProperty =
GridView.ColumnHeaderContextMenuProperty.AddOwner(
typeof(GridViewHeaderRowPresenter),
new FrameworkPropertyMetadata(
new PropertyChangedCallback(PropertyChanged))
);
/// <summary>
/// ColumnHeaderContextMenu
/// </summary>
public ContextMenu ColumnHeaderContextMenu
{
get { return (ContextMenu)GetValue(ColumnHeaderContextMenuProperty); }
set { SetValue(ColumnHeaderContextMenuProperty, value); }
}
#endregion ColumnHeaderContextMenu
#region ColumnHeaderToolTip
/// <summary>
/// ColumnHeaderToolTip DependencyProperty
/// </summary>
public static readonly DependencyProperty ColumnHeaderToolTipProperty =
GridView.ColumnHeaderToolTipProperty.AddOwner(
typeof(GridViewHeaderRowPresenter),
new FrameworkPropertyMetadata(
new PropertyChangedCallback(PropertyChanged))
);
/// <summary>
/// ColumnHeaderToolTip
/// </summary>
public object ColumnHeaderToolTip
{
get { return GetValue(ColumnHeaderToolTipProperty); }
set { SetValue(ColumnHeaderToolTipProperty, value); }
}
private static void PropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
GridViewHeaderRowPresenter presenter = (GridViewHeaderRowPresenter)d;
if (e.Property == ColumnHeaderTemplateProperty || e.Property == ColumnHeaderTemplateSelectorProperty)
{
// Check to prevent Template and TemplateSelector at the same time
Helper.CheckTemplateAndTemplateSelector("GridViewHeaderRowPresenter", ColumnHeaderTemplateProperty, ColumnHeaderTemplateSelectorProperty, presenter);
}
presenter.UpdateAllHeaders(e.Property);
}
#endregion ColumnHeaderToolTip
#endregion
//-------------------------------------------------------------------
//
// Protected Methods
//
//-------------------------------------------------------------------
#region Protected Methods
/// <summary>
/// Override of <seealso cref="FrameworkElement.MeasureOverride" />.
/// </summary>
/// <param name="constraint">Constraint size is an "upper limit" that the return value should not exceed.</param>
/// <returns>The GridViewHeaderRowPresenter's desired size.</returns>
protected override Size MeasureOverride(Size constraint)
{
GridViewColumnCollection columns = Columns;
UIElementCollection children = InternalChildren;
double maxHeight = 0.0; // Max height of children.
double accumulatedWidth = 0.0; // Total width consumed by children.
double constraintHeight = constraint.Height;
bool desiredWidthListEnsured = false;
if (columns != null)
{
// Measure working headers
for (int i = 0; i < columns.Count; ++i)
{
UIElement child = children[GetVisualIndex(i)];
if (child == null) { continue; }
double childConstraintWidth = Math.Max(0.0, constraint.Width - accumulatedWidth);
GridViewColumn column = columns[i];
if (column.State == ColumnMeasureState.Init)
{
if (!desiredWidthListEnsured)
{
EnsureDesiredWidthList();
LayoutUpdated += new EventHandler(OnLayoutUpdated);
desiredWidthListEnsured = true;
}
child.Measure(new Size(childConstraintWidth, constraintHeight));
DesiredWidthList[column.ActualIndex] = column.EnsureWidth(child.DesiredSize.Width);
accumulatedWidth += column.DesiredWidth;
}
else if (column.State == ColumnMeasureState.Headered
|| column.State == ColumnMeasureState.Data)
{
childConstraintWidth = Math.Min(childConstraintWidth, column.DesiredWidth);
child.Measure(new Size(childConstraintWidth, constraintHeight));
accumulatedWidth += column.DesiredWidth;
}
else // ColumnMeasureState.SpecificWidth
{
childConstraintWidth = Math.Min(childConstraintWidth, column.Width);
child.Measure(new Size(childConstraintWidth, constraintHeight));
accumulatedWidth += column.Width;
}
maxHeight = Math.Max(maxHeight, child.DesiredSize.Height);
}
}
// Measure padding header
Debug.Assert(_paddingHeader != null, "padding header is null");
_paddingHeader.Measure(new Size(0.0, constraintHeight));
maxHeight = Math.Max(maxHeight, _paddingHeader.DesiredSize.Height);
// reserve space for padding header next to the last column
accumulatedWidth += c_PaddingHeaderMinWidth;
// Measure indicator & floating header in re-ordering
if (_isHeaderDragging)
{
Debug.Assert(_indicator != null, "_indicator is null");
Debug.Assert(_floatingHeader != null, "_floatingHeader is null");
// Measure indicator
_indicator.Measure(constraint);
// Measure floating header
_floatingHeader.Measure(constraint);
}
return (new Size(accumulatedWidth, maxHeight));
}
/// <summary>
/// GridViewHeaderRowPresenter computes the position of its children inside each child's Margin and calls Arrange
/// on each child.
