I'm taking a computer sciences class and we have to make a calculator using a GUI. I have been banging my head into a wall trying to even get input though.
Understand how to use pointers and GetValue(), to take in the input as a wxString but that does me no good, If I can't get the string as a double or integer then I can't perform operations on it.
Does anyone know how to convert wxString to Double? or even int?
Thanks in Advance
For this purpose, there are the two functions ToDouble and ToLong.
For details take a look at the offical documentation:
http://docs.wxwidgets.org/stable/wx_wxstring.html#wxstringtolong
http://docs.wxwidgets.org/stable/wx_wxstring.html#wxstringtodouble
EDIT: Example:
wxTextCtrl ctrl;
// user has entered a number
double number;
if( !ctrl.GetValue().ToDouble( &number ) )
// handle error
else
// continue...
Please note: It will only work if you enter a number. If you enter a term like 2+3 the function should return false. In this case you have to split the string up and interpret all numbers seperately.
Related
I've been breaking my head over this for a few days now and can't seem to be able to figure it out. Perhaps it's glaringly obvious, but I don't seem to be able to spot it. I've read up on all the basics of unicode, UTF-8, UTF-16, normalisation, etc, but to no avail. Hopefully somebody's able to help me out here...
I'm using Go's Value function from the testing/quick package to generate random values for the fields in my data structs, in order to implement the Generator interface for the structs in question. Specifically, given a Metadata struct, I've defined the implementation as follows:
func (m *Metadata) Generate(r *rand.Rand, size int) (value reflect.Value) {
value = reflect.ValueOf(m).Elem()
for i := 0; i < value.NumField(); i++ {
if t, ok := quick.Value(value.Field(i).Type(), r); ok {
value.Field(i).Set(t)
}
}
return
}
Now, in doing so, I'll end up with both the receiver and the return value being set with random generated values of the appropriate type (strings, ints, etc. in the receiver and reflect.Value in the returned reflect.Value).
Now, the implementation for the Value function states that it will return something of type []rune converted to type string. As far as I know, this should allow me to then use the functions in the runes, unicode and norm packages to define a filter which filters out everything which is not part of 'Latin', 'Letter' or 'Number'. I defined the following filter which uses a transform to filter out letters which are not in those character rangetables (as defined in the unicode package):
func runefilter(in reflect.Value) (out reflect.Value) {
out = in // Make sure you return something
if in.Kind() == reflect.String {
instr := in.String()
t := transform.Chain(norm.NFD, runes.Remove(runes.NotIn(rangetable.Merge(unicode.Letter, unicode.Latin, unicode.Number))), norm.NFC)
outstr, _, _ := transform.String(t, instr)
out = reflect.ValueOf(outstr)
}
return
}
Now, I think I've tried just about anything, but I keep ending up with a series of strings which are far from the Latin range, e.g.:
𥗉똿穊
𢷽嚶
秓䝏小𪖹䮋
𪿝ท솲
𡉪䂾
ʋ𥅮ᦸ
堮𡹯憨𥗼𧵕ꥆ
𢝌𐑮𧍛併怃𥊇
鯮
𣏲𝐒
⓿ꐠ槹𬠂黟
𢼭踁퓺𪇖
俇𣄃𔘧
𢝶
𝖸쩈𤫐𢬿詢𬄙
𫱘𨆟𑊙
欓
So, can anybody explain what I'm overlooking here and how I could instead define a transformer which removes/replaces non-letter/number/latin characters so that I can use the Value function as intended (but with a smaller subset of 'random' characters)?
Thanks!
Confusingly the Generate interface needs a function using the type not a the pointer to the type. You want your type signature to look like
func (m Metadata) Generate(r *rand.Rand, size int) (value reflect.Value)
You can play with this here. Note: the most important thing to do in that playground is to switch the type of the generate function from m Metadata to m *Metadata and see that Hi Mom! never prints.
