To keep a Stylesheet dynamic regarding DPI settings, I want to set certain parts of it from code.
This works:
my_label->setStyleSheet( QString( "font-size: 30px;" ) );
Yet, this doesn't:
my_label->setStyleSheet( QString( "font-size: %1px;" ).arg( 30 ) );
Can anyone enlighten me, why this is? Running Qt 5.7.
The issue was a combination of two things:
I needed to convert the value to a string first
The actual value passed to the arg() during runtime had a decimal place, the "30" was just for testing
While I did try different combinations (integer values (30), converting to QString first), I did not try using an integer value AND converting it to QString together.
So everyone was kinda right. Thanks for the patience.
Conver the number to a string, QString::number:
my_label->setStyleSheet(QString("QLabel{font-size: %1 px;}").arg(QString::number(30));
Or try it by using QFont, use this generic function for this purpose:
void updateFontSize(QLabel* label, int fontSize) {
QFont font = label->font();
if (font.pointSize() != fontSize) {
font.setPointSize(fontSize);
label->setFont(font);
}
}
Related
Let me introduce myself.
My name is Vladimir, C++ programmer, I am from Serbia. two weeks ago I have started to learn objective-C and it was fine until tonight.
Problem:
I cant remove double quotes from my NSLog output.
NSLog(#"The best singers:%#", list.best);
Strings are joined with componentsJoinedByString:#" and "
I would like to get something like this:
The best singers: Mickey and John.
But I get this:
The best singers: ("Mickey", and "John").
I cant remove comma (,) and parentheses either.
I have tried with "replaceOccurencesOfString" but with no success. It can remove any character except qoute and comma.
Also I have used -(NSString *)description method to return string.
You are getting the raw output from your list (which I assume is an array). You will have to do your own formatting to get this to display in the format that you want. You can achieve this by building your string by iterating through your array. Note that this probably isn't the most efficient nor the most robust way to achieve this.
NSMutableString *finalString = [NSMutableString string];
BOOL first = YES;
for (NSString *nameString in list) {
if (first) {
[finalString appendString:nameString];
first = NO;
} else {
[finalString appendString:[NSString stringWithFormat:#" and %#", nameString]];
}
}
I'm trying to write code that appends ending _my_ending to the filename, and does not change file extension.
Examples of what I need to get:
"test.bmp" -> "test_my_ending.bmp"
"test.foo.bar.bmp" -> "test.foo.bar_my_ending.bmp"
"test" -> "test_my_ending"
I have some experience in PCRE, and that's trivial task using it. Because of the lack of experience in Qt, initially I wrote the following code:
QString new_string = old_string.replace(
QRegExp("^(.+?)(\\.[^.]+)?$"),
"\\1_my_ending\\2"
);
This code does not work (no match at all), and then I found in the docs that
Non-greedy matching cannot be applied to individual quantifiers, but can be applied to all the quantifiers in the pattern
As you see, in my regexp I tried to reduce greediness of the first quantifier + by adding ? after it. This isn't supported in QRegExp.
This is really disappointing for me, and so, I have to write the following ugly but working code:
//-- write regexp that matches only filenames with extension
QRegExp r = QRegExp("^(.+)(\\.[^.]+)$");
r.setMinimal(true);
QString new_string;
if (old_string.contains(r)){
//-- filename contains extension, so, insert ending just before it
new_string = old_string.replace(r, "\\1_my_ending\\2");
} else {
//-- filename does not contain extension, so, just append ending
new_string = old_string + time_add;
}
But is there some better solution? I like Qt, but some things that I see in it seem to be discouraging.
How about using QFileInfo? This is shorter than your 'ugly' code:
QFileInfo fi(old_string);
QString new_string = fi.completeBaseName() + "_my_ending"
+ (fi.suffix().isEmpty() ? "" : ".") + fi.suffix();
How can I fill with zeros at left? My code is:
QString reelId = QString("Month %1").arg(QDate::currentDate().month());
qDebug() << reelId;
and out is: Month 2 and I want Month 02;
The term you're really looking for is "pad", as in padding a string with something. Look through the QString documentation for this, specifically the various QString::arg() functions, which describes how to achieve this in a variety of ways :)
Have a look at QString::rightJustified()
QString reelId = QString( "Month %1" ).arg(
QString::number( QDate::currentDate().month() ).rightJustified( 2, '0' )
);
Another useful trick is to use QDate's toString() method thus:
QString reelId = QDate::currentDate().toString( "'Month' MM" );
The single quotes around "Month" prevent the word being interpreted as a placeholder.
