[RFC 1/2] Introduce wl_probe_visible protocol
Jonas Ådahl
jadahl at gmail.com
Wed Sep 30 23:51:45 PDT 2015
wl_probe_visible (for now _wl_probe_visible) is a reintroduction of
the "wl_probe" method of making it possible to position a surface so
that it is completely visible, when positioning it relative to some
other already mapped surface. It works by checking what parts of a
rectangle relative to an existing surface would be visible, allowing
the client to reposition its surface accordingly.
The protocol and implementation is based on patches by Rob Bradford
from 2013[0][1].
[1] http://lists.freedesktop.org/archives/wayland-devel/2013-April/008665.html
[2] http://lists.freedesktop.org/archives/wayland-devel/2013-April/008666.html
Signed-off-by: Jonas Ådahl <jadahl at gmail.com>
---
Hi,
Some time ago I took the old "wl_probe" patches and updated them to
work today. The approach is mostly the same, but with some renaming and
moving around (it's for example not part of wl_shell anymore). It was
brought up on the mailing list recently, so I thought it could be a good
idea to make it easier to test on todays weston, so here it is.
The are a few problems with this approach, such as:
1) It requires an extra roundtrip to create a popup/tooltip (not that
big of a deal though, I'd say).
2) When the parent surface has non-trivial transformations (non-90
degree rotation etc), a resulting rectangle is ambigous. This could be
made implementation specific or with some required semantics (such as
prefer rectangles where more corners are untouched, prefer larger
rectangle etc).
3) It may be abused to get an (incorrect) absolute surface position.
4) It is racy - for a moving surface, the visibility will change as it
moves.
A different approach of solving the same issue is to shift the
responsibility for positioning popups from the client to the
compositor. This requires a more complex protocol allowing the client
describing the expected semantics, as well as a roundtrip then the
client needs to know how the compositor positioned a given rectangle.
For the position readback case, this approach has the same racyness as
the approach in this patch, and adding a new kind of positioning logic
would need changing the protocol. This approach is what Mir is taking.
Personally, I'm not completely convinced a "wl_probe" way of improving
the menu positioning is the better option here, and would like to hear
what other think about this.
Jonas
Makefile.am | 3 ++
protocol/probe-visible.xml | 91 +++++++++++++++++++++++++++++++++
src/compositor.c | 125 +++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 219 insertions(+)
create mode 100644 protocol/probe-visible.xml
diff --git a/Makefile.am b/Makefile.am
index 1900390..00f3ad2 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -125,6 +125,8 @@ nodist_weston_SOURCES = \
protocol/workspaces-server-protocol.h \
protocol/presentation_timing-protocol.c \
protocol/presentation_timing-server-protocol.h \
+ protocol/probe-visible-protocol.c \
+ protocol/probe-visible-server-protocol.h \
protocol/scaler-protocol.c \
protocol/scaler-server-protocol.h \
protocol/linux-dmabuf-protocol.c \
@@ -1345,6 +1347,7 @@ EXTRA_DIST += \
protocol/xdg-shell.xml \
protocol/fullscreen-shell.xml \
protocol/presentation_timing.xml \
+ protocol/probe-visible.xml \
protocol/scaler.xml \
protocol/ivi-application.xml \
protocol/ivi-hmi-controller.xml \
diff --git a/protocol/probe-visible.xml b/protocol/probe-visible.xml
new file mode 100644
index 0000000..0af9ed7
--- /dev/null
+++ b/protocol/probe-visible.xml
@@ -0,0 +1,91 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<protocol name="probe_visible_area">
+
+ <copyright>
+ Copyright © 2013 Intel Corporation
+ Copyright © 2015 Red Hat Inc.
