private static void FindCommandBinding(CommandBindingCollection commandBindings, object sender, RoutedEventArgs e, ICommand command, bool execute)
{
int index = 0;
while (true)
{
CommandBinding commandBinding = commandBindings.FindMatch(command, ref index);
if (HandleCommandBinding(sender, e, commandBinding, execute))
{
break;
}
}
}
private static void FindCommandBinding(CommandBindingCollection commandBindings, object sender, RoutedEventArgs e, ICommand command, bool execute)
{
int index = 0;
while (true)
{
CommandBinding commandBinding = commandBindings.FindMatch(command, ref index);
if ((commandBinding == null) ||
(execute && ExecuteCommandBinding(sender, (ExecutedRoutedEventArgs)e, commandBinding)) ||
(!execute && CanExecuteCommandBinding(sender, (CanExecuteRoutedEventArgs)e, commandBinding)))
{
break;
}
}
}
private static void FindCommandBinding(object sender, RoutedEventArgs e, ICommand command, bool execute)
{
// Check local command bindings
CommandBindingCollection commandBindings = null;
DependencyObject senderAsDO = sender as DependencyObject;
if (InputElement.IsUIElement(senderAsDO))
{
commandBindings = ((UIElement)senderAsDO).CommandBindingsInternal;
}
else if (InputElement.IsContentElement(senderAsDO))
{
commandBindings = ((ContentElement)senderAsDO).CommandBindingsInternal;
}
else if (InputElement.IsUIElement3D(senderAsDO))
{
commandBindings = ((UIElement3D)senderAsDO).CommandBindingsInternal;
}
if (commandBindings != null)
{
FindCommandBinding(commandBindings, sender, e, command, execute);
}
// If no command binding is found, check class command bindings
// First find the relevant command bindings, under the lock.
// Most of the time there are no such bindings; most of the rest of
// the time there is only one. Lazy-allocate with this in mind.
Tuple <Type, CommandBinding> tuple = null; // zero or one binding
List <Tuple <Type, CommandBinding> > list = null; // more than one
lock (_classCommandBindings.SyncRoot)
{
// Check from the current type to all the base types
Type classType = sender.GetType();
while (classType != null)
{
CommandBindingCollection classCommandBindings = _classCommandBindings[classType] as CommandBindingCollection;
if (classCommandBindings != null)
{
int index = 0;
while (true)
{
CommandBinding commandBinding = classCommandBindings.FindMatch(command, ref index);
if (commandBinding != null)
{
if (tuple == null)
{
tuple = new Tuple <Type, CommandBinding>(classType, commandBinding);
}
else
{
if (list == null)
{
list = new List <Tuple <Type, CommandBinding> >();
list.Add(tuple);
}
list.Add(new Tuple <Type, CommandBinding>(classType, commandBinding));
}
}
else
{
break;
}
}
}
classType = classType.BaseType;
}
}
// execute the bindings. This can call into user code, so it must
// be done outside the lock to avoid deadlock.
if (list != null)
{
// more than one binding
ExecutedRoutedEventArgs exArgs = execute ? (ExecutedRoutedEventArgs)e : null;
CanExecuteRoutedEventArgs canExArgs = execute ? null : (CanExecuteRoutedEventArgs)e;
for (int i = 0; i < list.Count; ++i)
{
// invoke the binding
if ((execute && ExecuteCommandBinding(sender, exArgs, list[i].Item2)) ||
(!execute && CanExecuteCommandBinding(sender, canExArgs, list[i].Item2)))
{
// if it succeeds, advance past the remaining bindings for this type
Type classType = list[i].Item1;
while (++i < list.Count && list[i].Item1 == classType)
{
// no body needed
}
--i; // back up, so that the outer for-loop advances to the right place
}
}
}
else if (tuple != null)
{
// only one binding
if (execute)
{
ExecuteCommandBinding(sender, (ExecutedRoutedEventArgs)e, tuple.Item2);
}
else
{
CanExecuteCommandBinding(sender, (CanExecuteRoutedEventArgs)e, tuple.Item2);
}
}
}
/// <summary>
/// Scans input and command bindings for matching gestures and executes the appropriate command
/// </summary>
/// <remarks>
/// Scans for command to execute in the following order:
/// - input bindings associated with the targetElement instance
/// - input bindings associated with the targetElement class
/// - command bindings associated with the targetElement instance
/// - command bindings associated with the targetElement class
/// </remarks>
/// <param name="targetElement">UIElement/ContentElement to be scanned for input and command bindings</param>
/// <param name="inputEventArgs">InputEventArgs to be matched against for gestures</param>
internal static void TranslateInput(IInputElement targetElement, InputEventArgs inputEventArgs)
{
if ((targetElement == null) || (inputEventArgs == null))
{
return;
}
ICommand command = null;
