GTK 4 porting

[MostlyKIGuess]

On Works

• Most of the decision will be described on the blogs whose link I will soon update in this PR, I will be explaining the process with as much detail as I can on changes that I make
• I will keep updating the changes, based on the commits here are few changes:

Porting.md

Progress Tracking

Completed

• Updated gi.require_version calls to 4.0 in Python files
• Updated import statements
• Updated build system GIR includes (Gtk-4.0, Gdk-4.0)
• Fixed GdkEvent opaque struct access in sugar-event-controller.c
• Fixed GTK 4 event handling in all event controllers
• Migrated from GdkPoint to custom SugarPoint structure

In Progress

• Find and update remaining 3.0 version references
• Fix eggaccelerator errors

TODO

• Replace GtkToolbar with GtkBox
• Migrate GtkEventBox to GtkWidget + EventControllers
• Update GtkContainer usage to new child management
• Convert draw() methods to snapshot()
• Update size request/allocation APIs
• Replace widget "event" signal with proper event controllers

Breaking Changes

• GdkEvent Opaque Structure: In GTK 4, GdkEvent structs are now opaque and immutable. Direct field access like event->type and event->grab_broken.keyboard is no longer allowed.

  • Solution: Use accessor functions like gdk_event_get_event_type()
  • Reference: https://docs.gtk.org/gdk4/class.Event.html

• GDK_GRAB_BROKEN Event Removed: The GDK_GRAB_BROKEN event type and related grab broken handling has been removed/changed in GTK 4.

  • Solution: Removed grab broken handling entirely as GTK 4 uses automatic grab management
  • Reference: https://docs.gtk.org/gtk4/input-handling.html

• GdkPoint Removed: The GdkPoint structure was removed in GTK 4.

  • Solution: Created custom SugarPoint structure for internal use
  • Reference: https://docs.gtk.org/gtk4/migrating-3to4.html

• Event Coordinate Access: Direct access to event coordinates changed in GTK 4.

  • Old: event->touch.x, event->touch.y
  • New: gdk_event_get_position(event, &x, &y)
  • Reference: https://docs.gtk.org/gdk4/method.Event.get_position.html

• Widget "event" Signal: The generic widget "event" signal is deprecated in favor of specific event controllers.

  • Current Status: Still using for compatibility, needs migration to proper event controllers
  • Reference: https://docs.gtk.org/gtk4/input-handling.html

Build Status

• Last successful build: Pending - working on build system updates
• Current blockers: Need to update configure.ac and remaining GTK 3.0 references

[chimosky]

Haven't reviewed yet, most of your opening comment should be in your commit message, that gets preserved by git which is what we want.

You've also opened the PR from the main branch, that's not our usual workflow.

[MostlyKIGuess]

Haven't reviewed yet, most of your opening comment should be in your commit message, that gets preserved by git which is what we want.

So is the current commit, is that fine? I am not sure what exactly to change in that, I am just writing what I did and in the description about stuff I changed

You've also opened the PR from the main branch, that's not our usual workflow.

Correct, I will close that.

[chimosky]

So is the current commit, is that fine? I am not sure what exactly to change in that, I am just writing what I did and in the description about stuff I changed

I haven't reviewed the commit, just looked at the commit message and your opening comment.

Look at making commits if you haven't before now.

Your current commit message is bland and monotonic, and for the change you're making it'll be great if it wasn't.