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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.ComponentModel;
using System.Windows.Automation;
using System.Windows.Automation.Peers;
using System.Windows.Data;
using System.Windows.Input;
using MS.Internal;
using MS.Internal.Commands;
using MS.Internal.KnownBoxes;
using MS.Internal.Telemetry.PresentationFramework;
namespace System.Windows.Controls.Primitives
{
/// <summary>
/// ScrollBars are the UI widgets that both let a user drive scrolling from the UI
/// and indicate status of scrolled content.
/// These are used inside the ScrollViewer.
/// Their visibility is determined by the scroller visibility properties on ScrollViewer.
/// </summary>
/// <seealso cref="Control" />
[Localizability(LocalizationCategory.NeverLocalize)]
[TemplatePart(Name = "PART_Track", Type = typeof(Track))]
public class ScrollBar : RangeBase
{
//-------------------------------------------------------------------
//
// Constructors
//
//-------------------------------------------------------------------
#region Constructors
/// <summary>
/// Instantiates a new instance of a ScrollBar.
/// </summary>
public ScrollBar() : base()
{
}
#endregion Constructors
//-------------------------------------------------------------------
//
// Public Properties
//
//-------------------------------------------------------------------
#region Public Properties
/// <summary>
/// Event fires when user press mouse's left button on the thumb.
/// </summary>
public static readonly RoutedEvent ScrollEvent = EventManager.RegisterRoutedEvent("Scroll", RoutingStrategy.Bubble, typeof(ScrollEventHandler), typeof(ScrollBar));
/// <summary>
/// Add / Remove Scroll event handler
/// </summary>
[Category("Behavior")]
public event ScrollEventHandler Scroll { add { AddHandler(ScrollEvent, value); } remove { RemoveHandler(ScrollEvent, value); } }
/// <summary>
/// This property represents the ScrollBar's <see cref="Orientation" />: Vertical or Horizontal.
/// On vertical ScrollBars, the thumb moves up and down. On horizontal bars, the thumb moves left to right.
/// </summary>
public Orientation Orientation
{
get { return (Orientation) GetValue(OrientationProperty); }
set { SetValue(OrientationProperty, value); }
}
/// <summary>
/// ViewportSize is the amount of the scrolled extent currently visible. For most scrolled content, this value
/// will be bound to one of <see cref="ScrollViewer" />'s ViewportSize properties.
/// This property is in logical scrolling units.
/// </summary>
[DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)]
public double ViewportSize
{
get { return (double)GetValue(ViewportSizeProperty); }
set { SetValue(ViewportSizeProperty, value); }
}
/// <summary>
/// DependencyProperty for <see cref="Orientation" /> property.
/// </summary>
public static readonly DependencyProperty OrientationProperty
= DependencyProperty.Register("Orientation", typeof(Orientation), typeof(ScrollBar),
new FrameworkPropertyMetadata(Orientation.Vertical),
new ValidateValueCallback(IsValidOrientation));
/// <summary>
/// DependencyProperty for <see cref="ViewportSize" /> property.
/// </summary>
public static readonly DependencyProperty ViewportSizeProperty
= DependencyProperty.Register("ViewportSize", typeof(double), typeof(ScrollBar),
new FrameworkPropertyMetadata(0.0d),
new ValidateValueCallback(System.Windows.Shapes.Shape.IsDoubleFiniteNonNegative));
/// <summary>
/// Gets reference to ScrollBar's Track element.
/// </summary>
public Track Track
{
get
{
return _track;
}
}
#endregion Properties
#region Method Overrides
/// <summary>
/// Creates AutomationPeer (<see cref="UIElement.OnCreateAutomationPeer"/>)
/// </summary>
protected override AutomationPeer OnCreateAutomationPeer()
{
return new ScrollBarAutomationPeer(this);
}
/// <summary>
/// ScrollBar supports 'Move-To-Point' by pre-processes Shift+MouseLeftButton Click.
