| using a hyperlink with a Table/TableViewer/TreeViewer - options and performance [message #310469] |
Tue, 05 December 2006 00:31  |
Eclipse User |
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I'm writing a search facility for my product. When searching, it's
possible for hundreds of results to be returned. Each result is shown
as a table row with up to 3 links in it (to various levels of the
hierarchy representing the result). The table is shown through a dialog
of a few rows.
Previously this all worked fine (except without the hyperlinks) by
having a TableViewer. The scrolling and resizing was fast, even if
there were thousands of results.
Now I'm trying to add the links. I see the following options:
1) Using a plain Table with a TableEditor (which refers to a Link
control). This worked reasonably well, except for performance. It's
unusable with more than a small number of rows. There is also this bug:
https://bugs.eclipse.org/bugs/show_bug.cgi?id=166720
So this option won't work (unless I'm doing it wrong or there is another
way to do it).
2) TableViewer - I don't think it's possible to have an arbitrary
control for rendering a table cell in use with a TableViewer unless I
subclass it. Creating a CellEditor does no good, as this replaces the
control only when the cell is edited.
My next step is to consider subclassing TableViewer and having it use a
TableEditor referring to a Link, however, I'm concerned I will run into
the same issues I have with option 1.
3) Use a TreeViewer. The search results can be represented as a tree,
where each node then has only one link in it. I have not looked into
this, but I would assume I will have to subclass TreeViewer as in option
2 to have it render a Link.
Are there other options? Am I missing something obvious?
TIA,
Francis
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| Re: using a hyperlink with a Table/TableViewer/TreeViewer - options and performance [message #310470 is a reply to message #310469] |
Tue, 05 December 2006 02:54  |
| Eclipse User |
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Francis Upton schrieb:
> I'm writing a search facility for my product. When searching, it's
> possible for hundreds of results to be returned. Each result is shown
> as a table row with up to 3 links in it (to various levels of the
> hierarchy representing the result). The table is shown through a dialog
> of a few rows.
>
> Previously this all worked fine (except without the hyperlinks) by
> having a TableViewer. The scrolling and resizing was fast, even if
> there were thousands of results.
>
> Now I'm trying to add the links. I see the following options:
>
> 1) Using a plain Table with a TableEditor (which refers to a Link
> control). This worked reasonably well, except for performance. It's
> unusable with more than a small number of rows. There is also this bug:
>
> https://bugs.eclipse.org/bugs/show_bug.cgi?id=166720
>
> So this option won't work (unless I'm doing it wrong or there is another
> way to do it).
>
Well if you really have so many results that's a problem because your
Table has to handle very many Widgets whereas is in TableViewer there
aren't hardly any!
> 2) TableViewer - I don't think it's possible to have an arbitrary
> control for rendering a table cell in use with a TableViewer unless I
> subclass it. Creating a CellEditor does no good, as this replaces the
> control only when the cell is edited.
>
> My next step is to consider subclassing TableViewer and having it use a
> TableEditor referring to a Link, however, I'm concerned I will run into
> the same issues I have with option 1.
>
Why does it have to be a TableEditor. You could make the String look
like a link (underlining maybe is a problem but you can resolve it using
custom drawing).
To change the foreground color ITableColorProvider and to underline an
item you can look at the owner draw support:
Owner Draw is shown in:
- http://www.eclipse.org/swt/snippets/
-
http://www.eclipse.org/articles/Article-CustomDrawingTableAn dTreeItems/customDraw.htm
If you want to open a link when the user clicks one of the emulated
links you only need to track mouse clicks on your like shown in this
snippet.
http://dev.eclipse.org/viewcvs/index.cgi/%7Echeckout%7E/org. eclipse.swt.snippets/src/org/eclipse/swt/snippets/Snippet110 .java
If you are using 3.3 for development and there is/will be a bunch of new
API which make all the above fairly easy.
OwnerDraw:
http://dev.eclipse.org/viewcvs/index.cgi/org.eclipse.jface.s nippets/Eclipse%20JFace%20Snippets/org/eclipse/jface/snippet s/viewers/Snippet010OwnerDraw.java?rev=HEAD&content-type =text/vnd.viewcvs-markup
(broken if you run it against current CVS)
CellSelection:
https://bugs.eclipse.org/bugs/show_bug.cgi?id=151377
> 3) Use a TreeViewer. The search results can be represented as a tree,
> where each node then has only one link in it. I have not looked into
> this, but I would assume I will have to subclass TreeViewer as in option
> 2 to have it render a Link.
>
> Are there other options? Am I missing something obvious?
>
The same as for TableViewer.
> TIA,
>
> Francis
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| Re: using a hyperlink with a Table/TableViewer/TreeViewer - options and performance [message #310472 is a reply to message #310470] |
Tue, 05 December 2006 04:19 |
| Eclipse User |
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Thanks Tom, I was thinking along the lines you suggested. I will make a
link by changing the color and drawing a line using owner draw.
I decided to handle the clicking by just responding to the selection
event on the TableViewer (thus allowing keyboard selection).
