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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.
// Description: HWND-based ListBox Proxy
//
using System;
using System.Collections;
using System.Text;
using System.Runtime.InteropServices;
using System.ComponentModel;
using System.Windows.Automation;
using System.Windows.Automation.Provider;
using System.Windows;
using Accessibility;
using MS.Win32;
namespace MS.Internal.AutomationProxies
{
// This class represents ListBox and ListBox with check buttons.
class WindowsListBox: ProxyHwnd, ISelectionProvider
{
// ------------------------------------------------------
//
// Constructors
//
// ------------------------------------------------------
#region Constructors
internal WindowsListBox (IntPtr hwnd, ProxyFragment parent, int item, bool parentedByCombo)
: base(hwnd, parent, item)
{
// Set the strings to return properly the properties.
_parentedByCombo = parentedByCombo;
_fIsKeyboardFocusable = true;
_cControlType = ControlType.List;
_fIsContent = !_parentedByCombo;
if (parentedByCombo)
{
_sAutomationId = "ListBox"; // This string is a non-localizable string
}
// support for events
_createOnEvent = new WinEventTracker.ProxyRaiseEvents (RaiseEvents);
}
#endregion
#region Proxy Create
// Static Create method called by UIAutomation to create this proxy.
// returns null if unsuccessful
internal static IRawElementProviderSimple Create(IntPtr hwnd, int idChild, int idObject)
{
return Create(hwnd, idChild);
}
internal static IRawElementProviderSimple Create(IntPtr hwnd, int idChild)
{
bool parentedByCombo = false;
ProxyFragment parent = null;
int item = 0;
try
{
int style = Misc.GetWindowStyle(hwnd);
// If can not get windows style the hwnd is bad so do not create a proxy for it.
if (style == 0)
{
return null;
}
if (Misc.IsBitSet(style, NativeMethods.LBS_COMBOBOX))
{
// List portion of combo box
NativeMethods.COMBOBOXINFO cbInfo = new NativeMethods.COMBOBOXINFO(NativeMethods.comboboxInfoSize);
if (WindowsComboBox.GetComboInfo(hwnd, ref cbInfo) && (cbInfo.hwndCombo != IntPtr.Zero))
{
parent = (ProxyFragment)WindowsComboBox.Create(cbInfo.hwndCombo, 0);
parentedByCombo = true;
item = (int)WindowsComboBox.ComboChildren.List;
}
}
}
catch (ElementNotAvailableException)
{
return null;
}
WindowsListBox listbox = new WindowsListBox (hwnd, parent, item, parentedByCombo);
if (idChild == 0)
{
return listbox;
}
else
{
return listbox.CreateListboxItem(idChild - 1);
}
}
// Static Create method called by the event tracker system
// WinEvents are one throwns because items exist. so it makes sense to create the item and
// check for details afterward.
internal static void RaiseEvents (IntPtr hwnd, int eventId, object idProp, int idObject, int idChild)
{
// NOTE: List may be a portion of the Combobox
// Use WindowsListBox.Create in order to set-up a correct parenthood chain
switch (idObject)
{
case NativeMethods.OBJID_WINDOW:
RaiseEventsOnWindow(hwnd, eventId, idProp, idObject, idChild);
break;
case NativeMethods.OBJID_CLIENT:
RaiseEventsOnClient(hwnd, eventId, idProp, idObject, idChild);
break;
case NativeMethods.OBJID_VSCROLL :
case NativeMethods.OBJID_HSCROLL :
break;
default :
ProxySimple el = (ProxyHwnd)WindowsListBox.Create(hwnd, 0);
if (el != null)
{
el.DispatchEvents(eventId, idProp, idObject, idChild);
}
break;
}
}
#endregion
//------------------------------------------------------
//
// Patterns Implementation
//
//------------------------------------------------------
#region ProxySimple Interface
// Returns a pattern interface if supported.
internal override object GetPatternProvider (AutomationPattern iid)
{
// selection is always supported
if (iid == SelectionPattern.Pattern)
{
return this;
}
// the scroll pattern is only supported when the list is scrollable.
