straight to the point:
Im learning wxsmith and wxwidgets toolkit, i created some basic GUI containing one button and 2 static text fields. GUI is compilling ok so far. My frame name is proba2Frame, then im adding my own function which is not a member of any class but i declared in header file for proba2Frame that my function is a friend. Below is code of my function:
wxStaticText * dawajpointera()
{
wxStaticText * text;
text = proba2Frame.wxStaticText.StaticText1;
return text;
}
im getting error:
expected primary-expression before ‘.’ token
What exactly im doing wrong and how to get a pointer StaticText in case my solution is completely wrong ?
Thank You in advance
You make it sound like proba2Frame is the name of a class inheriting wxFrame?
If so, you're haveing problems because you haven't created an instance of proba2Frame, and you're trying to access a part of it that hasn't been constructed. Your main frame class is simply a template for your GUI, not the GUI itself.
The best way to go about it would probably be to take an instance of proba2Frame as a parameter-
wxStaticText* dawajpointera(proba2Frame *frame)
{
return frame->StaticText1;
}
Of course, that function itself was a bit pointless, but I'll assume that you're going to do something more involved with the pointer afterwards, and want it set to a pointer named text within the function for the sake of brevity.
void func(proba2Frame *frame)
{
wxStaticText *text = frame->StaticText1;
// Do something with text
}
If you're doing this, though, please consider making the function a method of proba2Frame.
wxStaticText is the name of a wxWidgets class. You should not be naming attributes of your frame 'wxStaticText'. Despite the code you have posted, I doubt that you have really done such a terrible thing. What you probably meant to write, I would guess, is:
text = proba2Frame.StaticText1;
I am guessing that the name of the attribute is StaticText1, a pointer to an instance of the wxStaticText class.
Related
I'm sorry if this question is duplicate but i am really struggling with finding any answer.
Please take in mind that i am novice in c++ programmming.
My problem is this. I have an GUI made in QtCreator. There are two listeners binding keyReleaseEvent, one on main class (SuperFalcon) , one on QTextEdit ( which is separate and modified class ). I have QFrame which i would like to toggle hide/show on "Ctrl + f" key event. Since that QFrame (object name is findWidget) widget belongs to SuperFalcon->ui, there's no problem, everything works fine, problem starts when i try to make "Ctrl + f" in QTextEdit because it's separate event listener. Basically i tried this.
main class name is "SuperFalcon" so:
in superfalcon.h i've made an public static pointer like this:
public:
static QFrame *fWidget;
then in superfalcon.cpp, i firstly execute
ui->findWidget->hide(); and then
fWidget = ui->findWidget; hoping to get pointer on widget.
Next in my QTextEdit class in keyReleaseEvent function i've tried to get that pointer like SuperFalcon::fWidget->show() but i get undefined reference on it.
So , to make things simpler, i don't know how , if possible, to get reference of QFrame widget which is part of one class (SuperFalcon), from another class (QTextEdit class) in order to execute some commands on QFrame.
If it's not clear enough i can provide some code.
You must have a definition of any static member variable.
This definition has to be in a source file because of the one definition rule.
Simply add the line:
QFrame* SuperFalcon::fWidget;
to "superfalcon.cpp".
You have to initialize your static variable, in superfalcon.cpp:
QFrame* SuperFalcon::fWigdet = nullptr;
I have the following wxDialog parent window:
I have created that parent window by the following code:
settingsFrm settingsWindow(this, "Settings");
settingsWindow.ShowModal();
I have tried to use FindWindowByName to get the value of the first text ctrl as follow:
wxLogMessage(dynamic_cast<wxTextCtrl*>(settingsWindow->FindWindowByName("keywords_txt"))->GetValue());
But unfortunately, it doesn't work and gives me a runtime error.
I don't know if that method suitable to do what I want.
How to get the value/other of a control through its parent window?
From your comments, it seems like you expect the function to find the control from the name of the variable in your code which is not how it works and would be pretty much impossible.
