How do I attach a QRegexpValidator to QFileDialog if I only want say identifier file names? - qt5

The question is pretty straightforward and in the title.
Googling didn't help on this one. How do I get the QFileDialog to use a QValidator on its save name field?
Thanks.

The following is a bit of a kludge but appears to work.
You can use QObject::findChildren to locate the dialog's QLineEdit child widgets. Assuming there's only one such widget you can then apply the validator to that...
QFileDialog fd;
auto children = fd.findChildren<QLineEdit *>();
if (children.size() == 1) {
/*
* Apply a validator that forces the user to enter a name
* beginning with a lower case `a' -- a bit pointless but...
*/
QRegExpValidator validator(QRegExp("^a"));
/*
* Apply the validator.
*/
children.front()->setValidator(&validator);
fd.exec();
}
A quick test suggests it appears to work just fine. Like I said though: it does feel like a bit of a kludge.

Related

why this idea in using while loop. is it trivial?

I have met this a lot recently reading other people's scripts. A short example is below:
Say we need input and store them in var A and B, the scheme is below:
int ok;
ok = false;
while(!ok){
//ask input for A
//ask input for B
ok = true;
}
I understand what it wants, but why is this scheme necessary? can I only have "ask input for A and B".
but why is this scheme necessary?
It is not necessary.
can I only have "ask input for A and B".
You sure can.
However, if user gives you input that is not useful (for example: you ask for the users age, and they type "horse"), then you might want to ask again. Allowing re-trying of input is generally a useful feature. The canonical control structure for repeating a piece of program is a loop.
Your example program however, sets ok unconditionally, so in that case there is really no use for the loop. The loop makes sense only if there is some form of validation that must be passed before the input is OK.
When there are no checks in the code you omitted, but you see this same construct all over the place, then it's a copy&paste artifact.
Someone had a piece of code that was reading input and validating it, then copied the code somewhere else, removed the validation bits, and left the rest as-is. Then they copy&pasted that code all over the place.
In my experience, this happens very often.

Change cursor to pointer on hover right side of td

I have a table with td's. I would like it so that the user sees the cursor change into a pointer when he/she reaches the right border of the specific td, and revert back to the normal pointer when the user is not hovering the right border.
Googled a lot but I cannot seem to find an answer. There's hope someone here can help me...?
I would like it to be pure CSS, but maybe there is need for some query too?
you can use CSS to modify the behavior of the type of cursor in your case you can use
your_td_tag:hover {
cursor:progress
}
If you specifically want to select border only you have to use some javascript hacky stuff
$('div').click(function(e){
if( e.offsetX <= parseInt($(this).css('borderLeftWidth'))){
$("div").css("cursor:progress");
}
});
here div can be replaced by any tag and cursor-progress can be replaced by your desired cursor.
there are various types of cursors available by default
auto
crosshair
default
e-resize
grab
help
move
n-resize
ne-resize
nw-resize
pointer
progress
s-resize
se-resize
sw-resize
text
w-resize
wait
not-allowed
no-drop
you can also use your custom cursor as follows
your_td_tag_selector:hover{
cursor: url('some-cursor.ico'), default;
}
the default here is used as a fallback mechanism so if some-cursor.ico is not supported or not available it will fall back to default cursor.
let me know if it solves your problem..

Putting the cursor in a specific place in a live template

I just wanted to know how you put a cursor in a specific place in a live template for IntelliJ
For example:
# $var$ is an insance of the $objectType$ class
assert isinstance($var$, $objectType$)$END$
What happens here is that your cursor gets dragged to $var$ in the comment string first and then to your other values inside assert. What I wanted to know is how you chose where the cursor goes first.
I've read the documentation, but this is not mentioned, although a lot of other things are.
You can arrange the order that your variables are visited in. You find the information under bullet number five in this IntelliJ help document: http://www.jetbrains.com/idea/webhelp/creating-and-editing-template-variables.html
To arrange variables in the order you want IntelliJ IDEA to switch between associated input fields, use the Move Up and Move Down buttons.
Edit
You have to update the macro definition to similar to this:
# $varComment$ is an insance of the $objectTypeComment$ class
assert isinstance($var$, $objectType$)$END$
And then you define the order and expression to something like this (I didn't have any good expression for the var and orderType for you):
Since you fill in the Skip if defined for the two comment variable they will just take the values from the var and orderType and fill it in. This will do exactly what you are looking for :-)

