Editing WoW:Creating tabbed windows (section)

== Tabs in LUA ==
Look at the OnLoad code which registers our tabbed frame with Blizzard's UI code, sets which tab should be selected, and then shows and hides the appropriate pages:

  PanelTemplates_SetNumTabs(myTabContainerFrame, 2);  -- 2 because there are 2 frames total.
  PanelTemplates_SetTab(myTabContainerFrame, 1);      -- 1 because we want tab 1 selected.
  myTabPage1:Show();  -- Show page 1.
  myTabPage2:Hide();  -- Hide all other pages (in this case only one).

These lines should be executed before your frame is displayed for the first time. myFrame is the name of your frame, n is the number of tabs you specified.

Take your time to understand what the PanelTemplates_SetTab()-function does. This is basically the whole trick behind it all. PanelTemplates_SetTab() goes some graphics magic, making the selected tab appear to be selected, while you're left to actually display the proper page.

Now, let's take a look at the Tab_OnClick() function that we used when creating our button template. What it basically does is setting the selectedTab and then calling UpdateTabs()!
You know what that means, don't you? Go ahead and fire up WoW right now (you should outcomment the myButtonHandler() call in the template to avoid errors). You will notice that your tabs are already working just fine! Beside one little thing: They don't do anything yet!

In your Lua button handler (the one I left for an exercise), you probably already know what to do: Extract the number of the selected tab from the button's name which was passed as a parameter ('''this:GetID()'''), then show the UI elements of the new tab and hide all of the other UI elements. Shouldn't be any problem now, since all of the hard work is already done by the library. So rather than boring you with the details of the implementation, I'll close with some tips on efficient techniques for writing button handlers:
* Always wrap up your tabs inside of separate Frame-tags. Thus you'll only have to hide that very frame once, instead of iterating through every single UI element and hiding it by hand.
* Use a string table that contains the names of these frames. Thus you can iterate through the table with a single for loop, instead of writing hundreds of lines. Your code becomes a whole lot more clear, making maintenance so much easier
* Notice that you can also change the background textures when switching tabs. This is done a lot in WoW and is extremely useful when you have very different UIs in the various tabs