[Qt-interest] Height of QPushButton and QLineEdit different

[Jens Bache-Wiig]

Good answer Girish!

Actually I was thinking about adding some layout assistance on this topic 
not too long ago. It seems like a common use case that you would want to 
align controls at the same height. Perhaps a setHomogenous/setUniformHeight 
property on boxlayouts would be the way to go in the future so people can 
hint that their layouts should stay uniform.

Jens


"Girish Ramakrishnan" <girish at forwardbias.in> wrote in message 
news:4A2E4C4A.5010804 at forwardbias.in...
> Hi Oliver,
>
> Oliver Demetz wrote:
>> Hi all,
>>
>> Simple example:
>>
>>   QHBoxLayout * lay = new QHBoxLayout;
>>   lay->addWidget(new QPushButton("Hello World"));
>>   lay->addWidget(new QLineEdit("Foo Bar"));
>>   this->setLayout(lay);
>>
>> Executing this code, you will see, that the QLineEdit's
>> height is smaller than the QPushButton's height.
>>
>> I think it depends on the particular system, but on
>> my Windows box here the button has height 28 whereas
>> the lineedit only has 22 pixels.
>>
>> *How can I adjust this???*
>>
>> I tried several things:
>>
>> (A:)  lineedit->setMinimumSize(button->height());
>>     Didn't change anything.
>>
>
> The height() is usually not a valid size until the layout has got a
> chance to provide geometry to child widgets. Also, height() is the
> actual height() that you see on the screen. You will have to manually
> activate the layout to make height() something reasonable before the
> widget is visible. But even then, after the widget is shown, it may get
> a different height().
>
>> (B:)  lineedit->setMinimumHeight(button->height());
>>       lineedit->setMaximumHeight(button->height());
>>      Leads to crap, the lineedit gets a huge height,
>>      I don't know why.
>>
>
> Same as above, height() won't be valid.
>
>> (C:)  lineedit.setSizePolicy(
>>                 lineedit.sizePolicy().horizontalPolicy(),
>>                 QSizePolicy::Ignored);
>>       The idea is to make the lineedit *expand* in the
>>       layout in vertical direction, but this leads also
>>       to a way too huge height
>>
>
> The layout sets geometry based on widget's sizePolicy + sizeHint. The
> push button has a fixed size policy in its vertical direction. This
> means that if the sizeHint returned 80px vertically and the layout has
> 100 px of vertical space, the layout would resize the button only to
> 80px (and use alignment to figure out the position). When you set the
> line edit's policy to ignored, the layout would make the line edit 100px
> in height. See the problem?
>
> One solution is to just
> lineEdit->setFixedHeight(pushButton->sizeHint().height()); sizeHint will
> take care of polishing, so you don't need ensurePolished().
>
>> Why are the recommended heights for these two controls
>> different at all?
>>
>
> Girish