I have made an editor in which i have to enter a Hex or decimal value in each field. Here the field i am using is QLineEdit.
Now requirement is that each Qlineedit box accept only one value without spaces. Then i can read this text value & convert it directly from string to decimal.
Is it possible to make QlineEdit to accept only one value without spaces ? Boxes in below figure are QLineEdit.
I do not want to use combo box here.
If the answer was just decimal, I'd suggest you use a QSpinBox instead. I did find a thread on how to implement a Hexidecimal SpinBox, but unfortunately the link to the third-party widget is dead. However it does say you could:
subclass QSpinBox and reimplement textFromValue() and valueFromText() to show hexadecimal values.
With the right Decimal-to-Hexidecimal function (you don't mention what language you are using) this would be a suitable solution.
The other alternative, is to use the QLineEdit.setValidator function with a custom subclass of QValidator to provide a validation method. For this, just re-implement the QValidator.validate function to check what a "valid" value.
To build on Lego Stormtroopr's answer, I think QValidator is a good and simple option. For example
dialog->lineedit1->setValidator(new QRegExpValidator( QRegExp("[0-9]{1,20}"), this ));
Here, the QRegExp denotes that you shall only accept digits from 0 to 9 and no other key-presses (spaces or letters) and you shall accept atleast 1 and maximum 20 characters (digits). You then set your lineedit's validator to this value. For more information, you can visit http://qt-project.org/doc/qt-5.0/qtcore/qregexp.html
or for a double,
QDoubleValidator *myDblVal = new QDoubleValidator( 0.0, MAX_VALUE, 1, this);
myDblVal->setNotation( QDoubleValidator::StandardNotation );
dialog->lineedit1->setValidator( myDblVal );
Here you simply use the inbuilt Qt functionality for double validation. You shall only accept a decimal between 0 and MAX_VALUE.
Related
I have a QLineEdit for Date in mm/dd/yyyy format. I am getting input using the keyboard and not using QDateEdit because of the requirement. And when the lineEdit comes to view, it has to show to the user the current date. I need the following for the lineEdit.
I need the two slashes always to be displayed and the cursor has to skip while entering or deleting.
I should not allow the user to enter an invalid date i.e while entering itself the lineEdit should not get invalid numbers.
I have to set the current date as the default text when the lineEdit comes to view.
For the first point, I tried using setInputMask("99/99/9999") but with this I can't set the current date using setText(). And how to use QRegExp to not to allow lineEdit get an invalid number while employing setInputMask()?
QDateEdit will serve your purpose.
use setDisplayFormat("dd/MM/yyyy").
QDateEdit wont allow invalid dates
You can use QDateEdit::setDate() obtained from
QDateTime::currentDateTime()
For setting text into QLineEdit with setInputMask("99/99/9999") you should format text depending on your mask:
lineEdit.setText("{:02d}/{:02d}/{:04d}".format(m, d, y))
Alternatively, you can temporary disable InputMask, format your date without /, set it and re-enable InputMask. But make sure that number of symbols in every part is correct.
lineEdit.setInputMask("")
lineEdit.setText(date_str.replace("/", ""))
lineEdit.setInputMask("99/99/9999")
I have a QLineEdit and I am using it for a measurement conversion application. In that QLineEdit I have to use only integer values, so I used the QDoubleValidator.
q_LineEdit->setValidator(new QDoubleValidator(this));
Now I want the QLineEdit to accept only " and / characters to it, as well as the integers, as it is required for the conversion application. How can I make my QLineEdit accept it while using a QDoubleValidator?
Note: I want my QLineEdit to accept something like this (eg. 70“1/2).
Note: The QLineEdit should not accept any other characters other than " and /.
At last I figured out the answer by myself. It's very simple. Just use QRegExpValidator.
Here's my piece of code:
QRegExp rx("(|\"|/|\\.|[0-9]){30}");
m_LineEdit->setValidator(new QRegExpValidator(rx, this));
I'm working on a Spring MVC Project and ran into a problem with the internationalization in forms, especially the number formatting.
I already use fmt:formatNumber to format the numbers according to the current selected locale.
<fmt:formatNumber value="${object[field]}"/>
Like this, number formatting works well when I display numbers. But how about the forms?