else if (iid == ScrollPattern.Pattern && WindowScroll.HasScrollableStyle(_hwnd))
{
// delegate work to the NonClientArea implementation of IScrollProvider
IScrollProvider scroll = NonClientArea.Create(_hwnd, 0) as IScrollProvider;
if (scroll != null)
{
return scroll;
}
}
return null;
}
// Process all the Element Properties
internal override object GetElementProperty(AutomationProperty idProp)
{
if (idProp == AutomationElement.IsControlElementProperty)
{
return IsParentedByCombo() || SafeNativeMethods.IsWindowVisible(_hwnd);
}
else if (idProp == AutomationElement.IsOffscreenProperty)
{
if (IsParentedByCombo())
{
// Since the bounding rectangle of a collapsed listbox protion of a combo-box is still
// on the virtal desktop needs to check to make sure the listbox protion is
// expanded, i.e. visible.
if (!SafeNativeMethods.IsWindowVisible(_hwnd))
{
return true;
}
}
}
return base.GetElementProperty(idProp);
}
#endregion
#region ProxyFragment Interface
// ------------------------------------------------------
//
// RawElementProvider interface implementation
//
// ------------------------------------------------------
// Returns the next sibling element in the raw hierarchy.
// Peripheral controls have always negative values.
internal override ProxySimple GetNextSibling (ProxySimple child)
{
int item = child._item;
int count = Length;
// Next for an item that does not exist in the list
if (item >= count)
{
throw new ElementNotAvailableException ();
}
if (item >= 0 && (item + 1) < count)
{
return CreateListboxItem (item + 1);
}
else
{
return base.GetNextSibling (child);
}
}
// Returns the previous sibling element in the raw hierarchy.
// Peripheral controls have always negative values.
internal override ProxySimple GetPreviousSibling (ProxySimple child)
{
// start with the scrollbars
ProxySimple ret = base.GetPreviousSibling (child);
if (ret != null)
{
return ret;
}
// then try out the items
int item = child._item;
int count = Length;
// Next for an item that does not exist in the list
if (item >= count)
{
throw new ElementNotAvailableException ();
}
if (item > 0 && (item) < count)
{
return CreateListboxItem (item - 1);
}
else
{
return item != 0 && count > 0 ? CreateListboxItem (count - 1) : null;
}
}
// Returns the first child element in the raw hierarchy.
internal override ProxySimple GetFirstChild ()
{
if (Length > 0)
{
return CreateListboxItem (0);
}
// no content go for the scrollbars
return base.GetFirstChild ();
}
// Returns the last child element in the raw hierarchy.
internal override ProxySimple GetLastChild ()
{
// start with the scrollbars
ProxySimple ret = base.GetFirstChild ();
if (ret != null)
{
return ret;
}
int count = Length;
return count > 0 ? CreateListboxItem (count - 1) : null;
}
// Returns a Proxy element corresponding to the specified screen coordinates.
internal override ProxySimple ElementProviderFromPoint (int x, int y)
{
NativeMethods.Win32Rect listboxrect = new NativeMethods.Win32Rect ();
Misc.GetClientRectInScreenCoordinates(_hwnd, ref listboxrect);
if (Misc.PtInRect(ref listboxrect, x, y))
{
int ret = Misc.ProxySendMessageInt(_hwnd, NativeMethods.LB_ITEMFROMPOINT, IntPtr.Zero, NativeMethods.Util.MAKELPARAM(x - listboxrect.left, y - listboxrect.top));
if (NativeMethods.Util.HIWORD(ret) == 0)
{
int index = NativeMethods.Util.LOWORD(ret);
return CreateListboxItem(index);
}
}
return base.ElementProviderFromPoint (x, y);
}
// Returns an item corresponding to the focused element (if there is one),
// or null otherwise.
internal override ProxySimple GetFocus ()
{
int index = Misc.ProxySendMessageInt(_hwnd, NativeMethods.LB_GETCARETINDEX, IntPtr.Zero, IntPtr.Zero);
if (index != NativeMethods.LB_ERR)
{
return CreateListboxItem(index);
}
return this;
}
#endregion
#region Selection Pattern
// ------------------------------------------------------
//
// ISelectionProvider interface implementation
//
// ------------------------------------------------------
// Returns an enumerator over the current selection.
