Bug 36446 [Contributions] widgets: Associating Actions with Buttons
Actions can be associated with Menu items , and tool bar items using MenuManager and ToolBarManager but there is not way to associate Action with a regular button and obtaining a reference to that button the closest thing is creating an ActionContributionItem with the desired action in its constructor , then filling the parent composite with ActionContributionItem.fill(Control parent) this creats the button , but it doesn't return a reference to that button , so for example i can't give it any layout data i suggest the ActionContributionItem.fill(Control parent) returns the created widget
bundles/org.eclipse.jface/src/org/eclipse/jface/action/ActionContributionItem.java
result = (Boolean) event.getNewValue();
								}
							}
						}
					};
					action.addPropertyChangeListener(resultListener);
					callback.preExecute(action, e);
				}
				action.runWithEvent(e);
				if (callback != null) {
					if (result == null || result.equals(Boolean.TRUE)) {
						callback.postExecuteSuccess(action, Boolean.TRUE);
					} else {
						callback.postExecuteFailure(action,
								new ExecutionException(action.getText()
										+ " returned failure.")); 
					}
				}
				if (resultListener!=null) {
					result = null;
					action.removePropertyChangeListener(resultListener);
				}
				if (trace) {
					System.out.println((System.currentTimeMillis() - ms)
							+ " ms to run action: " + action.getText()); 
				}
			} else {
				if (callback != null) {
					callback.notEnabled(action, new NotEnabledException(action
							.getText()