+
+ Permission is hereby granted, free of charge, to any person obtaining a
+ copy of this software and associated documentation files (the "Software"),
+ to deal in the Software without restriction, including without limitation
+ the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ and/or sell copies of the Software, and to permit persons to whom the
+ Software is furnished to do so, subject to the following conditions:
+
+ The above copyright notice and this permission notice (including the next
+ paragraph) shall be included in all copies or substantial portions of the
+ Software.
+
+ THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ DEALINGS IN THE SOFTWARE.
+ </copyright>
+
+ <interface name="_wl_probe_visible" version="1">
+ <description summary="probe visible area of a rectangle">
+ Probe visibility of regions relative to surfaces.
+
+ Warning! The protocol described in this file is experimental. Each version
+ of this protocol should be considered incompatible with any other version,
+ and a client binding to a version different to the one advertised will be
+ terminated. Once the protocol is declared stable, backward compatibility
+ is guaranteed, the '_' prefix will be removed from the name and the
+ version will be reset to 1.
+ </description>
+
+ <enum name="error">
+ <entry name="version_mismatch" value="0"/>
+ </enum>
+
+ <request name="destroy" type="destructor"/>
+
+ <request name="probe_rectangle">
+ <description summary="probe visibilty of rectangle">
+ Asks the compositor what the visible area for a surface would be if it
+ was positioned with the proposed rectangle relative to the provided
+ surface. The visible_rectangle event will be fired with the rectangle
+ that the compositor would show. The client can then use this information
+ to reposition the surface as appropriate for its needs. The intention is
+ for this request to be used by clients looking to find the ideal
+ location for a popup window whilst still respecting the borders of the
+ output.
+
+ The object returned by this request will be destroyed by the compositor
+ after the rectangle is returned and as such the client must destroy the
+ object and not attempt to use it after that point.
+ </description>
+
+ <arg name="id" type="new_id" interface="_wl_probe_visible_result"/>
+ <arg name="surface" type="object" interface="wl_surface"/>
+ <arg name="x" type="int"/>
+ <arg name="y" type="int"/>
+ <arg name="width" type="int"/>
+ <arg name="height" type="int"/>
+ </request>
+ </interface>
+
+ <interface name="_wl_probe_visible_result" version="1">
+ <description summary="probed visibility result">
+ </description>
+
+ <event name="visible_rectangle">
+ <description summary="visible area">
+ This event is fired in response to the probe_rectangle request on the
+ wl_probe_visible object. It returns the visible rectangle that the
+ surface would occupy when taking into consideration the output's edges.
+ If the width or height is zero this indicates that the window would not
+ be visible at all in that dimension. In that case the x and y values
+ represent the distance to the edge of the viewable area.
+ </description>
+ <arg name="x" type="int"/>
+ <arg name="y" type="int"/>
+ <arg name="width" type="int"/>
+ <arg name="height" type="int"/>
+ </event>
+ </interface>
+
+</protocol>
diff --git a/src/compositor.c b/src/compositor.c
index 125afd5..ea46b97 100644
--- a/src/compositor.c
+++ b/src/compositor.c
@@ -56,6 +56,7 @@
#include "compositor.h"
#include "scaler-server-protocol.h"
#include "presentation_timing-server-protocol.h"
+#include "probe-visible-server-protocol.h"
#include "shared/helpers.h"
