Home » U++ Library support » ArrayCtrl, HeaderCtrl & GridCtrl » How to create a GridCtrl with fixed cell size
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| Re: How to create a GridCtrl with fixed cell size [message #15939 is a reply to message #15938] |
Mon, 19 May 2008 12:32   |
cbpporter
Messages: 1428
Registered: September 2007
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Ultimate Contributor |
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| mrjt wrote on Mon, 19 May 2008 13:23 |
Do you mean something like a spreadsheet?
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No, not like a spreadsheet. For example, if at first I have 5 columns, and after resize 6 could fit, then I need the control to add a column and the first row to display the first 6 items, not just the first 5 as before the resize (and the rest of the rows to pick up the change, and also shift their items). I call this a vertical list  . Something like the way Toolbar expands and aligns items as you change the size of the window.
Anyway, I need to look into the difference between GridCtrl and ArrayCtrl. Believe it or not, I never needed anything else except ColumnList up until now.
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| Re: How to create a GridCtrl with fixed cell size [message #15949 is a reply to message #15938] |
Mon, 19 May 2008 17:23 |
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Please change your code to:
grd.Ready(false);
grd. Clear(true);
for (int i = 0; i < w; i++)
grd.AddColumn("Test", 105);
grd.Ready(true);
Ready(false) tells grid to not refresh util ready flag will be set again. Normally for each addcolumn grid recalculated widths of columns.
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| Re: How to create a GridCtrl with fixed cell size [message #15952 is a reply to message #15947] |
Mon, 19 May 2008 18:09 |
mrjt
Messages: 705
Registered: March 2007
Location: London
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Contributor |
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It seems to me that what you need is very similar to ColumnList, with only 2 (main) differences:
- items drawn left to right (not top to bottom)
- number of columns determined dynamically based on item width
so my suggestion would to modify that.
I've attached my quick and dirty attempt (it works quite well though). Use like a ColumnList, but you'll have to set ItemWidth to get sensible results when using a Display (default width is 50).
-
Attachment: RowList.zip
(Size: 6.09KB, Downloaded 399 times)
[Updated on: Mon, 19 May 2008 18:09] Report message to a moderator |
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| Re: How to create a GridCtrl with fixed cell size [message #15963 is a reply to message #15952] |
Tue, 20 May 2008 02:23 |
cbpporter
Messages: 1428
Registered: September 2007
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Ultimate Contributor |
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| mrjt wrote on Mon, 19 May 2008 19:09 |
It seems to me that what you need is very similar to ColumnList, with only 2 (main) differences:
- items drawn left to right (not top to bottom)
- number of columns determined dynamically based on item width
so my suggestion would to modify that.
I've attached my quick and dirty attempt (it works quite well though). Use like a ColumnList, but you'll have to set ItemWidth to get sensible results when using a Display (default width is 50).
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Thank you very much for using your free time to try this. You are right: I do need something like a ColumnList: actually I was using that before, but I need another draw order. It seems that the way such a list with multiple columns is drawn is confusing for a lot of people, so I had to disable the multiple column option, leaving it to a default of one. But because of the waste of space, I find myself in this situation...
I'll definitely try out you code and probably merge it into ColumnList if possible, seeing as U++ lacks a traditional list control with an optional "icons" layout (like CListCtrl from MFC).
But before that, since I already started with GridCtrl, I have to clear up some issues first.
I used this pretty ugly code to get the control to look and behave as I want it. By using Add variants I could only get a static number of items on a row, so I had to use Set:
void KanjiFlash::PopulateGrid()
{
if (!curList)
return;
grdKanji.Clear();
Vector<Kanji *> &v = *curList;
int cx = 0, cy = 0;
int w = grdKanji.GetSize().cx / CellHeight;
int h = v.GetCount() / w;
if (v.GetCount() * 1.0 / w != h)
h++;
//section 1
//for (int i = 0 ; i < h; i++)
// grdKanji.AddRow("").AlignBottom().Height(CellHeight);
for (int i = 0; i < v.GetCount(); i++)
{
const Kanji& kanji = *v[i];
grdKanji.Set(cy, cx, kanji.Literal());
cx++;
if (cx >= w)
{
cx = 0;
cy++;
}
}
//section 2
//for (int i = 0 ; i < h; i++)
// grdKanji.GetRow(i).AlignBottom().Height(CellHeight);
}
void KanjiFlash::Layout()
{
int w = grdKanji.GetSize().cx / CellHeight;
grdKanji.Ready(false);
grdKanji.Clear(true);
for (int i = 0; i < w; i++)
grdKanji.AddColumn("", CellHeight);
grdKanji.Ready(true);
PopulateGrid();
}
This pretty much works, except some problems.
There are two sections of commented out code. I need to uncomment the first section If I want to adjust the look of each individual row. Here I get two problems:
1. The control doesn't seem to show the scrollbar correctly, and even if it shows it, sometimes the last row is scrolled only about to the middle. It seems that the Height statement is the culprit (CellHeight is 40 under my tests).
2. AlignBottom or any other align doesn't seem to work.
If I uncomment the second section (it doesn't mater if the first is commented or not), rows are drawn at incorrect positions, but react to mouse at correct coordinates.