/// </summary>
/// <param name="e"></param>
protected override void OnPreviewMouseLeftButtonDown(MouseButtonEventArgs e)
{
_thumbOffset = new Vector();
if ((Track != null) &&
(Track.IsMouseOver) &&
((Keyboard.Modifiers & ModifierKeys.Shift) == ModifierKeys.Shift))
{
// Move Thumb to the Mouse location
Point pt = e.MouseDevice.GetPosition((IInputElement)Track);
double newValue = Track.ValueFromPoint(pt);
if (System.Windows.Shapes.Shape.IsDoubleFinite(newValue))
{
ChangeValue(newValue, false /* defer */);
}
if (Track.Thumb != null && Track.Thumb.IsMouseOver)
{
Point thumbPoint = e.MouseDevice.GetPosition((IInputElement)Track.Thumb);
_thumbOffset = thumbPoint - new Point(Track.Thumb.ActualWidth * 0.5, Track.Thumb.ActualHeight * 0.5);
}
else
{
e.Handled = true;
}
}
base.OnPreviewMouseLeftButtonDown(e);
}
/// <summary>
/// ScrollBar need to remember the point which ContextMenu is invoke in order to perform 'Scroll Here' command correctly.
/// </summary>
/// <param name="e"></param>
protected override void OnPreviewMouseRightButtonUp(MouseButtonEventArgs e)
{
if (Track != null)
{
// Remember the mouse point (relative to Track's co-ordinate).
_latestRightButtonClickPoint = e.MouseDevice.GetPosition((IInputElement)Track);
}
else
{
// Clear the mouse point
_latestRightButtonClickPoint = new Point(-1,-1);
}
base.OnPreviewMouseRightButtonUp(e);
}
/// <summary>
/// Fetches the value of the IsEnabled property
/// </summary>
/// <remarks>
/// The reason this property is overridden is so that ScrollBar
/// could infuse the value for EnoughContentToScroll into it.
/// </remarks>
protected override bool IsEnabledCore
{
get
{
return base.IsEnabledCore && _canScroll;
}
}
/// <summary>
/// ScrollBar locates the Track element when its visual tree is created
/// </summary>
public override void OnApplyTemplate()
{
base.OnApplyTemplate();
_track = GetTemplateChild(TrackName) as Track;
}
#endregion
/// <summary>
/// Scroll content by one line to the top.
/// </summary>
public static readonly RoutedCommand LineUpCommand = new RoutedCommand("LineUp", typeof(ScrollBar));
/// <summary>
/// Scroll content by one line to the bottom.
/// </summary>
public static readonly RoutedCommand LineDownCommand = new RoutedCommand("LineDown", typeof(ScrollBar));
/// <summary>
/// Scroll content by one line to the left.
/// </summary>
public static readonly RoutedCommand LineLeftCommand = new RoutedCommand("LineLeft", typeof(ScrollBar));
/// <summary>
/// Scroll content by one line to the right.
/// </summary>
public static readonly RoutedCommand LineRightCommand = new RoutedCommand("LineRight", typeof(ScrollBar));
/// <summary>
/// Scroll content by one page to the top.
/// </summary>
public static readonly RoutedCommand PageUpCommand = new RoutedCommand("PageUp", typeof(ScrollBar));
/// <summary>
/// Scroll content by one page to the bottom.
/// </summary>
public static readonly RoutedCommand PageDownCommand = new RoutedCommand("PageDown", typeof(ScrollBar));
/// <summary>
/// Scroll content by one page to the left.
/// </summary>
public static readonly RoutedCommand PageLeftCommand = new RoutedCommand("PageLeft", typeof(ScrollBar));
/// <summary>
/// Scroll content by one page to the right.
/// </summary>
public static readonly RoutedCommand PageRightCommand = new RoutedCommand("PageRight", typeof(ScrollBar));
/// <summary>
/// Horizontally scroll to the beginning of the content.
/// </summary>
public static readonly RoutedCommand ScrollToEndCommand = new RoutedCommand("ScrollToEnd", typeof(ScrollBar));
/// <summary>
/// Horizontally scroll to the end of the content.
/// </summary>
public static readonly RoutedCommand ScrollToHomeCommand = new RoutedCommand("ScrollToHome", typeof(ScrollBar));
/// <summary>
/// Horizontally scroll to the beginning of the content.
/// </summary>
public static readonly RoutedCommand ScrollToRightEndCommand = new RoutedCommand("ScrollToRightEnd", typeof(ScrollBar));
/// <summary>
/// Horizontally scroll to the end of the content.
/// </summary>
public static readonly RoutedCommand ScrollToLeftEndCommand = new RoutedCommand("ScrollToLeftEnd", typeof(ScrollBar));
/// <summary>
/// Vertically scroll to the beginning of the content.
