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This is an automatically generated e-mail. To reply, visit:
<a href="http://svn.reviewboard.kde.org/r/5396/">http://svn.reviewboard.kde.org/r/5396/</a>
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<p style="margin-top: 0;">On September 23rd, 2010, 4:11 p.m., <b>David Jarvie</b> wrote:</p>
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<pre style="white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;">Labelling the states "active" and "inactive" seems misleading, and not necessarily intuitive to use. The summary of the purpose of the class says it's "an action which represents two actions, switching from one to the other whenever it is triggered". In other words, both actions/states have an equal status, so neither is necessarily "active" as compared to the other one? I suggest renaming the states (in the apidox and code) - perhaps simply use 'state1' and 'state2' instead.</pre>
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<p>On September 23rd, 2010, 8:07 p.m., <b>Aurélien Gâteau</b> wrote:</p>
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<pre style="white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;">What I like about the "active" and "inactive" terms is that they map quite well to boolean values. This is important because it makes it possible to use bool in signals. If we go for state1 and state2, then how do we name the signals? stateChanged(bool) would be weird, and stateChanged(int) would be error prone and not handy because it would not be possible to connect to existing slots which accept a bool parameter.
Having said that, I agree these terms do not feel like the best match: if you have an idea for a signal name with a bool parameter when using state1 and state2, I am all ears!</pre>
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<p>On September 24th, 2010, 12:05 p.m., <b>David Jarvie</b> wrote:</p>
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<pre style="white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;">I can understand your comments about using a bool parameter - the problem with a bool is that it's not really able to intuitively represent two equal status items. But I don't think the argument about needing to connect to existing slots which take a bool parameter is a good one. IMO, it's better to design a good API and then change existing code to fit with it, rather than to make the API of a new class adhere to existing code when there's no need for source or binary compatibility. The main idea of this class is to provide two alternative but otherwise equal actions, so I don't think imposing a precedence on them is really appropriate. Perhaps using an enum would be better than a bool or int.
Another idea for the two action names might be 'default' and 'alternative' (apart from 'default' being a keyword, of course). That might get round the equal status issue, but still allow bool to be used.</pre>
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<p>On September 24th, 2010, 9:08 p.m., <b>Aurélien Gâteau</b> wrote:</p>
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<pre style="white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;">I have to disagree with not using a bool: developers used KToggleAction with setCheckedState() despite the fact that it looked wrong because it was convenient. If KDualAction is not at least as easy to use as KToggleAction it won't be used.
I am not sure about "default/alternative". When you use the action to show/hide a sidebar, which one is "default" and which one is "alternative"? and how does it map to true/false? I think "active/inactive" maps more naturally to true/false.</pre>
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<pre style="white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;">I don't object to using a bool if it has a reasonably natural meaning in the context where it's used.
When I suggested the possible use of "default"/"alternative", I meant that the "default" action would be the one which was initially set as the selected action in the constructor, or if the default constructor was used, the action which was set later corresponding to true.</pre>
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<p>- David</p>
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<p>On September 23rd, 2010, 2:29 p.m., Aurélien Gâteau wrote:</p>
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<div>Review request for kdelibs.</div>
<div>By Aurélien Gâteau.</div>
<p style="color: grey;"><i>Updated 2010-09-23 14:29:29</i></p>
<h1 style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Description </h1>
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<pre style="margin: 0; padding: 0; white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;">This review-request introduces a new class named KDualAction. The goal of this class is to make it easy to create a dual-state action: an action which represents two actions, switching from one to the other whenever it is triggered. KDualAction can be used to implement actions such as the Play/Pause action of a media player or the Reload/Stop action of a web browser.
Right now some applications mis-use KToggleAction to implement such dual-state actions: They set the first action as the unchecked state and provide an alternative KGuiItem for the checked state with KToggleAction::setCheckedState(). This is wrong because when the user clicks a button representing the action in a toolbar, the button stays down. The appropriate use cases for toggle buttons (and thus KToggleAction) are documented in a recent addition to the HIG:
http://techbase.kde.org/Projects/Usability/HIG/Toggle_Buttons
Potential users for this class:
- Dragon, Juk, Amarok to implement their Play/Pause action.
- Rekonq to implement its Reload/Stop action. Konqueror could also use this but it does not feature a dual reload/stop action as far as I know.
- Dolphin could maybe use it to implement its Split/Close action (although it's a bit more involved in this case because the close action changes depending on which panel it is going to close)
- Any application which incorrectly uses KToggleAction + setCheckedState() to show/hide a UI element (a search on lxr.kde.org shows quite a lot of misuse: http://lxr.kde.org/ident?i=setCheckedState )</pre>
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<h1 style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Testing </h1>
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<pre style="margin: 0; padding: 0; white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;">The class comes with unit-tests. I tested the API made sense by porting Dragon, Konqueror and creating a showHideMenubar action in KStandardAction (review requests to come if the class is accepted).</pre>
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<h1 style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Diffs</b> </h1>
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<li>trunk/KDE/kdelibs/kdeui/CMakeLists.txt <span style="color: grey">(1171068)</span></li>
<li>trunk/KDE/kdelibs/kdeui/actions/kdualaction.h <span style="color: grey">(PRE-CREATION)</span></li>
<li>trunk/KDE/kdelibs/kdeui/actions/kdualaction.cpp <span style="color: grey">(PRE-CREATION)</span></li>
<li>trunk/KDE/kdelibs/kdeui/actions/kdualaction_p.h <span style="color: grey">(PRE-CREATION)</span></li>
<li>trunk/KDE/kdelibs/kdeui/tests/CMakeLists.txt <span style="color: grey">(1171068)</span></li>
<li>trunk/KDE/kdelibs/kdeui/tests/kdualactiontest.cpp <span style="color: grey">(PRE-CREATION)</span></li>
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<p><a href="http://svn.reviewboard.kde.org/r/5396/diff/" style="margin-left: 3em;">View Diff</a></p>
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