Also on a side note, I couldn't find a GetRowCount, event though a GetColumnCount is present.
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| Re: How to create a GridCtrl with fixed cell size [message #15964 is a reply to message #15963] |
Tue, 20 May 2008 08:19 |
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| Quote: |
1. The control doesn't seem to show the scrollbar correctly, and even if it shows it, sometimes the last row is scrolled only about to the middle. It seems that the Height statement is the culprit (CellHeight is 40 under my tests).
2. AlignBottom or any other align doesn't seem to work.
If I uncomment the second section (it doesn't mater if the first is commented or not), rows are drawn at incorrect positions, but react to mouse at correct coordinates.
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Ok, I'll check it (AlignBottom should work - maybe I broke sth..)
| Quote: |
Also on a side note, I couldn't find a GetRowCount, event though a GetColumnCount is present.
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simply use GetCount(). Maybe I'll add GetRowCount alias too.
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| Re: How to create a GridCtrl with fixed cell size [message #15965 is a reply to message #15964] |
Tue, 20 May 2008 09:07 |
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Please do following corrections to your code:
in Layout()
for (int i = 0; i < w; i++)
grd.AddColumn("").AlignBottom();
and in PopulateGrid()
//section 1
for (int i = 0 ; i < h; i++)
grd.AddRow(1, CellHeight);
Now everything should work. Height() is a only sytnax sugar. It dosn't couse grid refresh, rows heights recaluclation. However it can be confusign. I'll think about it. Align* for particualr row doesn't work now. I'll fix that in the next release.
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| Re: How to create a GridCtrl with fixed cell size [message #15968 is a reply to message #15966] |
Tue, 20 May 2008 11:13 |
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| mrjt wrote on Tue, 20 May 2008 04:49 |
I have exactly the same issue, I hate the way ColumnList works. My main issues:
- Lack of key/value support (every other list-style control supports it, why not ColumnList?)
- Bizarre scrolling. A columnized list should scroll sideways to show new columns, not the vertically one item at a time. I think this is the one that really confuses people.
- Difficult selection determination
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I like scrolling in column list. It dosn't scroll columns but items in visible columns. This is a very good solution for long list (at least for me). You can adjust columns count by changing the width of just one column (I mean here it's easy to make more items visible without resizing the widget). Of course similar possibility could be implemented in classical approach.
What you need is arrayctrl/gridctrl which adjust columns count automaticaly for given list count. It can be easily done. However grid/array ctrl are heavy controls. I would suggest creating a new control (RowList e.g).
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| Re: How to create a GridCtrl with fixed cell size [message #15971 is a reply to message #15966] |
Tue, 20 May 2008 14:18 |
cbpporter
Messages: 1428
Registered: September 2007
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Ultimate Contributor |
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Well I don't like the scrolling but I definitely appreciate how useful it is for list of a lot of items and I've gotten used to it. But if the user is unable to scroll and desperately tries to find an item on a different column only after a small scroll, that's a problem. Anyway, I'm OK with it in general, and in this case I'll use grid.
| mrjt wrote on Tue, 20 May 2008 11:49 |
I would be surprised you could do this, the changes are too widespread and complete to be integrated as an addition feature without adding considerable bloat and complexity.
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I did some diff's and the bloat wouldn't be that great, but the complexity would define telly take a hard hit. ColumnList is nice and light weight, and since it is called ColumnList, maybe it's not the best idea to merge the two? Then how about some testing, debugging if necessary, and maybe adding key/value support and including it in Bazaar?
I have one last question regarding GridCtrl: what does Item::Clickable do? It does not seem to do what I imagined. And can I set a cell so that it is not clickable/selectable. I need this only for tail cells.
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| Re: How to create a GridCtrl with fixed cell size [message #15973 is a reply to message #15971] |
Tue, 20 May 2008 15:33 |
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| Quote: |
I have one last question regarding GridCtrl: what does Item::Clickable do? It does not seem to do what I imagined. And can I set a cell so that it is not clickable/selectable. I need this only for tail cells.
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Clicakble means cell is clickable or not, i.e cell can or can't be selected. Could you post here your whole package so I could test it?
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| Re: How to create a GridCtrl with fixed cell size [message #15982 is a reply to message #15981] |
Wed, 21 May 2008 15:58 |
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| cbpporter wrote on Wed, 21 May 2008 09:48 |
Now I need to determine the current row & column. I found a GetCurrentRow (but no GetCurrentColumn), but the value which it returned seems to be off (and even constant in my case). There is also GetCursor, which returns (-1, -1)? And which is the event for cell change?
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GetCursorPos return Point with currently pointed cell otherwise it returns Point(-1, -1). It should work. If not please give me some more information (calling context) or attach a test case.
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And is there an easier way to do key/value stuff than using a Value and GridDisplay?
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What you mean exactely? What do you want to achieve?
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| Re: How to create a GridCtrl with fixed cell size [message #15984 is a reply to message #15983] |
Wed, 21 May 2008 17:45 |
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| Quote: |
GetCursorPos worked. I just had to change event from WhenCursor to WhenChangeRow & WhenChangeCol. With WhenCursor it was always (-1,-1), even though this event triggered on cell change.