In addition, I think you would be better served using your own type and writing a generate method for that type using a list of all of the characters you want to use. For example:
type LatinString string
const latin = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz01233456789"
and then use the generator
func (l LatinString) Generate(rand *rand.Rand, size int) reflect.Value {
var buffer bytes.Buffer
for i := 0; i < size; i++ {
buffer.WriteString(string(latin[rand.Intn(len(latin))]))
}
s := LatinString(buffer.String())
return reflect.ValueOf(s)
}
playground
Edit: also this library is pretty cool, thanks for showing it to me
The answer to my own question is, it seems, a combination of the answers provided in the comments by #nj_ and #jimb and the answer provided by #benjaminkadish.
In short, the answer boils down to:
"Not such a great idea as you thought it was", or "Bit of an ill-posed question"
"You were using the union of 'Letter', 'Latin' and 'Number' (Letter || Number || Latin), instead of the intersection of 'Latin' with the union of 'Letter' and 'Number' ((Letter || Number) && Latin))
Now for the longer version...
The idea behind me using the testing/quick package is that I wanted random data for (fuzzy) testing of my code. In the past, I've always written the code for doing things like that myself, again and again. This meant a lot of the same code across different projects. Now, I could of course written my own package for it, but it turns out that, even better than that, there's actually a standard package which does just about exactly what I want.
Now, it turns out the package does exactly what I want very well. The codepoints in the strings which it generates are actually random and not just restricted to what we're accustomed to using in everyday life. Now, this is of course exactly the thing which you want in doing fuzzy testing in order to test the code with values outside the usual assumptions.
In practice, that means I'm running into two problems:
There's some limits on what I would consider reasonable input for a string. Meaning that, in testing the processing of a Name field or a URL field, I can reasonably assume there's not going to be a value like 'James Mc⌢' (let alone 'James Mc🙁') or 'www.🕸site.com', but just 'James McFrown' and 'www.website.com'. Hence, I can't expect a reasonable system to be able to support it. Of course, things shouldn't completely break down, but it also can't be expected to handle the former examples without any problems.
When I filter the generated string on values which one might consider reasonable, the chance of ending up with a valid string is very small. The set of possible characters in the set used by the testing/quick is just so large (0x10FFFF) and the set of reasonable characters so small, you end up with empty strings most of the time.
So, what do we need to take away from this?
So, whilst I hoped to use the standard testing/quick package to replace my often repeated code to generate random data for fuzzy testing, it does this so well that it provides data outside the range of what I would consider reasonable for the code to be able to handle. It seems that the choice, in the end, is to:
Either be able to actually handle all fuzzy options, meaning that if somebody's name is 'Arnold 💰💰' ('Arnold Moneybags'), it shouldn't go arse over end. Or...
Use custom/derived types with their own Generator. This means you're going to have to use the derived type instead of the basic type throughout the code. (Comparable to defining a string as wchar_t instead of char in C++ and working with those by default.). Or...
Don't use testing/quick for fuzzy testing, because as soon as you run into a generated string value, you can (and should) get a very random string.
As always, further comments are of course welcome, as it's quite possible I overlooked something.
Can I use the output from ScriptShape/ScriptItemize in Uniscribe to get the char codes and pass the char codes to GetGlyphOutline to get the beziers?
Does Uniscribe have a call to get the outlines directly?
For anyone wondering the same.
The short answer: Yes. It works.
Uniscribe returns a WORD whereas the GetCharacterPlacement one gives out an LPCSTR though, so just look at that, should be trivial.
Nothing surprising though, this was just to confirm before I spend my time on it :)
i am having a little trouble with printf specifiers...so before asking you guys i read almost everything onC++Reference page, but couldnt fix the problem, and since i am new at c i cant even understand the problem, its most likely a syntax error but i can't find it...
for(i = 1; i <= 10; i++) {
printf("\n%d.%s%n",i,names[i-1],offset);
printf("%*s%.2f TL",10-offset," ",prices[i-1]);
}
so basically i have this code to print a list, and i want the prices to start from the same column.
For e.g:
water 1.00
oj 1.00
and the logic behind my code (incase it's not obvious, i can't tell if it is) is:
print id number and name, count how many chars we've written so far and assign it to offset.
print (starting column of price list)-offset spaces before price
once i couldn't get the result i want, i checked and found out that offset is 3 for all names which is not the case(and no value is assigned to offset before this procedure).
Thanks for any kind of help !