/// </summary>
public static readonly RoutedCommand ScrollToTopCommand = new RoutedCommand("ScrollToTop", typeof(ScrollBar));
/// <summary>
/// Vertically scroll to the end of the content.
/// </summary>
public static readonly RoutedCommand ScrollToBottomCommand = new RoutedCommand("ScrollToBottom", typeof(ScrollBar));
/// <summary>
/// Scrolls horizontally to the double value provided in <see cref="System.Windows.Input.ExecutedRoutedEventArgs.Parameter" />.
/// </summary>
public static readonly RoutedCommand ScrollToHorizontalOffsetCommand = new RoutedCommand("ScrollToHorizontalOffset", typeof(ScrollBar));
/// <summary>
/// Scrolls vertically to the double value provided in <see cref="System.Windows.Input.ExecutedRoutedEventArgs.Parameter" />.
/// </summary>
public static readonly RoutedCommand ScrollToVerticalOffsetCommand = new RoutedCommand("ScrollToVerticalOffset", typeof(ScrollBar));
/// <summary>
/// Scrolls horizontally by dragging to the double value provided in <see cref="System.Windows.Input.ExecutedRoutedEventArgs.Parameter" />.
/// </summary>
public static readonly RoutedCommand DeferScrollToHorizontalOffsetCommand = new RoutedCommand("DeferScrollToToHorizontalOffset", typeof(ScrollBar));
/// <summary>
/// Scrolls vertically by dragging to the double value provided in <see cref="System.Windows.Input.ExecutedRoutedEventArgs.Parameter" />.
/// </summary>
public static readonly RoutedCommand DeferScrollToVerticalOffsetCommand = new RoutedCommand("DeferScrollToVerticalOffset", typeof(ScrollBar));
/// <summary>
/// Scroll to the point where user invoke ScrollBar ContextMenu. This command is always handled by ScrollBar.
/// </summary>
public static readonly RoutedCommand ScrollHereCommand = new RoutedCommand("ScrollHere", typeof(ScrollBar));
//-------------------------------------------------------------------
//
// Private Methods (and Event Handlers)
//
//-------------------------------------------------------------------
#region Private Methods
private static void OnThumbDragStarted(object sender, DragStartedEventArgs e)
{
ScrollBar scrollBar = sender as ScrollBar;
if (scrollBar == null) { return; }
scrollBar._hasScrolled = false;
scrollBar._previousValue = scrollBar.Value;
}
// Event handler to listen to thumb events.
private static void OnThumbDragDelta(object sender, DragDeltaEventArgs e)
{
ScrollBar scrollBar = sender as ScrollBar;
if (scrollBar == null) { return; }
scrollBar.UpdateValue(e.HorizontalChange + scrollBar._thumbOffset.X, e.VerticalChange + scrollBar._thumbOffset.Y);
}
// Update ScrollBar Value based on the Thumb drag delta.
// Deal with pixel -> logical scrolling unit conversion, and restrict the value to within [Minimum, Maximum].
private void UpdateValue(double horizontalDragDelta, double verticalDragDelta)
{
if (Track != null)
{
double valueDelta = Track.ValueFromDistance(horizontalDragDelta, verticalDragDelta);
if ( System.Windows.Shapes.Shape.IsDoubleFinite(valueDelta)
&& !DoubleUtil.IsZero(valueDelta))
{
double currentValue = Value;
double newValue = currentValue + valueDelta;
double perpendicularDragDelta;
// Compare distances from thumb for horizontal and vertical orientations
if (Orientation == Orientation.Horizontal)
{
perpendicularDragDelta = Math.Abs(verticalDragDelta);
}
else //Orientation == Orientation.Vertical
{
perpendicularDragDelta = Math.Abs(horizontalDragDelta);
}
if (DoubleUtil.GreaterThan(perpendicularDragDelta, MaxPerpendicularDelta))
{
newValue = _previousValue;
}
if (!DoubleUtil.AreClose(currentValue, newValue))
{
_hasScrolled = true;
ChangeValue(newValue, true /* defer */);
RaiseScrollEvent(ScrollEventType.ThumbTrack);
}
}
}
}
/// <summary>
/// Listen to Thumb DragCompleted event.
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private static void OnThumbDragCompleted(object sender, DragCompletedEventArgs e)
{
((ScrollBar)sender).OnThumbDragCompleted(e);
}
/// <summary>
/// Called when user dragging the Thumb.
/// This function can be override to customize the way Slider handles Thumb movement.