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Starange, you should get correct values in WhenCursor. I'll try to check it.
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Like in most other cases, I need to insert some data in the container widget, but I need it to display some text. From what I could tell from the interface of GridCtrl, is that you insert some arbitrary type converted to a Value, and write a custom Display to display a string while the control holds you values.
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Ok, now I understand. One cell holds one Value object. If you want key/value pair conected with one cell you have to use some structure as Value. As for displaying. You have to extend GridDisplay class which contain some useful methods like SetLeft/Right/CenterImage.
You could also do somehting like this:
grd.AddIndex(); this column will hold keys (and it will be invisible)
grd.AddColumn(); this column will hold values
grd.AddIndex()
grd.AddColumn
In GridDisplay you can access via parent member neighbours' values. You can also read current position via col, row members.
Hope that will help you somehow
[Updated on: Wed, 21 May 2008 17:45] Report message to a moderator |
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| Re: How to create a GridCtrl with fixed cell size [message #15999 is a reply to message #15984] |
Thu, 22 May 2008 11:50 |
cbpporter
Messages: 1428
Registered: September 2007
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Ultimate Contributor |
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[quote title=unodgs wrote on Wed, 21 May 2008 18:45]| Quote: |
Ok, now I understand. One cell holds one Value object. If you want key/value pair conected with one cell you have to use some structure as Value. As for displaying. You have to extend GridDisplay class which contain some useful methods like SetLeft/Right/CenterImage.
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Yes, I know that. This was not a question of how, it was a question of principle. I was asking why isn't there and easier method of doing it. The scenario I described is a fairly common one IMO. It's great that you can use a Display and do really fancy stuff if you need it, but in most cases I just want to display a simple text extracted from the Value in exactly the same position and with same style as if I had inserted a string directly. In such cases, using Display is a little overkill, and witting them can be repetitive and tedious.
Let's take for example a Paint method from Dispaly:
virtual void Paint(Draw& w, const Rect& r, const Value& q,
Color ink, Color paper, dword style) const
It has 6 parameters, and all have useful predefined values which you'll rarely ignore or change and go ahead and use them. A large portion of these displays consists of a simple w.DrawText and maybe some position calculation. Since U++ is in general good at detecting common idioms and offering some API, mechanism or clever trick for it, I was wondering why it doesn't offer something like that in this case. For example, something like:
struct MyDisplay: TextDisplay
{
virtual String Text(const Value &q) const;
} |
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| Re: How to create a GridCtrl with fixed cell size [message #16001 is a reply to message #15999] |
Thu, 22 May 2008 12:10 |
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You can use converters. For example:
struct SexConv : Convert
{
Value Format(const Value& q) const
{
switch(int(q))
{
case SEX_MALE: return "Male";
case SEX_FEMALE: return "Female";
case SEX_CHILD: return "Child";
}
return Null;
}
};
grid.AddColumn("Key column").SetConvert(Single<SexConverter>());
grid.Add(SEX_MALE).Add(SEX_FEMALE);
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| Re: How to create a GridCtrl with fixed cell size [message #16005 is a reply to message #16001] |
Thu, 22 May 2008 15:03 |
cbpporter
Messages: 1428
Registered: September 2007
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Ultimate Contributor |
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Great! I never though about using a Converter for this. And since String is ref counted (and my strings are also short), it should be fairly quick to extract a field from the value this way.
I've done some code clean-up and am very happy with the result. I do miss the ColumnList look a little, so I'm going to add an option to switch between a ColumnList output and a GridCtrl one, with grid being default .
I still have 2 questions not 100% related to GridCtrl:
1. I noticed that displaying a large number of CJK characters is pretty slow. I tried replacing all the CJK characters with English ones, and the control was blazing fast again, so I don't believe it's related to GridCtrl. I wonder if there is a native limitation in the drawing sped of these chars (they are quite a bit more complex that other ones), or is this related to U++. I remember Mirek saying once that after he fixed some bugs regarding the determination of the metrics for these chars, it became slow, so he had to speed it up.
2. Is there an Array like container, but which does not free the memory occupied by it's items? I'm using Vector<Foo *> right now.
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| Re: How to create a GridCtrl with fixed cell size [message #16337 is a reply to message #16205] |
Mon, 09 June 2008 10:08 |
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| cbpporter wrote on Mon, 02 June 2008 05:06 |
A secondary issue appeared in cases when after a layout change which resulted in a scrollbar the user executed another one: the top row would not be updated on scroll.
So I decided to investigate GridCtrl and I found the solution to both problems. After calling Ready(false), a Clear(true) does not update the scrollbar information, so that computations done in layout still have the scrollbar size included, because of the way GetSize investigates the frame count to return the adjusted size.
So the issues can be solved by either swapping the order of the Ready and Clear call, or by calling UpdateScrollbars after the clear.
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The problem is UpdateSb in Clear is called when grid is in ready state, but I think it can be called always - then you will get proper values in your Layout method. I will commit the change today to uvs.
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