Re: Mouse events on a Cairo Context
Hi, Thank you for your help, guys. Finally I tried with goocanvasmm and everything works fine, as I wanted. There are some simple examples in the libgoocanvasmm-2.0-doc package for Ubuntu, so I could deal with the problem :) The most similar example there is moving_shapes. Thank you! ___ gtk-app-devel-list mailing list gtk-app-devel-list@gnome.org https://mail.gnome.org/mailman/listinfo/gtk-app-devel-list
Re: Mouse events on a Cairo Context
Hi Colomban This is probably the simplest solution, it's meant for this kind of things. 4 - Handle the events yourself: listen to the button-press-event/button-release-event of your DrawingArea and do the math to know whether the click is on your circle or not. Maybe Cairo has this kind of thing, like is that point in that shape, not sure. The problem with (4) is dragdrop. I think it could be very difficult to deal with it, so I'm going to try the third solution, with goocanvasmm. Do you know any example of use of goocanvasmm? Thank you! :) ___ gtk-app-devel-list mailing list gtk-app-devel-list@gnome.org https://mail.gnome.org/mailman/listinfo/gtk-app-devel-list
Re: Mouse events on a Cairo Context
On Mon, 2013-07-01 at 17:42 +0200, Borja Mon Serrano wrote: The problem with (4) is dragdrop. I think it could be very difficult to deal with it, so I'm going to try the third solution, with goocanvasmm. Do you know any example of use of goocanvasmm? Yes, dragdrop may be not very easy. And zooming and panning/scrolling for a plain (cairo) drawing area may be not really trivial, when you need to grab objects with the mouse. I did try it two years ago from Ruby -- not really difficult, but it takes some time to get the math right. Have not found time to clean it up yet. ( http://www.ssalewski.de/PetEd.html.en) Of course, if you do C++ and have not much experience in GTK already you may try https://qt-project.org/doc/qt-4.8/graphicsview.html I have never find time and motivation to test that. ___ gtk-app-devel-list mailing list gtk-app-devel-list@gnome.org https://mail.gnome.org/mailman/listinfo/gtk-app-devel-list
Re: Mouse events on a Cairo Context
There is another solution that I have used extensively, which is to draw the cairo commands twice. Once for the actual drawing, and once again in an offline image (called label image), with the following differences: 1. Use solid colors corresponding to labels of the different graphical components. 2. Turn off anti-aliasing. When the user clicks on the image, the x,y of the event is referenced in the label image. The label is then used as a lookup to the component which can be modified. You can see an example of how to do this at https://github.com/dov/dovtk-lasso . Note that there is a special gtk3 branch. Regards, Dov On Mon, Jul 1, 2013 at 7:54 PM, Stefan Salewski m...@ssalewski.de wrote: On Mon, 2013-07-01 at 17:42 +0200, Borja Mon Serrano wrote: The problem with (4) is dragdrop. I think it could be very difficult to deal with it, so I'm going to try the third solution, with goocanvasmm. Do you know any example of use of goocanvasmm? Yes, dragdrop may be not very easy. And zooming and panning/scrolling for a plain (cairo) drawing area may be not really trivial, when you need to grab objects with the mouse. I did try it two years ago from Ruby -- not really difficult, but it takes some time to get the math right. Have not found time to clean it up yet. ( http://www.ssalewski.de/PetEd.html.en) Of course, if you do C++ and have not much experience in GTK already you may try https://qt-project.org/doc/qt-4.8/graphicsview.html I have never find time and motivation to test that. ___ gtk-app-devel-list mailing list gtk-app-devel-list@gnome.org https://mail.gnome.org/mailman/listinfo/gtk-app-devel-list ___ gtk-app-devel-list mailing list gtk-app-devel-list@gnome.org https://mail.gnome.org/mailman/listinfo/gtk-app-devel-list
Mouse events on a Cairo Context
Hi all, I'm developing an application with C++ and GTK3 but I'm stucked. I've created a visual application with glade which has three columns and one of them, the middle one, is a DrawingArea. In that DrawingArea I want to draw some circles at the point I want to after pressing a button and have different mouse events on that circles (like drag and drop, double click, right click...). I've made the first thing (draw a circle after pressing a button) following the official documentationhttps://developer.gnome.org/gtkmm-tutorial/3.2/chapter-drawingarea.html.en, but the problem is that I don't know how to do the mouse events, but I thought about it and I have some different solutions (I don't know if they are the bests solutions or maybe there are better): 1 - I think the best way is to create a signal to the cairomm context, but I didn't see anything to do that. Maybe the way would be to create a cairo surface or something like that. 2 - Every time I click to create a circle, I would have to create a gtk widget in which I can handle mouse events. The problem here is that I think it is impossible to put a widget on a DrawingArea, is it possible? 3 - Use goocanvasmm. The problem here is that goocanvasmm has a little documentation https://developer.gnome.org/goocanvasmm/stable/ and I think this is not the best solution, I prefer to use cairomm. This application was written in C using GTK2, and the circles were drawn using gnomecanvas, adding signals in an easy way to each circle; and now I'm moving this application to C++ and GTK3 to renew it. I'm very new to GTK (and graphical interfaces in general), but I looked for solutions for hours and I don't know what is the best way in order to continue my work. I also looked for similar messages in this list, but I didn't find it. Although I think the best way is the first option, I tried to make the second because I think it is the regular way. Anyway, if you know how to deal with this problem, could you give me an example of how to do that? Thank you for your help :) ___ gtk-app-devel-list mailing list gtk-app-devel-list@gnome.org https://mail.gnome.org/mailman/listinfo/gtk-app-devel-list
Re: Mouse events on a Cairo Context
Le 30/06/2013 21:10, Borja Mon Serrano a écrit : Hi all, [...] 1 - I think the best way is to create a signal to the cairomm context, but I didn't see anything to do that. Maybe the way would be to create a cairo surface or something like that. I don't think Cairo has this kind of thing. It's a library for drawing, not interacting with the drawing. 2 - Every time I click to create a circle, I would have to create a gtk widget in which I can handle mouse events. The problem here is that I think it is impossible to put a widget on a DrawingArea, is it possible? No you can't. And no stock widget will give you a circular event area. 3 - Use goocanvasmm. The problem here is that goocanvasmm has a little documentation https://developer.gnome.org/goocanvasmm/stable/ and I think this is not the best solution, I prefer to use cairomm. This is probably the simplest solution, it's meant for this kind of things. 4 - Handle the events yourself: listen to the button-press-event/button-release-event of your DrawingArea and do the math to know whether the click is on your circle or not. Maybe Cairo has this kind of thing, like is that point in that shape, not sure. Regards, Colomban ___ gtk-app-devel-list mailing list gtk-app-devel-list@gnome.org https://mail.gnome.org/mailman/listinfo/gtk-app-devel-list