/// </summary>
/// <param name="e"></param>
private void OnThumbDragCompleted(DragCompletedEventArgs e)
{
if (_hasScrolled)
{
FinishDrag();
RaiseScrollEvent(ScrollEventType.EndScroll);
}
}
private IInputElement CommandTarget
{
get
{
IInputElement target = TemplatedParent as IInputElement;
if (target == null)
{
target = this;
}
return target;
}
}
private void FinishDrag()
{
double value = Value;
IInputElement target = CommandTarget;
RoutedCommand command = (Orientation == Orientation.Horizontal) ? DeferScrollToHorizontalOffsetCommand : DeferScrollToVerticalOffsetCommand;
if (command.CanExecute(value, target))
{
// If we were reporting drag commands, we need to give a final scroll command
ChangeValue(value, false /* defer */);
}
}
private void ChangeValue(double newValue, bool defer)
{
newValue = Math.Min(Math.Max(newValue, Minimum), Maximum);
if (IsStandalone) { Value = newValue; }
else
{
IInputElement target = CommandTarget;
RoutedCommand command = null;
bool horizontal = (Orientation == Orientation.Horizontal);
// Fire the deferred (drag) version of the command
if (defer)
{
command = horizontal ? DeferScrollToHorizontalOffsetCommand : DeferScrollToVerticalOffsetCommand;
if (command.CanExecute(newValue, target))
{
// The defer version of the command is enabled, fire this command and not the scroll version
command.Execute(newValue, target);
}
else
{
// The defer version of the command is not enabled, reset and try the scroll version
command = null;
}
}
if (command == null)
{
// Either we're not dragging or the drag command is not enabled, try the scroll version
command = horizontal ? ScrollToHorizontalOffsetCommand : ScrollToVerticalOffsetCommand;
if (command.CanExecute(newValue, target))
{
command.Execute(newValue, target);
}
}
}
}
/// <summary>
/// Scroll to the position where ContextMenu was invoked.
/// </summary>
internal void ScrollToLastMousePoint()
{
Point pt = new Point(-1,-1);
if ((Track != null) && (_latestRightButtonClickPoint != pt))
{
double newValue = Track.ValueFromPoint(_latestRightButtonClickPoint);
if (System.Windows.Shapes.Shape.IsDoubleFinite(newValue))
{
ChangeValue(newValue, false /* defer */);
_latestRightButtonClickPoint = pt;
RaiseScrollEvent(ScrollEventType.ThumbPosition);
}
}
}
internal void RaiseScrollEvent(ScrollEventType scrollEventType)
{
ScrollEventArgs newEvent = new ScrollEventArgs(scrollEventType, Value);
newEvent.Source=this;
RaiseEvent(newEvent);
}
private static void OnScrollCommand(object target, ExecutedRoutedEventArgs args)
{
ScrollBar scrollBar = ((ScrollBar)target);
if (args.Command == ScrollBar.ScrollHereCommand)
{
scrollBar.ScrollToLastMousePoint();
}
if (scrollBar.IsStandalone)
{
if (scrollBar.Orientation == Orientation.Vertical)
{
if (args.Command == ScrollBar.LineUpCommand)
{
scrollBar.LineUp();
}
else if (args.Command == ScrollBar.LineDownCommand)
{
scrollBar.LineDown();
}
else if (args.Command == ScrollBar.PageUpCommand)
{
scrollBar.PageUp();
}
else if (args.Command == ScrollBar.PageDownCommand)
{
scrollBar.PageDown();
}
else if (args.Command == ScrollBar.ScrollToTopCommand)
{
scrollBar.ScrollToTop();
}
else if (args.Command == ScrollBar.ScrollToBottomCommand)
{
scrollBar.ScrollToBottom();
}
}
else //Horizontal
{
if (args.Command == ScrollBar.LineLeftCommand)
{
scrollBar.LineLeft();
}
else if (args.Command == ScrollBar.LineRightCommand)
{
scrollBar.LineRight();
}
else if (args.Command == ScrollBar.PageLeftCommand)
{
scrollBar.PageLeft();
}
