bool
TabNavigationWalker::Focus (UIElement *element, bool forwards)
{
bool focused = false;
UIElement *current = element;
UIElement *root = element;
Types *types = Deployment::GetCurrent ()->GetTypes ();
// If tabbing in reverse, we immediately go up a level from initial root as
// we know we will not be focusing any of its children.
if (!forwards && root->GetVisualParent ())
root = root->GetVisualParent ();
do {
// If we're starting a tab sequence and the parent of the current element is set to
// the 'Once' navigation mode, we should not traverse the children
if (!(root == current &&
root->GetVisualParent () &&
GetActiveNavigationMode (root->GetVisualParent (), types) == KeyboardNavigationModeOnce)) {
focused |= WalkChildren (root, current, forwards, types);
}
if (!focused && GetActiveNavigationMode (root, types) == KeyboardNavigationModeCycle)
return true;
current = root;
root = root->GetVisualParent ();
} while (!focused && root);
if (!focused)
focused |= WalkChildren (current, NULL, forwards, types);
return focused;
}
bool
Control::Focus (bool recurse)
{
if (!IsAttached ())
return false;
/* according to msdn, these three things must be true for an element to be focusable:
*
* 1. the element must be visible
* 2. the element must have IsTabStop = true
* 3. the element must be part of the plugin's visual tree, and must have had its Loaded event fired.
*/
/*
* If the current control is not focusable, we walk the visual tree and stop as soon
* as we find the first focusable child. That then becomes focused
*/
Types *types = GetDeployment ()->GetTypes ();
Surface *surface = GetDeployment ()->GetSurface ();
DeepTreeWalker walker (this);
while (UIElement *e = walker.Step ()) {
if (!types->IsSubclassOf (e->GetObjectType (), Type::CONTROL))
continue;
Control *c = (Control *)e;
if (!c->GetIsEnabled ()) {
if (!recurse)
return false;
walker.SkipBranch ();
continue;
}
// A control is focusable if it is attached to a visual tree whose root
// element has been loaded
bool loaded = false;
for (UIElement *check = this; !loaded && check != NULL; check = check->GetVisualParent ())
loaded |= check->IsLoaded ();
if (loaded && c->GetRenderVisible () && c->GetIsTabStop ())
return surface->FocusElement (c);
if (!recurse)
return false;
}
return false;
}