IRawElementProviderSimple[] ISelectionProvider.GetSelection()
{
int count = Length;
int countSelection = IsMultipleSelection() ? GetSelectionCount() : 1;
if (count <= 0 || countSelection <= 0)
{
return null;
}
IRawElementProviderSimple[] selection = new IRawElementProviderSimple[countSelection];
int index = 0;
for (int itemPos = 0; itemPos < count; itemPos++)
{
if (ListboxItem.IsSelected(_hwnd, itemPos))
{
selection[index] = CreateListboxItem(itemPos);
index++;
}
}
if (index == 0)
{
return null;
}
return selection;
}
// Returns whether the control supports multiple selection.
bool ISelectionProvider.CanSelectMultiple
{
get
{
return IsMultipleSelection ();
}
}
// Returns whether the control requires a minimum of one
// selected element at all times.
bool ISelectionProvider.IsSelectionRequired
{
// If ListBox supports multipleselection - this property always returns false
// since user can unselect everything using the Ctrl + Click
// This property is dynamic in the case of single-selected listbox.
// This should be documented, user should not cached this value (single-selection lb)
get
{
if (IsMultipleSelection ())
{
return false;
}
return Misc.ProxySendMessageInt(_hwnd, NativeMethods.LB_GETCURSEL, IntPtr.Zero, IntPtr.Zero) >= 0;
}
}
#endregion
// ------------------------------------------------------
//
// Protected Methods
//
// ------------------------------------------------------
#region Protected Methods
// Picks a WinEvent to track for a UIA property
protected override int[] PropertyToWinEvent(AutomationProperty idProp)
{
// Upon creation, a single selection Listbox can have no selection to start with
// however once an item has been selection, the selection cannot be removed.
// The notification handler is set based on the type of Listbox (single selection)
// and if nothing is selected.
if (idProp == SelectionPattern.IsSelectionRequiredProperty && !IsMultipleSelection() && !HasSelection())
{
return new int[] { NativeMethods.EventObjectSelection };
}
return base.PropertyToWinEvent(idProp);
}
#endregion
//------------------------------------------------------
//
// Private Methods
//
//------------------------------------------------------
#region Private Method
// Creates a list item RawElementBase Item
private ProxySimple CreateListboxItem (int index)
{
return new ListboxItem (_hwnd, this, index);
}
// Return the number of items (non peripheral) in the listbox.
private int Length
{
get
{
return Misc.ProxySendMessageInt(_hwnd, NativeMethods.LB_GETCOUNT, IntPtr.Zero, IntPtr.Zero);
}
}
private bool IsParentedByCombo ()
{
return _parentedByCombo;
}
private static void RaiseEventsOnClient(IntPtr hwnd, int eventId, object idProp, int idObject, int idChild)
{
ProxySimple el = null;
WindowsListBox wlb = (WindowsListBox)WindowsListBox.Create(hwnd, 0);
// Upon creation, a single selection Listbox can have no selection to start with
// however once an item has been selection, the selection cannot be removed.
// This WinEvent can only be received once, on the first selection.
// Once the notification is received the notification handler is removed to not get it a
// second time.
if ((eventId == NativeMethods.EventObjectSelection || eventId == NativeMethods.EventObjectSelectionAdd) && (idProp as AutomationProperty) == SelectionPattern.IsSelectionRequiredProperty)
{
// This array must be kept in sync with the array in PropertyToWinEvent
WinEventTracker.EvtIdProperty[] aEvtIdProperties = new WinEventTracker.EvtIdProperty[] { new WinEventTracker.EvtIdProperty(NativeMethods.EventObjectSelection, SelectionPattern.IsSelectionRequiredProperty) };
WinEventTracker.RemoveToNotificationList(hwnd, aEvtIdProperties, null, aEvtIdProperties.Length);
el = wlb;
}
else if (eventId == NativeMethods.EventObjectSelection || eventId == NativeMethods.EventObjectSelectionRemove || eventId == NativeMethods.EventObjectSelectionAdd)
{
bool isMultipleSelection = wlb.IsMultipleSelection();
// User should send SelectionAdd for a Multiselect listbox but it sends instead
// Selection. The code below fixes the bug in User
if (eventId == NativeMethods.EventObjectSelection && isMultipleSelection && wlb.HasOtherSelections(idChild - 1))
{
eventId = NativeMethods.EventObjectSelectionAdd;
}
// The spec says a ElementSelectionEvent should be fired when action causes only one
// selection.
if ((eventId == NativeMethods.EventObjectSelectionRemove || eventId == NativeMethods.EventObjectSelectionAdd) &&
isMultipleSelection && wlb.GetSelectionCount() == 1)
{
// The net result of the user action is that there is only one item selected in the
// listbox, so change the event to an EventObjectSelected.
