Assuming you're going for the old widgets' look n' feel, achieving the exact same result will inevitably involve replacing images and messing with the widgets' layout properties (e.g applying negative margins, altering offsets).
Having said that, I managed to get a quick CSS-based solution that seem to target your needs, and is free of further manipulations. I'm sure a more accurate solution is available, as this attempt is far from perfect, but it should provide you with a good starting point.
Abstract
To simulate the old widgets' looks:
- Round up the top corners for the item headers.
- Apply a background color to the underling container, to avoid those ugly white corners.
- Use top round corners on that container as well, to avoid ugly blue corners on it as a result of the background color applied.
- Reset the bottom padding of the header items to re-center their content.
Implementation
Add the following rules to your stylesheet:
.gwt-StackLayoutPanel,
.gwt-StackLayoutPanel .gwt-StackLayoutPanelHeader {
background-color: #D3DEF6;
border-radius: 5px 5px 0 0;
}
.gwt-StackLayoutPanel .gwt-StackLayoutPanelHeader {
padding-bottom: 0;
}
Illustration
Here's an snapshot of the final result, as created by manipulating the CSS properties on the GWT showcase live example:
