XorgCtrlAltBackspace
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| * '''Launchpad Entry''': UbuntuSpec:foo | * '''Launchpad Entry''': UbuntuSpec:xorg-ctrl-alt-backspace |
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| This should provide an overview of the issue/functionality/change proposed here. Focus here on what will actually be DONE, summarising that so that other people don't have to read the whole spec. | The Ctrl-Alt-Backspace key combination currently "zaps" (hard-restarts) the X server, and thus loses any unsaved data in applications, etc. This key combination is also largely undocumented, so users (probably ex-Windows users) may press this key combination without expecting data loss. This spec proposes to modify how this key combination works such that by default the user must hold the keys for 2 seconds in order for it to take effect. |
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| This section should include a paragraph describing the end-user impact of this change. It is meant to be included in the release notes of the first release in which it is implemented. (Not all of these will actually be included in the release notes, at the release manager's discretion; but writing them is a useful exercise.) It is mandatory. |
The key combination of Ctrl-Alt-Backspace, which previously immediately exited X (and thus reset the graphics system back to the login screen), has been modified to require it to be held for 2 seconds before taking effect. This should help reduce the frequency of unexpected data loss and activity interruption for users unaware of its function that strike it accidentally. |
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| This should cover the _why_: why is this change being proposed, what justifies it, where we see this justified. | The key combination of Ctrl-Alt-Backspace terminates the user's current graphical shell, which can cause data loss if invoked accidentally. For some keyboards, backspace is in a location that can lead to accidentally hitting Ctrl-Alt-Backspace when using other Ctrl-Alt- key combinations. This can cause unexpected data loss and workflow interruption. However, disabling the key combination entirely would not be desirable, as it is an important way for exiting/restarting X that is useful particularly when X has locked up. A pop-up confirmation dialog is also not desirable, firstly because in one of the main use-cases for the key combo (a stuck Xorg), it's highly likely the window manager could not be depended on to display a dialog, and secondly because having a dialog would be an irritant both for accidental and intentional users. Making the key combination require being held for a couple seconds seems like a reasonable compromise. |
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| * Brian is a relatively new Ubuntu user working on a large image file in the GIMP, but also has Blender open on a different workspace which he used to render the image. Brian wants to close Blender as he is finished with it and needs to free up some memory for the GIMP. He remembers in Windows he could bring up an application list via Ctrl-Alt-Delete, but that doesn't work so he tries pressing Ctrl-Alt-Backspace. The key combination does nothing so he decides to open the System Monitor from the System > Administration menu instead. Once Blender is closed he continues to work on his image in the GIMP, saving it when he is finished. * Katie is writing a guide to help people who are used to Windows to migrate over to Ubuntu. She reads the help manuals for inspiration, then later she is experimenting to find similar functionality between the two systems that she can document. She avoids pressing Ctrl-Alt-Backspace and losing the document, which she has not saved yet, because she read in the help manuals that this would lose her work and send her back to the login screen. * Joel's computer interface has frozen due to a graphics driver problem. He still has daemons running which need to remain open, so he cannot reboot. He remembered that Ctrl-Alt-Backspace would restart X, and is surprised at first that it doesn't restart immediately but he holds it down just in case, and after a couple seconds X restarts and he's back in business. He's curious why it didn't restart immediately, but after investigating it he learns that he can control the delay in his xorg.conf, but he doesn't mind the new behavior so leaves it as is. |
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This spec assumes that users do not use the Ctrl-Alt-Backspace functionality regularly, and that those who do will not be terribly inconvenienced by having to hold it for 2 seconds. |
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| You can have subsections that better describe specific parts of the issue. | A 2 second delay to the Ctrl-Alt-Backspace key combination will be added to xorg-server. A new 'ZapDelayTime' ServerFlag configuration parameter will be added for users to use in xorg.conf to control the delay before terminating the X session. Setting it to 0 will restore the old behavior, where X exits immediately. |