idProp = SelectionItemPattern.ElementSelectedEvent;
eventId = NativeMethods.EventObjectSelection;
// Now need to find what item is selected.
int selection = wlb.GetOtherSelection(idChild - 1);
if (selection != NativeMethods.LB_ERR)
{
idChild = selection;
}
}
el = wlb.CreateListboxItem(idChild - 1);
}
else
{
el = wlb;
}
// Special case for logical element change for listbox item
if ((idProp as AutomationEvent) == AutomationElement.StructureChangedEvent &&
(eventId == NativeMethods.EventObjectDestroy || eventId == NativeMethods.EventObjectCreate))
{
// Since children are referenced by position in the tree, addition and removal
// of items leads to different results when asking properties for the same element
// On removal, item + 1 is now item!
// Use Children Invalidated to let the client knows that all the cached
AutomationInteropProvider.RaiseStructureChangedEvent( wlb, new StructureChangedEventArgs( StructureChangeType.ChildrenInvalidated, wlb.MakeRuntimeId() ) );
return;
}
if (el != null)
{
el.DispatchEvents(eventId, idProp, idObject, idChild);
}
}
private static void RaiseEventsOnWindow(IntPtr hwnd, int eventId, object idProp, int idObject, int idChild)
{
AutomationProperty automationProperty = idProp as AutomationProperty;
ProxySimple el = null;
if ((eventId == NativeMethods.EventObjectShow || eventId == NativeMethods.EventObjectHide) &&
(automationProperty != null && automationProperty == ExpandCollapsePattern.ExpandCollapseStateProperty))
{
if (Misc.IsBitSet(Misc.GetWindowStyle(hwnd), NativeMethods.LBS_COMBOBOX))
{
// List portion of combo: We'll hit it in the case when user hovers over it
NativeMethods.COMBOBOXINFO cbInfo = new NativeMethods.COMBOBOXINFO(NativeMethods.comboboxInfoSize);
if (WindowsComboBox.GetComboInfo(hwnd, ref cbInfo) && (cbInfo.hwndCombo != IntPtr.Zero))
{
WindowsComboBox cb = (WindowsComboBox)WindowsComboBox.Create(cbInfo.hwndCombo, 0);
if (!cb.IsSimpleCombo())
{
el = cb;
}
}
}
}
if (el != null)
{
el.DispatchEvents(eventId, idProp, idObject, idChild);
}
}
#region Selection Pattern Helpers
private int GetOtherSelection(int skipItem)
{
for (int i = 0, count = Length; i < count; i++)
{
if (i != skipItem && ListboxItem.IsSelected(_hwnd, i))
{
// Win32 listbox items are 0 based, UIAutomation listbox items are 1 based.
return i + 1;
}
}
return NativeMethods.LB_ERR;
}
private int GetSelectionCount()
{
int result = Misc.ProxySendMessageInt(_hwnd, NativeMethods.LB_GETSELCOUNT, IntPtr.Zero, IntPtr.Zero);
return result != NativeMethods.LB_ERR ? result : 0;
}
// Detect if there any selections in
// This is used by the WindowsListBoxItem class
// returns true if any items are selected
private bool HasSelection ()
{
int i, count;
for (i = 0, count = Length; i < count && !ListboxItem.IsSelected (_hwnd, i); i++)
;
return (i < count);
}
// Detect if listbox has any element except skipItem selected
// This is used by the WindowsListBoxItem class
// returns true if any items
private bool HasOtherSelections (int skipItem)
{
for (int i = 0, count = Length; i < count; i++)
{
if (i != skipItem && ListboxItem.IsSelected (_hwnd, i))
{
return true;
}
}
return false;
}
// Clears all elements in the multiple-selection listbox
// This is used by the WindowsListBoxItem class
// returns true if operation succeeded
private bool ClearAll ()
{
// clear all possible only in the multi-select case
System.Diagnostics.Debug.Assert (IsMultipleSelection (), "Calling ClearAll on single-selected listbox");
return Misc.ProxySendMessageInt(_hwnd, NativeMethods.LB_SETSEL, IntPtr.Zero, new IntPtr(-1)) != NativeMethods.LB_ERR;
}
// Check the LBS_MULTIPLESEL or/and LBS_EXTENDEDSEL for multiple selection
// This is used by WindowListBoxItem class
// returns true if multiple selection is supported
private bool IsMultipleSelection ()
{
return (0 != (WindowStyle & (NativeMethods.LBS_MULTIPLESEL | NativeMethods.LBS_EXTENDEDSEL)));
}
private bool IsWinFormCheckedListBox()
{
if (WindowsFormsHelper.IsWindowsFormsControl(_hwnd))
{
return ((WindowStyle & NativeMethods.LBS_OWNERDRAWFIXED) == NativeMethods.LBS_OWNERDRAWFIXED) &&
((WindowStyle & NativeMethods.LBS_WANTKEYBOARDINPUT) == NativeMethods.LBS_WANTKEYBOARDINPUT);
}
return false;
}
#endregion
#endregion
//------------------------------------------------------
//
// Private Fields
//
//------------------------------------------------------
#region Private Fields
private bool _parentedByCombo;
#endregion
// ------------------------------------------------------
//
// ListboxItem Private Class
//
//------------------------------------------------------
#region ListBoxItem
// Summary description for WindowsListboxItem.