It would be nice if there was a simpler way to include links using the
Viewers, since the TableEditor solution is so impractical.
Thanks again for your help!
Francis
Tom Schindl wrote:
> Francis Upton schrieb:
>> I'm writing a search facility for my product. When searching, it's
>> possible for hundreds of results to be returned. Each result is shown
>> as a table row with up to 3 links in it (to various levels of the
>> hierarchy representing the result). The table is shown through a dialog
>> of a few rows.
>>
>> Previously this all worked fine (except without the hyperlinks) by
>> having a TableViewer. The scrolling and resizing was fast, even if
>> there were thousands of results.
>>
>> Now I'm trying to add the links. I see the following options:
>>
>> 1) Using a plain Table with a TableEditor (which refers to a Link
>> control). This worked reasonably well, except for performance. It's
>> unusable with more than a small number of rows. There is also this bug:
>>
>> https://bugs.eclipse.org/bugs/show_bug.cgi?id=166720
>>
>> So this option won't work (unless I'm doing it wrong or there is another
>> way to do it).
>>
>
> Well if you really have so many results that's a problem because your
> Table has to handle very many Widgets whereas is in TableViewer there
> aren't hardly any!
>
>> 2) TableViewer - I don't think it's possible to have an arbitrary
>> control for rendering a table cell in use with a TableViewer unless I
>> subclass it. Creating a CellEditor does no good, as this replaces the
>> control only when the cell is edited.
>>
>> My next step is to consider subclassing TableViewer and having it use a
>> TableEditor referring to a Link, however, I'm concerned I will run into
>> the same issues I have with option 1.
>>
>
> Why does it have to be a TableEditor. You could make the String look
> like a link (underlining maybe is a problem but you can resolve it using
> custom drawing).
>
> To change the foreground color ITableColorProvider and to underline an
> item you can look at the owner draw support:
>
> Owner Draw is shown in:
> - http://www.eclipse.org/swt/snippets/
> -
> http://www.eclipse.org/articles/Article-CustomDrawingTableAn dTreeItems/customDraw.htm
>
> If you want to open a link when the user clicks one of the emulated
> links you only need to track mouse clicks on your like shown in this
> snippet.
>
> http://dev.eclipse.org/viewcvs/index.cgi/%7Echeckout%7E/org. eclipse.swt.snippets/src/org/eclipse/swt/snippets/Snippet110 .java
>
> If you are using 3.3 for development and there is/will be a bunch of new
> API which make all the above fairly easy.
>
> OwnerDraw:
> http://dev.eclipse.org/viewcvs/index.cgi/org.eclipse.jface.s nippets/Eclipse%20JFace%20Snippets/org/eclipse/jface/snippet s/viewers/Snippet010OwnerDraw.java?rev=HEAD&content-type =text/vnd.viewcvs-markup
> (broken if you run it against current CVS)
> CellSelection:
> https://bugs.eclipse.org/bugs/show_bug.cgi?id=151377
>
>> 3) Use a TreeViewer. The search results can be represented as a tree,
>> where each node then has only one link in it. I have not looked into
>> this, but I would assume I will have to subclass TreeViewer as in option
>> 2 to have it render a Link.
>>
>> Are there other options? Am I missing something obvious?
>>
>
> The same as for TableViewer.
>
>> TIA,
>>
>> Francis
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| Re: using a hyperlink with a Table/TableViewer/TreeViewer - options and performance [message #310475 is a reply to message #310474] |
Tue, 05 December 2006 05:48 |
| Eclipse User |
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Tom Schindl wrote:
>
> Well but if you have 3 different links in one line where from you know
> which of the links has been clicker?
I decided to abandon this part of the requirement, so I will treat the
entire row as a single link (to the lowest level item). In my product,
it's easy to get to the higher level items through other means.
>
> And once more in 3.3 we will add API for the Keyboard Navigation and
> CellSelections using the API mentionned in bug 151377. I expect to have
> the whole stuff integrate in M5
> (https://bugs.eclipse.org/bugs/show_bug.cgi?id=151295).
This will help helpful when I provide complete keyboard support (and go
up to 3.3).
>
> The corresponding feature request is:
> https://bugs.eclipse.org/bugs/show_bug.cgi?id=36977
Thanks for this, this made interesting reading; for a link in
particular, it's important to give a native look and feel for visual
niceness. My drawing the underline trick will not look the same as true
underlined text.
>
> To solve the performance impact we need to provide some logic to only
> keep the widgets who are visible. If you want a Table holding native
> widgets I can point you to the nebula project which provides a control
> called CompositeTable which works with native widgets and has the great
> advantage that it holds the logic to only create/hold as many widgets it
> needs to fill the table area. I think you need to check it out from the
> CVS-Repository.
Somehow, I thought this was the point of the Viewers, to only add
underlying Tree/TableItems as they are needed. Of course, I think the
implementation keeps them once they are initially added. It would be
nice to have them go away when they are not needed.
The CompositeTable will be an SWT-level component then? So this goes
along way in solving 36977, at least for tables.
I will have a look at this, thanks.
Francis
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