Instantiating a scrollable Gtk::Grid

Platform
,
1

I am trying to create a Gtk::Grid containing Gtk::Pictures. I would like to be able to scroll through this grid of pictures so that I can select them and perform actions on them. I had a gtkmm3 GUI that could do this using a Gtk::ScrolledWindow, Gtk::Viewport, and Gtk::Grid. I used Glade to design that GUI and did not have to do much in C++ to get the desired effect. Now, I’m in GTK4 and creating these widgets in source code and what I am seeing is that the grid resizes the images when the number of rows would cause it to adjust the scrollbar so that all images are displayed at once.

Below is a code snippet of how the Gtk::Frame, Gtk::ScrolledWindow, and Gtk::Grid are built. I removed the Gtk::Viewport because the Gtk::ScrolledWindow documentation suggested one would be created for me (I also tested creating one myself).

captures_frame_ = Glib::RefPtr<Gtk::Frame>(new Gtk::Frame());
captures_frame_->set_label("Captures");
image_box_->append(*(captures_frame_.get()));

captures_scrolledwindow_ = Glib::RefPtr<Gtk::ScrolledWindow>(new Gtk::ScrolledWindow());
captures_scrolledwindow_->set_min_content_height(200);
captures_frame_->set_child(*(captures_scrolledwindow_.get()));

captures_grid_ = Glib::RefPtr<Gtk::Grid>(new Gtk::Grid());
captures_scrolledwindow_->set_child(*(captures_grid_.get()));

application_window_->present();

Can you advise on how to properly create these widgets? Thanks!

2

Don’t use Glib::RefPtr with widgets. There’s an example with a Gtk::Grid in
a Gtk::ScrolledWindow at examples/book/scrolledwindow · master · GNOME / gtkmm-documentation · GitLab

That example does not contain images. It probably does not solve the unwanted resizing.
I’m not sure what to do here. Are your images stored in Gtk::Image objects?
You can try calling Gtk::Widget::set_size_request() on the images.

3

I’ve put images in a scrollable grid view in Python. I used a box for the grid entries so that I could include a text label with each image.

I hit issues with my first implementation just adding the fixed sized images to the box and then adding the boxes to the grid. Once I had several thousand entries (big appreciation for GridView supporting this nicely), I started to see issues scrolling a long way - the images would grow, there would be fewer entries per grid row and sometimes large white space gaps between rows.

In the end I looked at how Gnome Files worked (the nautilus-grid-* files in src · main · GNOME / Files · GitLab) It uses Bin and Clamp in the grid entry objects in ways I don’t understand but copying that approach solved my issues with the grid.

4

You can try Cambalache which is the Glade equivalent for GTK4 by the same developer. It’s still in the works, but should be good enough for most common use cases.

5

Thanks for the replies, everyone. After going through some of your comments, I noticed that I was using set_can_shrink(false) for my main Gtk::Picture, but not the ones in the grid. Once I set that to false for the grid entries, the total size exceeded the allocation for the Gtk::ScrolledWindow and the scroll bars activated. Problem solved!

6

This topic was automatically closed 30 days after the last reply. New replies are no longer allowed.