class ListboxItem : ProxySimple, ISelectionItemProvider, IScrollItemProvider, IToggleProvider
{
// ------------------------------------------------------
//
// Constructors
//
// ------------------------------------------------------
#region Constructors
// Constructor.
internal ListboxItem (IntPtr hwnd, ProxyFragment parent, int item)
: base (hwnd, parent, item)
{
// Set the strings to return properly the properties.
_cControlType = ControlType.ListItem;
_fHasPersistentID = false;
_fIsKeyboardFocusable = true;
_listBox = (WindowsListBox) parent;
}
#endregion
//------------------------------------------------------
//
// Patterns Implementation
//
//------------------------------------------------------
#region ProxySimple Interface
// Returns a pattern interface if supported.
internal override object GetPatternProvider (AutomationPattern iid)
{
if (iid == SelectionItemPattern.Pattern)
{
return this;
}
else if (iid == ScrollItemPattern.Pattern && WindowScroll.IsScrollable(_hwnd))
{
return this;
}
else if (_listBox.IsWinFormCheckedListBox() && iid == TogglePattern.Pattern)
{
return this;
}
return null;
}
// Gets the bounding rectangle for this element
internal override Rect BoundingRectangle
{
get
{
// Don't need to normalize, LB_GETITEMRECT returns absolute coordinates.
return BoundingRect().ToRect(false);
}
}
//Gets the localized name
// Returns the text of ListBox item. Check value is not included.
internal override string LocalizedName
{
get
{
// NOTE: List can be a part of the combobox. Many times
// sending LB_ message will work, however many apps have ownerdraw combos,
// in this case only CB_ type message will work
if (((WindowsListBox)_parent).IsParentedByCombo())
{
WindowsComboBox cb = (WindowsComboBox)_parent._parent;
return cb.GetListItemText(_item);
}
int iTextLen = Misc.ProxySendMessageInt(_hwnd, NativeMethods.LB_GETTEXTLEN, new IntPtr(_item), IntPtr.Zero);
if (iTextLen != 0)
{
if (Misc.GetClassName(_hwnd).Equals("Internet Explorer_TridentLstBox"))
{
// The Trident listbox is a superclassed standard listbox.
// Trident listboxes are owner draw that does not have the hasstring style set.
// All the control contains is the owner draw data and not text. Private
// messages were added to retrieve the owner draw data as text. The new messages
// are used just like the normally LB_GETTEXT and CB_GETTEXT messages.
return XSendMessage.GetItemText(_hwnd, NativeMethods.WM_USER + NativeMethods.LB_GETTEXT, _item, iTextLen);
}
else
{
string text = Misc.GetUnsafeText(_hwnd, NativeMethods.LB_GETTEXT, new IntPtr(_item), iTextLen);
// The application engineer has most likely hidden associated information in the
// listbox item's text with a tab, '\t'. If this is the case remove that hidden
// information.
int iPos = text.IndexOf('\t');
if (iPos > 0)
{
text = text.Substring(0, iPos);
}
return text;
}
}
return "";
}
}
#endregion
#region SelectionItem Pattern
// Selects this element
void ISelectionItemProvider.Select ()
{
// Check that control can be interacted with.
