I need some guidance on how to add a drop down list from an array of data after the read info from the MP4 Tag data is parsed. The mechanism I'm using is 100% operational, this is a creature feature addition. The MP4 tag I'm working with is Genre using the ID3V1 standard. There are 191 choices. The way my app was inherited, there are 2 columns, property/value and multiple rows. All of that works. The Genre tag was setup willy nilly so you could basically type whatever and it would store it. I want to remove that and have the 191 elements in the array to choose from using the drop down list. Part of the loading process is that it will pull in whatever was in the MP4 file. So, I want the user to be able to leave as is (most likely tagged by something that supports ID3V2), or select from the populated 191 elements in the dropdown list.
The object looks like this information.h:
protected:
CMFCPropertyGridCtrl m_wndProperties;
The information.cpp looks like this:
void CInformationView::OnInitialUpdate()
{
// create property grid
VERIFY(m_wndProperties.Create(WS_CHILD|WS_VISIBLE|WS_TABSTOP| WS_BORDER, CRect(0,0,0,0), this, 0));
// get document
CMovieDoc *lpkDoc = GetDocument();
ASSERT_VALID_PTR(lpkDoc);
// add properties //Information ORDER Loading <<<<< List shortened Stack overflow question
m_wndProperties.AddProperty(lpkDoc->m_pkArtist);
m_wndProperties.AddProperty(lpkDoc->m_pkTempo);
m_wndProperties.AddProperty(lpkDoc->m_pkGenre);
CView::OnInitialUpdate();
}
The way it pulls the data in from mp4.cpp:
// Genre
m_pkGenre = new CMFCPropertyGridProperty(_T("Genre"),
COleVariant(AfxStringFromUtf8(lptTags->genre), VT_BSTR));
The pointers in mp4.h:
CMFCPropertyGridProperty *m_pkArtist;
CMFCPropertyGridProperty *m_pkTempo;
CMFCPropertyGridProperty *m_pkGenre;
Now I know that pull downs in the 2nd column (Values) can be done because other tags have simple TRUE/FALSE that can be selected, so that tells me it should be possible to create the drop down list I'm looking to do. An example of the TRUE/FALSE looks like this:
// Compilation
m_pkCompilation = new CMFCPropertyGridProperty(_T("Compilation"),
COleVariant((!VALID_PTR(lptTags->compilation)) ? (short)0 : (short)*lptTags->compilation, VT_BOOL));
I've done arrays in C for things like microcontrollers, but not entirely sure if it is the same in C++. I'm thinking it should look like this:
// Initialize Genre Array
const char *genre[4] = { "Rock", "Rap", "Soul", "House" };
The questions are:
How do I create an the array (or does my example above look correct?) to house fixed strings like "Rock", "Rap", "Soul", etc. etc?
How to modify the VALUE row to have the pull down that contains the parsed Genre tag present and then when opened, show the 191 Genre tags where one can be selected to choose from (and ultimately save which is already working).
Actual code, not references to the learn.microsoft.com, the few things I've tried crashes when I try to alter the AddProperties I assume because of the lpkDoc pointers being used.
You should not use a plain old C-style array if you do not have a strong reason to. Use a std::vector instead. You don't even need to indicate the [size].
The same goes for char *. Use a CString or astd::string instead.
const std::vector<CString> = { L"Rock", L"Rap", L"Soul", L"House" };
Don't make your life harder than it needs to be.
2.
for (size_t i= 0; i < genre.size(); i++)
{
auto gnr= genre[i];
lpkDoc->m_pkGenre->AddOption(gnr);
}
or even better
for (auto it : genre)
{
lpkDoc->m_pkGenre->AddOption(it);
}
Important note: You should not have code about properties in your doc object. You are mixing business logic with user interaction logic. Your code in the future will be a nightmare to maintain.
I do not see your lpkDoc->m_pk variable init'ed anywhere, and I bet those pointers are pointing to no man's land.
Related
Let's say I have struct :
struct Planet {
var id : UUID
var name: String
...
}
I have an array of such structs which is constructed from data fetched from a database. I use this for a form in a browser where the user can:
edit the fields (eg change the name of Planet)
create one or more new Planets
at this time the user may not delete a Planet but it would be great if the solution would support that too
When the form is submitted I get an array with those structures (the order is also not the same as the original). What is the best/most efficient way to do update the data in the original array with the data from the second.
My current idea is:
map the original array to a dictionary with key= id, value= aPlanetStructure
loop over the second array (with the edited data) and if that 'key' can be retrieved in the dictionary (=data from first array)-> update the struct there, if not create an additional planet in the first array.
