Ubuntu
qtmir package

Unity8 not informing clients that they are not visible and thus can stop rendering

Bug #1475678 reported by Gerry Boland on 2015-07-17

This bug affects 4 people

	Status	Importance	Assigned to	Milestone
Canonical System Image	Fix Released	High	Michał Sawicz	Canonical System Image 13 "OTA13"
qtmir (Ubuntu)	Fix Released	High	Nick Dedekind
unity8 (Ubuntu)	Fix Released	High	Nick Dedekind

Bug Description

Currently on the phone, apps stop rendering when shell hides them, because shell also lifecycle stops the app. App isn't actually told it should stop rendering, we just SIGSTOP its process.

But some apps are not lifecycle stopped, e.g. music. So we should have unity8 tell the app to stop rendering.

This will be a multi-step process:
1. Qtubuntu
Mir has a attribute to set on surfaces to tell them they are visible/occluded: (see mir/include/common/mir_toolkit/common.h)
mir_surface_attrib_visibility - part of the MirSurfaceAttrib enum.

This indicates these possible values:
typedef enum MirSurfaceVisibility
{
mir_surface_visibility_occluded = 0,
mir_surface_visibility_exposed
} MirSurfaceVisibility;

On the client side (qtubuntu), you need to listen for this attribute change, and connect it to QWindowSystemInterface::handleExposeEvent() which tells Qt how much of a QWindow is being drawn.
Note there is also a QWindowSystemInterface::handleWindowStateChanged() handler, which use use to explicitly set QWindow show/hide, but Qt tends to release its GL context on hide, which we may not desire. It may not hurt, worth a look.

2. QtMir
There are methods on mir::scene::Surface to set and get the MirSurfaceAttrib attributes. I think it would make sense to use the pre-existing MirSurfaceItem::visible property, so that if a surface is marked visible=false, then that will dispatch the mir_surface_visibility_occluded event to the client, so it will stop drawing.

3. Unity8
Correctly set visible=false when an application surface is occluded, and true when visible. QML has no automatic way of doing that (i.e. occlusion detection)

