Sortable ListBox

LaplaceOperator · **Posted:** Sat Dec 08, 2007 6:39 pm

I have some problems regarding the sortable listbox. I noticed that GG::ListBox has already support for sorting rows. But it seems not finished or just buggy or I am using it wrong. I made a small testcase and noticed a couple of things that are not how they should be.

1. If I supply a compare function it is ignored during row insertion. Only string comparison is done here. So I have to set the Sort column again after the list has been populated and sort it again.
2. But this introduces another problem. During this sorting the positions of the rows are not corrected. So now the rows have been sorted but they are drawn at the same positions as before. And if you select them, the selection is drawn at the correct position where the row should be.
3. During a call to ListBox::Clear() the head row also gets deleted.

So should I fix this in ListBox, just hack around it in CUISortedListBox or just implement something that works for the BuildDesignator only?

Question regarding rows: How can I make the control in the rightmost cell automatically scale up to the available space?

Geoff the Medio · **Posted:** Sat Dec 08, 2007 7:46 pm

Have you e mailed tzlaine? He's probably the only person who can usefully answer...

LaplaceOperator · **Posted:** Mon Dec 10, 2007 11:00 am

Nope. I haven't. I don't have his email adress. Or should I just PM him?

pd · **Posted:** Mon Dec 10, 2007 2:05 pm

He checks his PMs regularly and that's the way I've been talking to him lately.

tzlaine · **Joined:** Thu Jun 26, 2003 1:33 pm **Posts:** 1092

This sure looks like a bug. Can you provide a code snippet that exercises the bug?

LaplaceOperator · **Posted:** Tue Dec 11, 2007 8:41 am

I just toyed around with ListBox in your controls.cpp tutorial example. If you step through the Insert code you will notice
that DefaultRowCMP<...> is not called (line 1443-1446).
In this particular example it doesn't make any difference though:

Code:

m_lb->SetSortCmp(GG::ListBox::DefaultRowCmp<GG::ListBox::Row>());

m_lb->Insert(new CustomTextRow("Number", 3));
m_lb->Insert(new CustomTextRow("Number", 5));
m_lb->Insert(new CustomTextRow("Number", 1));
m_lb->Insert(new CustomTextRow("Number", 7));
m_lb->Insert(new CustomTextRow("Number", 2));
m_lb->Insert(new CustomTextRow("Number", 4));
m_lb->Insert(new CustomTextRow("Number", 6));

m_lb->SetSortCol(1);

Whereas in "Insert" the vertical row positions are determined correctly, any later sorting (by calling SetSortCol or SetStyle) doesn't update them.
I was wondering anyway wouldn't it be more elegant to have row as a lightweight object that only knows how high it is, and where it's cells are aligned horizontally. But the position is determined by ListBox?
Then to fix the problem that the head row gets deleted during Clear, i just made a little fix. It's not that elegant but it works:

Code:

Index: src/ListBox.cpp
===================================================================
 --- src/ListBox.cpp>----(revision 623)
+++ src/ListBox.cpp>----(working copy)
 @@ -901,7 +901,9 @@
     bool signal = !m_rows.empty(); // inhibit signal if the list box was already empty
     m_rows.clear();
     m_caret = -1;
+    DetachChild(m_header_row); //header_row gets deleted in DeleteChildren() without this
     DeleteChildren();
+    AttachChild(m_header_row);
     m_vscroll = 0;
     m_hscroll = 0;
     m_first_row_shown = m_first_col_shown = 0;

tzlaine · **Joined:** Thu Jun 26, 2003 1:33 pm **Posts:** 1092

Wow. I just looked at the relevant place in the code. It looks like a drunk person wrote it. I'll have a fix in tonight.

tzlaine · **Joined:** Thu Jun 26, 2003 1:33 pm **Posts:** 1092

These problems should be fixed in GG.

LaplaceOperator · **Posted:** Wed Dec 12, 2007 10:40 am

Thanks. Works perfectly now.

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Sortable ListBox

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