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| This section should describe a plan of action (the "how") to implement the changes discussed. Could include subsections like: === UI Changes === Should cover changes required to the UI, or specific UI that is required to implement this === Code Changes === Code changes should include an overview of what needs to change, and in some cases even the specific details. === Migration === Include: * data migration, if any * redirects from old URLs to new ones, if any * how users will be pointed to the new way of doing things, if necessary. |
* hw/xfree86/parser/xf86tokens.h: add ZAPDELAYTIME token * hw/xfree86/common/xf86Privstr.h: add zapDelayTime field * hw/xfree86/common/xf86Globals.c: set default value of zapDelayTime to 2 * hw/xfree86/common/xf86Config.c: add FLAG_ZAPDELAYTIME with call to xf86GetOptValBool() * hw/xfree86/parser/Flags.c add to ServerFlagsTab[] structure and xf86parseFlagsSection(void)'s case statement * hw/xfree86/xorgconf.cpp: Add "ZapDelayTime" option * hw/xfree86/doc/man/Xorg.man.pre man page * hw/xfree86/doc/man/xorg.conf.man.pre man page * hw/xfree86/utils/xorgconfig/xorgconfig.c xorg.conf template * hw/xfree86/common/xf86Events.c: Modify the KEY_BackSpace case branch in xf86CommonSpecialKey so it calls xf86ProcessActionEvent(ACTION_TERMINATE, NULL) only after zapDelayTime's configured time delay. * Need to record when the Press action started * On subsequent Press or Release actions, compare time to zapDelayTime * If Release happens before zapDelayTime, reset the delay timer * xkb/xkbActions.c: Ditto changes done to xf86Events.c |
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| It's important that we are able to test new features, and demonstrate them to users. Use this section to describe a short plan that anybody can follow that demonstrates the feature is working. This can then be used during CD testing, and to show off after release. | To test the implementation the keypress should be held for < 2 sec and if nothing happens until time == 2 sec, then it is successful. |
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| This need not be added or completed until the specification is nearing beta. | The ZapDelayTime parameter should be set to several values (0, 5, 100) and verified that the behavior is delayed by that amount of time. |
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| == Outstanding Issues == | == Discussion == |
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| This should highlight any issues that should be addressed in further specifications, and not problems with the specification itself; since any specification with problems cannot be approved. | Previous discussion has been taken into account with this version of the spec, and is archived at ["XorgCtrlAltBackspace/Discussion"]. |
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| == BoF agenda and discussion == | == External links == |
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| Use this section to take notes during the BoF; if you keep it in the approved spec, use it for summarising what was discussed and note any options that were rejected. | See also: * http://bugs.freedesktop.org/show_bug.cgi?id=10507 -- Ctrl-Alt-Backspace should request confirmation before killing Xorg * http://bugs.freedesktop.org/show_bug.cgi?id=10510 -- Xorg should use a more unlikely key combination than Control-Alt-Backspace as the server zap key |
Please check the status of this specification in Launchpad before editing it. If it is Approved, contact the Assignee or another knowledgeable person before making changes.
Launchpad Entry: xorg-ctrl-alt-backspace
Packages affected:
Summary
The Ctrl-Alt-Backspace key combination currently "zaps" (hard-restarts) the X server, and thus loses any unsaved data in applications, etc. This key combination is also largely undocumented, so users (probably ex-Windows users) may press this key combination without expecting data loss. This spec proposes to modify how this key combination works such that by default the user must hold the keys for 2 seconds in order for it to take effect.
Release Note
The key combination of Ctrl-Alt-Backspace, which previously immediately exited X (and thus reset the graphics system back to the login screen), has been modified to require it to be held for 2 seconds before taking effect. This should help reduce the frequency of unexpected data loss and activity interruption for users unaware of its function that strike it accidentally.
Rationale
The key combination of Ctrl-Alt-Backspace terminates the user's current graphical shell, which can cause data loss if invoked accidentally. For some keyboards, backspace is in a location that can lead to accidentally hitting Ctrl-Alt-Backspace when using other Ctrl-Alt- key combinations. This can cause unexpected data loss and workflow interruption.
However, disabling the key combination entirely would not be desirable, as it is an important way for exiting/restarting X that is useful particularly when X has locked up. A pop-up confirmation dialog is also not desirable, firstly because in one of the main use-cases for the key combo (a stuck Xorg), it's highly likely the window manager could not be depended on to display a dialog, and secondly because having a dialog would be an irritant both for accidental and intentional users.