I'm not sure if this is a good approach, it seems like there could be a more efficient way (but I can't think of it). It would also not support deleting a Planet
In general, if you can separate out the elements of the array by action, you'll make your life easier.
For example:
var created= [Planet]()
var updated= [Planet]()
var deleted = [Planet]()
In your UI layer, when an edit is made, add the edited planet to the
updated array, when a planet is deleted, add it to the deleted array, etc.
Submit all 3 arrays with your form.
Loop over the results of each and pass too your create, update, and delete methods that access your database.
That will require restructuring your form code a bit, but... in general it's easier in your UI layer to tell whether someone is doing a create, an update, or a delete, than it is to mush them all together and try to figure it out after the fact by doing comparisons.
I've finally started to understand a lot of info regarding FireStore, but I'm wondering if I can get some assistance.
If I had a setup similar to or like this:
races
Android
name: Android
size: medium
stats <---- this is the map
str: 10
sex: 12.... (more values)
How would I parse this? I am looking to make specific TextViews apply values found in the database so that I can simply update the database and my app will populate those values so that hard coding and code updating won't be nearly as troublesome in the future.
I currently use something like this:
val androidRef = db.collection("races").document("Android")
androidRef.get().addOnSuccessListener { document ->
if (document != null) {
oneOfTheTextViews.text = document.getString("str")
} else {
}
The issue is currently I can only seem to access from collection (races) / document (android) / then a single field (I have "str" set as a single field, not part of a map or array)
What would the best practice be to do this? Should I not nest them at all? And if I can reference said nesting/mapping/array, what functions need to be called? (To be clear, I am not asking only whether or not it is possible - the reference guides and documents allude to such - but what property/class/method/etc needs to be called in order to access only one of those values or point to one of those values?).
Second question: Is there a way to get a list of document names? If I have several races, and simply want to make a spinner or recycler view based on document names as part of a collection, can I read that to the app?
What would the best practice be to do this?
If you want to get the value of your str property which is nested within your stats map, please change the following line of code:
oneOfTheTextViews.text = document.getString("str")
to
oneOfTheTextViews.text = document.getString("stats.str")
If your str property is a number and not a String, then instead of the above line of code please use this one:
oneOfTheTextViews.text = document.getLong("stats.str")
Should I not nest them at all?
No, you can nest as many properties as you want within a Map.
Is there a way to get a list of document names?
Yes, simply iterate the collection and get the document ids using getId() function.
I woukld like to form an Array which contains the widths of each label inside the customTableCell. As illustrated in the attached image, I managed to extract all the widths I am interested in but they are not all in the same array. Any idea how can I extrac t all the widths in ONE array?
#BrunoPastre is correct, but appending is also not the way to assign the values in the array. This function will be run many times for some cells, as you scroll up and down. You will end up with the same widths listed many times at different places in the array.
You should create the array with the right dimension, then assign them as cellsWidthsArray[indexPath.row] = cell.cellTextLabel.frame.size.width.
You should create your array only once, not every time tableView(_: UITableView, cellForRowAt: IndexPath) -> UITableViewCell is called. This can be achieved by moving the declaration of your array, on line 83, to somewhere outside of the function scope, but inside the class scope, like line 92. When you do that, cellsWitdhsArray will become a class variable, or an attribute, that can be accessed from anywhere inside the class
That method is called once per cell, if you declare a local variable cellsWidthArray its not going to persist across multiple calls of that function.
What you need is to "save" this array somewhere that isn't a local, temporary scope. The best way to do this is to save it as a property on the class.
I can see in your code you already have another array thats a property: tableViewRowsInsideSectionsArray. Scroll up to (hopefully) the very top of the class declaration in the same scope add your own cellsWidthArray.
It should look something like
class MyViewController {
...
private var cellsWidthArray: [CGFloat] = []
...
That way that local array isn't lost every time the function ends - it's owned by the view controller and is available anywhere within that class as long as that class exists.
HOWEVER, it may not work as you expect because another issue with that method (tableView(cellForRowAt:) is that it's only called when a cell is being displayed (visible on the screen). And it will be called multiple times if you scroll a cell off and back on the screen.
You can solve potential duplication by creating a dictionary where the key is something uniquely identifying the cell (it seems like its just going to be the text here) and the value is the width. Something like:
class MyViewController {
...
private var cellsWidthDictionary: [String: CGFloat] = [:]
...
func tableView(cellForRowAt:) { // I didn't feel like typing it all out
...
cellsWidthDictionary[theTextYouAreUsing] = width
But you now have another issue, the way you are getting the width, accessing the frame of the label just after you set the text, might not actually be correct. This function just prepares the cell, auto layout and frame adjustments might happen later.