/// </summary>
/// <param name="arrangeSize">Size the GridViewHeaderRowPresenter will assume.</param>
protected override Size ArrangeOverride(Size arrangeSize)
{
GridViewColumnCollection columns = Columns;
UIElementCollection children = InternalChildren;
double accumulatedWidth = 0.0;
double remainingWidth = arrangeSize.Width;
Rect rect;
HeadersPositionList.Clear();
if (columns != null)
{
// Arrange working headers
for (int i = 0; i < columns.Count; ++i)
{
UIElement child = children[GetVisualIndex(i)];
if (child == null) { continue; }
GridViewColumn column = columns[i];
// has a given value or 'auto'
double childArrangeWidth = Math.Min(remainingWidth, ((column.State == ColumnMeasureState.SpecificWidth) ? column.Width : column.DesiredWidth));
// calculate the header rect
rect = new Rect(accumulatedWidth, 0.0, childArrangeWidth, arrangeSize.Height);
// arrange header
child.Arrange(rect);
//Store rect in HeadersPositionList as i-th column position
HeadersPositionList.Add(rect);
remainingWidth -= childArrangeWidth;
accumulatedWidth += childArrangeWidth;
}
// check width to hide previous header's right half gripper, from the first working header to padding header
// only happens after column delete, insert, move
if (_isColumnChangedOrCreated)
{
for (int i = 0; i < columns.Count; ++i)
{
GridViewColumnHeader header = children[GetVisualIndex(i)] as GridViewColumnHeader;
header.CheckWidthForPreviousHeaderGripper();
}
_paddingHeader.CheckWidthForPreviousHeaderGripper();
_isColumnChangedOrCreated = false;
}
}
// Arrange padding header
Debug.Assert(_paddingHeader != null, "padding header is null");
rect = new Rect(accumulatedWidth, 0.0, Math.Max(remainingWidth, 0.0), arrangeSize.Height);
_paddingHeader.Arrange(rect);
HeadersPositionList.Add(rect);
// if re-order started, arrange floating header & indicator
if (_isHeaderDragging)
{
_floatingHeader.Arrange(new Rect(new Point(_currentPos.X - _relativeStartPos.X, 0), HeadersPositionList[_startColumnIndex].Size));
Point pos = FindPositionByIndex(_desColumnIndex);
_indicator.Arrange(new Rect(pos, new Size(_indicator.DesiredSize.Width, arrangeSize.Height)));
}
return arrangeSize;
}
/// <summary>
/// This is the method that responds to the MouseButtonEvent event.
/// </summary>
/// <param name="e">Event arguments</param>
protected override void OnMouseLeftButtonDown(MouseButtonEventArgs e)
{
GridViewColumnHeader header = e.Source as GridViewColumnHeader;
if (header != null && AllowsColumnReorder)
{
PrepareHeaderDrag(header, e.GetPosition(this), e.GetPosition(header), false);
MakeParentItemsControlGotFocus();
}
e.Handled = true;
base.OnMouseLeftButtonDown(e);
}
/// <summary>
/// This is the method that responds to the MouseButtonEvent event.
/// </summary>
/// <param name="e">Event arguments</param>
protected override void OnMouseLeftButtonUp(MouseButtonEventArgs e)
{
// Important to clean the prepare dragging state
_prepareDragging = false;
if (_isHeaderDragging)
{
FinishHeaderDrag(false);
}
e.Handled = true;
base.OnMouseLeftButtonUp(e);
}
/// <summary>
/// This is the method that responds to the MouseEvent event.
/// </summary>
/// <param name="e">Event arguments</param>
protected override void OnMouseMove(MouseEventArgs e)
{
base.OnMouseMove(e);
if (e.LeftButton == MouseButtonState.Pressed)
{
// if prepare re-order or already re-order
if (_prepareDragging)
{
Debug.Assert(_draggingSrcHeader != null, "_draggingSrcHeader is null");
_currentPos = e.GetPosition(this);
_desColumnIndex = FindIndexByPosition(_currentPos, true);
if (!_isHeaderDragging)
{
// Re-order begins only if horizontal move exceeds threshold
if (CheckStartHeaderDrag(_currentPos, _startPos))
{
// header dragging start
StartHeaderDrag();
// need to measure indicator because floating header is updated
InvalidateMeasure();
}
}
else // NOTE: Not-Dragging/Dragging should be divided into two stages in MouseMove
{
// Check floating & indicator visibility
// Display floating header if vertical move not exceeds header.Height * 2
bool isDisplayingFloatingHeader = IsMousePositionValid(_floatingHeader, _currentPos, 2.0);
// floating header and indicator are visibile/invisible at the same time
_indicator.Visibility = _floatingHeader.Visibility = isDisplayingFloatingHeader ? Visibility.Visible : Visibility.Hidden;
InvalidateArrange();
}
}
}
e.Handled = true;
}
/// <summary>
/// Cancel header dragging if we lost capture
/// </summary>
/// <param name="e"></param>
protected override void OnLostMouseCapture(MouseEventArgs e)
{
base.OnLostMouseCapture(e);
// OnLostMouseCapture is invoked before OnMouseLeftButtonUp, so we need to distinguish
// the cause of capture lose
// if LeftButton is pressed when lost mouse capture, we treat it as cancel
// Because GridViewHeaderRowPresenter never capture Mouse (GridViewColumnHeader did this),
// the Mouse.Captured is always null
if (e.LeftButton == MouseButtonState.Pressed && _isHeaderDragging)
{
FinishHeaderDrag(true);
}
// Important to clean the prepare dragging state
_prepareDragging = false;
}
#endregion Protected Methods
//-------------------------------------------------------------------
//
// Internal Methods
//
//-------------------------------------------------------------------
#region Internal Methods
/// <summary>
/// create the headers tree
/// </summary>
internal override void OnPreApplyTemplate()
{
// +-- GridViewHeaderRowPresenter ----------------------------+
// | |
// | +- Header1 ---+ +- Header2 ---+ +- PaddingHeader -+ |
// | | +--------+ +--------+ | |
// | | +Gripper + +Gripper + | ... |
// | | +--------+ +--------+ | |
// | +-------------+ +-------------+ +---------------+ |
// +----------------------------------------------------------+
//
// Given a column collection with 3 columns
//
// { A, B, C },
//
// Visually, GridViewHeaderRowPresenter will them present as:
//
// { A, B, C, Padding }
//
// If in Reorder-Mode, there will be 2 more be visible:
//
// { A, [Indctr], B, C, Padding }
// { [-- Float --] }
//
// And internally the visual child collection is in order of:
//
// { Padding, C, B, A, Indicator, Float}
//
// Method GetVisualIndex() is for coverting a Columns based
// index to visual child collection based index.