How to cast a Revit Element as a Revit.DB.Opening

I am relatively new at programming in Revit. I am currently getting a list of elements in my drawing that are of type door or window. What I want to do is cast these as an opening however I get an error when I try to cast them as a Autodesk.Revit.DB.Opening.
Code Below:
// filter for current design option
var designOptionFilter = S2E.Revit.Tools.Library.Cache.DesignOptionFilter;
List<Element> elements = collector.WherePasses(designOptionFilter).ToElements().ToList();
var list = new List<Autodesk.Revit.DB.Opening>();
foreach (var element in elements) {
var opening = (Opening)element;
if (opening.Host.Id == wallId) {
list.Add(opening);
}
}
return list;
As you can see I am testing if the id of the host matches the wall I am woking on. At least that is what I would like to do. All I am looking for is how to cast an element as an Opening.
Thanks, Rich
Considering a Door is a FamilyInstance and an Opening is not, I am unsure of how you would cast the door FamilyInstance to an opening type.
But, since the FamilyInstance has a Host parameter, just check that against the wall ID and it should work, no casting needed.
It depends on what your filter is selecting on whether the cast you have will work. As you don't provide details on the exact error you are getting it is hard to be more precise.
Also you have in one place (Opening) used as your cast yet you use the full type name "Autodesk.Revit.DB.Opening" when you create your list. If you really need to do that maybe Opening is not the "Opening" you thought it was.
You can also use element.Cast() to perform the cast.
Likewise if you know that all your elements returned by the filter are only ever going to be Opening types then you can use
collector.WherePasses(designOptionFilter).Cast<Opening>()
to achieve the same thing.