FindWindowByName() uses the window name (and, as a fallback, label, but this is irrelevant here because text controls don't have labels anyhow), so for it to work you need to set the window name when creating the control, using the corresponding parameter of its ctor. This is very rarely useful in C++ code, however, as it's simpler to just store a pointer to the control in some variable and use this instead.
FindWindowByName() can often be useful when creating controls from XRC, however. If you do this, then you should specify names for your controls in XRC and pass the same name to this function.
How did you create the TextCtrl instance? You should have something like wxTextCtrl m_textCtrl1 = new wxTextCtrl(/// arguments); Accessing the value should be very easy, as wxString text = m_textCtrl1->GetValue(); You definitely don't need FindWindowByName just for what you are trying to do here.
Coming from making single-page applications with the visual WYSISWYG editor in JUCE, I'm having a bit of trouble figuring out how to invoke new windows (outside of the main GUI window). I made a test application that just has a small minimal main GUI that I created with the visual editor. It has a button "Make New Window." My goal is to be able to click that button and have a new window pop up and that this new window is a JUCE "GUI component," (AKA, the graphical / visual GUI editor file). Now, I actually have sort of achieved this, however, its throwing errors and assertions, so it would be great to get a very simple, step-by-step tutorial.
I studied the main.cpp file that the Projucer automatically created in order to get a feel for how they are creating a window. Here's what I did.
1) In my project, I added a new GUI Component (which becomes a class) and called it "InvokedWindow."
2) In my main GUI component class header, I added a new scoped pointer of type InvokedWindow: ScopedPointer<InvokedWindow> invokedWindow;
3) I created a new button in the main GUI editor called "Make New Window" and added this to the handler code:
newWindowPtr = new InvokedWindow; so that any time the button is hit, a new object of type InvokedWindow is created.
4) In the InvokedWindow class, in the constructor, on top of the automatically generated code, I added:
setUsingNativeTitleBar (true);
setCentrePosition(400, 400);
setVisible (true);
setResizable(false, false);
Which I sort of got from the main file of the JUCE application.
I also added a slider to this new window just to add functionality to it.
5) I added an overloaded function to let me close the window:
void InvokedWindow::closeButtonPressed()
{
delete this;
}
So, now when I run the app and click the make new window button, a new window does pop up, but I get an assertion:
/* Agh! You shouldn't add components directly to a ResizableWindow - this class
manages its child components automatically, and if you add your own it'll cause
trouble. Instead, use setContentComponent() to give it a component which
will be automatically resized and kept in the right place - then you can add
subcomponents to the content comp. See the notes for the ResizableWindow class
for more info.
If you really know what you're doing and want to avoid this assertion, just call
Component::addAndMakeVisible directly.
*/
Also, I'm able to close the window once and hit the button in the main GUI to create another instance of a newWindow, but closing it a second time leads to an error:
template <typename ObjectType>
struct ContainerDeletePolicy
{
static void destroy (ObjectType* object)
{
// If the line below triggers a compiler error, it means that you are using
// an incomplete type for ObjectType (for example, a type that is declared
// but not defined). This is a problem because then the following delete is
// undefined behaviour. The purpose of the sizeof is to capture this situation.
// If this was caused by a ScopedPointer to a forward-declared type, move the
// implementation of all methods trying to use the ScopedPointer (e.g. the destructor
// of the class owning it) into cpp files where they can see to the definition
// of ObjectType. This should fix the error.
ignoreUnused (sizeof (ObjectType));
delete object;
}
};
This is all a bit over my head. I was figuring it wouldn't be too bad to be able to create a new window, via a button. A new window that I could edit with the graphical GUI editor, but I'm not able to fully figure it out all on my own, through I did try. Could anyone post a step-by-step guide to doing this the correct way? I did post this at the JUCE forums, but due to my lack of GUI programming, I was unable to understand the solutions posted (my own fault), so I'm hoping to get a very simple guide to this. It would be very much appreciated. Thank you.