//
// E.g., Columns based index of column A is 0, while
// and it lives 3rd in the visual collection, so
//
// GetVisualIndex(0) = 3.
//
base.OnPreApplyTemplate();
if (NeedUpdateVisualTree)
{
// build the whole collection from draft.
// IMPORTANT!
// The correct sequence to build the VisualTree in Z-order:
// 1. Padding header
// 2. The working Column header (if any)
// 3. Indicator
// 4. Floating header
//
UIElementCollection children = InternalChildren;
GridViewColumnCollection columns = Columns;
// renew ScrollViewer, ScrollChanged event, ItemsControl and KeyDown event
RenewEvents();
if (children.Count == 0)
{
// Build and add the padding header, even if no GridViewColumn is defined
AddPaddingColumnHeader();
// Create and add indicator
AddIndicator();
// Create and add floating header
AddFloatingHeader(null);
}
else if (children.Count > 3)
{
// clear column headers left from last view.
int count = children.Count - 3;
for (int i = 0; i < count; i++)
{
RemoveHeader(null, 1);
}
}
UpdatePaddingHeader(_paddingHeader);
//
// Build the column header.
// The interesting thing is headers must be built from right to left,
// in order to make the left header's gripper overlay the right header
//
if (columns != null)
{
int visualIndex = 1;
for (int columnIndex = columns.Count - 1; columnIndex >= 0; columnIndex--)
{
GridViewColumn column = columns[columnIndex];
GridViewColumnHeader header = CreateAndInsertHeader(column, visualIndex++);
}
}
// Link headers
BuildHeaderLinks();
NeedUpdateVisualTree = false;
_isColumnChangedOrCreated = true;
}
}
/// <summary>
/// Override column's PropertyChanged event handler. Update correspondent
/// property if change is of Width / Header /
/// HeaderContainerStyle / Template / Selector.
/// </summary>
internal override void OnColumnPropertyChanged(GridViewColumn column, string propertyName)
{
Debug.Assert(column != null);
if (column.ActualIndex >= 0)
{
GridViewColumnHeader header = FindHeaderByColumn(column);
if (header != null)
{
if (GridViewColumn.WidthProperty.Name.Equals(propertyName)
|| GridViewColumn.c_ActualWidthName.Equals(propertyName))
{
InvalidateMeasure();
}
else if (GridViewColumn.HeaderProperty.Name.Equals(propertyName))
{
if (!header.IsInternalGenerated /* the old header is its own container */
|| column.Header is GridViewColumnHeader /* the new header is its own container */)
{
// keep the header index in Children collection
int i = InternalChildren.IndexOf(header);
// Remove the old header
RemoveHeader(header, -1);
// Insert a (the) new header
GridViewColumnHeader newHeader = CreateAndInsertHeader(column, i);
// Link headers
BuildHeaderLinks();
}
else
{
UpdateHeaderContent(header);
}
}
else
{
DependencyProperty columnDP = GetColumnDPFromName(propertyName);
if (columnDP != null)
{
UpdateHeaderProperty(header, columnDP);
}
}
}
}
}
internal override void OnColumnCollectionChanged(GridViewColumnCollectionChangedEventArgs e)
{
base.OnColumnCollectionChanged(e);
int index;
GridViewColumnHeader header;
UIElementCollection children = InternalChildren;
GridViewColumn column;
switch (e.Action)
{
case NotifyCollectionChangedAction.Move:
int start = GetVisualIndex(e.OldStartingIndex);
int end = GetVisualIndex(e.NewStartingIndex);
header = (GridViewColumnHeader)children[start];
children.RemoveAt(start);
children.InsertInternal(end, header);
break;
case NotifyCollectionChangedAction.Add:
index = GetVisualIndex(e.NewStartingIndex);
column = (GridViewColumn)(e.NewItems[0]);
CreateAndInsertHeader(column, index + 1); // index + 1 because visual index is reversed from column index
break;
case NotifyCollectionChangedAction.Remove:
RemoveHeader(null, GetVisualIndex(e.OldStartingIndex));
break;
case NotifyCollectionChangedAction.Replace:
index = GetVisualIndex(e.OldStartingIndex);
RemoveHeader(null, index);
column = (GridViewColumn)(e.NewItems[0]);
CreateAndInsertHeader(column, index);
break;
case NotifyCollectionChangedAction.Reset:
int count = e.ClearedColumns.Count;
for (int i = 0; i < count; i++)
{
RemoveHeader(null, 1);
}
break;
}
// Link headers
BuildHeaderLinks();
_isColumnChangedOrCreated = true;
}
// Make the parent got focus if it's ItemsControl
// make this method internal, so GVCH can call it when header is invoked through access key
internal void MakeParentItemsControlGotFocus()
{
if (_itemsControl != null && !_itemsControl.IsKeyboardFocusWithin)
{
// send focus to item.
ListBox parent = _itemsControl as ListBox;
if (parent != null && parent.LastActionItem != null)
{
parent.LastActionItem.Focus();
}
else
{
_itemsControl.Focus();
}
}
}
/// <summary>
/// Refresh a dp of a header. Column is the 1st priority source, GridView 2nd.