Proportional font IDE

I would really like to see a proportional font IDE, even if I have to build it myself (perhaps as an extension to Visual Studio). What I basically mean is MS Word style editing of code that sort of looks like the typographical style in The C++ Programming Language book.
I want to set tab stops for my indents and lining up function signatures and rows of assignment statements, which could be specified in points instead of fixed character positions. I would also like bold and italics. Various font sizes and even style sheets would be cool.
Has anyone seen anything like this out there or know the best way to start building one?
I'd still like to see a popular editor or IDE implement elastic tabstops.
Thinking with Style suggests to use your favorite text-manipulation software like Word or Writer. Create your programme code in rich XML and extract the compiler-relevant sections with XSLT. The "Office" software will provide all advanced text-manipulation and formatting features.
i expected you'll get down-modded and picked on for that suggestion, but there's some real sense to the idea.
The main advantage of the traditional 'non-proportional' font requirement in code editors is to ease the burden of performing code formatting.
But with all of the interactive automatic formatting that occurs in modern IDE's, it's really possible that a proportional font could improve the readability of the code (rather than hampering it, as i'm sure many purists would expect).
A character called Roedy Green (famous for his 'how to write unmaintainable code' articles) wrote about a theoretical editor/language, based on Java and called Bali. It didn't include non-proportional fonts exactly, but it did include the idea of having non-uniform font-sizes.
Also, this short Joel Spolsky post posts to a solution, elastic tab stops (as mentioned by another commentor) that would help with the support of non-proportional (and variable sized) fonts.
#Thomas Owens
I don't find code formatted like that easier to read.
That's fine, it is just a personal preference and we can disagree. Format it the way you think is best and I'll respect it. I frequently ask myself 'how should I format this or that thing?' My answer is always to format it to improve readability, which I admit can be subjective.
Regarding your sample, I just like having that nicely aligned column on the right hand side, its sort of a quick "index" into the code on the left. Having said that, I would probably avoid commenting every line like that anyway because the code itself shouldn't need that much explanation. And if it does I tend to write a paragraph above the code.
But consider this example from the original poster. Its easier to spot the comments in the second one in my opinion.
for (size-type i = 0; i<v.size(); i++) { // rehash:
size-type ii = has(v[i].key)%b.size9); // hash
v[i].next = b[ii]; // link
b[ii] = &v[i];
}
for (size-type i = 0; i<v.size(); i++) { // rehash:
size-type ii = has(v[i].key)%b.size9); // hash
v[i].next = b[ii]; // link
b[ii] = &v[i];
}
#Thomas Owens
But do people really line comments up
like that? ... I never try to
line up declarations or comments or
anything, and the only place I've ever
seen that is in textbooks.
Yes people do line up comments and declarations and all sorts of things. Consistently well formatted code is easier to read and code that is easier to read is easier to maintain.
I wonder why nobody actually answers your question, and why the accepted answer doesn't really have anything to do with your question. But anyway...
a proportional font IDE
In Eclipse you can cchoose any font on your system.
set tab stops for my indents
In Eclipse you can configure the automatic indentation, including setting it to "tabs only".
lining up function signatures and rows of assignment statements
In Eclipse, automatic indentation does that.
which could be specified in points instead of fixed character positions.
Sorry, I don't think Eclipse can help you there. But it is open source. ;-)
bold and italics
Eclipse has that.
Various font sizes and even style sheets would be cool
I think Eclipse only uses one font and font-size for each file type (for example Java source file), but you can have different "style sheets" for different file types.
When I last looked at Eclipse (some time ago now!) it allowed you to choose any installed font to work in. Not so sure whether it supported the notion of indenting using tab stops.
It looked cool, but the code was definitely harder to read...
Soeren: That's kind of neat, IMO. But do people really line comments up like that? For my end of line comments, I always use a single space then // or /* or equivalent, depending on language I'm using. I never try to line up declarations or comments or anything, and the only place I've ever seen that is in textbooks.
#Brian Ensink: I don't find code formatted like that easier to read.
int var1 = 1 //Comment
int longerVar = 2 //Comment
int anotherVar = 4 //Command
versus
int var2 = 1 //Comment
int longerVar = 2 //Comment
int anotherVar = 4 //Comment
I find the first lines easier to read than the second lines, personally.
The indentation part of your question is being done today in a real product, though possibly to even a greater level of automation than you imagined, the product I mention is an XSLT IDE, but the same formatting principles would work with most (but not all) conventional code syntaxes.
This really has to be seen in video to get the sense of it all (sorry about the music back-track). There's also a light XML editor spin-off product, XMLQuire, that serves as a technology demonstrator.
The screenshot below shows XML formatted with quite complex formatting rules in this XSLT IDE, where all indentation is performed word-processor style, using the left margin - not space or tab characters.
To emphasise this formatting concept, all characters have been highlighted to show where the left-margin extends to keep indentation. I use the term Virtual Formatting to describe this - it's not like elastic tab stops, because there simply are no tabs, just margin information which is part of the 'paragraph' formatting (RTF codes are used here). The parser reformats continuously, in the same pass as syntax coloring.
A proportional font hasn't been used here, but it could have been quite easily - because the indentation is set in TWIPS. The editing experience is quite compelling because, as you refactor the code (XML in this case), perhaps through drag and drop, or by extending the length of an attribute value, the indentation just re-flows itself to fit - there's no tab-key or 'reformat' button to press.
So, the indentation is there, but the font work is a more complex problem. I've experimented with this, but found that if fonts are re-selected as you type, the horizontal shifting of the code is too distracting - there would need to be a user-initiated 'format fonts' command probably. The product also has Ink/Handwriting technology built-in for annotating code, but I've yet to exploit this in the live release.
Folks are all complaining about comments not lining up.
Seems to me that there's a very simple solution: Define the unit space as the widest character in the font. Now, proportionally space all characters except the space. the space takes up as much room so as to line up the next character where it would be if all preceeding characters on the line were the widest in the font.
ie:
iiii_space_Foo
xxxx_space_Foo
would line up the "Foo", with the space after the "i" being much wider than after the "x".
So call it elastic spaces. rather than tab-stops.
If you're a smart editor, treat comments specially, but that's just gravy
Let me recall arguments about using the 'var' keyword in C#. People hated it, and thought it would make code less clear. For example, you couldn't know the type in something like:
var x = GetResults("Main");
foreach(var y in x)
{
WriteResult(x);
}
Their argument was, that you couln't see if x was an array, an List or any other IEnumerable. Or what the type of y was. In my opinion the unclearity did not arise from using var, but from picking unclear variable names. Why not just type:
var electionResults = GetRegionalElactionResults("Main");
foreach(var result in electionResults)
{
Write(result); // you can see what you're writing!!
}
"But you still cannot see the type of electionResults!" - does it really matter? If you want to change the return type of GetRegionalElectionResults, you can do so. Any IEnumerable will do.
Fast forward to now. People want to align comments en similar code:
int var2 = 1; //The number of days since startup, including the first
int longerVar = 2; //The number of free days per week
int anotherVar = 38; //The number of working hours per week
So without the comment everything is unclear. And if you don't align the values, you cannot seperate them from the variales. But do you? What about this (ignore the bullets please)
int daysSinceStartup = 1; // including first
int freeDaysPerWeek = 2;
int workingHoursPerWeek = 38;
If you need a comment on EVERY LINE, you're doing something wrong. "But you still need to align the VALUES" - do you? what does 38 have to do with 2?
In C# Most code blocks can easily be aligned using only tabs (or acually, multiples of four spaces):
var regionsWithIncrease =
from result in GetRegionalElectionResults()
where result.TotalCount > result > PreviousTotalCount &&
result.PreviousTotalCount > 0 // just new regions
select result.Region;
foreach (var region in regionsWithIncrease)
{
Write(region);
}
You should never use line-to-line comments and you should rarely need to vertically align things. Rarely, not never. So I understand if some of you guys prefer a monospaced font. I prefer the readibility of font Noto Sans or Source Sans Pro. These fonts are available freely from Google, and resemble Calibri, but are designed for programming and thus have all the neccesary characteristics:
Big : ; . , so you can clearly see the difference
Clearly distinct 0Oo and distinct Il|
The major problem with proportional fonts is they destroy the vertical alignment of the code and this is a fairly major loss when it comes to writing code.
The vertical alignment makes it possible to manipulate rectangular blocks of code that span multiple lines by allowing block operations like cut, copy, paste, delete and indent, unindent etc to be easily performed.
As an example consider this snippet of code:
a1 = a111;
B2 = aaaa;
c3 = AAAA;
w4 = wwWW;
W4 = WWWW;
In a mono-spaced font the = and the ; all line up.
Now if this text is loded into Word and display using a proportional font the text effectively turns into this:
NOTE: Extra white space added to show how the = and ; no longer line up:
a1 = a1 1 1;
B2 = aaaa;
c3 = A A A A;
w4 = w w W W;
W4 = W W W W;
With the vertical alignment gone those nice blocks of code effectively disappear.
Also because the cursor is no longer guaranteed to move vertically (i.e. the column number is not always constant from one line to the next) it makes it more difficult to write throw away macro scripts designed to manipulated similar looking lines.