c++ - Stroustrup's Simple_window.h

Question

I am trying to get the graphics examples to work from Stroustrup's Principles and Practices ...C++, to no avail (yet). I have installed the fltk stuff, and know that is working fine as I managed to get a window to display using with a program suggested in the appendix of his book:

#include <FL/Fl.H>
#include <FL/Fl_Box.H>
#include <FL/Fl_Window.H>

int main(){

    Fl_Window window(200,200, "title here");
    Fl_Box box(0,0,200,200,"Hey, hello wrld");
    window.show();
    return Fl::run();
}

However, trying my own using his Simple_window.h (can be found on his site) gives "reference to ‘Window’ is ambiguous", since it's already at usr/include/X11/X.h . So I tried specifying the namespace to the relevant one:

struct Simple_window : Graph_lib::Window {  //Changed Window to inc. namespace
    Simple_window(Point xy, int w, int h, const string& title );

    bool wait_for_button(); // simple event loop

.
.
.

But this gives me a bunch more errors I don't understand:

$ clear; g++ -Wno-deprecated window.cpp -o holz
    /tmp/ccIFivNg.o: In function `main':
    window.cpp:(.text+0x64): undefined reference to `Simple_window::Simple_window(Point, int, int, String const&)'
    /tmp/ccIFivNg.o: In function `Graph_lib::Window::~Window()':
    window.cpp:(.text._ZN9Graph_lib6WindowD2Ev[_ZN9Graph_lib6WindowD5Ev]+0x14): undefined reference to `vtable for Graph_lib::Window'

etc.

I feel mastering graphics is going to be a long and rocky road -_-

Answer 1

To anyone in the same predicament, I leave here what I did to finally be able to compile and get the window of the first program with FLTK on section 12.3 of Stroustrup's book "Programming: Principles and Practice using C++, 2nd Edition".

After installing FLTK on Kubuntu 14.04 with

$ sudo apt install libfltk1.3-dev

I could compile the example program on Appendix D with the use of

$ fltk-config --compile fltkTest.cpp

Thanks to this post, I could see how I could finally get it on track with the first example of chapter 12. Comparing the command of cwivagg and Nathan with the command generated with fltk-config, I ended with this command

$ clang++ -I/usr/include/cairo -I/usr/include/glib-2.0 -I/usr/lib/x86_64-linux-gnu/glib-2.0/include -I/usr/include/pixman-1 -I/usr/include/freetype2 -I/usr/include/libpng12 -I/usr/include/freetype2 -I/usr/include/cairo -I/usr/include/glib-2.0 -I/usr/lib/x86_64-linux-gnu/glib-2.0/include -I/usr/include/pixman-1 -I/usr/include/freetype2 -I/usr/include/libpng12 -g -O2 -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_THREAD_SAFE -D_REENTRANT -Wl,-Bsymbolic-functions -lfltk_images -lfltk -lX11 -std=c++11 -o 's12_3_first' 's12_3_first.cpp' Simple_window.cpp Graph.cpp GUI.cpp Window.cpp

I had to add -lfltk_images and -std=c++11

However, now I had to deal with the errors that the compiler gave me. To get a working program, I had to do several changes to the sources that Stroustrup gave on http://www.stroustrup.com/Programming/PPP2code/

1. I uncommented std_lib_facilities.h on Graph.h
2. To resolve the ambiguity of Window, I needed to specify Graph_lib::Window on line 9 of Simple_window.h
3. std_lib_facilities.h on lines 107 and 113 uses a i<0 comparison when i is unsigned (but these are just warnings).
4. Graph.h line 159 uses fl_color() but the compiler says it should be Fl_Color
5. I needed to uncomment the constructors for Point in Point.h
6. There are several redefinitions on Simple_window.cpp of Simple_window.h On Simple_window.cpp I commented out the definitions for the constructor, cb_next and wait_for_button (which is not the same as the one on Simple_window.h). On Simple_window.h I commented out the definitions of wait_for_button and next. By the way, wait_for_button does not work in either form.
7. In GUI.cpp there is another redefinition for the constructor of Menu. I commented it out.
8. I changed the last line of the example of section 12.3 from win.wait_for_button; to Fl::run(); which I took from the example on Appendix D, because otherwise the window does not close with its close button.

With all these changes I finally have the window as it should be, and the window close either with the Next button or the close button of the said window (with wait_for_button I needed to end the program from Konsole with Ctrl-c after I tried to close it with the close button of the window).

I hope the next person do not have to spend all the time I had to.

Edit: Well, checking at my system and the compiling command, I realized that there are several carpets repeated... and that they actually don't exist in my Kubuntu system. So, I have to write down in my answer what I finally do to get the window working:

To get an object file:

$ clang++ -O2 -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_THREAD_SAFE -D_REENTRANT -g -std=c++11 -c  Simple_window.cpp

To get the first program that we wanted

% clang++ -O2 -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_THREAD_SAFE -D_REENTRANT -Wl,-Bsymbolic-functions -lfltk_images -lfltk -lX11 -g -std=c++11 Simple_window.o Graph.o GUI.o Window.o -o z3 s12_3_first.cpp

These are a hell lot easier (I almost can write them every time I need them)