I need to limit the entries that appear in my list control since two much entries make my MFC program slow. Is there a way to show only the last few entries (say for an example the most recent 100 entries) in a list control???
Thank You!!!
Take a look at virtual list control:
http://msdn.microsoft.com/en-us/library/ye4z8x58%28VS.80%29.aspx
http://www.codeguru.com/cpp/controls/listview/advanced/article.php/c4151
Either you:
don't add too many items (clear contents, only add the 100 you want in it)
use virtual list mode like Alex says.
Related
I have a list that should display 7 items that each look like this:
Date Weekday Distance Time
Long text that may span many lines
two column text Distance Time
two column text Distance Time
two column text Distance Time
The last lines repeat in a number depending on the data, i e there may be different amounts of such lines for each list item.
I have tried implementing this with a ListCellRenderer that creates a table according to the requirements above, but I have a few problems with it:
The long text that may span many lines is implemented in a SpanLabel. But this text will not display more than one line anyway
Each item in the list will get space for the same number of lines below the first two..
So it seems that items in a list must be of the same size.
Later I also want to be able to detect selection on the entire list item, not just individual fields of it.
Is there a better way to do this?
How do I ensure that the SpanLabel actually gets as much space as it needs?
How do I ensure that the unknown number of lines gets the space they need, depending on how many they are?
Don't use a list: https://www.codenameone.com/blog/deeper-in-the-renderer.html
Lists in Codename One assume every entry is exactly the same height and provide no flexibility here.
I suggest doing something like the property cross demo: https://www.udemy.com/learn-mobile-programming-by-example-with-codename-one/
Where we use a Container with components within to provide a list like behavior with the full flexibility that arbitrary components allow.
I am running a NetLogo model in BehaviorSpace each time varying number of runs. I have turtle-breed pigs, and they accumulate a table with patch-types as keys and number of visits to each patch-type as values.
In the end I calculate a list of mean number of visits from all pigs. The list has the same length as long as the original table has the same number of keys (number of patch-types). I would like to export this mean number of visits to each patch-type with BehaviorSpace.
Perhaps I could write a separate csv file (tried - creates many files, so lots of work later on putting them together). But I would rather have everything in the same file output after a run.
I could make a global variable for each patch-type but this seems crude and wrong. Especially if I upload a different patch configuration.
I tried just exporting the list, but then in Excel I see it with brackets e.g. [49 0 31.5 76 7 0].
So my question Q1: is there a proper way to export a list of values so that in BehaviorSpace table output csv there is a column for each value?
Q2: Or perhaps there is an example of how to output a single csv that looks exactly as I want it from BehaviorSpace?
PS: In my case the patch types are costs. And I might change those in the future and rerun everything. Ideally I would like to have as output: a graph of costs vs frequency of visits.
Thanks
If the lists are a fixed length that doesn't vary from run to run, you can get the items into separate columns by using one metric for each item. So in your BehaviorSpace experiment definition, instead of putting mylist, put item 0 mylist and item 1 mylist and so on.
If the lists aren't always the same length, you're out of luck. BehaviorSpace isn't flexible that way. You would have to write a separate program (in the programming language of your choice, perhaps NetLogo itself, perhaps an Excel macro, perhaps something else) to postprocess the BehaviorSpace output and make it look how you want.
I have two very large lists. They both were originally in excel, but the larger one is a list of emails (about 160,000) of them with other information like their name and address etc. And the smaller one is a list of just 18,000 emails.
My question is what would be the easiest way to get rid of all 18,000 rows from the first document that contain the email addresses from the second?
I was thinking regex or maybe there is another application I can use? I have tried searching online but it seems like there isn't much specific to this. I also tried notepad++ but it freezes when I try to compare these large files.
-Thank You in Advance!!