I've got a string like so
Jamie(123)
And I'm trying to just show Jamie without the brackets etc
All the names are different lengths so I was wondering if there was a simple way of replacing everything from the first bracket onwards?
Some others are displayed like this
Tom(Test(123))
Jack ((4u72))
I've got a simple replace of the bracket at the moment like this
mystring.Replace("(", "").Replace(")","")
Any help would be appreciated
Thanks
VB.NET
mystring.Substring(0, mystring.IndexOf("("C)).Trim()
C#
mystring.Substring(0, mystring.IndexOf('(')).Trim();
One logic; get the index of the ( and you can trim the later part from that position.
public static string Remove(string value)
{
int pos = value.IndexOf("(");
if (pos >= 0)
{
return value.Remove(pos, remove.Length);
}
return value;
}
aneal's will work. The alternative I generally use because it's a bit more flexible is .substring.
string newstring = oldstring.substring(0,oldstring.indexof("("));
If you aren't sure that oldstring will have a "(" you will have to do the test first just as aneal shows in their answer.
String.Remove(Int32) will do what you need:
Deletes all the characters from this string beginning at a
specified position and continuing through the last position.
You will also have to .Trim() as well given the data with padding:
mystring = mystring.Remove(mystring.IndexOf("("C))).Trim()
Well I'm using the following code to get the filename for a file that needs to be stored ..
QString fileName = QFileDialog::getSaveFileName(this, tr("Save File"),"/home/user/MyDocs/",tr("JPG files (*.jpg);;BMP files (*.bmp);;PNG files (*.png)"));
I'm providing the user with a number of options regarding the file format in which the file is to be saved. However, the returned QString only gives me the prefix filename the user have chosen, not the suffix and thus I don't know which file format the user chose. How can I detect such a file format?
The code in the question works in Windows (Qt 4.6.2 and Win XP). fileName contains the selected extension. But you are obviously using something else Windows, so you could try this workaround:
QFileDialog dialog(this, tr("Save as ..."), "/home/user/MyDocs/");
dialog.setAcceptMode(QFileDialog::AcceptSave);
QStringList filters;
filters << "JPG files (*.jpg)" << "BMP files (*.bmp)" << "PNG files (*.png)";
dialog.setNameFilters(filters);
if (dialog.exec() == QDialog::Accepted)
{
QString selectedFilter = dialog.selectedNameFilter();
QString fileName = dialog.selectedFiles()[0];
}
That is a slighty modified code from here.
You need to use the 5th optional string
I usually do it like this:
#define JPEG_FILES "JPG files (*.jpg)"
#define BMP_FILES "BMP files (*.bmp)"
#define PNG_FILES "PNG files (*.png)"
QString selectedFilter;
QString fileName = QFileDialog::getSaveFileName(this, tr("Save File"),
"/home/user/MyDocs/",
JPEG_FILES ";;" BMP_FILES ";;" PNG_FILES, &selectedFilter);
if (fileName.isNull())
return;
if (selectedFilter == JPEG_FILES) {
...
} else if (selectedFilter == BMP_FILES) {
...
} else if (selectedFilter == PNG_FILES) {
...
} else {
// something strange happened
}
The compiler takes care to concatenate the literal strings in the argument.
I'm not sure how the returned string interacts with tr(). You'll have to test and find out. probably need to un-translate it.
It could have been nicer if the function would return the index of the selected filter but alas, it does not.
A nicer solution would be to put the filters in a list, create a string from it and then compare to the returned selected filter string to the ones in the list. This would also solve the tr() problem.
Have a look to this discussion. It uses QFileInfo on the string that was entered in a QFileDialog.