Visual Inheritance: designing a "composite"

[jldupont]

I created a simple GWT "composite" class and I am having trouble editing this widget through the "design" facility.

Every time I try changing the position of a widget through the Design window, I get something along the lines of:

Unable to parse source.
GWT Designer was not able to parse source System.out.println(62.0);

Code: Select all

package x.y.z;

import com.google.gwt.user.client.ui.Composite;
import com.google.gwt.user.client.ui.Label;
import com.google.gwt.user.client.ui.LayoutPanel;
import com.google.gwt.core.client.GWT;
import com.google.gwt.dom.client.Style.Unit;

public class System extends Composite {

   private static final AppConstants CONSTANTS = GWT.create(AppConstants.class);
   public System() {
      
      LayoutPanel layoutPanel = new LayoutPanel();
      initWidget(layoutPanel);
      layoutPanel.setSize("594px", "460px");
      
      Label label1 = new Label(CONSTANTS.system_info_text());
      label1.setStyleName("label-center");
      layoutPanel.add(label1);
      layoutPanel.setWidgetTopHeight(label1, 0, Unit.PX, 25.0, Unit.PX);
      layoutPanel.setWidgetLeftRight(label1, 0, Unit.PX, 0, Unit.PX);
      
      LayoutPanel layoutPanel_1 = new LayoutPanel();
      layoutPanel.add(layoutPanel_1);
      layoutPanel.setWidgetLeftWidth(layoutPanel_1, 35.0, Unit.PX, 200.0, Unit.PX);
      layoutPanel.setWidgetTopHeight(layoutPanel_1, 94.0, Unit.PX, 50.0, Unit.PX);
   }
}


NOTE: I am using the latest GWT Designer build on Linux Ubuntu 9.04, Eclipse Galileo.

[jldupont]

I found what the issue was: the usage of "System" as class name confuses GWT Designer a whole lot.

[Eric Clayberg]

System is a core JDK class that is used by GWT Designer internally.

In general, it is a bad idea to reuse class names from the java.lang package.