// This state could change anytime
if (!SafeNativeMethods.IsWindowEnabled(_hwnd))
{
throw new ElementNotEnabledException();
}
// get needed info about lbItem
bool multipleSelected = _listBox.IsMultipleSelection ();
bool itemSelected = IsSelected (_hwnd, _item);
bool parentedByCombo = _listBox.IsParentedByCombo();
if (multipleSelected)
{
if (_listBox.HasOtherSelections(_item))
{ // some other elements are selected
// unselect all. It is just simplier to unselect all
// and re-select us, than unselect each element one by one
_listBox.ClearAll ();
}
else if (itemSelected)
{
// multi-selected lbItem with
// only 1 selected element - us
return;
}
}
else if (itemSelected)
{
// if it is a combo, then always perform the selection otherwise the listbox won't disappear
if (!parentedByCombo)
{
// single-selection and we selected already
return;
}
}
if (parentedByCombo)
{
// if this is a combo and the listbox is not displayed the selection will not stick, so
// display the listbox before doing the select.
if (((IExpandCollapseProvider)_listBox._parent).ExpandCollapseState == ExpandCollapseState.Collapsed)
{
((IExpandCollapseProvider)_listBox._parent).Expand();
}
}
// do the selection
if (!Select(multipleSelected))
{
throw new InvalidOperationException(SR.OperationCannotBePerformed);
}
}
// Adds this element to the selection
void ISelectionItemProvider.AddToSelection ()
{
// Check that control can be interacted with.
// This state could change anytime
if (!SafeNativeMethods.IsWindowEnabled(_hwnd))
{
throw new ElementNotEnabledException();
}
// check if item already selected
if (ListboxItem.IsSelected (_hwnd, _item) && !_listBox.IsParentedByCombo())
{
// if it is a combo, then always perform the selection otherwise the listbox won't disappear
return;
}
bool multipleSelection = _listBox.IsMultipleSelection();
// object does not support multi-selection
if (!multipleSelection)
{
IRawElementProviderSimple container = ((ISelectionItemProvider)this).SelectionContainer;
bool selectionRequired = container != null ? ((ISelectionProvider)container).IsSelectionRequired : true;
// For single selection containers that IsSelectionRequired == false and nothing is selected
// an AddToSelection is valid.
if (selectionRequired || _listBox.HasSelection())
{
throw new InvalidOperationException(SR.DoesNotSupportMultipleSelection);
}
}
if (_listBox.IsParentedByCombo())
{
// if this is a combo and the listbox is not displayed the selection will not stick, so
// display the listbox before doing the select.
if (((IExpandCollapseProvider)_listBox._parent).ExpandCollapseState == ExpandCollapseState.Collapsed)
{
((IExpandCollapseProvider)_listBox._parent).Expand();
}
}
// At this point we know: Item either supports multiple selection or nothing
// is selected in the list
// Try to select an item
if (!Select(multipleSelection))
{
throw new InvalidOperationException(SR.OperationCannotBePerformed);
}
}
// Removes this element from the selection
void ISelectionItemProvider.RemoveFromSelection ()
{
// Check that control can be interacted with.
// This state could change anytime
if (!SafeNativeMethods.IsWindowEnabled(_hwnd))
{
throw new ElementNotEnabledException();
}
if (!IsSelected(_hwnd, _item))
{
// simple case, item is not selected
return;
}
// object does not support multi-selection
if (!_listBox.IsMultipleSelection())
{
// single-selected lb - user cannot remove the selection using keyboard and mouse
// At this point we know that item is selected, lb is single-selected hence
// RemoveFromSelection is not possible
throw new InvalidOperationException(SR.SelectionRequired);
}
if (!UnSelect(_hwnd, _item))
{
throw new InvalidOperationException(SR.OperationCannotBePerformed);
}
}
// True if this element is part of the the selection
bool ISelectionItemProvider.IsSelected
{
get
{
return ListboxItem.IsSelected (_hwnd, _item);
}
}
// Returns the container for this element
IRawElementProviderSimple ISelectionItemProvider.SelectionContainer
{
get
{
System.Diagnostics.Debug.Assert (_parent is WindowsListBox, "Invalid Parent for a Listbox Item");
return _parent;
}
}
#endregion SelectionItem Pattern
#region ScrollItem Pattern
void IScrollItemProvider.ScrollIntoView ()
{
if (_listBox._parentedByCombo && !SafeNativeMethods.IsWindowVisible(_hwnd))
{
throw new InvalidOperationException(SR.OperationCannotBePerformed);
}
if (!WindowScroll.IsScrollable(_hwnd))
{
throw new InvalidOperationException(SR.OperationCannotBePerformed);