else if (args.Command == ScrollBar.PageRightCommand)
{
scrollBar.PageRight();
}
else if (args.Command == ScrollBar.ScrollToLeftEndCommand)
{
scrollBar.ScrollToLeftEnd();
}
else if (args.Command == ScrollBar.ScrollToRightEndCommand)
{
scrollBar.ScrollToRightEnd();
}
}
}
}
private void SmallDecrement()
{
double newValue = Math.Max(Value - SmallChange, Minimum);
if (Value != newValue)
{
Value = newValue;
RaiseScrollEvent(ScrollEventType.SmallDecrement);
}
}
private void SmallIncrement()
{
double newValue = Math.Min(Value + SmallChange, Maximum);
if (Value != newValue)
{
Value = newValue;
RaiseScrollEvent(ScrollEventType.SmallIncrement);
}
}
private void LargeDecrement()
{
double newValue = Math.Max(Value - LargeChange, Minimum);
if (Value != newValue)
{
Value = newValue;
RaiseScrollEvent(ScrollEventType.LargeDecrement);
}
}
private void LargeIncrement()
{
double newValue = Math.Min(Value + LargeChange, Maximum);
if (Value != newValue)
{
Value = newValue;
RaiseScrollEvent(ScrollEventType.LargeIncrement);
}
}
private void ToMinimum()
{
if (Value != Minimum)
{
Value = Minimum;
RaiseScrollEvent(ScrollEventType.First);
}
}
private void ToMaximum()
{
if (Value != Maximum)
{
Value = Maximum;
RaiseScrollEvent(ScrollEventType.Last);
}
}
private void LineUp()
{
SmallDecrement();
}
private void LineDown()
{
SmallIncrement();
}
private void PageUp()
{
LargeDecrement();
}
private void PageDown()
{
LargeIncrement();
}
private void ScrollToTop()
{
ToMinimum();
}
private void ScrollToBottom()
{
ToMaximum();
}
private void LineLeft()
{
SmallDecrement();
}
private void LineRight()
{
SmallIncrement();
}
private void PageLeft()
{
LargeDecrement();
}
private void PageRight()
{
LargeIncrement();
}
private void ScrollToLeftEnd()
{
ToMinimum();
}
private void ScrollToRightEnd()
{
ToMaximum();
}
private static void OnQueryScrollHereCommand(object target, CanExecuteRoutedEventArgs args)
{
args.CanExecute = (args.Command == ScrollBar.ScrollHereCommand);
}
private static void OnQueryScrollCommand(object target, CanExecuteRoutedEventArgs args)
{
args.CanExecute = ((ScrollBar)target).IsStandalone;
}
#endregion
//-------------------------------------------------------------------
//
// Private Members
//
//-------------------------------------------------------------------
#region Private Members
#endregion
//-------------------------------------------------------------------
//
// Static Constructor & Delegates
//
//-------------------------------------------------------------------
#region Static Constructor & Delegates
static ScrollBar()
{
DefaultStyleKeyProperty.OverrideMetadata(typeof(ScrollBar), new FrameworkPropertyMetadata(typeof(ScrollBar)));
_dType = DependencyObjectType.FromSystemTypeInternal(typeof(ScrollBar));
var onScrollCommand = new ExecutedRoutedEventHandler(OnScrollCommand);
var onQueryScrollCommand = new CanExecuteRoutedEventHandler(OnQueryScrollCommand);
FocusableProperty.OverrideMetadata(typeof(ScrollBar), new FrameworkPropertyMetadata(BooleanBoxes.FalseBox));
// Register Event Handler for the Thumb
EventManager.RegisterClassHandler(typeof(ScrollBar), Thumb.DragStartedEvent, new DragStartedEventHandler(OnThumbDragStarted));
EventManager.RegisterClassHandler(typeof(ScrollBar), Thumb.DragDeltaEvent, new DragDeltaEventHandler(OnThumbDragDelta));
EventManager.RegisterClassHandler(typeof(ScrollBar), Thumb.DragCompletedEvent, new DragCompletedEventHandler(OnThumbDragCompleted));
// ScrollBar has common handler for ScrollHere command.
