I have a large project of mixed C/C++. I've created a simple visualizer for the ICU UnicodeString class as follows...
[inside autoexp.dat]
icu_4_2::UnicodeString {
preview ([$c.fUnion.fFields.fArray,su])
}
...and that works fine. Inside the debugger wherever I see the object I now see the text inside in the preview line.
I then created a wrapper class containing one of these objects as follows...
class StringHandleData
{
public:
icu_4_2::UnicodeString str;
};
...and then created another visualizer for this...
[inside autoexp.dat]
StringHandleData {
preview ([$c.str.fUnion.fFields.fArray,su])
}
...which again, works fine. Whenever I see a StringHandleData object in the debugger I see the text inside in the string.
However, my problem comes when I define a typedef I can use inside C code like this...
typedef void* StringHandle;
...which under the hood is actually just a ptr to a StringHandleData object. So when I try and create a visualizer for the StringHandle type like this...
[inside autoexp.dat]
StringHandle {
preview ([((StringHandleData)$c).str.fUnion.fFields.fArray,su])
}
...it doesn't work. I've tried lots of other ways of casting the object too but with no luck so far. If I go to my watch window and cast a StringHandle like this... (StringHandleData*)stringHandle then the debugger makes the cast and previews correctly - but I just can't seem to get it to do it automatically from inside autoexp.dat
Thanks for any help.
Visual studio's visualiser is blind to typedefs and will think StringHandle is a void *.
Related
I would like to modify the default code snippets for C++ in Visual Studio Code. I've found a similar question here, but they actually show how to create your own snippets - and not how to modify the default snippets.
The reason I want to do this is because I'm used to doing some things a bit differently than how they are done in the snippets. For example, this is what appears when I use the if snippet:
if (/* condition */)
{
/* code */
}
And I would like it to be like this:
if(/* condition */){
/* code */
}
Is there any way to achieve what I want to do? Thank you.
Press Ctrl + ,(opens vs code settings);
Type "snippet" in settings search bar;
In Extentions List choose C/C++
Untick "Suggest Snippets" button;
Close settings tab.
Go to settings again and create new User Snippets 😊as you liked.enter image description here
Is there any proper way to set a conditional breakpoint in Visual Studio 2015 such that it breaks whenever a pointer to a base class points to a specified subclass type? (see example screenshot below)
I don't want to have to spend time writing debug utility code for this, nor do I want to hack virtual table data.
Two ways to do it:
Add below as your breakpoint condition in your IDE:
dynamic_cast<DerivedClassYouWantToBreak*>(ptr.get())
Or add below code to your code and compile:
if (dynamic_cast<DerivedClassYouWantToBreak*>(ptr.get()))
{
int breaksHere = 0; // put breakpoint 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 would like to change the text of my UIBarButtonItem from another class (objective-C++) that I use in my project.
I have an IBOutlet myButton setup in myViewController and I can successfully do something like:
[ myButton setTitle:#"newTitle" ];
in myViewController.mm
Now I would like to do the same but from myCppClass that I use in my project.
Is there a way for myCppClass to access myViewController's myButton?
Shall I use some type of delegation mechanism?
I am pretty new to Ios and objective-C.
Thanks,
Baba
Create a method within your myViewController class to change the button title, then call that method from myCppClass by following the instructions described in this answer:
How to call method from one class in another (iOS)
https://stackoverflow.com/a/9731162/2274694
The short answer is, don't. You should treat a view controller's views as private. Instead, add a method to your VC like changeButtonTitle. Then call that method from from your other class.
The answers above are correct, but from your comments I suspect you aren't yet happy.
If you are super lazy, and you don't mind the string being the same in all instances of the VC (which in practice is usually the case) you could simply write a getter and setter for the string name as a class variable in the destination class. That way you don't even need access to the actual instance of the class, just its name. Tacky but super easy.
As others have pointed out, don't try and modify the buttons on a different VC directly. Pass a message and have the owning VC do it when it loads.
Well, passing messages forwards (to a new VC) is very easy. At the bottom of every VC class code there is #pragma navigation section commented out which gives you a handle to the destination VC. Cast it to the proper type and you set properties in the destination VC instance. In your case, create a public property NSString which holds the button text in your destination VC, and set it in your navigation section. This could be any class, or even a delegate, but a simple string should work.
Passing messages backwards (to previous VCs) can work the same way but it starts to get messy. You can programatically step back through the stack of VCs to find a particular (instance of) a VC. One of the answers to Get to UIViewController from UIView? gives sample code for stepping back through view controllers.
But if its simply forward communication, passing messages or information through
(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
at the bottom of the VC code and the commented out lines below is very easy and safe.
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();