/// </summary>
/// <param name="header">the header to update</param>
/// <param name="property">the DP which trigger this update</param>
internal void UpdateHeaderProperty(GridViewColumnHeader header, DependencyProperty property)
{
DependencyProperty gvDP, columnDP, headerDP;
GetMatchingDPs(property, out gvDP, out columnDP, out headerDP);
UpdateHeaderProperty(header, headerDP, columnDP, gvDP);
}
#endregion Internal Methods
//-------------------------------------------------------------------
//
// Accessibility
//
//-------------------------------------------------------------------
#region Accessibility
/// <summary>
/// Creates AutomationPeer (<see cref="UIElement.OnCreateAutomationPeer"/>)
/// </summary>
protected override AutomationPeer OnCreateAutomationPeer()
{
return new GridViewHeaderRowPresenterAutomationPeer(this);
}
#endregion
//-------------------------------------------------------------------
//
// Private Methods
//
//-------------------------------------------------------------------
#region Private Methods
private void OnLayoutUpdated(object sender, EventArgs e)
{
bool desiredWidthChanged = false; // whether the shared minimum width has been changed since last layout
GridViewColumnCollection columns = Columns;
if (columns != null)
{
foreach (GridViewColumn column in columns)
{
if ((column.State != ColumnMeasureState.SpecificWidth))
{
if (column.State == ColumnMeasureState.Init)
{
column.State = ColumnMeasureState.Headered;
}
if (DesiredWidthList == null || column.ActualIndex >= DesiredWidthList.Count)
{
// How can this happen?
// Between the last measure was called and this update is called, there can be a
// change done to the ColumnCollection and result in DesiredWidthList out of sync
// with the columnn collection. What can we do is end this call asap and the next
// measure will fix it.
desiredWidthChanged = true;
break;
}
if (!DoubleUtil.AreClose(column.DesiredWidth, DesiredWidthList[column.ActualIndex]))
{
// Update the record because collection operation latter on might
// need to verified this list again, e.g. insert an 'auto'
// column, so that we won't trigger unnecessary update due to
// inconsistency of this column.
DesiredWidthList[column.ActualIndex] = column.DesiredWidth;
desiredWidthChanged = true;
}
}
}
}
if (desiredWidthChanged)
{
InvalidateMeasure();
}
LayoutUpdated -= new EventHandler(OnLayoutUpdated);
}
// Map column collection index to header collection index in visual tree
private int GetVisualIndex(int columnIndex)
{
// Elements in visual tree: working headers, padding header, indicator, and floating header
int index = InternalChildren.Count - 3 - columnIndex;
Debug.Assert(index >= 0 && index < InternalChildren.Count, "Error index when GetVisualIndex");
return index;
}
// Link headers from right to left
private void BuildHeaderLinks()
{
GridViewColumnHeader lastHeader = null;
if (Columns != null)
{
// link working headers.
for (int i = 0; i < Columns.Count; i++)
{
GridViewColumnHeader header = (GridViewColumnHeader)InternalChildren[GetVisualIndex(i)];
header.PreviousVisualHeader = lastHeader;
lastHeader = header;
}
}
// link padding header to last header
if (_paddingHeader != null)
{
_paddingHeader.PreviousVisualHeader = lastHeader;
}
}
//
// This method will do following tasks:
// 1. Disconnect header from visual parent and logical parent, if any.
// 2. Create a new header or use the header directly if the GridViewColumn.Header property
// is qualify for its own container;
// 3. Insert the header in the InternalChildren collection
// 4. Perform routine update and hookup jobs
//
private GridViewColumnHeader CreateAndInsertHeader(GridViewColumn column, int index)
{
object header = column.Header;
GridViewColumnHeader headerContainer = header as GridViewColumnHeader;
//
// NOTE: when theme chagned, all properties, templates and styles will be reevaluated.
// But there are 2 cases we need to handle:
//
// 1: header property is a qualified container for itself
// <GridViewColumn>
// <GridViewColumnHeader />
// </GridViewColumn>
//
// 2: header property is a Visual element
// <GridViewColumn>
// <Button />
// </GridViewColumn>
//
// In both cases, we need to diconnect them from the visual and logical tree before
// they got inserted into the new tree.
//
if (header != null)
{
DependencyObject d = header as DependencyObject;
if (d != null)
{
// disconnect from visual tree
Visual headerAsVisual = d as Visual;
if (headerAsVisual != null)
{
Visual parent = VisualTreeHelper.GetParent(headerAsVisual) as Visual;
if (parent != null)
{
if (headerContainer != null)
{
// case 1
GridViewHeaderRowPresenter parentAsGVHRP = parent as GridViewHeaderRowPresenter;
if (parentAsGVHRP != null)
{
parentAsGVHRP.InternalChildren.RemoveNoVerify(headerContainer);
}
else
{
Debug.Assert(false, "Head is container for itself, but parent is neither GridViewHeaderRowPresenter nor null.");
}
}
else
{
// case 2
GridViewColumnHeader parentAsGVCH = parent as GridViewColumnHeader;
if (parentAsGVCH != null)
{
parentAsGVCH.ClearValue(ContentControl.ContentProperty);
}
}
}
}
// disconnect from logical tree
DependencyObject logicalParent = LogicalTreeHelper.GetParent(d);
if (logicalParent != null)
{
LogicalTreeHelper.RemoveLogicalChild(logicalParent, header);
}
}
}
if (headerContainer == null)
{
headerContainer = new GridViewColumnHeader();
headerContainer.IsInternalGenerated = true;
}
// Pass column reference to GridViewColumnHeader
headerContainer.SetValue(GridViewColumnHeader.ColumnPropertyKey, column);
// Hookup _itemsControl.KeyDown event for canceling resizing if user press 'Esc'.
HookupItemsControlKeyboardEvent(headerContainer);
InternalChildren.InsertInternal(index, headerContainer);
// NOTE: the order here is important!
// Need to add headerContainer into visual tree first, then apply Style, Template etc.