CommandHelpers.RegisterCommandHandler(typeof(ScrollBar), ScrollBar.ScrollHereCommand, onScrollCommand, new CanExecuteRoutedEventHandler(OnQueryScrollHereCommand));
// Vertical Commands
CommandHelpers.RegisterCommandHandler(typeof(ScrollBar), ScrollBar.LineUpCommand, onScrollCommand, onQueryScrollCommand, Key.Up);
CommandHelpers.RegisterCommandHandler(typeof(ScrollBar), ScrollBar.LineDownCommand, onScrollCommand, onQueryScrollCommand, Key.Down);
CommandHelpers.RegisterCommandHandler(typeof(ScrollBar), ScrollBar.PageUpCommand, onScrollCommand, onQueryScrollCommand, Key.PageUp);
CommandHelpers.RegisterCommandHandler(typeof(ScrollBar), ScrollBar.PageDownCommand, onScrollCommand, onQueryScrollCommand, Key.PageDown);
CommandHelpers.RegisterCommandHandler(typeof(ScrollBar), ScrollBar.ScrollToTopCommand, onScrollCommand, onQueryScrollCommand, new KeyGesture(Key.Home, ModifierKeys.Control));
CommandHelpers.RegisterCommandHandler(typeof(ScrollBar), ScrollBar.ScrollToBottomCommand, onScrollCommand, onQueryScrollCommand, new KeyGesture(Key.End, ModifierKeys.Control));
// Horizontal Commands
CommandHelpers.RegisterCommandHandler(typeof(ScrollBar), ScrollBar.LineLeftCommand, onScrollCommand, onQueryScrollCommand, Key.Left);
CommandHelpers.RegisterCommandHandler(typeof(ScrollBar), ScrollBar.LineRightCommand, onScrollCommand, onQueryScrollCommand, Key.Right);
CommandHelpers.RegisterCommandHandler(typeof(ScrollBar), ScrollBar.PageLeftCommand, onScrollCommand, onQueryScrollCommand);
CommandHelpers.RegisterCommandHandler(typeof(ScrollBar), ScrollBar.PageRightCommand, onScrollCommand, onQueryScrollCommand);
CommandHelpers.RegisterCommandHandler(typeof(ScrollBar), ScrollBar.ScrollToLeftEndCommand, onScrollCommand, onQueryScrollCommand, Key.Home);
CommandHelpers.RegisterCommandHandler(typeof(ScrollBar), ScrollBar.ScrollToRightEndCommand, onScrollCommand, onQueryScrollCommand, Key.End);
MaximumProperty.OverrideMetadata(typeof(ScrollBar), new FrameworkPropertyMetadata(new PropertyChangedCallback(ViewChanged)));
MinimumProperty.OverrideMetadata(typeof(ScrollBar), new FrameworkPropertyMetadata(new PropertyChangedCallback(ViewChanged)));
ContextMenuProperty.OverrideMetadata(typeof(ScrollBar), new FrameworkPropertyMetadata(null, new CoerceValueCallback(CoerceContextMenu)));
ControlsTraceLogger.AddControl(TelemetryControls.ScrollBar);
}
private static void ViewChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
ScrollBar scrollBar = (ScrollBar)d;
bool canScrollNew = scrollBar.Maximum > scrollBar.Minimum;
if (canScrollNew != scrollBar._canScroll)
{
scrollBar._canScroll = canScrollNew;
scrollBar.CoerceValue(IsEnabledProperty);
}
}
// Consider adding a verify for ViewportSize to check > 0.0
internal static bool IsValidOrientation(object o)
{
Orientation value = (Orientation)o;
return value == Orientation.Horizontal
|| value == Orientation.Vertical;
}
// Is the scrollbar outside of a scrollviewer?
internal bool IsStandalone
{
get { return _isStandalone; }
set { _isStandalone = value; }
}
// Maximum distance you can drag from thumb before it snaps back
private const double MaxPerpendicularDelta = 150;
private const string TrackName = "PART_Track";
private Track _track;
private Point _latestRightButtonClickPoint = new Point(-1,-1);
private bool _canScroll = true; // Maximum > Minimum by default
private bool _hasScrolled; // Has the thumb been dragged
private bool _isStandalone = true;
private bool _openingContextMenu;
private double _previousValue;
private Vector _thumbOffset;
#endregion
#region DTypeThemeStyleKey
// Returns the DependencyObjectType for the registered ThemeStyleKey's default
// value. Controls will override this method to return approriate types.
internal override DependencyObjectType DTypeThemeStyleKey
{
get { return _dType; }
}
private static DependencyObjectType _dType;
#endregion DTypeThemeStyleKey
#region ContextMenu
private static object CoerceContextMenu(DependencyObject o, object value)
{
bool hasModifiers;
ScrollBar sb = (ScrollBar)o;
if (sb._openingContextMenu &&
sb.GetValueSource(ContextMenuProperty, null, out hasModifiers) == BaseValueSourceInternal.Default && !hasModifiers)
{
// Use a default menu
if (sb.Orientation == Orientation.Vertical)
{
return VerticalContextMenu;
}
else if (sb.FlowDirection == FlowDirection.LeftToRight)
{
return HorizontalContextMenuLTR;
}
else
{
return HorizontalContextMenuRTL;
}
}
return value;
}
/// <summary>
/// Called when ContextMenuOpening is raised on this element.
