[Icon Plasmoid] Provide a generic plasmoid class for icon based plasmoid

[Marco Martin]

On Sunday 01 June 2008, Loïc Marteau wrote:
> Sorry i forgot the attached files....
>
> Aaron J. Seigo wrote:
> > On Saturday 31 May 2008, Loïc Marteau wrote:
> >> I would like to have icon plasmoid with the same default size (the same
> >> as the screenshot) perhaps 75 %
> >> but size should be configurable (by setting an other percentage in the
> >> class ?) .
> >> In the screenshot the K button is bigger than others and i think it's
> >> great to can do this.
> >
> > i think this is really up to the Containment, in this case the Panel,
> > to provide some mechanism for varying the size of select applets.
> > perhaps something like zones of differing height.
> >
> > sebas and alexis have both working on graphics items groupers that
> > might be applicable in such situations.
>
> good :)
>
> >> What do you think about proposing a recommended way to implement an icon
> >> plasmoid ?
> >
> > that's probably a good idea.
> >
> >> In fact there is still a space (too big imho) between each plasmoid. Is
> >> it possible to reduce it ?
> >
> > the best way would be to ensure that each applet accurately reports
> > the size it needs. this can be tricky with icons because they often
> > have an unspecified amount of whitespace on their edges.
> >
> > having them square ensures there is a consistent spacing of them,
> > though due to the whitespace issue the apparent visual spacing may
> > vary slightly. in the end it is up to the artists to ensure a
> > reasonable centering of the image(s) that make up an icon.
>
> In fact there is two points
> 1- the most important : due to plasmoid itself :
>                     - not correct size setting in the code -> i confirm
> that plasma::square is a good solution and for the moment a lot of icon
> based plasmoid  doesnt seems to use it
plasma::square is not really good, because when using a vertical panel it 
becomes really big and the square things will become really huge and you 
would end up with like the kmenu that takes a quarter of the panel height.
i think it would be needed something more like what is in the kickoff applet 
now, even if a bit less intuitive. when it's in an horizontal panel the width 
can't be more than the height (but height can be more than width)
and the opposite in a vertical panel

Cheers,
Marco Martin
>                     - or like you said here too because of icon with
> "portrait" format -> art issue
>
> 2- a less minor one : the constant size between each plasmoid in a
> panel. I tink that even between 2 square icon plasmoids (implemented
> with plasma:square sizeconstraint methode) the space between them is too
> high. But this is certainly subject to discussion. This don't depend
> direclty of plasmoids but certainly on the panel and probably rejoin
> what you are talking with zone containments (space on each plasmoid
> should depends on which zone we are ?!). What do you think reduce (a
> litlle) the distance between two plasmoids in the default panel settings ?
>
> >>> in the case of the icons, we probably don't actually want to be using
> >>> Plasma::Square, but just set the size policy to be minimum for the
> >>> growth
> >>> direction (horizontally on horizontal panels, vertically on vertical
> >>> panels)
> >>
> >> so isn't the idea to provide a generic class for them not good ?
> >
> > i'm just not sure how much code would end up being saved by this,
> > since making an icon applet takes 6 lines of code: set the form factor
> > to Square, create the Plasma::Icon, create a layout, set the margins
> > and spacing to 0, add the icon to the layout.
> >
> > if there was a generic applet, you'd still need to define which  icon
> > by name to load, so we save 5 lines per applet. those 5 lines are not
> > exactly tricky, and i don't think they justify having another library
> > class.
> >
> > what we *could* do, perhaps, it add another special constructor or
> > method to Plasma::Icon that would put the icon inside a layout in the
> > applet and make applets that are a simple icon based thing use that.
> > even that's a bit drastic, but is a nicer solution imho than a whole
> > new class.
> >
> > also remember that some of these applets will expand to be more than
> > just an icon when moved out of a Vertical or Horizontal Containment,
>
> Yes i am aware of the problem and i was thinking that the majority (not
> all) of plasmoid want in final the same comportment about the adjustment
> needed with vertical or horizontal containment.
>
> By looking the code of some of icon based plasmoid I was thinking that
> the implementation of this constraint stuff was not trivial. I attach a
> basic (trivial) iconplasmoid code based on your recommendations. Could
> you check if this is ok for you.
>
> Perhaps the problem with this is that we dont put max size constraint
> when panel is big. I dont know if it is important. If it is, the
> solution have to be directly in plasma::square related code or can your
> proposed solution deal with this  ?
>
> When we will found a proper solution perhaps i can start to propose
> patch to existing plasmoid ?!
> showdesktop (petri already use a layout), showdashboard, trashcan,
> .desktop shortcut plasmoid, notify, new device notifier...
>
> > and others, such as the battery which is essentially just an icon,
> > need to do extra painting themselves anyways (such as on mouse hover
> > in the case of the battery)... so the actual code savings would be
> > pretty low and getting them all consistent isn't very hard ... =)
>
> is it not possible to let the class share the icon and the child class
> add slot/signal for him, and provide setter to change the icon when he
> want ? However it's true that (for the moment) the skelet code for icon
> plasmoid with layout and plasma:square is very simple.
>
> I'm not an expert of c++ and dont know plasma, sorry if some of my
> questions/remarks are stupid :o).
>
> Hope this can help.
>
> Cheers,
>
> Loic