UpdateHeader(headerContainer);
_gvHeadersValid = false;
return headerContainer;
}
private void RemoveHeader(GridViewColumnHeader header, int index)
{
Debug.Assert(header != null || index != -1);
_gvHeadersValid = false;
if (header != null)
{
InternalChildren.Remove(header);
}
else
{
header = (GridViewColumnHeader)InternalChildren[index];
InternalChildren.RemoveAt(index);
}
UnhookItemsControlKeyboardEvent(header);
}
// find needed elements and hook up events
private void RenewEvents()
{
ScrollViewer oldHeaderSV = _headerSV;
_headerSV = Parent as ScrollViewer;
if (oldHeaderSV != _headerSV)
{
if (oldHeaderSV != null)
{
oldHeaderSV.ScrollChanged -= new ScrollChangedEventHandler(OnHeaderScrollChanged);
}
if (_headerSV != null)
{
_headerSV.ScrollChanged += new ScrollChangedEventHandler(OnHeaderScrollChanged);
}
}
ScrollViewer oldSV = _mainSV; // backup the old value
_mainSV = TemplatedParent as ScrollViewer;
if (oldSV != _mainSV)
{
if (oldSV != null)
{
oldSV.ScrollChanged -= new ScrollChangedEventHandler(OnMasterScrollChanged);
}
if (_mainSV != null)
{
_mainSV.ScrollChanged += new ScrollChangedEventHandler(OnMasterScrollChanged);
}
}
// hook up key down event from ItemsControl,
// because GridViewColumnHeader and GridViewHeaderRowPresenter can not get focus
ItemsControl oldIC = _itemsControl; // backup the old value
_itemsControl = FindItemsControlThroughTemplatedParent(this);
if (oldIC != _itemsControl)
{
if (oldIC != null)
{
// NOTE: headers have unhooked the KeyDown event in RemoveHeader.
oldIC.KeyDown -= new KeyEventHandler(OnColumnHeadersPresenterKeyDown);
}
if (_itemsControl != null)
{
// register to HeadersPresenter to cancel dragging
_itemsControl.KeyDown += new KeyEventHandler(OnColumnHeadersPresenterKeyDown);
// NOTE: headers will hookup the KeyDown event latter in CreateAndInsertHeader.
}
}
//Set GridViewHeaderRowPresenter to ListView
ListView lv = _itemsControl as ListView;
if (lv != null && lv.View != null && lv.View is GridView)
{
((GridView)lv.View).HeaderRowPresenter = this;
}
}
private void UnhookItemsControlKeyboardEvent(GridViewColumnHeader header)
{
Debug.Assert(header != null);
if (_itemsControl != null)
{
_itemsControl.KeyDown -= new KeyEventHandler(header.OnColumnHeaderKeyDown);
}
}
private void HookupItemsControlKeyboardEvent(GridViewColumnHeader header)
{
Debug.Assert(header != null);
if (_itemsControl != null)
{
_itemsControl.KeyDown += new KeyEventHandler(header.OnColumnHeaderKeyDown);
}
}
// The following two scroll changed methods will not be called recursively and lead to dead loop.
// When scrolling _masterSV, OnMasterScrollChanged will be called, so _headerSV also scrolled
// to the same offset. Then, OnHeaderScrollChanged be called, and try to scroll _masterSV, but
// it's already scrolled to that offset, so OnMasterScrollChanged will not be called.
// When master scroll viewer changed its offset, change header scroll viewer accordingly
private void OnMasterScrollChanged(object sender, ScrollChangedEventArgs e)
{
if (_headerSV != null && _mainSV == e.OriginalSource)
{
_headerSV.ScrollToHorizontalOffset(e.HorizontalOffset);
}
}
// When header scroll viewer changed its offset, change master scroll viewer accordingly
private void OnHeaderScrollChanged(object sender, ScrollChangedEventArgs e)
{
if (_mainSV != null && _headerSV == e.OriginalSource)
{
_mainSV.ScrollToHorizontalOffset(e.HorizontalOffset);
}
}
// Create the last padding column header in GridViewHeaderRowPresenter
private void AddPaddingColumnHeader()
{
GridViewColumnHeader paddingHeader = new GridViewColumnHeader();
paddingHeader.IsInternalGenerated = true;
paddingHeader.SetValue(GridViewColumnHeader.RolePropertyKey, GridViewColumnHeaderRole.Padding);
paddingHeader.Content = null;
paddingHeader.ContentTemplate = null;
paddingHeader.ContentTemplateSelector = null;
paddingHeader.MinWidth = 0;
paddingHeader.Padding = new Thickness(0.0);
paddingHeader.Width = Double.NaN;
paddingHeader.HorizontalAlignment = HorizontalAlignment.Stretch;
if (!AccessibilitySwitches.UseNetFx472CompatibleAccessibilityFeatures)
{
// There is no point in this padding column header being focusable.
