在Draw2d中,Lightweight是gef图形系统的”shell”及”display”,其在swt中的代理是canvas,所以所有的GEF的事件来源于这个canvas,下面就看下gef事件处理的流程,首先肯定要监听canvas的事件,这个通过LightweightSystem的addListeners函数注册其内的canvas的各种事件监听器。
1.SWT层事件监听器安装:
Class ScrollingGraphicalViewer. createControl(Composite parent)
Class FigureCanvas(int style, Composite parent, LightweightSystem lws)-> lws.setControl(this);
Class LightweightSystem. setControl(Canvas c)-> addListeners();
getEventDispatcher()
protected class EventHandler
handleEvent(Event event)
2. LightweightSystem层消息分发器安装:
class GraphicalEditor. createGraphicalViewer(Composite parent). setGraphicalViewer(viewer);
class EditDomain. addViewer(EditPartViewer viewer): viewer.setEditDomain(this);
class GraphicalViewer. setEditDomain(EditDomain domain):
getLightweightSystem()
.setEventDispatcher(eventDispatcher = new DomainEventDispatcher(domain, this));
class LightweightSystem.setEventDispatcher(EventDispatcher dispatcher) ;
3. LightweightSystem消息分发器处理流程:
以键盘消息为例
class EventDispatcher.dispatchMousePressed(org.eclipse.swt.events.MouseEvent me)-> domain.mouseDown(me, viewer);
class Editdomain
public void mouseDown(MouseEvent mouseEvent, EditPartViewer viewer) {
Tool tool = getActiveTool();
if (tool != null)
tool.mouseDown(mouseEvent, viewer);
}
之后就是具体的Tool层的实现类中的事件处理了
SWT-GEF事件转义相关类
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转载自aquarion.iteye.com/blog/2101191
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周排行