PS: This is a practice code just to get better at using specifiers efficiently.
edit:
so i did this :
for(i=1;i<=10;i++)
{
printf("%d.%s%n",i,names[i-1],&offset);
printf("%*s%.2f TL\n",10-offset," ",prices[i-1]);
}
but what i get as a result is huge empty black command screen.
The %n format specifier requires a pointer. Your code is missing the & operator for offset:
printf("\n%d.%s%n",i,names[i-1],&offset);
The good ol' C interface doesn't know what types you supply to printf so it doesn't complain and happily reads the 4 byte integer value of offset on the stack as a memory location -> core dump.
Actually, g++ with -Wall does warn. So
hd1 has a point here because C++ output is type safe (even though it's a pain);
Heed thy warnings.
When you use %n in a printf format, the corresponding parameter must be a pointer. printf will store the information in the int you point it to.
Assuming you've declared int offset somewhere, you should use &offset as the last argument in your printf call.
While we're here, allow me to comment on this excerpt:
printf("\n
ARGH NO! Newline is a terminator. It goes at the end of a line, not the beginning.
so i did this :
for(i=1;i<=10;i++)
{
printf("%d.%s%n",i,names[i-1],&offset);
printf("%*s%.2f TL\n",10-offset," ",prices[i-1]);
}
but what i get as a result is huge empty black command screen.
edit: Can you guys try this and tell me if you get normal results? I can't understand the mistake occuring, so i can't get past it...Maybe some other examples will lead me to where is the mistake.
I'm quite new to C++.
Right at the moment I'm trying to write and read an ini file. As I'm working with VS 2010 I d'like to use the WritePrivateProfileString function.
testwise it works like this
WritePrivateProfileString("testsection","testkey","testvalue","testfile.ini");
I can run this successfully.
My idea now is to hand overthe value within a variable of course which represents an int value.
WritePrivateProfileString("testsection","testkey",testvalue,"testfile.ini");
I understand that I would have to cast it first to LPCSTR or char so it works.
int testvalue =12;
WritePrivateProfileString("testsection","testkey",intToChar(testvalue),"testfile.ini");
//convert int to LPCSTR
char* intToChar(int temp){
char wert[8];
itoa(temp, wert, 10);
cout << wert;
return wert;
it does write to the file. but instead of a number i get random signs like "<º-" and stuff.
I've been trying for an hour now. Using different convertion (to LPCSTR, to char, to string) without any success.
what am I doing wrong? I really stat to get desperate.
thanks for any hint.
}
WritePrivateProfileString function can handle only "string", not "Integer Value".
You can make string from integer using itoa().
having a bit of trouble finding a solution to this.
I want to take a large ordered text file of words and create - in the same order - a text file of fixed length numeric values.
For example:
Input File Output File
AAA -> 00000001
AAH -> 00002718
AAZ -> 71827651
Initially it seemed a hash function would do the trick. However they are one way. Also perhaps they are a bit "heavyweight" for this. After all, I don't need any cryptography. Plus, it's a reference file. It will never change.
Any compression is a bonus not essential. That said, I don't want the file to get any bigger than it already is. Which is why I don't just want to write out the words as text but with fixed lengths.
So, bottom line; input is a NSString of variable length, output is an integer of fixed length. And, I must be able to take the integer and figure out the string.
Any help much appreciated!
Thanks!
xj
Well, this would be a bit of a brute force method, but here's my guess.
Start by making a custom function to convert one letter of text to an integer less than 100. (I'm not sure if such a function already exists, if so then great!) You might need to just go to stuff like "if ([input isEqual: #"a"]){ return 1;}
Then, run that function on each letter of text, and get the final integer by combining the previous results.
For example:
int myVal1 = [intConverter firstLetter];
int myVal2 = [intConverter secondLetter];
int myVal3 = [intConverter thirdLetter];
int finalValue =100^3 + 100^2*myVal1 + 100*myVal2 + myVal3;
Then, finalValue would be of the form 1(myVal1)(myVal2)(myVal3), which is what I think you're looking for.
To get back the original string, simply use the mod (%) and division functions to get the individual values back, then run the intConverter function backwards. (This would probably mean writing a new function that basically runs those if statements in reverse, but oh well.)
I hope this helps.