A simple one line solution one might be tempted to do is to force a layout on the cell, after setting the text on the label, something like:
cell.cellTextLabel.sizeToFit() or cell.layoutIfNeeded()
that will just adjust the frame of the label to perfectly wrap the existing content.. but a much better solution would be to actually calculate it..
You could use https://developer.apple.com/documentation/foundation/nsstring/1531844-size
something like
let labelSize = (label.text?.size(attributes: [NSFontAttributeName: UIFont(name: label.font.fontName , size: label.font.pointSize)!]))
then accessing labelSize.width
You're still left with the problem of only having that function called when a cell is about to be displayed on the screen. You can either manually scroll through every cell to build that table if you're using it for debugging/testing/informative purposes. But otherwise you would need to do something else...
Fortunately, Swift has a function that calculates the size a string would take - you just have to make sure you specify the text/font/size/any other styling elements. I pointed it out above... you can just iterate through all the strings that you're feeding into the cells and generate the dictionary right then and there as soon as you get the data.
Keep in mind this assumes a single line, if you have a max width for the label or other constraints that would cause the text to be cut off you would need to be even more explicit - I encourage you to google how to calculate the size of a label based off your needs if so.
I am interested if it is possible to make variable name in PowerBuilder using a loop and a string. For example:
long ll_go
string lst_new
for ll_go = 1 to 8
lst_new = "text" + ll_go
lst_new.tag = 5500
next
So, it should give me variables text1, text2..,.,text8 and I would be able to assign values for them. Let me know if anybody succeeded, thanks in advance
Your description is lacking some term precision.
If you actually want to dynamically create new variables as "variable in a powerscript subroutine or function" this is simply not possible.
If instead you want to create dynamically some new controls statictext or textedit objects in a window or visual userobject this is possible:
use a local variable of the type of the new object you need to create, e.g. static text
make it a live object (instantiate) with create
set the object properties to whatever you need
"attach" the new object to its parent (either a window or a visual userobject - though any graphicobject is possible with using the win32api SetParent function) with the OpenUserObject() method. Note that you cannot simply add it directly to the parent's Control[] array.
you can also keep the object in your own array for later convenience access to the created objects instead of looping on the Control[] array
once the object is attached it its parent, you can reuse the local variable to create another one
Here is an example:
//put this in a button clicked() event on a window
//i_myedits is declared in instances variables as
//SingleLineEdit i_myedits[]
SingleLineEdit sle
int i
for i = 1 to 8
sle = create singlelineedit
sle.text = string(i)
sle.tag = "text_" + string(i)
sle.height = pixelstounits(20, ypixelstounits!)
sle.width = pixelstounits(100, xpixelstounits!)
parent.openuserobject(sle, pixelstounits(10, xpixelstounits!), pixelstounits(22 * i, ypixelstounits!))
i_myedits[i] = sle //keep our own reference
next
An exemple of values access:
//put that in another button clicked() event
SingleLineEdit sle
int i
string s_msg
for i = 1 to upperbound(i_myedits[])
sle = i_myedits[i]
if i > 1 then s_msg += "~r~n"
s_msg += "edit #" + string(i) + " (" + sle.tag + ") says '" + sle.text + "'"
next
messagebox("Edits values", s_msg)
As you can see, one practicality problem is that you cannot refer to these controls by constructing the control's name like "text"+2, instead you must access the my edits[] array or loop through the controls and test their .tag property if you set it to something specific.
I do not think that it is possible. Workaround could be an array maybe.
Br. Gábor
I'd see two ways to do this, but they aren't as easy as it seems that you were hoping:
1. Control Array
First method would be to go through the control arrays (on windows, tabs and user objects). I'd create a function that took the control name as a string, then another that overloaded the same function and took control name and an array of windowobject. The string-only method would just call the string/array method, passing the string through and adding the window.Control as the second parameter. The string/array method would go through the array, and for each element, get the ClassDefinition. Pull the name off of it, and parse it apart the way you want it to match the string parameter (e.g. for w_test`tab_first`tabpage_first`cb_here, do you want cb_here to match, or tab_first`tabpage_first`cb_here?). Deal with matches as appropriate. When you find a control of type tab or user object, call the string/array function again with the Control array from that object; deal with success/fail returns as appropriate.