paddingHeader.Focusable = false;
}
InternalChildren.AddInternal(paddingHeader);
_paddingHeader = paddingHeader;
}
// Create the indicator for column re-ordering
private void AddIndicator()
{
Separator indicator = new Separator();
indicator.Visibility = Visibility.Hidden;
// Indicator style:
//
// <Setter Property="Margin" Value="0" />
// <Setter Property="Width" Value="2" />
// <Setter Property="Template">
// <Setter.Value>
// <ControlTemplate TargetType="{x:Type Separator}">
// <Border Background="#FF000080"/>
// </ControlTemplate>
// </Setter.Value>
// </Setter>
indicator.Margin = new Thickness(0);
indicator.Width = 2.0;
FrameworkElementFactory border = new FrameworkElementFactory(typeof(Border));
border.SetValue(Border.BackgroundProperty, new SolidColorBrush(Color.FromUInt32(0xFF000080)));
ControlTemplate template = new ControlTemplate(typeof(Separator));
template.VisualTree = border;
template.Seal();
indicator.Template = template;
InternalChildren.AddInternal(indicator);
_indicator = indicator;
}
// Create the floating header
private void AddFloatingHeader(GridViewColumnHeader srcHeader)
{
GridViewColumnHeader header;
// #1426973: Because users may put subclassed header as the column header,
// we need to create the same type per source header as the floating one
// Get source header's type
Type headerType = (srcHeader != null ? srcHeader.GetType() : typeof(GridViewColumnHeader));
try
{
// Instantiate the same type for floating header
header = Activator.CreateInstance(headerType) as GridViewColumnHeader;
}
catch (MissingMethodException e)
{
throw new ArgumentException(SR.Format(SR.ListView_MissingParameterlessConstructor, headerType), e);
}
Debug.Assert(header != null, "Cannot instantiate GridViewColumnHeader in AddFloatingHeader");
header.IsInternalGenerated = true;
header.SetValue(GridViewColumnHeader.RolePropertyKey, GridViewColumnHeaderRole.Floating);
header.Visibility = Visibility.Hidden;
InternalChildren.AddInternal(header);
_floatingHeader = header;
}
// Fill necessary properties in floating header
private void UpdateFloatingHeader(GridViewColumnHeader srcHeader)
{
Debug.Assert(srcHeader != null, "srcHeader is null");
Debug.Assert(_floatingHeader != null, "floating header is null");
_floatingHeader.Style = srcHeader.Style;
_floatingHeader.FloatSourceHeader = srcHeader;
_floatingHeader.Width = srcHeader.ActualWidth;
_floatingHeader.Height = srcHeader.ActualHeight;
_floatingHeader.SetValue(GridViewColumnHeader.ColumnPropertyKey, srcHeader.Column);
_floatingHeader.Visibility = Visibility.Hidden;
// override floating header's MinWidth/MinHeight to disable users to change floating header's Width/Height
_floatingHeader.MinWidth = srcHeader.MinWidth;
_floatingHeader.MinHeight = srcHeader.MinHeight;
object template = srcHeader.ReadLocalValue(GridViewColumnHeader.ContentTemplateProperty);
if ((template != DependencyProperty.UnsetValue) && (template != null))
{
_floatingHeader.ContentTemplate = srcHeader.ContentTemplate;
}
object selector = srcHeader.ReadLocalValue(GridViewColumnHeader.ContentTemplateSelectorProperty);
if ((selector != DependencyProperty.UnsetValue) && (selector != null))
{
_floatingHeader.ContentTemplateSelector = srcHeader.ContentTemplateSelector;
}
if (!(srcHeader.Content is Visual))
{
_floatingHeader.Content = srcHeader.Content;
}
}
/// <summary>
/// This method is invoked when mouse move and left button is pressed.
/// This method judges if the mouse move exceeds a threshold to start re-order.
/// </summary>
/// <param name="currentPos">The current mouse position, relative to GridViewHeaderRowPresenter</param>
/// <param name="originalPos">The original start position, relative to GridViewHeaderRowPresenter</param>
/// <returns></returns>
private bool CheckStartHeaderDrag(Point currentPos, Point originalPos)
{
return (DoubleUtil.GreaterThan(Math.Abs(currentPos.X - originalPos.X), c_thresholdX));
}
// Find ItemsControl through TemplatedParent
private static ItemsControl FindItemsControlThroughTemplatedParent(GridViewHeaderRowPresenter presenter)
{
FrameworkElement fe = presenter.TemplatedParent as FrameworkElement;
ItemsControl itemsControl = null;
while (fe != null)
{
itemsControl = fe as ItemsControl;
if (itemsControl != null)
{
break;
}
fe = fe.TemplatedParent as FrameworkElement;
}
return itemsControl;
}
private void OnColumnHeadersPresenterKeyDown(object sender, KeyEventArgs e)
{
// if press Escape when re-ordering, cancel re-order
if (e.Key == Key.Escape && _isHeaderDragging)
{
// save the source header b/c FinishHeaderDrag will clear it
GridViewColumnHeader srcHeader = _draggingSrcHeader;
FinishHeaderDrag(true);
PrepareHeaderDrag(srcHeader, _currentPos, _relativeStartPos, true);
InvalidateArrange();
}
}
// Find the column header from the visual tree by column
private GridViewColumnHeader FindHeaderByColumn(GridViewColumn column)
{
GridViewColumnCollection columns = Columns;
UIElementCollection children = InternalChildren;
if (columns != null && children.Count > columns.Count)
{
int index = columns.IndexOf(column);
if (index != -1)
{
// Becuase column headers is generated from right to left
int visualIndex = GetVisualIndex(index);
GridViewColumnHeader header = children[visualIndex] as GridViewColumnHeader;
if (header.Column != column)
{
// NOTE: if user change the GridViewColumn.Header/HeaderStyle
// in the event handler of column move. And in such case, the header
// we found by the algorithm above will be fail. So we turn to below
// a more reliable one.