Good question. One way I would tackle this is making a C++ program [you could extrapolate the idea to the language of your choice; You never mentioned which languages you were proficient in] that read each item of the smaller file into a vector of strings. First, of course, use Excel to save the files as CSV instead of XLS or XLSX, which will comma-separate the values so you can work with them easier. For the larger list, "Save As" a copy of just email addresses, deleting the other rows for now.
Then, you could open the larger list and use a nested loop to check if you should output to an output file. Something like:
bool foundMatch=false;
for(int y=0;y<LargeListVector.size();y++) {
for(int x=0;x<SmallListVector.size();x++) {
if(SmallListVector[x]==LargeListVector[y]) foundMatch=true;
}
if(!foundMatch) OutputVector.append(LargeListVector[y]);
foundMatch=false;
}
That might be partially pseudo-code, but do you get the idea?
So I read a forum post at : Here
=MATCH(B1,$A$1:$A$3,0)>0
Column B would be the large list, with the 160,000 inputs and column A was my list of things I needed to delete of 18,000.
I used this to match everything, and in a separate column pasted this formula. It would print out either an error or TRUE. If the data was in both columns it printed out true.
Then because I suck with excel, I threw this text into Notepad++ and searched for all lines that contained TRUE (match case, because in my case some of the data had the word true in it without caps.) I marked those lines, then under search, bookmarks, I removed all lines with bookmarks. Pasted that back into excel and voila.
I would like to thank you guys for helping and pointing me in the right direction :)
What is the choise better than QListWidget to display a lot of log lines in GUI that are coming from backend at average speed 40 lines per second?
QListWidget gives a flickering and even white box instead of a widget for a long time when a lot of strings are already placed into ListWidget.
Is there any better solution to dynamically display log lines to a user?
update:
Changed architecture. Adding new QStrings to std::deque< QString* >. Using QTimer i add that strings every 1/10 of second to QPlainTextEdit, deleting from deque. boost::mutex is used to protect std::deque (log lines are coming from different threads).
Would be nice to have a time to implement my own QListView and keep strings in big chunks of pre-allocated memory.
Are you sure you need the functionalities of a QListWidget? If you just want to display log lines, I think a simple read-only QPlainTextEdit would be more appropriate.
You might try to use QListView and you own implementation of QAbstractItemModel. Then you can store your lines as you wish and append new lines in big groups (about every second should be ok). Then view is not refreshed at adding every line but only in groups, which should highly improve performace.
I would suggest setting a refresh rate and append all gathered items at once. You will avoid repaint of widget every line you append.
Long story short:
QTimer with refresh rate (~1-3 seconds would be enough), QListWidget::addItems instead of QListWidget::addItem
I have a MFC dialog with 32 CComboBoxes on it that all have the same data in the listbox. Its taking a while to come up, and it looks like part of the delay is the time I need to spend using InsertString() to add all the data to the 32 controls. How can I subclass CComboBox so that the 32 instances share the same data?
Turn off window redrawing when filling the combos. e.g.:
m_wndCombo.SetRedraw(FALSE);
// Fill combo here
...
m_wndCombo.SetRedraw(TRUE);
m_wndCombo.Invalidate();
This might help.
The first thing I would try is calling "InitStorage" to preallocate the internal memory for the strings.
From MSDN:
// Initialize the storage of the combo box to be 256 strings with
// about 10 characters per string, performance improvement.
int n = pmyComboBox->InitStorage(256, 10);
In addition to what has already been said, you might also turn off sorting in your combo box and presort the data before you insert it.
One way along the lines of your request would be to go owner drawn - you will be writing a fair chunk of code, but you won't have to add the data to all of them.
"CComboBox::DrawItem"
Support.microsoft have this article on subclassing a Combo box which might also be of interest
"How to subclass CListBox and Cedit inside of CComboBox"
Really one has to ask if it is worth the effort, and alot of that depends things like
number of entries in the list
number of times the dialog will show
variability of the combo content
optomising elsewhere
not drawing until the screen is complete
only building the dialog once and re showing it.
using the one combo but showing it in different locations at different times