On Tue, Mar 24, 2015 at 5:27 PM, Peter Hutterer <[email protected]> wrote: > The axis_source event determines how an axis event was generated. This enables > clients to judge when to use kinetic scrolling. > > The axis_stop event notifies a client about the termination of a scroll > sequence, likewise needed to calculate kinetic scrolling parameters. > > The axis_discrete event provides the wheel click count. Previously the axis > value was some hardcoded number (10), with the discrete steps this enables a > client to differ between line-based scrolling on a mouse wheel and smooth > scrolling with a touchpad. > > We can't extend the existing wl_pointer.axis events so we introduce a new > concept: latching events. These events (axis_source and axis_discrete) > are prefixed before a wl_pointer.axis or axis_stop event, i.e. the sequence > becomes: > > wl_pointer.axis_source > wl_pointer.axis > wl_pointer.axis_source > wl_pointer.axis > wl_pointer.axis_source > wl_pointer.axis > wl_pointer.axis_source > wl_pointer.axis_stop > > or: > > wl_pointer.axis_source > wl_pointer.axis_discrete > wl_pointer.axis_axis > > Clients need to combine the state of all events where needed. > --- > Changes to v1: > - introduce axis_stop and axis_discrete as separate events instead of flags > - couple of documentation updates > - wl_seat/keyboard/touch/pointer bumped to version 5 > > This is for the API review only so far, I don't have the weston patches to > match yet. > > protocol/wayland.xml | 87 > +++++++++++++++++++++++++++++++++++++++++++++++++--- > 1 file changed, 83 insertions(+), 4 deletions(-) > > diff --git a/protocol/wayland.xml b/protocol/wayland.xml > index c5963e8..29e6f01 100644 > --- a/protocol/wayland.xml > +++ b/protocol/wayland.xml > @@ -1337,7 +1337,7 @@ > wl_seat.get_keyboard or wl_seat.get_touch, the returned object is > always of the same version as the wl_seat. > --> > - <interface name="wl_seat" version="4"> > + <interface name="wl_seat" version="5"> > <description summary="group of input devices"> > A seat is a group of keyboards, pointer and touch devices. This > object is published as a global during start up, or when such a > @@ -1411,7 +1411,7 @@ > </interface> > > <!-- for the version see the comment in wl_seat --> > - <interface name="wl_pointer" version="3"> > + <interface name="wl_pointer" version="5"> > <description summary="pointer input device"> > The wl_pointer interface represents one or more input devices, > such as mice, which control the pointer location and pointer_focus > @@ -1572,10 +1572,89 @@ > <description summary="release the pointer object"/> > </request> > > + <!-- Version 4 additions: none --> > + > + <!-- Version 5 additions --> > + > + <enum name="axis_source"> > + <description summary="axis source types"> > + Describes the axis types of scroll events. > + </description> > + <entry name="unknown" value="0"/> > + <entry name="wheel" value="1"/> > + <entry name="finger" value="2"/> > + <entry name="continuous" value="3"/>
Please document what these are. "finger" is fairly obvious. But what's the difference between "continuous" and "wheel"? I have a mouse with a continuous wheel. Coincidentally, it also has a button you can click that makes the wheel rotate in discrete steps. Other than that, this looks fine to me. I can't say much about whether or not this is a good way to implement kinetic scrolling, but the protocol looks fine. --Jason > + </enum> > + > + <event name="axis_source" since="5"> > + <description summary="axis source event"> > + Scroll and other axis source notification. > + > + This event does not occur on its own. It is sent before a > + wl_pointer.axis or wl_pointer.axis_stop event and carries the source > + information for that event. A client is expected to accumulate the > + data in both events before proceeding. > + > + The axis and timestamp values are identical to the one in the > + subsequent wl_pointer.axis or wl_pointer.axis_stop event. For the > + interpretation of the axis value, see the wl_pointer.axis event > + documentation. > + > + The source specifies how this event was generated. If the source is > + finger, a wl_pointer.axis_stop event will be sent when the user > + lifts the finger off the device. > + </description> > + <arg name="time" type="uint" summary="timestamp with millisecond > granularity"/> > + <arg name="axis" type="uint"/> > + <arg name="axis_source" type="uint"/> > + </event> > + > + <event name="axis_stop" since="5"> > + <description summary="axis stop event"> > + Scroll and other axis stop notification. > + > + For some wl_pointer.axis_source type, a wl_pointer.axis_stop event > + is sent to notify a client that the axis sequence has terminated. > + This enables the client to implement kinetic scrolling. > + See the wl_pointer.axis_source documentation for information on when > + this event may be generated. > + > + Any wl_pointer.axis events after this event should be considered as > + the start of a new axis motion. > + > + The axis and timestamp values are to be interpreted identical to the > + ones in the wl_pointer.axis event. > + </description> > + <arg name="time" type="uint" summary="timestamp with millisecond > granularity"/> > + <arg name="axis" type="uint"/> > + </event> > + > + <event name="axis_discrete" since="5"> > + <description summary="axis click event"> > + Scroll and other axis discrete step information. > + > + This event does not occur on its own. It is sent before a > + wl_pointer.axis event and carries the axis value of the > + wl_pointer.axis event in discrete steps (e.g. mouse wheel clicks). > + > + This event is optional, continuous scrolling devices > + like two-finger scrolling on touchpads do not have discrete > + steps. > + > + The axis and timestamp values are to be interpreted identical to the > + ones in the wl_pointer.axis event. > + > + The discrete value carries the directional information. e.g. a value > + of -2 is two steps towards the negative direction of this axis. > + <arg name="time" type="uint" summary="timestamp with millisecond > granularity"/> > + <arg name="axis" type="uint"/> > + <arg name="discrete" type="int"/> > + </description> > + </event> > </interface> > > <!-- for the version see the comment in wl_seat --> > - <interface name="wl_keyboard" version="4"> > + <interface name="wl_keyboard" version="5"> > <description summary="keyboard input device"> > The wl_keyboard interface represents one or more keyboards > associated with a seat. > @@ -1690,7 +1769,7 @@ > </interface> > > <!-- for the version see the comment in wl_seat --> > - <interface name="wl_touch" version="3"> > + <interface name="wl_touch" version="5"> > <description summary="touchscreen input device"> > The wl_touch interface represents a touchscreen > associated with a seat. > -- > 2.3.3 > _______________________________________________ wayland-devel mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/wayland-devel