/// </summary>
/// <param name="e">Event arguments</param>
protected override void OnContextMenuOpening(ContextMenuEventArgs e)
{
base.OnContextMenuOpening(e);
if (!e.Handled)
{
_openingContextMenu = true;
CoerceValue(ContextMenuProperty);
}
}
/// <summary>
/// Called when ContextMenuOpening is raised on this element.
/// </summary>
/// <param name="e">Event arguments</param>
protected override void OnContextMenuClosing(ContextMenuEventArgs e)
{
base.OnContextMenuClosing(e);
_openingContextMenu = false;
CoerceValue(ContextMenuProperty);
}
private static ContextMenu VerticalContextMenu
{
get
{
ContextMenu verticalContextMenu = new ContextMenu();
verticalContextMenu.Items.Add(CreateMenuItem(nameof(SR.ScrollBar_ContextMenu_ScrollHere), "ScrollHere", ScrollBar.ScrollHereCommand));
verticalContextMenu.Items.Add(new Separator());
verticalContextMenu.Items.Add(CreateMenuItem(nameof(SR.ScrollBar_ContextMenu_Top), "Top", ScrollBar.ScrollToTopCommand));
verticalContextMenu.Items.Add(CreateMenuItem(nameof(SR.ScrollBar_ContextMenu_Bottom), "Bottom", ScrollBar.ScrollToBottomCommand));
verticalContextMenu.Items.Add(new Separator());
verticalContextMenu.Items.Add(CreateMenuItem(nameof(SR.ScrollBar_ContextMenu_PageUp), "PageUp", ScrollBar.PageUpCommand));
verticalContextMenu.Items.Add(CreateMenuItem(nameof(SR.ScrollBar_ContextMenu_PageDown), "PageDown", ScrollBar.PageDownCommand));
verticalContextMenu.Items.Add(new Separator());
verticalContextMenu.Items.Add(CreateMenuItem(nameof(SR.ScrollBar_ContextMenu_ScrollUp), "ScrollUp", ScrollBar.LineUpCommand));
verticalContextMenu.Items.Add(CreateMenuItem(nameof(SR.ScrollBar_ContextMenu_ScrollDown), "ScrollDown", ScrollBar.LineDownCommand));
return verticalContextMenu;
}
}
// LeftToRight menu
private static ContextMenu HorizontalContextMenuLTR
{
get
{
ContextMenu horizontalContextMenuLeftToRight = new ContextMenu();
horizontalContextMenuLeftToRight.Items.Add(CreateMenuItem(nameof(SR.ScrollBar_ContextMenu_ScrollHere), "ScrollHere", ScrollBar.ScrollHereCommand));
horizontalContextMenuLeftToRight.Items.Add(new Separator());
horizontalContextMenuLeftToRight.Items.Add(CreateMenuItem(nameof(SR.ScrollBar_ContextMenu_LeftEdge), "LeftEdge", ScrollBar.ScrollToLeftEndCommand));
horizontalContextMenuLeftToRight.Items.Add(CreateMenuItem(nameof(SR.ScrollBar_ContextMenu_RightEdge), "RightEdge", ScrollBar.ScrollToRightEndCommand));
horizontalContextMenuLeftToRight.Items.Add(new Separator());
horizontalContextMenuLeftToRight.Items.Add(CreateMenuItem(nameof(SR.ScrollBar_ContextMenu_PageLeft), "PageLeft", ScrollBar.PageLeftCommand));
horizontalContextMenuLeftToRight.Items.Add(CreateMenuItem(nameof(SR.ScrollBar_ContextMenu_PageRight), "PageRight", ScrollBar.PageRightCommand));
horizontalContextMenuLeftToRight.Items.Add(new Separator());
horizontalContextMenuLeftToRight.Items.Add(CreateMenuItem(nameof(SR.ScrollBar_ContextMenu_ScrollLeft), "ScrollLeft", ScrollBar.LineLeftCommand));
horizontalContextMenuLeftToRight.Items.Add(CreateMenuItem(nameof(SR.ScrollBar_ContextMenu_ScrollRight), "ScrollRight", ScrollBar.LineRightCommand));
return horizontalContextMenuLeftToRight;
}
}
// RightToLeft menu
private static ContextMenu HorizontalContextMenuRTL
{
get
{
ContextMenu horizontalContextMenuRightToLeft = new ContextMenu();
