RE: [PATCH 1/2] ui/gtk: use widget size for cursor motion event

[Kasireddy, Vivek]

Hi Erico,

> 
> The gd_motion_event size has some calculations for the cursor position,
> which also take into account things like different size of the
> framebuffer compared to the window size.
> The use of window size makes things more difficult though, as at least
> in the case of Wayland includes the size of ui elements like a menu bar
> at the top of the window. This leads to a wrong position calculation by
> a few pixels.
> Fix it by using the size of the widget, which already returns the size
> of the actual space to render the framebuffer.
> 
> Signed-off-by: Erico Nunes <ernunes@redhat.com>
> ---
>  ui/gtk.c | 8 +++-----
>  1 file changed, 3 insertions(+), 5 deletions(-)
> 
> diff --git a/ui/gtk.c b/ui/gtk.c
> index fd82e9b1ca..d1b2a80c2b 100644
> --- a/ui/gtk.c
> +++ b/ui/gtk.c
> @@ -868,7 +868,6 @@ static gboolean gd_motion_event(GtkWidget *widget,
> GdkEventMotion *motion,
>  {
>      VirtualConsole *vc = opaque;
>      GtkDisplayState *s = vc->s;
> -    GdkWindow *window;
>      int x, y;
>      int mx, my;
>      int fbh, fbw;
> @@ -881,10 +880,9 @@ static gboolean gd_motion_event(GtkWidget *widget,
> GdkEventMotion *motion,
>      fbw = surface_width(vc->gfx.ds) * vc->gfx.scale_x;
>      fbh = surface_height(vc->gfx.ds) * vc->gfx.scale_y;
> 
> -    window = gtk_widget_get_window(vc->gfx.drawing_area);
> -    ww = gdk_window_get_width(window);
> -    wh = gdk_window_get_height(window);
> -    ws = gdk_window_get_scale_factor(window);
> +    ww = gtk_widget_get_allocated_width(widget);
> +    wh = gtk_widget_get_allocated_height(widget);
[Kasireddy, Vivek] Could you please confirm if this works in X-based compositor
environments as well? Last time I checked (with Fedora 36 and Gnome + X), the
get_allocated_xxx APIs were not accurate in X-based environments. Therefore,
I restricted the above change to Wayland-based environments only:
https://lists.nongnu.org/archive/html/qemu-devel/2022-11/msg03100.html


Thanks,
Vivek

> +    ws = gtk_widget_get_scale_factor(widget);
> 
>      mx = my = 0;
>      if (ww > fbw) {
> --
> 2.39.2
>