IInputElement target = null;
object parameter = null;
// Determine UIElement/ContentElement/Neither type
DependencyObject targetElementAsDO = targetElement as DependencyObject;
bool isUIElement = InputElement.IsUIElement(targetElementAsDO);
bool isContentElement = !isUIElement && InputElement.IsContentElement(targetElementAsDO);
bool isUIElement3D = !isUIElement && !isContentElement && InputElement.IsUIElement3D(targetElementAsDO);
// Step 1: Check local input bindings
InputBindingCollection localInputBindings = null;
if (isUIElement)
{
localInputBindings = ((UIElement)targetElement).InputBindingsInternal;
}
else if (isContentElement)
{
localInputBindings = ((ContentElement)targetElement).InputBindingsInternal;
}
else if (isUIElement3D)
{
localInputBindings = ((UIElement3D)targetElement).InputBindingsInternal;
}
if (localInputBindings != null)
{
InputBinding inputBinding = localInputBindings.FindMatch(targetElement, inputEventArgs);
if (inputBinding != null)
{
command = inputBinding.Command;
target = inputBinding.CommandTarget;
parameter = inputBinding.CommandParameter;
}
}
// Step 2: If no command, check class input bindings
if (command == null)
{
lock (_classInputBindings.SyncRoot)
{
Type classType = targetElement.GetType();
while (classType != null)
{
InputBindingCollection classInputBindings = _classInputBindings[classType] as InputBindingCollection;
if (classInputBindings != null)
{
InputBinding inputBinding = classInputBindings.FindMatch(targetElement, inputEventArgs);
if (inputBinding != null)
{
command = inputBinding.Command;
target = inputBinding.CommandTarget;
parameter = inputBinding.CommandParameter;
break;
}
}
classType = classType.BaseType;
}
}
}
// Step 3: If no command, check local command bindings
if (command == null)
{
// Check for the instance level ones Next
CommandBindingCollection localCommandBindings = null;
if (isUIElement)
{
localCommandBindings = ((UIElement)targetElement).CommandBindingsInternal;
}
else if (isContentElement)
{
localCommandBindings = ((ContentElement)targetElement).CommandBindingsInternal;
}
else if (isUIElement3D)
{
localCommandBindings = ((UIElement3D)targetElement).CommandBindingsInternal;
}
if (localCommandBindings != null)
{
command = localCommandBindings.FindMatch(targetElement, inputEventArgs);
}
}
// Step 4: If no command, look at class command bindings
if (command == null)
{
lock (_classCommandBindings.SyncRoot)
{
Type classType = targetElement.GetType();
while (classType != null)
{
CommandBindingCollection classCommandBindings = _classCommandBindings[classType] as CommandBindingCollection;
if (classCommandBindings != null)
{
command = classCommandBindings.FindMatch(targetElement, inputEventArgs);
if (command != null)
{
break;
}
}
classType = classType.BaseType;
}
}
}
// Step 5: If found a command, then execute it (unless it is
// the special "NotACommand" command, which we simply ignore without
// setting Handled=true, so that the input bubbles up to the parent)
if (command != null && command != ApplicationCommands.NotACommand)
{
// We currently do not support declaring the element with focus as the target
// element by setting target == null. Instead, we interpret a null target to indicate
// the element that we are routing the event through, e.g. the targetElement parameter.
if (target == null)
{
target = targetElement;
}
bool continueRouting = false;
RoutedCommand routedCommand = command as RoutedCommand;
if (routedCommand != null)
{
if (routedCommand.CriticalCanExecute(parameter,
target,
inputEventArgs.UserInitiated /*trusted*/,
out continueRouting))
{
// If the command can be executed, we never continue to route the
// input event.
continueRouting = false;
ExecuteCommand(routedCommand, parameter, target, inputEventArgs);
}
}
else
{
if (command.CanExecute(parameter))
{
command.Execute(parameter);
}
}
// If we mapped an input event to a command, we should always
// handle the input event - regardless of whether the command
// was executed or not. Unless the CanExecute handler told us
// to continue the route.
inputEventArgs.Handled = !continueRouting;
}
}
private static void FindCommandBinding(CommandBindingCollection commandBindings, object sender, RoutedEventArgs e, ICommand command, bool execute)
{
int index = 0;
while (true)
{
CommandBinding commandBinding = commandBindings.FindMatch(command, ref index);
if ((commandBinding == null) ||
(execute && ExecuteCommandBinding(sender, (ExecutedRoutedEventArgs)e, commandBinding)) ||
(!execute && CanExecuteCommandBinding(sender, (CanExecuteRoutedEventArgs)e, commandBinding)))
{
break;
}
}
}