2. DataWindow
What you're describing works extremely well with DataWindows, and their Describe() and Modify() functions. Since you pass these functions only a string, you can build not only the control names, but the values they're set to as you would build any string. In fact, you can build multiple Modify() strings together (delimited by a space) and make a single call to Modify(); this is not only faster, but reduces window flicker and visible activity.
Don't fall into the trap of thinking that, since your data isn't from a database, you can't use a DataWindow. Create an external DataWindow, and simply use it with one row inserted during the Constructor event.
As you might guess, I'd strongly favour the DataWindow approach. Not only is it going to perform better, but it's going to provide a lot more flexibility when you want to move on and tag more control types than just static text. (You'll have to do some type casting even with one control type, but if you want to get into multiples, you'll need to start a CHOOSE CASE to handle all your types.)
Good luck,
Terry
You can't create a variable name in a script because the variables have to be declared before you can use them. With PBNI it's possible to generate a name the way you describe and then get a reference to a variable of that name that already exists but I don't think that's what you want. If you want to keep track of additional properties for your controls, just inherit a new user object from whatever it is (sle, mle, etc.) and add the properties you want. Then you can place your user object on a window and use the properties. Another approach is to use the control's Tag property. It holds a string that you can put whatever you want in. PFC uses this technique. Terry's DataWindow solution is a good approach for storing arbitrary data.
Yes, and there are more than one way to skin a cat.
Sounds like you have several properties so I'd use an array of custom non visual user objects, or an array of structures. Otherwise you could probably use something from the .NET framework like a dictionary object or something like that, or a datawidnow using an external datasource, where you can refer to column names as col + ll_index.ToString().
SIMPLE Example:
Make custom NVO with following instance variables, plus getter/setter functions for each, name it n_single_field
// add the properties and recommend getter and setter functions
public string myTag
public string myText
public int myTabOrder
...
// To USE the NVO define an unbounded array
n_single_field fields[]
// to process the populated fields
integer li_x, li_max_fields
// loop through field 1 through max using array index for field number
li_max_fields = upperbound(fields)
for li_x = 1 to li_max_fields
fields[li_x].myTag = 'abc'
fields[li_x].myText = 'text for field number ' + li_x.ToString()
fields[li_x].myTabOrder = li_x * 10
next
Maybe I'm oversimplifying if so let me know, if there is a will there is always a way. ;)
My project has classes which, unavoidably, contain hundreds upon hundreds of variables that I'm always having to keep straight. For example, I'm always having to keep track of specific kinds of variables for a recurring set of "items" that occur inside of a class, where placing those variables between multiple classes would cause a lot of confusion.
How do I better sort my variables to keep from going crazy, especially when it comes time to save my data?
Am I missing something? Actionscript is an Object Oriented language, so you might have hundreds of variables, but unless you've somehow treated it like a grab bag and dumped it all in one place, everything should be to hand. Without knowing what all you're keeping track of, it's hard to give concrete advice, but here's an example from a current project I'm working on, which is a platform for building pre-employment assessments.
The basic unit is a Question. A Question has a stem, text that can go in the status bar, a collection of answers, and a collection of measures of things we're tracking about what the user does in that particular type of questions.
The measures are, again, their own type of object, and come in two "flavors": one that is used to track a time limit and one that isn't. The measure has a name (so we know where to write back to the database) and a value (which tells us what). Timed ones also have a property for the time limit.
When we need to time the question, we hand that measure to yet another object that counts the time down and a separate object that displays the time (if appropriate for the situation). The answers, known as distractors, have a label and a value that they can impart to the appropriate measure based on the user selection. For example, if a user selects "d", its value, "4" is transferred to the measure that stores the user's selection.
Once the user submits his answer, we loop through all the measures for the question and send those to the database. If those were not treated as a collection (in this case, a Vector), we'd have to know exactly what specific measures are being stored for each question and each question would have a very different structure that we'd have to dig through. So if looping through collections is your issue, I think you should revisit that idea. It saves a lot of code and is FAR more efficient than "var1", "var2", "var3."
If the part you think is unweildy is the type checking you have to do because literally anything could be in there, then Vector could be a good solution for you as long as you're using at least Flash Player 10.
So, in summary:
When you have a lot of related properties, write a Class that keeps all of those related bits and pieces together (like my Question).
When objects have 0-n "things" that are all of the same or very similar, use a collection of some sort, such as an Array or Vector, to allow you to iterate through them as a group and perform the same operation on each (for example, each Question is part of a larger grouping that allows each question to be presented in turn, and each question has a collection of distractors and another of measures.
These two concepts, used together, should help keep your information tidy and organized.
