1 <protocol name="fullscreen_shell">
2 <interface name="_wl_fullscreen_shell" version="1">
3 <description summary="Displays a single surface per output">
4 Displays a single surface per output.
6 This interface provides a mechanism for a single client to display
7 simple full-screen surfaces. While there technically may be multiple
8 clients bound to this interface, only one of those clients should be
11 To present a surface, the client uses either the present_surface or
12 present_surface_for_mode requests. Presenting a surface takes effect
13 on the next wl_surface.commit. See the individual requests for
14 details about scaling and mode switches.
16 The client can have at most one surface per output at any time.
17 Requesting a surface be presented on an output that already has a
18 surface replaces the previously presented surface. Presenting a null
19 surface removes its content and effectively disables the output.
20 Exactly what happens when an output is "disabled" is
21 compositor-specific. The same surface may be presented on multiple
22 outputs simultaneously.
24 Once a surface is presented on an output, it stays on that output
25 until either the client removes it or the compositor destroys the
26 output. This way, the client can update the output's contents by
27 simply attaching a new buffer.
30 <request name="release" type="destructor">
31 <description summary="release the wl_fullscreen_shell interface">
32 Release the binding from the wl_fullscreen_shell interface
34 This destroys the server-side object and frees this binding. If
35 the client binds to wl_fullscreen_shell multiple times, it may wish
36 to free some of those bindings.
40 <enum name="capability">
41 <description summary="capabilities advertised by the compositor">
42 Various capabilities that can be advertised by the compositor. They
43 are advertised one-at-a-time when the wl_fullscreen_shell interface is
44 bound. See the wl_fullscreen_shell.capability event for more details.
47 This is a hint to the client that indicates that the compositor is
48 capable of setting practially any mode on its outputs. If this
49 capability is provided, wl_fullscreen_shell.present_surface_for_mode
50 will almost never fail and clients should feel free to set whatever
51 mode they like. If the compositor does not advertise this, it may
52 still support some modes that are not advertised through wl_global.mode
53 but it is less likely.
56 This is a hint to the client that indicates that the compositor can
57 handle a cursor surface from the client without actually compositing.
58 This may be because of a hardware cursor plane or some other mechanism.
59 If the compositor does not advertise this capability then setting
60 wl_pointer.cursor may degrade performance or be ignored entirely. If
61 CURSOR_PLANE is not advertised, it is recommended that the client draw
62 its own cursor and set wl_pointer.cursor(NULL).
64 <entry name="arbitrary_modes" value="1" summary="compositor is capable of almost any output mode"/>
65 <entry name="cursor_plane" value="2" summary="compositor has a seperate cursor plane"/>
68 <event name="capability">
69 <description summary="advertises a capability of the compositor">
70 Advertises a single capability of the compositor.
72 When the wl_fullscreen_shell interface is bound, this event is emitted
73 once for each capability advertised. Valid capabilities are given by
74 the wl_fullscreen_shell.capability enum. If clients want to take
75 advantage of any of these capabilities, they sould use a
76 wl_display.sync request immediatly after binding to ensure that they
77 recieve all the capability events.
79 <arg name="capabilty" type="uint"/>
82 <enum name="present_method">
83 <description summary="different method to set the surface fullscreen">
84 Hints to indicate to the compositor how to deal with a conflict
85 between the dimensions of the surface and the dimensions of the
86 output. The compositor is free to ignore this parameter.
88 <entry name="default" value="0" summary="no preference, apply default policy"/>
89 <entry name="center" value="1" summary="center the surface on the output"/>
90 <entry name="zoom" value="2" summary="scale the surface, preserving aspect ratio, to the largest size that will fit on the output" />
91 <entry name="zoom_crop" value="3" summary="scale the surface, preserving aspect ratio, to fully fill the output cropping if needed" />
92 <entry name="stretch" value="4" summary="scale the surface to the size of the output ignoring aspect ratio" />
95 <request name="present_surface">
96 <description summary="present surface for display">
97 Present a surface on the given output.
99 If the output is null, the compositor will present the surface on
100 whatever display (or displays) it thinks best. In particular, this
101 may replace any or all surfaces currently presented so it should
102 not be used in combination with placing surfaces on specific
105 The method parameter is a hint to the compositor for how the surface
106 is to be presented. In particular, it tells the compostior how to
107 handle a size mismatch between the presented surface and the
108 output. The compositor is free to ignore this parameter.