I figured it out. I needed to create:
A new GUI component (Remember, this is the visual editor in JUCE)
A class (I called it BasicWindow, based on the JUCE demo code) that acts as a shell to run this new window and holds the GUI component.
A JUCE SafePointer that makes a new object of type BasicWindow whenever the button is clicked and sets the attributes to that window.
Here is my code:
Referring to line 3) Inside the handler section of the button to create the new window:
basicWindow = new BasicWindow("Information", Colours::grey, DocumentWindow::allButtons);
basicWindow->setUsingNativeTitleBar(true);
basicWindow->setContentOwned(new InformationComponent(), true);// InformationComponent is my GUI editor component (the visual editor of JUCE)
basicWindow->centreWithSize(basicWindow->getWidth(), basicWindow->getHeight());
basicWindow->setVisible(true);
Referring to line 2) A .cpp file that defines what the BasicWindow is:
#include "../JuceLibraryCode/JuceHeader.h"
class BasicWindow : public DocumentWindow
{
private:
JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (BasicWindow)
public:
BasicWindow (const String& name, Colour backgroundColour, int buttonsNeeded)
: DocumentWindow (name, backgroundColour, buttonsNeeded)
{
}
void closeButtonPressed() override
{
delete this;
}
};
And referring to line 1) Make the GUI editor component, which this is easy to do. You just right add a new file in the JUCE file manager. "Add New GUI Component," then visually add all your elements and handler code.
My biggest issue was that I was using a JUCE ScopedPointer, so after deleting the object, the pointer pointing to it wasn't being set back to NULL. The SafePointer does this. If any more explanation is needed, I'm happy to help, as this was terrible for someone with not much GUI development "under his belt."
I'm trying to make a custom sprite, which could receive touch and handle the function as callback.
Okay, first step, receive the touch, easy, we can search it online everywhere.
The one I couldn't do is, I want to make it receive SOMETHING in the class the sprite is created, a function that will be called when the sprite is touched.
I was searching on internet and I think (not really sure) that SEL_Callfunc can do what I want, but I couldn't understand how this one work, so can you guys give me an example please?
For example, my custom class is BSprite, so when I create new object in HelloWorld.cpp, it should be
BSprite* sprite = BSprite::create("HelloWorld.png",HelloWorld::TouchCallback);
Thanks for reading :)
sprite->addTouchEventListener(CC_CALLBACK_0(HelloWorld::onTouchSprite, this));
void HelloWorld::onTouchSprite() {
}
Note: onTouchSprite method should not have any parameters
My friend and I have each created parts of a GUI using Qt 4. They both work independently and I am trying to integrate his form with the my main window. As of now this is the code I am using to try and load his form:
//connect buttons and such
connect(exitbtn, SIGNAL(triggered()),this,SLOT(terminated()));
connect(add, SIGNAL(triggered()),this,SLOT(add_rec()));
void MainWindowImpl::add_rec()
{
//form quits as soon as it loads...?
DialogImpl dia;//name of his form
dia.show();
}
I have included his header file. The program compiles but when I hit the trigger his form loads up for maybe half a second and then closes. Does anyone know what I am doing wrong?
You have almost get it right. This is because the RAII of C++. If you allocate the Dialog on stack, it would be destructed as soon as the function return.
Assuming MainWindowImpl inherits publically from QWidget, you're looking for this:
void MainWindowImpl::add_rec()
{
// passing "this" to the constructor makes sure dialog will be cleaned up.
// Note that DialogImpl will need a constructor that takes a
// QObject* parent parameter.
DialogImpl* dialog = new DialogImpl(this);
dialog->show();
}
Look at the Qt documentation for examples of how the constructors should look.
Apparently QT4 only allows one instance of an object at a time, however pointers are another matter. Change both the main.cpp and what ever your main window to look something like this:
DialogImpl *dia=new DialogImpl;
dia->show();