for (int i = 1; i < children.Count; i++)
{
header = children[i] as GridViewColumnHeader;
if (header != null && header.Column == column)
{
return header;
}
}
}
else
{
return header;
}
}
}
return null;
}
// Find logic column index by position
// If parameter 'findNearestColumn' is true, find the nearest column relative to mouse position
private int FindIndexByPosition(Point startPos, bool findNearestColumn)
{
int index = -1;
if (startPos.X < 0.0)
{
return 0;
}
for (int i = 0; i < HeadersPositionList.Count; i++)
{
index++;
Rect rect = HeadersPositionList[i];
double startX = rect.X;
double endX = startX + rect.Width;
if (DoubleUtil.GreaterThanOrClose(startPos.X, startX) &&
DoubleUtil.LessThanOrClose(startPos.X, endX))
{
if (findNearestColumn)
{
double midX = (startX + endX) * 0.5;
if (DoubleUtil.GreaterThanOrClose(startPos.X, midX))
{
// if not the padding header
if (i != HeadersPositionList.Count - 1)
{
index++;
}
}
}
break;
}
}
return index;
}
// Find position by logic column index
private Point FindPositionByIndex(int index)
{
Debug.Assert(index >= 0 && index < HeadersPositionList.Count, "wrong index");
return new Point(HeadersPositionList[index].X, 0);
}
// Update header Content, Style, ContentTemplate, ContentTemplateSelector, ContentStringFormat, ContextMenu and ToolTip
private void UpdateHeader(GridViewColumnHeader header)
{
UpdateHeaderContent(header);
for (int i = 0, n = s_DPList[0].Length; i < n; i++)
{
UpdateHeaderProperty(header, s_DPList[2][i] /* header */,
s_DPList[1][i] /* column */, s_DPList[0][i] /* GV */);
}
}
// Update Content of GridViewColumnHeader
private void UpdateHeaderContent(GridViewColumnHeader header)
{
if (header != null && header.IsInternalGenerated)
{
GridViewColumn column = header.Column;
if (column != null)
{
if (column.Header == null)
{
header.ClearValue(ContentControl.ContentProperty);
}
else
{
header.Content = column.Header;
}
}
}
}
// Update Style, ContextMenu and ToolTip properties for padding header.
// GridView.ColumnHeaderTemplate(Selector) and GridView.ColumnHeaderStringFormat
// don't work on padding header.
private void UpdatePaddingHeader(GridViewColumnHeader header)
{
UpdateHeaderProperty(header, ColumnHeaderContainerStyleProperty);
UpdateHeaderProperty(header, ColumnHeaderContextMenuProperty);
UpdateHeaderProperty(header, ColumnHeaderToolTipProperty);
}
private void UpdateAllHeaders(DependencyProperty dp)
{
DependencyProperty gvDP, columnDP, headerDP;
GetMatchingDPs(dp, out gvDP, out columnDP, out headerDP);
int iStart, iEnd;
GetIndexRange(dp, out iStart, out iEnd);
UIElementCollection children = InternalChildren;
for (int i = iStart; i <= iEnd; i++)
{
GridViewColumnHeader header = children[i] as GridViewColumnHeader;
if (header != null)
{
UpdateHeaderProperty(header, headerDP, columnDP, gvDP);
}
}
}
/// <summary>
/// get index range of header for need update
/// </summary>
/// <param name="dp">the GridView DP in this update</param>
/// <param name="iStart">starting index of header need update</param>
/// <param name="iEnd">ending index of header need update</param>
private void GetIndexRange(DependencyProperty dp, out int iStart, out int iEnd)
{
// whether or not include the padding header
iStart = (dp == ColumnHeaderTemplateProperty ||
dp == ColumnHeaderTemplateSelectorProperty ||
dp == ColumnHeaderStringFormatProperty)
? 1 : 0;
iEnd = InternalChildren.Count - 3; // skip the floating header and the indicator.
}
private void UpdateHeaderProperty(
GridViewColumnHeader header, // the header need to update
DependencyProperty targetDP, // the target DP on header
DependencyProperty columnDP, // the DP on Column as 1st source, can be Null
DependencyProperty gvDP // the DP on GridView as 2nd source
)
{
if (gvDP == ColumnHeaderContainerStyleProperty
&& header.Role == GridViewColumnHeaderRole.Padding)
{
// Because padding header has no chance to be instantiated by a sub-classed GridViewColumnHeader,
// we ignore GridView.ColumnHeaderContainerStyle silently if its TargetType is not GridViewColumnHeader (or parent)
// I.e. for padding header, only accept the GridViewColumnHeader as TargetType
Style style = ColumnHeaderContainerStyle;
if (style != null && !style.TargetType.IsAssignableFrom(typeof(GridViewColumnHeader)))
{
// use default style for padding header in this case
header.Style = null;
return;
}
}
GridViewColumn column = header.Column;
object value = null;
if (column != null /* not the padding one */
&& columnDP != null /* Column doesn't has ContextMenu property*/)
{
value = column.GetValue(columnDP);
}
if (value == null)
{
value = this.GetValue(gvDP);
}
header.UpdateProperty(targetDP, value);
}
// Prepare column header re-ordering
private void PrepareHeaderDrag(GridViewColumnHeader header, Point pos, Point relativePos, bool cancelInvoke)
{
if (header.Role == GridViewColumnHeaderRole.Normal)
{
_prepareDragging = true;
_isHeaderDragging = false;
_draggingSrcHeader = header;
_startPos = pos;
_relativeStartPos = relativePos;
if (!cancelInvoke)
{
_startColumnIndex = FindIndexByPosition(_startPos, false);
}
}
}
// Start header drag
private void StartHeaderDrag()
{
_startPos = _currentPos;
_isHeaderDragging = true;
// suppress src header's click event
_draggingSrcHeader.SuppressClickEvent = true;
// lock Columns during header dragging
if (Columns != null)
{
Columns.BlockWrite();
}
// Remove the old floating header,
// then create & add the new one per the source header's type
InternalChildren.Remove(_floatingHeader);