Related branches

lp:~nick-dedekind/unity-api/lp1475678.surface-occlude

Merged into lp:unity-api at revision 193

Michał Sawicz: Approve on 2015-11-05

PS Jenkins bot (community): Approve (continuous-integration) on 2015-10-27

Daniel d'Andrada: Pending requested 2015-10-27

lp:~nick-dedekind/qtubuntu/lp1475678.surface-occlude

Merged into lp:qtubuntu at revision 284

Nick Dedekind (community): Abstain on 2015-11-06

Daniel d'Andrada (community): Needs Fixing on 2015-11-05

PS Jenkins bot: Approve (continuous-integration) on 2015-10-12

lp:~nick-dedekind/qtmir/lp1475678.surface-occlude

Merged into lp:qtmir at revision 401

Daniel d'Andrada (community): Approve on 2015-10-20

PS Jenkins bot (community): Needs Fixing (continuous-integration) on 2015-10-20

lp:~nick-dedekind/unity8/lp1475678.surface-occlude

Superseded for merging into lp:unity8

PS Jenkins bot (community): Needs Fixing (continuous-integration) on 2015-10-27

Michał Sawicz: Needs Fixing on 2015-10-26

Michael Zanetti (community): Abstain on 2015-10-21

Daniel d'Andrada (community): Needs Fixing on 2015-10-13

lp:~unity-team/unity8/lp1475678.surface-occlude

Merged into lp:unity8 at revision 2032

PS Jenkins bot (community): Needs Fixing (continuous-integration) on 2015-10-31

Daniel d'Andrada (community): Approve on 2015-10-30

Michał Sawicz: Pending requested 2015-10-27

Michael Zanetti: Pending requested 2015-10-27

lp:~nick-dedekind/qtubuntu/occlusion-2.0

Merged into lp:qtubuntu at revision 332

Daniel d'Andrada (community): Approve on 2016-06-21

Unity8 CI Bot: Approve (continuous-integration) on 2016-06-14

PS Jenkins bot: Pending (continuous-integration) requested 2016-06-14

Michael Terry: Pending requested 2016-06-14

lp:~nick-dedekind/qtmir/occlusion-2.0

Merged into lp:qtmir at revision 530

Daniel d'Andrada (community): Approve on 2016-06-21

Unity8 CI Bot (community): Needs Fixing (continuous-integration) on 2016-06-14

PS Jenkins bot (community): Needs Fixing (continuous-integration) on 2016-01-19

Michael Terry: Pending requested 2016-01-19

Mirco Müller (macslow) on 2015-07-17

Changed in qtmir:
assignee:	nobody → Mirco Müller (macslow)
Changed in qtubuntu:
assignee:	nobody → Mirco Müller (macslow)
Changed in unity8 (Ubuntu):
assignee:	nobody → Mirco Müller (macslow)

Mirco Müller (macslow) on 2015-07-20

Changed in qtmir:
importance:	Undecided → High
Changed in qtubuntu:
importance:	Undecided → High
Changed in unity8 (Ubuntu):
importance:	Undecided → High
Changed in qtmir:
status:	New → In Progress
Changed in qtubuntu:
status:	New → In Progress
Changed in unity8 (Ubuntu):
status:	New → In Progress

Revision history for this message

Michael Zanetti (mzanetti) wrote on 2015-07-23:

Should probably be added to this Qt api:

http://doc.qt.io/qt-5/qml-qtqml-qt.html#application-prop

Pat McGowan (pat-mcgowan) on 2015-09-21

Changed in canonical-devices-system-image:
assignee:	nobody → kevin gunn (kgunn72)
importance:	Undecided → High
milestone:	none → ww46-2015
status:	New → In Progress

Michał Sawicz (saviq) on 2015-09-21

no longer affects:	qtubuntu
Changed in qtmir:
assignee:	Mirco Müller (macslow) → nobody
Changed in unity8 (Ubuntu):
assignee:	Mirco Müller (macslow) → nobody

Michał Sawicz (saviq) on 2015-09-21

Changed in qtmir:
assignee:	nobody → Nick Dedekind (nick-dedekind)
Changed in unity8 (Ubuntu):
assignee:	nobody → Nick Dedekind (nick-dedekind)

Jean-Baptiste Lallement (jibel) on 2015-11-06

Changed in canonical-devices-system-image:
status:	In Progress → Fix Committed

Revision history for this message

Launchpad Janitor (janitor) wrote on 2015-11-06:

This bug was fixed in the package unity8 - 8.11+16.04.20151104-0ubuntu1

---------------
unity8 (8.11+16.04.20151104-0ubuntu1) xenial; urgency=medium

  [ Albert Astals Cid ]
  * Add an Item that proxies for old and new audio roles (LP: #1493851)
  * CroppedImageMinimumSourceSize: Fix 'Binding loop detected for
    property "imageAspectRatio"'
  * Make the scope settings list scroll to text visible area (LP:
    #1499084)
  * Move to importing QtQuick 2.4 & friends
  * Use SDK 1.3 across all files (LP: #1503498, #1508363, #1449628)

  [ Andrea Cimitan ]
  * Add sharing widget to zoomable image and video playback
  * Make zoomable and video playback widgets edge to edge
  * Updated all 1.3 UbuntuShape to use new APIs where possible
  * Use SDK 1.3 across all files (LP: #1503498, #1508363, #1449628)

[ CI Train Bot ]
* Resync trunk.

[ Christopher Lee ]
* Quick spelling fix in process control output.

  [ Daniel d'Andrada ]
  * Enable support for overriding application orientations based on
    device type (LP: #1478637)
  * Use SDK 1.3 across all files (LP: #1503498, #1508363, #1449628)
  * Use SDK 1.3 across all files (LP: #1503498, #1508363, #1449628)

  [ Josh Arenson ]
  * Enable support for overriding application orientations based on
    device type (LP: #1478637)

  [ Michael Terry ]
  * Avoid showing the shutdown dialog when turning on the screen if your
    device is under heavy load. (LP: #1508563)
  * Handle lifecycle policy exceptions ourselves, instead of letting
    qtmir do it for us and allow non-Touch apps to opt-out of the Touch
    lifecycle.