Making the key combination require being held for a couple seconds seems like a reasonable compromise.
Use Cases
* Brian is a relatively new Ubuntu user working on a large image file in the GIMP, but also has Blender open on a different workspace which he used to render the image. Brian wants to close Blender as he is finished with it and needs to free up some memory for the GIMP. He remembers in Windows he could bring up an application list via Ctrl-Alt-Delete, but that doesn't work so he tries pressing Ctrl-Alt-Backspace. The key combination does nothing so he decides to open the System Monitor from the System > Administration menu instead. Once Blender is closed he continues to work on his image in the GIMP, saving it when he is finished.
* Katie is writing a guide to help people who are used to Windows to migrate over to Ubuntu. She reads the help manuals for inspiration, then later she is experimenting to find similar functionality between the two systems that she can document. She avoids pressing Ctrl-Alt-Backspace and losing the document, which she has not saved yet, because she read in the help manuals that this would lose her work and send her back to the login screen.
* Joel's computer interface has frozen due to a graphics driver problem. He still has daemons running which need to remain open, so he cannot reboot. He remembered that Ctrl-Alt-Backspace would restart X, and is surprised at first that it doesn't restart immediately but he holds it down just in case, and after a couple seconds X restarts and he's back in business. He's curious why it didn't restart immediately, but after investigating it he learns that he can control the delay in his xorg.conf, but he doesn't mind the new behavior so leaves it as is.
Assumptions
This spec assumes that users do not use the Ctrl-Alt-Backspace functionality regularly, and that those who do will not be terribly inconvenienced by having to hold it for 2 seconds.
Design
A 2 second delay to the Ctrl-Alt-Backspace key combination will be added to xorg-server.
A new 'ZapDelayTime' ServerFlag configuration parameter will be added for users to use in xorg.conf to control the delay before terminating the X session. Setting it to 0 will restore the old behavior, where X exits immediately.
Implementation
- hw/xfree86/parser/xf86tokens.h: add ZAPDELAYTIME token
- hw/xfree86/common/xf86Privstr.h: add zapDelayTime field
- hw/xfree86/common/xf86Globals.c: set default value of zapDelayTime to 2
- hw/xfree86/common/xf86Config.c: add FLAG_ZAPDELAYTIME with call to xf86GetOptValBool()
hw/xfree86/parser/Flags.c add to ServerFlagsTab[] structure and xf86parseFlagsSection(void)'s case statement
hw/xfree86/xorgconf.cpp: Add "ZapDelayTime" option
- hw/xfree86/doc/man/Xorg.man.pre man page
- hw/xfree86/doc/man/xorg.conf.man.pre man page
- hw/xfree86/utils/xorgconfig/xorgconfig.c xorg.conf template
hw/xfree86/common/xf86Events.c: Modify the KEY_BackSpace case branch in xf86CommonSpecialKey so it calls xf86ProcessActionEvent(ACTION_TERMINATE, NULL) only after zapDelayTime's configured time delay.
- Need to record when the Press action started
- On subsequent Press or Release actions, compare time to zapDelayTime
- If Release happens before zapDelayTime, reset the delay timer
- xkb/xkbActions.c: Ditto changes done to xf86Events.c
Test/Demo Plan
To test the implementation the keypress should be held for < 2 sec and if nothing happens until time == 2 sec, then it is successful.
The ZapDelayTime parameter should be set to several values (0, 5, 100) and verified that the behavior is delayed by that amount of time.
Discussion
Previous discussion has been taken into account with this version of the spec, and is archived at ["XorgCtrlAltBackspace/Discussion"].
External links
See also:
* http://bugs.freedesktop.org/show_bug.cgi?id=10507 -- Ctrl-Alt-Backspace should request confirmation before killing Xorg * http://bugs.freedesktop.org/show_bug.cgi?id=10510 -- Xorg should use a more unlikely key combination than Control-Alt-Backspace as the server zap key
XorgCtrlAltBackspace (last edited 2010-06-12 04:57:24 by dhcp198-158)