}
// It is assumed that in a listbox an item will always be smaller than the scrolling area
Misc.ProxySendMessage(_hwnd, NativeMethods.LB_SETTOPINDEX, new IntPtr(_item), IntPtr.Zero);
}
#endregion ScrollItem Pattern
#region IToggleProvider
void IToggleProvider.Toggle()
{
// Check that button can be clicked
// This state could change anytime
if (!SafeNativeMethods.IsWindowEnabled(_hwnd))
{
throw new ElementNotEnabledException();
}
if (!SafeNativeMethods.IsWindowVisible(_hwnd))
{
throw new InvalidOperationException(SR.OperationCannotBePerformed);
}
Toggle();
}
ToggleState IToggleProvider.ToggleState
{
get
{
return ToggleState;
}
}
#endregion IToggleProvider
//------------------------------------------------------
//
// Internal Methods
//
//------------------------------------------------------
#region Internal Methods
#region Selection Pattern Helpers
// Detects if an item is selected
internal static bool IsSelected (IntPtr hwnd, int item)
{
return Misc.ProxySendMessageInt(hwnd, NativeMethods.LB_GETSEL, new IntPtr(item), IntPtr.Zero) > 0;
}
internal static bool Select (IntPtr hwnd, int item, bool fMultipleSelection)
{
int SendMessageResult = 0;
if (fMultipleSelection)
{
SendMessageResult = Misc.ProxySendMessageInt(hwnd, NativeMethods.LB_SETSEL, new IntPtr(1), new IntPtr(item));
}
else
{
SendMessageResult = Misc.ProxySendMessageInt(hwnd, NativeMethods.LB_SETCURSEL, new IntPtr(item), IntPtr.Zero);
}
return NativeMethods.LB_ERR != SendMessageResult;
}
#endregion
#region Focus Helper
// Returns an item corresponding to the focused element (if there is one), or null otherwise.
internal override bool SetFocus ()
{
if (_listBox.IsMultipleSelection ())
{
return Misc.ProxySendMessageInt(_hwnd, NativeMethods.LB_SETCARETINDEX, new IntPtr(_item), new IntPtr(0)) != NativeMethods.LB_ERR;
}
else
{
return Select (_hwnd, _item, false);
}
}
#endregion
#endregion
//------------------------------------------------------
//
// Protected Methods
//
//------------------------------------------------------
#region Protected Methods
// This routine is only called on elements belonging to an hwnd that has the focus.
protected override bool IsFocused ()
{
if (_listBox.IsMultipleSelection ())
{
return Misc.ProxySendMessageInt(_hwnd, NativeMethods.LB_GETCARETINDEX, IntPtr.Zero, IntPtr.Zero) == _item;
}
else
{
return Misc.ProxySendMessageInt(_hwnd, NativeMethods.LB_GETSEL, new IntPtr(_item), IntPtr.Zero) >= 0;
}
}
#endregion
//------------------------------------------------------
//
// Private Methods
//
//------------------------------------------------------
#region Private Methods
private NativeMethods.Win32Rect BoundingRect()
{
NativeMethods.Win32Rect itemRect = new NativeMethods.Win32Rect();
Misc.ProxySendMessage(_hwnd, NativeMethods.LB_GETITEMRECT, new IntPtr(_item), ref itemRect);
return Misc.MapWindowPoints(_hwnd, IntPtr.Zero, ref itemRect, 2) ? itemRect : NativeMethods.Win32Rect.Empty;
}
// Process all the Toggle Properties
private ToggleState ToggleState
{
get
{
ToggleState icsState = ToggleState.Indeterminate;
// Special handling for forms
if (_windowsForms == WindowsFormsHelper.FormControlState.Undeterminate)
{
_windowsForms = WindowsFormsHelper.GetControlState(_hwnd);
}
if (_windowsForms == WindowsFormsHelper.FormControlState.True)
{
int childrenReturned;
object[] accChildren = Accessible.GetAccessibleChildren(this.AccessibleObject, out childrenReturned);
IAccessible accChild = (IAccessible)accChildren[_item];
if (((int)accChild.get_accState(NativeMethods.CHILD_SELF) & NativeMethods.STATE_SYSTEM_CHECKED) == NativeMethods.STATE_SYSTEM_CHECKED)
{
icsState = ToggleState.On;
}
else if (((int)accChild.get_accState(NativeMethods.CHILD_SELF) & NativeMethods.STATE_SYSTEM_MIXED) == NativeMethods.STATE_SYSTEM_MIXED)
{
icsState = ToggleState.Indeterminate;
}
else
{
icsState = ToggleState.Off;
}
}
return icsState;
}
}
#region Selection Pattern Helpers
private void Toggle()
{
// Convoluted way fake a mouse action
NativeMethods.Win32Point pt = new NativeMethods.Win32Point();
if (GetClickablePoint(out pt, false))
{
// Mouse method is used here because following methods fail:
// -BM_CLICK message doesn't work with all buttons (e.g. Start)
// -WM_MOUSEACTIVATE + WM_LBUTTONDOWN + WM_LBUTTONUP messages don't work with all buttons
// -WM_KEYDOWN + WM_KEYUP messages for space bar
// -SendKeyboardInput for space bar
// See prior versions of this file for alternative code.