AddFloatingHeader(_draggingSrcHeader);
UpdateFloatingHeader(_draggingSrcHeader);
}
// Finish header drag
private void FinishHeaderDrag(bool isCancel)
{
// clear related fields
_prepareDragging = false;
_isHeaderDragging = false;
// restore src header's click event
_draggingSrcHeader.SuppressClickEvent = false;
_floatingHeader.Visibility = Visibility.Hidden;
_floatingHeader.ResetFloatingHeaderCanvasBackground();
_indicator.Visibility = Visibility.Hidden;
// unlock Columns during header dragging
if (Columns != null)
{
Columns.UnblockWrite();
}
// if cancelled, do nothing
if (!isCancel)
{
// Display floating header if vertical move not exceeds header.Height * 2
bool isMoveHeader = IsMousePositionValid(_floatingHeader, _currentPos, 2.0);
Debug.Assert(Columns != null, "Columns is null in OnHeaderDragCompleted");
// Revise the destinate column index
int newColumnIndex = (_startColumnIndex >= _desColumnIndex) ? _desColumnIndex : _desColumnIndex - 1;
if (isMoveHeader)
{
Columns.Move(_startColumnIndex, newColumnIndex);
}
}
}
// check if the Mouse position is in the given valid area
private static bool IsMousePositionValid(FrameworkElement floatingHeader, Point currentPos, double arrange)
{
// valid area: - height * arrange <= currentPos.Y <= height * ( arrange + 1)
return DoubleUtil.LessThanOrClose(-floatingHeader.Height * arrange, currentPos.Y) &&
DoubleUtil.LessThanOrClose(currentPos.Y, floatingHeader.Height * (arrange + 1));
}
#endregion Private Methods
//-------------------------------------------------------------------
//
// Private Class / Properties / Fields
//
//-------------------------------------------------------------------
#region Private Class / Properties / Fields
//Return the actual column headers array
internal List<GridViewColumnHeader> ActualColumnHeaders
{
get
{
if (_gvHeaders == null || !_gvHeadersValid)
{
_gvHeadersValid = true;
_gvHeaders = new List<GridViewColumnHeader>();
if (Columns != null)
{
UIElementCollection children = InternalChildren;
for (int i = 0, count = Columns.Count; i < count; ++i)
{
GridViewColumnHeader header = children[GetVisualIndex(i)] as GridViewColumnHeader;
if (header != null)
{
_gvHeaders.Add(header);
}
}
}
}
return _gvHeaders;
}
}
private bool _gvHeadersValid;
private List<GridViewColumnHeader> _gvHeaders;
// Store the column header's position in visual tree
// including the padding header
private List<Rect> HeadersPositionList
{
get
{
if (_headersPositionList == null)
{
_headersPositionList = new List<Rect>();
}
return _headersPositionList;
}
}
private List<Rect> _headersPositionList;
private ScrollViewer _mainSV;
private ScrollViewer _headerSV;
private GridViewColumnHeader _paddingHeader;
private GridViewColumnHeader _floatingHeader;
private Separator _indicator;
// parent ItemsControl
private ItemsControl _itemsControl;
// source header when header dragging
private GridViewColumnHeader _draggingSrcHeader;
// start position when dragging (position relative to GridViewHeaderRowPresenter)
private Point _startPos;
// relative start position when dragging (position relative to Header)
private Point _relativeStartPos;
// current mouse position (position relative to GridViewHeaderRowPresenter)
private Point _currentPos;
// start column index when begin dragging
private int _startColumnIndex;
// destination column index when finish dragging
private int _desColumnIndex;
// indicating if header is dragging
private bool _isHeaderDragging;
// indicating column is changed or created for the first
private bool _isColumnChangedOrCreated;
// indicating a mouse down, ready to drag the header
private bool _prepareDragging;
// the threshold for horizontal move when header dragging
private const double c_thresholdX = 4.0;
#endregion Private Properties
#region DP resolve helper
// resolve dp from name
private static DependencyProperty GetColumnDPFromName(string dpName)
{
foreach (DependencyProperty dp in s_DPList[1])
{
if ((dp != null) && dpName.Equals(dp.Name))
{
return dp;
}
}
return null;
}
// resolve matching DPs from one
private static void GetMatchingDPs(DependencyProperty indexDP,
out DependencyProperty gvDP, out DependencyProperty columnDP, out DependencyProperty headerDP)
{
for (int i = 0; i < s_DPList.Length; i++)
{
for (int j = 0; j < s_DPList[i].Length; j++)
{
if (indexDP == s_DPList[i][j])
{
gvDP = s_DPList[0][j];
columnDP = s_DPList[1][j];
headerDP = s_DPList[2][j];
goto found;
}
}
}
gvDP = columnDP = headerDP = null;
found: ;
}
private static readonly DependencyProperty[][] s_DPList = new DependencyProperty[][]
{
// DPs on GridViewHeaderRowPresenter
new DependencyProperty[] {
ColumnHeaderContainerStyleProperty,
ColumnHeaderTemplateProperty,
ColumnHeaderTemplateSelectorProperty,
ColumnHeaderStringFormatProperty,
ColumnHeaderContextMenuProperty,
ColumnHeaderToolTipProperty,
},
// DPs on GridViewColumn
new DependencyProperty[] {
GridViewColumn.HeaderContainerStyleProperty,
GridViewColumn.HeaderTemplateProperty,
GridViewColumn.HeaderTemplateSelectorProperty,
GridViewColumn.HeaderStringFormatProperty,
null,
null,
},
// DPs on GridViewColumnHeader
new DependencyProperty[] {
GridViewColumnHeader.StyleProperty,
GridViewColumnHeader.ContentTemplateProperty,
GridViewColumnHeader.ContentTemplateSelectorProperty,
GridViewColumnHeader.ContentStringFormatProperty,
GridViewColumnHeader.ContextMenuProperty,
GridViewColumnHeader.ToolTipProperty,
}
};
#endregion
}
}
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