Hello again, @Giacomo!
We appreciate your interest and efforts on upgrading to Ext.NET 4 and we hope you deem it worth the effort!
For one thing, that can't be helped, we're talking about a 3-version-away upgrade, so there will be breaking changes between them. Especially between version 1 and 2, there were many structural changes. We thrive to keep the breaking changes to a minimum (or zero!) between minor version releases, but it is just not possible to do so between the major ones. Technology changes, and so we must follow.
We have some recent threads about other people upgrading their systems, and I believe from v2 to v4, with at least
one reported success case. Usually the success reports comes mixed in with questions, so it is not really easy to dig out reports of success migration from version x to y; they come clear from inquiries like yours ("can I migrate from v1 to v4?") then probably tracking that person threads eventually elucidates the success throughout the migration.
This one should give you a good grasp of what expects you on upgrading the project:
Upgrading to 4.1 with support for legacy 1.x, and the progress (without really a clue of when it was fully ported to v4, but that the project went fully to at least v4.5 at some point) from the
posts history.
I'm sure if you further surf through the threads you'll get an even better overview of that.
Back to the main topic here, I understand you don't want to have the layout changed so much as to remove the little top-right 'x' close handle from the tabs. We still use this in our examples explorers too.
This seems to be enough to keep the layout you are using and allow the direct method to happen, just by wrapping away the tabstrip's close handle to the tab panel's
closeTab() call. Just add the block below within your
ext:TabPanel definition:
<TabBarConfig runat="server">
<CustomConfig>
<ext:ConfigItem Name="closeTab" Value="function(tabHandle) { return tabHandle.tabBar.tabPanel.closeTab(tabHandle.card); }" Mode="Raw" />
</CustomConfig>
</TabBarConfig>
I hope this helps for now.