//
Misc.MouseClick(pt.x, pt.y);
}
}
private bool Select(bool fMultipleSelection)
{
int sendMessageResult = 0;
bool success = true;
if (!((WindowsListBox)_parent).IsParentedByCombo())
{
if (fMultipleSelection)
{
sendMessageResult =
Misc.ProxySendMessageInt(_hwnd, NativeMethods.LB_SETSEL, new IntPtr(1), new IntPtr(_item));
}
else
{
sendMessageResult =
Misc.ProxySendMessageInt(_hwnd, NativeMethods.LB_SETCURSEL, new IntPtr(_item), IntPtr.Zero);
}
success = (NativeMethods.LB_ERR != sendMessageResult);
if (success)
{
// Whether multiple selection or not, send LBN_SELCHANGE.
// This is normally sent when a user presses an arrow key, but
// NOT when LB_SETCURSEL is sent programmatically. We need to
// mimic the action of a user, including all side effects.
int listBoxStyle = Misc.GetWindowStyle(_hwnd);
if (Misc.IsBitSet(listBoxStyle, NativeMethods.LBS_NOTIFY))
{
// Get the child ID of the listbox in its parent hwnd.
int idListBox = Misc.GetWindowId(_hwnd);
IntPtr wParam =
new IntPtr(NativeMethods.Util.MAKELONG(
idListBox, NativeMethods.LBN_SELCHANGE));
IntPtr hwndListBoxParent = Misc.GetParent(_hwnd);
// The return value indicates whether the WM_COMMAND was processed,
// which is irrelevant, so ignore the return value here.
Misc.ProxySendMessageInt(
hwndListBoxParent, NativeMethods.WM_COMMAND, wParam, _hwnd);
}
}
}
else
{
ProxyFragment combo = (WindowsComboBox)_parent._parent;
sendMessageResult =
Misc.ProxySendMessageInt(_hwnd, NativeMethods.LB_SETCURSEL, new IntPtr(_item), IntPtr.Zero);
success = (NativeMethods.LB_ERR != sendMessageResult);
if (success)
{
int id = Misc.GetWindowId(_hwnd);
IntPtr wParam = new IntPtr(NativeMethods.Util.MAKELONG(id, NativeMethods.LBN_SELCHANGE));
// The return value indicates whether the WM_COMMAND was processed,
// which is irrelevant, so ignore the return value here.
Misc.ProxySendMessageInt(combo._hwnd, NativeMethods.WM_COMMAND, wParam, _hwnd);
}
}
return success;
}
// This method should be called only on multi-selected listbox
private bool UnSelect (IntPtr hwnd, int item)
{
// Even though listbox item can be unselected in the single-selected lb programmaticaly
// user cannot do it using the keyboard and mouse hence we will not permit the "removal" of selection in the
// single-selected listbox
// ProxySendMessage(hwnd, NativeMethods.LB_SETCURSEL, new IntPtr (-1), IntPtr.Zero, ref SendMessageResult );
System.Diagnostics.Debug.Assert (_listBox.IsMultipleSelection (), "Calling UnSelect on single-selected listbox");
return Misc.ProxySendMessageInt(hwnd, NativeMethods.LB_SETSEL, IntPtr.Zero, new IntPtr(item)) != NativeMethods.LB_ERR;
}
#endregion
#endregion
//------------------------------------------------------
//
// Private Fields
//
//------------------------------------------------------
#region Private Fields
private WindowsListBox _listBox;
#endregion
}
#endregion
}
}
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