Function HandleActiveWidget

src/window.cpp:2407–2434

* Handle active widget (mouse dragging on widget) with the mouse. * @return State of handling the event. */

 * @return State of handling the event.
 */
static EventState HandleActiveWidget()
{
	for (Window *w : Window::Iterate()) {
		if (w->mouse_capture_widget >= 0) {
			/* Abort if no button is clicked any more. */
			if (!_left_button_down) {
				w->SetWidgetDirty(w->mouse_capture_widget);
				w->mouse_capture_widget = INVALID_WIDGET;
				return ES_HANDLED;
			}

			/* Handle scrollbar internally, or dispatch click event */
			WidgetType type = w->GetWidget<NWidgetBase>(w->mouse_capture_widget)->type;
			if (type == NWID_VSCROLLBAR || type == NWID_HSCROLLBAR) {
				HandleScrollbarScrolling(w);
			} else {
				/* If cursor hasn't moved, there is nothing to do. */
				if (_cursor.delta.x == 0 && _cursor.delta.y == 0) return ES_HANDLED;

				Point pt = { _cursor.pos.x - w->left, _cursor.pos.y - w->top };
				w->OnClick(pt, w->mouse_capture_widget, 0);
			}
			return ES_HANDLED;
		}
	}

	return ES_NOT_HANDLED;
}

/**
 * Handle viewport scrolling with the mouse.