[virt-tools-list] [PATCH virt-viewer] virt-viewer-window: Change zoom of the display only when it is possible

Pavel Grunt pgrunt at redhat.com
Sat Mar 28 17:24:56 UTC 2015


Hi, thanks for the review!

> 
> On Sat, Mar 28, 2015 at 1:24 PM, Pavel Grunt <pgrunt at redhat.com>
> wrote:
> > Do not allow to zoom out if it is not possible due to the width of
> > the top menu. It avoids emitting size allocation events that will
> > change the display resolution of the spice guest.
> >
> > Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1206460
> > ---
> >  src/virt-viewer-window.c | 46
> >  ++++++++++++++++++++++++++++++++++++++++++++--
> >  1 file changed, 44 insertions(+), 2 deletions(-)
> >
> > diff --git a/src/virt-viewer-window.c b/src/virt-viewer-window.c
> > index d668f74..205a09a 100644
> > --- a/src/virt-viewer-window.c
> > +++ b/src/virt-viewer-window.c
> > @@ -67,6 +67,8 @@ static void
> > virt_viewer_window_disable_modifiers(VirtViewerWindow *self);
> >  static void virt_viewer_window_resize(VirtViewerWindow *self,
> >  gboolean keep_win_size);
> >  static void virt_viewer_window_toolbar_setup(VirtViewerWindow
> >  *self);
> >  static GtkMenu*
> >  virt_viewer_window_get_keycombo_menu(VirtViewerWindow *self);
> > +static void
> > virt_viewer_window_get_minimal_dimensions(VirtViewerWindow *self,
> > guint *width, guint *height);
> > +static gboolean virt_viewer_window_can_zoom_out(VirtViewerWindow
> > *self);
> >
> >  G_DEFINE_TYPE (VirtViewerWindow, virt_viewer_window,
> >  G_TYPE_OBJECT)
> >
> > @@ -366,14 +368,16 @@ G_MODULE_EXPORT void
> >  virt_viewer_window_menu_view_zoom_out(GtkWidget *menu
> >  G_GNUC_UNUSED,
> >                                        VirtViewerWindow *self)
> >  {
> > -    virt_viewer_window_set_zoom_level(self, self->priv->zoomlevel
> > - 10);
> > +    if (virt_viewer_window_can_zoom_out(self))
> > +        virt_viewer_window_set_zoom_level(self,
> > self->priv->zoomlevel - 10);
> >  }
> >
> 
> I'm not sure if I prefer this treatment being done here or inside
> _set_zoom_level(), where you can know if you're zooming in or zooming
> out as well ... OTOH, I can agree with this here and with some other
> treatment being moved from _set_zoom_level() specifically to
> _zoom_in/out() functions ...

The main difference is that functions virt_viewer_window_menu_view_zoom_out/in()
are only invoked by the user. I wanted to avoid calling virt_viewer_display_set_zoom_level()
and virt_viewer_window_queue_resize() when it is not necessary.

> 
> >  G_MODULE_EXPORT void
> >  virt_viewer_window_menu_view_zoom_in(GtkWidget *menu
> >  G_GNUC_UNUSED,
> >                                       VirtViewerWindow *self)
> >  {
> > -    virt_viewer_window_set_zoom_level(self, self->priv->zoomlevel
> > + 10);
> > +    if (self->priv->zoomlevel < MAX_ZOOM_LEVEL)
> > +        virt_viewer_window_set_zoom_level(self,
> > self->priv->zoomlevel + 10);
> 
> This check is already done on set_zoom_level() ... no?

Probably it is not necessary, it is just avoiding _queue_resize()

> if (zoom_level > 400)
>     zoom_level = 400;
> 
> What, btw, should use MAX_ZOOM_LEVEL instead of 400 ...
>

Looking at the code there is more zoom related magic constants - maybe I should also introduce something like ZOOM_STEP, NORMAL_ZOOM_LEVEL ?

>
> Actually, I know it is not related, but on set_zoom_level() I'd like
> to see some treatment as (with a better debug message):
> if (priv->zoomlevel == zoom_level) {
>     g_debug ("Maximum/Minimum zoom level reached");
>     return;
> }
> 
Sure

>
> >  }
> >
> >  G_MODULE_EXPORT void
> > @@ -1467,6 +1471,44 @@
> > virt_viewer_window_set_kiosk(VirtViewerWindow *self, gboolean
> > enabled)
> >          g_debug("disabling kiosk not implemented yet");
> >  }
> >
> > +static void
> > +virt_viewer_window_get_minimal_dimensions(VirtViewerWindow *self,
> > +                                          guint *width,
> > +                                          guint *height)
> > +{
> > +    GtkRequisition req;
> > +    GtkWidget *top_menu;
> > +    g_return_if_fail(VIRT_VIEWER_IS_WINDOW(self));
> > +    g_return_if_fail(width != NULL);
> > +    g_return_if_fail(height != NULL);
> > +
> > +    top_menu =
> > GTK_WIDGET(gtk_builder_get_object(virt_viewer_window_get_builder(self),
> > "top-menu"));
> > +#if !GTK_CHECK_VERSION(3, 0, 0)
> > +    gtk_widget_get_child_requisition(top_menu, &req);
> > +#else
> > +    gtk_widget_get_preferred_size(top_menu, &req, NULL);
> > +#endif
> > +    *height = 50;
> > +    *width = req.width;
> 
> I would appreciate a comment here explaining that the minimum size is
> set to 50x50 (an arbitrary small value) but in the end it will be the
> top menu's width x 50
> 
Sure, or also remove magical constants ?
>
> > +}
> > +
> > +static gboolean
> > +virt_viewer_window_can_zoom_out(VirtViewerWindow *self)
> > +{
> > +    double zoom_level;
> > +    guint min_width = 0, min_height = 0, act_width = 0, act_height
> > = 0;
> > +
> > +    g_return_val_if_fail(VIRT_VIEWER_IS_WINDOW(self), FALSE);
> > +    if (self->priv->zoomlevel <= MIN_ZOOM_LEVEL ||
> > self->priv->display == NULL)
> > +        return FALSE;
> 
> This treatment is already done on _set_zoom_level() ... maybe we
> really should move the whole treatment to that function ...
> 
ok, I was thinking like giving the "complete" answer whether is possible to zoom out. 
>
> > +
> > +    virt_viewer_window_get_minimal_dimensions(self, &min_width,
> > &min_height);
> > +
> >    virt_viewer_display_get_desktop_size(virt_viewer_window_get_display(self),
> > &act_width, &act_height);
> 
> What does act stands for? actual? I'd use just width and height here

yes
> ...
> 
> > +    zoom_level = (self->priv->zoomlevel - 10) / 100.0;
> > +
> > +    return zoom_level * act_width >= min_width && zoom_level
> > *act_height >= min_height;
> > +}
> > +
> >  /*
> >   * Local variables:
> >   *  c-indent-level: 4
> > --
> > 2.3.4
> >
> > _______________________________________________
> > virt-tools-list mailing list
> > virt-tools-list at redhat.com
> > https://www.redhat.com/mailman/listinfo/virt-tools-list
> 
> 
> Let me know your thoughts about moving the _can_zoom_out() and the
> other checks you have added to the _set_zoom_level() function ... Or
> would it be a problem when starting virt-viewer setting a zoom-level
> by the command line?
> 

I wanted to avoid extra display_queue_resize(). And I was afraid of "the command line"
It will be possible to set the small zoom level from command line but not really setting it
because we return from window_set_zoom_level(). I have to try it..

I will send v2.

Thanks,

Pavel




More information about the virt-tools-list mailing list