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
mi.setAccelerator(accelerator);
					if (text == null) {
						text = updatedAction.getText();
					}
					if (text != null && acceleratorText == null) {
						
						
						
						acceleratorText = LegacyActionTools
								.extractAcceleratorText(text);
						if (acceleratorText == null && accelerator != 0) {
							acceleratorText = Action
									.convertAccelerator(accelerator);
						}
					}
					if (text == null) {
						text = ""; 
					} else {
						text = Action.removeAcceleratorText(text);
					}
					if (acceleratorText == null) {
						mi.setText(text);
					} else {
						mi.setText(text + '\t' + acceleratorText);
					}
				}
				if (imageChanged) {
					updateImages(false);
				}
				if (enableStateChanged) {