// Tests whether a view is valid, whether it still belongs to the window
// hierarchy of the FocusManager.
bool FocusManager::ContainsView(View* view)
{
DCHECK(view);
RootView* root_view = view->GetRootView();
if(!root_view)
{
return false;
}
Widget* widget = root_view->GetWidget();
if(!widget)
{
return false;
}
HWND top_window = widget_->GetNativeView();
HWND window = widget->GetNativeView();
while(window)
{
if(window == top_window)
{
return true;
}
window = ::GetParent(window);
}
return false;
}
void OnScroll(int code, HWND source, bool is_horizontal)
{
int pos;
if(code == SB_ENDSCROLL)
{
return;
}
// If we receive an event from the scrollbar, make the view
// component focused so we actually get mousewheel events.
if(source != NULL)
{
Widget* widget = parent_->GetWidget();
if(widget && widget->GetNativeView()!=GetFocus())
{
parent_->RequestFocus();
}
}
SCROLLINFO si;
si.cbSize = sizeof(si);
si.fMask = SIF_POS | SIF_TRACKPOS;
GetScrollInfo(scrollbar_, SB_CTL, &si);
pos = si.nPos;
ScrollBarController* sbc = parent_->GetController();
switch(code)
{
case SB_BOTTOM: // case SB_RIGHT:
pos = parent_->GetMaxPosition();
break;
case SB_TOP: // case SB_LEFT:
pos = parent_->GetMinPosition();
break;
case SB_LINEDOWN: // case SB_LINERIGHT:
pos += sbc->GetScrollIncrement(parent_, false, true);
pos = std::min(parent_->GetMaxPosition(), pos);
break;
case SB_LINEUP: // case SB_LINELEFT:
pos -= sbc->GetScrollIncrement(parent_, false, false);
pos = std::max(parent_->GetMinPosition(), pos);
break;
case SB_PAGEDOWN: // case SB_PAGERIGHT:
pos += sbc->GetScrollIncrement(parent_, true, true);
pos = std::min(parent_->GetMaxPosition(), pos);
break;
case SB_PAGEUP: // case SB_PAGELEFT:
pos -= sbc->GetScrollIncrement(parent_, true, false);
pos = std::max(parent_->GetMinPosition(), pos);
break;
case SB_THUMBPOSITION:
case SB_THUMBTRACK:
pos = si.nTrackPos;
if(pos < parent_->GetMinPosition())
{
pos = parent_->GetMinPosition();
}
else if(pos > parent_->GetMaxPosition())
{
pos = parent_->GetMaxPosition();
}
break;
default:
break;
}
sbc->ScrollToPosition(parent_, pos);
si.nPos = pos;
si.fMask = SIF_POS;
SetScrollInfo(scrollbar_, SB_CTL, &si, TRUE);
// Note: the system scrollbar modal loop doesn't give a chance
// to our message_loop so we need to call DidProcessMessage()
// manually.
//
// Sadly, we don't know what message has been processed. We may
// want to remove the message from DidProcessMessage()
MSG dummy;
dummy.hwnd = NULL;
dummy.message = 0;
MessageLoopForUI::current()->DidProcessMessage(dummy);
}