110 The "zoom", "zoom_crop", and "stretch" methods imply a scaling
111 operation on the surface. This will override any kind of output
112 scaling, so the buffer_scale property of the surface is effectively
115 <arg name="surface" type="object" interface="wl_surface" allow-null="true"/>
116 <arg name="method" type="uint"/>
117 <arg name="output" type="object" interface="wl_output" allow-null="true"/>
120 <request name="present_surface_for_mode">
121 <description summary="present surface for display at a particular mode">
122 Presents a surface on the given output for a particular mode.
124 If the current size of the output differs from that of the surface,
125 the compositor will attempt to change the size of the output to
126 match the surface. The result of the mode-switch operation will be
127 returned via the provided wl_fullscreen_shell_mode_feedback object.
129 If the current output mode matches the one requested or if the
130 compositor successfully switches the mode to match the surface,
131 then the mode_successful event will be sent and the output will
132 contain the contents of the given surface. If the compositor
133 cannot match the output size to the surface size, the mode_failed
134 will be sent and the output will contain the contents of the
135 previously presented surface (if any). If another surface is
136 presented on the given output before either of these has a chance
137 to happen, the present_cancelled event will be sent.
139 Due to race conditions and other issues unknown to the client, no
140 mode-switch operation is guaranteed to succeed. However, if the
141 mode is one advertised by wl_output.mode or if the compositor
142 advertises the ARBITRARY_MODES capability, then the client should
143 expect that the mode-switch operation will usually succeed.
145 If the size of the presented surface changes, the resulting output
146 is undefined. The compositor may attempt to change the output mode
147 to compensate. However, there is no guarantee that a suitable mode
148 will be found and the client has no way to be notified of success
151 The framerate parameter specifies the desired framerate for the
152 output in mHz. The compositor is free to ignore this parameter. A
153 value of 0 indicates that the client has no preference.
155 If the value of wl_output.scale differs from wl_surface.buffer_scale,
156 then the compositor may choose a mode that matches either the buffer
157 size or the surface size. In either case, the surface will fill the
160 <arg name="surface" type="object" interface="wl_surface"/>
161 <arg name="output" type="object" interface="wl_output"/>
162 <arg name="framerate" type="int"/>
163 <arg name="feedback" type="new_id" interface="_wl_fullscreen_shell_mode_feedback"/>
167 <description summary="wl_fullscreen_shell error values">
168 These errors can be emitted in response to wl_fullscreen_shell requests
170 <entry name="invalid_method" value="0" summary="present_method is not known"/>
174 <interface name="_wl_fullscreen_shell_mode_feedback" version="1">
175 <event name="mode_successful">
176 <description summary="mode switch succeeded">
177 This event indicates that the attempted mode switch operation was
178 successful. A surface of the size requested in the mode switch
179 will fill the output without scaling.
181 Upon receiving this event, the client should destroy the
182 wl_fullscreen_shell_mode_feedback object.
185 <event name="mode_failed">
186 <description summary="mode switch failed">
187 This event indicates that the attempted mode switch operation
188 failed. This may be because the requested output mode is not
189 possible or it may mean that the compositor does not want to allow it.
191 Upon receiving this event, the client should destroy the
192 wl_fullscreen_shell_mode_feedback object.
195 <event name="present_cancelled">
196 <description summary="mode switch cancelled">
197 This event indicates that the attempted mode switch operation was
198 cancelled. Most likely this is because the client requested a
199 second mode switch before the first one completed.
201 Upon receiving this event, the client should destroy the
202 wl_fullscreen_shell_mode_feedback object.