horizontalContextMenuRightToLeft.Items.Add(CreateMenuItem(nameof(SR.ScrollBar_ContextMenu_ScrollHere), "ScrollHere", ScrollBar.ScrollHereCommand));
horizontalContextMenuRightToLeft.Items.Add(new Separator());
horizontalContextMenuRightToLeft.Items.Add(CreateMenuItem(nameof(SR.ScrollBar_ContextMenu_LeftEdge), "LeftEdge", ScrollBar.ScrollToRightEndCommand));
horizontalContextMenuRightToLeft.Items.Add(CreateMenuItem(nameof(SR.ScrollBar_ContextMenu_RightEdge), "RightEdge", ScrollBar.ScrollToLeftEndCommand));
horizontalContextMenuRightToLeft.Items.Add(new Separator());
horizontalContextMenuRightToLeft.Items.Add(CreateMenuItem(nameof(SR.ScrollBar_ContextMenu_PageLeft), "PageLeft", ScrollBar.PageRightCommand));
horizontalContextMenuRightToLeft.Items.Add(CreateMenuItem(nameof(SR.ScrollBar_ContextMenu_PageRight), "PageRight", ScrollBar.PageLeftCommand));
horizontalContextMenuRightToLeft.Items.Add(new Separator());
horizontalContextMenuRightToLeft.Items.Add(CreateMenuItem(nameof(SR.ScrollBar_ContextMenu_ScrollLeft), "ScrollLeft", ScrollBar.LineRightCommand));
horizontalContextMenuRightToLeft.Items.Add(CreateMenuItem(nameof(SR.ScrollBar_ContextMenu_ScrollRight), "ScrollRight", ScrollBar.LineLeftCommand));
return horizontalContextMenuRightToLeft;
}
}
private static MenuItem CreateMenuItem(string name, string automationId, RoutedCommand command)
{
MenuItem menuItem = new MenuItem();
menuItem.Header = SR.GetResourceString(name);
menuItem.Command = command;
AutomationProperties.SetAutomationId(menuItem, automationId);
Binding binding = new Binding();
binding.Path = new PropertyPath(ContextMenu.PlacementTargetProperty);
binding.Mode = BindingMode.OneWay;
binding.RelativeSource = new RelativeSource(RelativeSourceMode.FindAncestor, typeof(ContextMenu), 1);
menuItem.SetBinding(MenuItem.CommandTargetProperty, binding);
return menuItem;
}
//
// This property
// 1. Finds the correct initial size for the _effectiveValues store on the current DependencyObject
// 2. This is a performance optimization
//
internal override int EffectiveValuesInitialSize
{
get { return 42; }
}
#endregion ContextMenu
}
/// <summary>
/// Type of scrolling that causes ScrollEvent.
/// </summary>
public enum ScrollEventType
{
/// <summary>
/// Thumb has stopped moving.
/// </summary>
EndScroll,
/// <summary>
/// Thumb was moved to the Minimum position.
/// </summary>
First,
/// <summary>
/// Thumb was moved a large distance. The user clicked the scroll bar to the left(horizontal) or above(vertical) the scroll box.
/// </summary>
LargeDecrement,
/// <summary>
/// Thumb was moved a large distance. The user clicked the scroll bar to the right(horizontal) or below(vertical) the scroll box.
/// </summary>
LargeIncrement,
/// <summary>
/// Thumb was moved to the Maximum position
/// </summary>
Last,
/// <summary>
/// Thumb was moved a small distance. The user clicked the left(horizontal) or top(vertical) scroll arrow.
/// </summary>
SmallDecrement,
/// <summary>
/// Thumb was moved a small distance. The user clicked the right(horizontal) or bottom(vertical) scroll arrow.
/// </summary>
SmallIncrement,
/// <summary>
/// Thumb was moved.
/// </summary>
ThumbPosition,
/// <summary>
/// Thumb is currently being moved.
/// </summary>
ThumbTrack
}
}
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