#include "shared/os-compatibility.h"
#include "shared/timespec-util.h"
@@ -4397,6 +4398,126 @@ bind_presentation(struct wl_client *client,
}
static void
+probe_visible_destroy(struct wl_client *client, struct wl_resource *resource)
+{
+ wl_resource_destroy(resource);
+}
+
+static void
+weston_view_constrain_visible_rectangle(struct weston_view *view,
+ int32_t *x, int32_t *y,
+ int32_t *width, int32_t *height)
+{
+ float xf1 = *x;
+ float yf1 = *y;
+ float xf2 = *x + *width;
+ float yf2 = *y + *height;
+ struct weston_output *output = view->output;
+
+ weston_view_to_global_float(view, xf1, yf1, &xf1, &yf1);
+ weston_view_to_global_float(view, xf2, yf2, &xf2, &yf2);
+
+ if (xf1 < output->x)
+ xf1 = output->x;
+ if (yf1 < output->y)
+ yf1 = output->y;
+ if (xf1 > output->x + output->width)
+ xf1 = output->x + output->width;
+ if (yf1 > output->y + output->height)
+ yf1 = output->y + output->height;
+
+ if (xf2 < output->x)
+ xf2 = output->x;
+ if (yf2 < output->y)
+ yf2 = output->y;
+ if (xf2 > output->x + output->width)
+ xf2 = output->x + output->width;
+ if (yf2 > output->y + output->height)
+ yf2 = output->y + output->height;
+
+ weston_view_from_global_float(view, xf1, yf1, &xf1, &yf1);
+ weston_view_from_global_float(view, xf2, yf2, &xf2, &yf2);
+
+ *x = (int32_t) xf1;
+ *y = (int32_t) yf1;
+ *width = (int32_t) (xf2 - xf1);
+ *height = (int32_t) (yf2 - yf1);
+}
+
+static void
+weston_surface_constrain_visible_rectangle(struct weston_surface *surface,
+ int32_t *x, int32_t *y,
+ int32_t *width, int32_t *height)
+{
+ struct weston_view *view;
+
+ wl_list_for_each(view, &surface->views, surface_link) {
+ weston_view_constrain_visible_rectangle(view,
+ x, y,
+ width, height);
+ }
+}
+
+static void
+probe_visible_probe_rectangle(struct wl_client *client,
+ struct wl_resource *resource,
+ uint32_t id,
+ struct wl_resource *surface_resource,
+ int32_t x, int32_t y,
+ int32_t width, int32_t height)
+{
+ struct wl_resource *result_resource;
+ struct weston_surface *surface = wl_resource_get_user_data(surface_resource);
+
+ result_resource = wl_resource_create(client,
+ &_wl_probe_visible_result_interface,
+ 1, id);
+ if (result_resource == NULL) {
+ wl_client_post_no_memory(client);
+ return;
+ }
+
+ weston_surface_constrain_visible_rectangle(surface,
+ &x, &y,
+ &width, &height);
+
+ _wl_probe_visible_result_send_visible_rectangle(result_resource,
+ x, y,
+ width, height);
+ wl_resource_destroy(result_resource);
+}
+
+static const struct _wl_probe_visible_interface probe_visible_implementation = {
+ probe_visible_destroy,
+ probe_visible_probe_rectangle,
+};
+
+static void
+bind_probe_visible(struct wl_client *client,
+ void *data, uint32_t version, uint32_t id)
+{
+ struct weston_compositor *compositor = data;
+ struct wl_resource *resource;
+
+ resource = wl_resource_create(client, &_wl_probe_visible_interface,
+ 1, id);
+ if (resource == NULL) {
+ wl_client_post_no_memory(client);
+ return;
+ }
+
+ if (version != 1) {
+ wl_resource_post_error(resource,
+ _WL_PROBE_VISIBLE_ERROR_VERSION_MISMATCH,
+ "Incompatible version");
+ return;
+ }
+
+ wl_resource_set_implementation(resource, &probe_visible_implementation,
+ compositor, NULL);
+}
+
+static void
compositor_bind(struct wl_client *client,
void *data, uint32_t version, uint32_t id)
{
@@ -4506,6 +4627,10 @@ weston_compositor_create(struct wl_display *display, void *user_data)
ec, bind_presentation))
goto fail;
+ if (!wl_global_create(ec->wl_display, &_wl_probe_visible_interface, 1,
+ ec, bind_probe_visible))
+ goto fail;
+
wl_list_init(&ec->view_list);
wl_list_init(&ec->plane_list);
wl_list_init(&ec->layer_list);
--
2.4.3
More information about the wayland-devel
mailing list