While I'm certain there are numerous ways of keeping arrays straight, I have found a method that works well for me. Best of all, it collapses large amounts of information into a handful of arrays that I can parse to an XML file or other storage method. I call this method my "indexed array system".
There are actually multiple ways to do this: creating a handful of 1-dimensional arrays, or creating 2-dimensional (or higher) array(s). Both work equally well, so choose the one that works best for your code. I'm only going to show the 1-dimensional method here. Those of you who are familiar with arrays can probably figure out how to rewrite this to use higher dimensional arrays.
I use Actionscript 3, but this approach should work with almost any programming or scripting language.
In this example, I'm trying to keep various "properties" of different "activities" straight. In this case, we'll say these properties are Level, High Score, and Play Count. We'll call the activities Pinball, Word Search, Maze, and Memory.
This method involves creating multiple arrays, one for each property, and creating constants that hold the integer "key" used for each activity.
We'll start by creating the constants, as integers. Constants work for this, because we never change them after compile. The value we put into each constant is the index the corresponding data will always be stored at in the arrays.
const pinball:int = 0;
const wordsearch:int = 1;
const maze:int = 2;
const memory:int = 3;
Now, we create the arrays. Remember, arrays start counting from zero. Since we want to be able to modify the values, this should be a regular variable.
Note, I am constructing the array to be the specific length we need, with the default value for the desired data type in each slot. I've used all integers here, but you can use just about any data type you need.
var highscore:Array = [0, 0, 0, 0];
var level:Array = [0, 0, 0, 0];
var playcount:Array = [0, 0, 0, 0];
So, we have a consistent "address" for each property, and we only had to create four constants, and three arrays, instead of 12 variables.
Now we need to create the functions to read and write to the arrays using this system. This is where the real beauty of the system comes in. Be sure this function is written in public scope if you want to read/write the arrays from outside this class.
To create the function that gets data from the arrays, we need two arguments: the name of the activity and the name of the property. We also want to set up this function to return a value of any type.
GOTCHA WARNING: In Actionscript 3, this won't work in static classes or functions, as it relies on the "this" keyword.
public function fetchData(act:String, prop:String):*
{
var r:*;
r = this[prop][this[act]];
return r;
}
That queer bit of code, r = this[prop][this[act]], simply uses the provided strings "act" and "prop" as the names of the constant and array, and sets the resulting value to r. Thus, if you feed the function the parameters ("maze", "highscore"), that code will essentially act like r = highscore[2] (remember, this[act] returns the integer value assigned to it.)
The writing method works essentially the same way, except we need one additional argument, the data to be written. This argument needs to be able to accept any
GOTCHA WARNING: One significant drawback to this system with strict typing languages is that you must remember the data type for the array you're writing to. The compiler cannot catch these type errors, so your program will simply throw a fatal error if it tries to write the wrong value type.
One clever way around this is to create different functions for different data types, so passing the wrong data type in an argument will trigger a compile-time error.
public function writeData(act:String, prop:String, val:*):void
{
this[prop][this[act]] = val;
}
Now, we just have one additional problem. What happens if we pass an activity or property name that doesn't exist? To protect against this, we just need one more function.
This function will validate a provided constant or variable key by attempting to access it, and catching the resulting fatal error, returning false instead. If the key is valid, it will return true.
function validateName(ID:String):Boolean
{
var checkthis:*
var r:Boolean = true;
try
{
checkthis = this[ID];
}
catch (error:ReferenceError)
{
r = false;
}
return r;
}
Now, we just need to adjust our other two functions to take advantage of this. We'll wrap the function's code inside an if statement.
If one of the keys is invalid, the function will do nothing - it will fail silently. To get around this, just put a trace (a.k.a. print) statement or a non-fatal error in the else construct.
public function fetchData(act:String, prop:String):*
{
var r:*;
if(validateName(act) && validateName(prop))
{
r = this[prop][this[act]];
return r;
}
}
public function writeData(act:String, prop:String, val:*):void
{
if(validateName(act) && validateName(prop))
{
this[prop][this[act]] = val;
}
}
Now, to use these functions, you simply need to use one line of code each. For the example, we'll say we have a text object in the GUI that shows the high score, called txtHighScore. I've omitted the necessary typecasting for the sake of the example.
//Get the high score.
txtHighScore.text = fetchData("maze", "highscore");
//Write the new high score.
writeData("maze", "highscore", txtHighScore.text);
I hope ya'll will find this tutorial useful in sorting and managing your variables.
(Afternote: You can probably do something similar with dictionaries or databases, but I prefer the flexibility with this method.)