At the moment, the input fields that are supposed to receive float values are prefilled with 0.0 and expect me to use "." as decimal separator, no matter what locale is selected. Values containing "," are refused by the server (...can not convert String to required type float...).
How can I make my input fields use and accept the appropriate number format as well?
Did you have a look at #NumberFormat? If you annotate the property the input field is bound to, this should result in the proper formatting. Something like:
#NumberFormat(style = Style.NUMBER)
private BigDecimal something;
This style is the "general-purpose number format for the current locale". I guess, the current locale is determined threadwise from the LocaleContextHolder.
Your app needs to be annotation-driven, also see the section "Annotation-driven Formatting" in the docs.
You might want to take a look at the DecimalFormatSymbols as suggested in this answer.
What I need
ok I googled this and there are many tutorials on how to get the charCode from the character but I cant seem to find out how to get the character from the charcode.
Basically I am I am listening for the KeyDown event on a TextInput.
I prevent the char from being typed via event.preventDefault();
Later I need to add the text-char to the TextInput.
I can get the charCode via event.charCode so if I can turn that into a string I can save it for later user.
Why I need it
Basically I am making a TextInput, that that I can set to display default text in it. When A user types into it, I want to remove the default text first then add the user typed text.
Currently I am either removing it all, or ending up with both.
It's simple:
var yourNewChar:String = String.fromCharCode(event.charCode);
If I add a listener to KeyboardEvent.KEY_DOWN, I can find out the keyCode and the charCode.
The keyCode maps to a different character depending on the keyboard.
The charCode is just as useless, according to the help:
The character code values are English keyboard values. For example, if you press Shift+3, charCode is # on a Japanese keyboard, just as it is on an English keyboard.
So, how can I find out which character the user pressed?
You left out a pretty important part of the quote or it was missing where you found it:
For example, if you press Shift+3, the
getASCIICode() method returns # on a
Japanese keyboard, just as it does on
an English keyboard.
http://livedocs.adobe.com/flex/201/langref/flash/events/KeyboardEvent.html
This is probably more helpful:
The charCode property is the numeric value of that key in the current character set (the default character set is UTF-8, which supports ASCII).
http://livedocs.adobe.com/flex/2/docs/wwhelp/wwhimpl/common/html/wwhelp.htm?context=LiveDocs_Parts&file=00000480.html
Your application determines what characters set is used, meaning that the even if you have to use separate keys of different keyboard locals to produce the same character, it will have the same charCode.
NOTE: (This is about keyboard messages in general and does not apply to actionscript alone. I misread the question and provided a deeper answer then was helpful)
Really, the path from keyboard to windows char is a VERY complex one, it goes something like this:
Keyboard send scancode to Keyboard device driver (KDD).
KDD sends a message to the system message queue.
The system then sends the message to the foreground thread that created the window with the current keyboard focus.
The thread's message loop picks up the message and figures out the correct character translation.
The 'real' char that was typed is not calculated until it finishes that whole process, as each window and thread can be on a different locale and you can't really 'translate' the key without knowing the locale and key buffer history.
The "WM_KEYDOWN" and "WM_KEYUP" messages cannot just be converted with MapVirtualKey or something because you don't know how many key presses make up a single char. The simple method is just handle the 'WM_CHAR' event and use that. Consider the following:
en-US locale, you press the following keys a + ' + a, you get the following output "a'a"
pt-BZ locale, you press the following keys a + ' + a, you get the following output "aá"
So in both examples you would get 3 KEYDOWN, KEYUP messages, but in the first you get 3 WM_CHAR and in the second you only get 2.
The following article is really good for the basic concepts:
http://msdn.microsoft.com/en-us/library/ms646267(VS.85).aspx
You cannot effectively use charCode or keyCode to determine the character that was entered. You must compare strings only. The KeyboardEvent does not give you the entered text, which is also silly.
In my case I implemented a KeyboardEvent.KEY_DOWN event in addition to a TextEvent.TEXT_INPUT event. In the handler for the latter I implemented all functionality where the charCode was needed and didn't vary per keyboard locale (eg. space bar or enter). In the the former I checked for the text property of the event to compare what I needed locale independent.
Forgot to mention that this post hinted me to that solution: How to find out the character pressed key in languages?
Typing Japanese hiragana etc characters often require several keystrokes and sometimes even selecting the appropriate character from a drop down menu. You probably want to listen for a different event, something like a textfield's change event.