Re: [Qemu-devel] [PATCH 6/8] gtk: add support for screen scaling and full screen (v2)

[Stefan Weil <sw@weilnetz.de>]

Am 27.02.2012 00:46, schrieb Anthony Liguori:
> Basic menu items to enter full screen mode and zoom in/out. Unlike SDL, we
> don't allow arbitrary scaling based on window resizing. The current 
> behavior
> with SDL causes a lot of problems for me.
>
> Sometimes I accidentally resize the window a tiny bit while trying to 
> move it
> (Ubuntu's 1-pixel window decorations don't help here). After that, 
> scaling is
> now active and if the screen changes size again, badness ensues since the
> aspect ratio is skewed.
>
> Allowing zooming by 25% in and out should cover most use cases. We can 
> add a
> more flexible scaling later but for now, I think this is a more friendly
> behavior.
>
> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
> ---
> v1 -> v2
> - fix scaling (Paolo)
> - use ctrl-alt-+ instead of ctrl-alt-= for zoom
> ---
> ui/gtk.c | 92 
> +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++---
> 1 files changed, 88 insertions(+), 4 deletions(-)
>
> diff --git a/ui/gtk.c b/ui/gtk.c
> index 0dac807..578cb94 100644
> --- a/ui/gtk.c
> +++ b/ui/gtk.c

[...]

>
> + s->full_screen_item = gtk_check_menu_item_new_with_mnemonic("_Full 
> Screen");

I suggest using the GTK standard widget GTK_STOCK_FULLSCREEN here.
That's not a check menu item, so some more changes will be needed.

Full screen mode does not need a check menu item, because you only
see the menu item when it is not in full screen mode.

> + gtk_menu_item_set_accel_path(GTK_MENU_ITEM(s->full_screen_item),
> + "<QEMU>/View/Full Screen");
> + gtk_accel_map_add_entry("<QEMU>/View/Full Screen", GDK_KEY_f, 
> GDK_CONTROL_MASK | GDK_MOD1_MASK);
> + gtk_menu_append(GTK_MENU(s->view_menu), s->full_screen_item);
> +
> + separator = gtk_separator_menu_item_new();
> + gtk_menu_append(GTK_MENU(s->view_menu), separator);
> +
> + s->zoom_in_item = 
> gtk_image_menu_item_new_from_stock(GTK_STOCK_ZOOM_IN, NULL);
> + gtk_menu_item_set_accel_path(GTK_MENU_ITEM(s->zoom_in_item),
> + "<QEMU>/View/Zoom In");
> + gtk_accel_map_add_entry("<QEMU>/View/Zoom In", GDK_KEY_plus, 
> GDK_CONTROL_MASK | GDK_MOD1_MASK);
> + gtk_menu_append(GTK_MENU(s->view_menu), s->zoom_in_item);
> +
> + s->zoom_out_item = 
> gtk_image_menu_item_new_from_stock(GTK_STOCK_ZOOM_OUT, NULL);
> + gtk_menu_item_set_accel_path(GTK_MENU_ITEM(s->zoom_out_item),
> + "<QEMU>/View/Zoom Out");
> + gtk_accel_map_add_entry("<QEMU>/View/Zoom Out", GDK_KEY_minus, 
> GDK_CONTROL_MASK | GDK_MOD1_MASK);
> + gtk_menu_append(GTK_MENU(s->view_menu), s->zoom_out_item);
> +
> separator = gtk_separator_menu_item_new();
> gtk_menu_append(GTK_MENU(s->view_menu), separator);
>

As was already said, GTK_STOCK_ZOOM_100 with accelerator GDK_KEY_0
would complete the zooming menu entries.

In your previous patch, you scaled s->scale_x *= 1.25 (which was correct)
and s->scale_x *= 0.75 (which should have been s->scale_x *= 0.8).

Why do you now use s->scale_x += .25, s->scale_x -= .25?
Linear scaling is uncommon and not what I'd expect when I read
25 % zooming in / out. I know that SDL also uses linear scaling,
but GTK wants to be better than SDL.

Regards,

Stefan Weil