  [ Michael Zanetti ]
  * Fixes for the panel buttons (LP: #1510360, #1504269, #1431566,
    #1443319)
  * Use SDK 1.3 across all files (LP: #1503498, #1508363, #1449628)

  [ Michał Sawicz ]
  * Add missing copyright to Cursor.qml
  * Enable support for overriding application orientations based on
    device type (LP: #1478637)
  * Support server->client visibility change to stop rendering
    (lp:#1475678) (LP: #1475678)

  [ Nick Dedekind ]
  * Support server->client visibility change to stop rendering
    (lp:#1475678) (LP: #1475678)

-- Michał Sawicz <email address hidden> Wed, 04 Nov 2015 14:58:41 +0000

This bug was fixed in the package unity8 - 8.11+16.04.20151104-0ubuntu1

---------------
unity8 (8.11+16.04.20151104-0ubuntu1) xenial; urgency=medium

[ CI Train Bot ]
  * Resync trunk.

[ Christopher Lee ]
  * Quick spelling fix in process control output.

[ Josh Arenson ]
  * Enable support for overriding application orientations based on
    device type (LP: #1478637)

[ Michael Zanetti ]
  * Fixes for the panel buttons (LP: #1510360, #1504269, #1431566,
    #1443319)
  * Use SDK 1.3 across all files (LP: #1503498, #1508363, #1449628)

[ Nick Dedekind ]
  * Support server->client visibility change to stop rendering
    (lp:#1475678) (LP: #1475678)

-- Michał Sawicz <michal.sawicz@canonical.com>  Wed, 04 Nov 2015 14:58:41 +0000

Changed in unity8 (Ubuntu):
status:	In Progress → Fix Released

Pat McGowan (pat-mcgowan) on 2015-11-19

Changed in canonical-devices-system-image:
status:	Fix Committed → Fix Released

Michał Sawicz (saviq) on 2015-11-30

Changed in canonical-devices-system-image:
status:	Fix Released → Triaged
Changed in unity8 (Ubuntu):
status:	Fix Released → Triaged
status:	Triaged → Fix Committed
status:	Fix Committed → In Progress
Changed in canonical-devices-system-image:
status:	Triaged → In Progress

Pat McGowan (pat-mcgowan) on 2015-12-03

Changed in canonical-devices-system-image:
milestone:	ww46-2015 → ww02-2016

Pat McGowan (pat-mcgowan) on 2016-01-19

Changed in canonical-devices-system-image:
milestone:	ww02-2016 → ww08-2016

Michał Sawicz (saviq) on 2016-02-04

Changed in canonical-devices-system-image:
assignee:	kevin gunn (kgunn72) → Michał Sawicz (saviq)

Michał Sawicz (saviq) on 2016-03-09

Changed in canonical-devices-system-image:
milestone:	ww08-2016 → 11

Michał Sawicz (saviq) on 2016-05-05

Changed in canonical-devices-system-image:
milestone:	11 → 12

Revision history for this message

Selene ToyKeeper (toykeeper) wrote on 2016-05-27:

Subscribing so I can get notified to power-test the changes when they're available.

Pat McGowan (pat-mcgowan) on 2016-06-29

Changed in canonical-devices-system-image:
milestone:	12 → 13

Jean-Baptiste Lallement (jibel) on 2016-08-05

Changed in canonical-devices-system-image:
status:	In Progress → Fix Committed

Michał Sawicz (saviq) on 2016-09-05

Changed in qtmir:
status:	In Progress → Fix Released
Changed in unity8 (Ubuntu):
status:	In Progress → Fix Released

Pat McGowan (pat-mcgowan) on 2016-09-20

Changed in canonical-devices-system-image:
status:	Fix Committed → Fix Released

Michał Sawicz (saviq) on 2017-03-13

affects:

qtmir → qtmir (Ubuntu)

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Ubuntuqtmir package

Unity8 not informing clients that they are not visible and thus can stop rendering

Bug Description

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Ubuntu
qtmir package