[Interest] TextMetrics give wrong metrics for some strings

[Elvis Stansvik]

2016-03-21 10:27 GMT+01:00 Elvis Stansvik <elvstone at gmail.com>:
> Hi all,
>
> I'm attempting to make a custom Button item where the size of the
> button is determined by the metrics of the text it holds. The reason
> is I want to put a thin rectangle below the text, sort of a stylistic
> underlining (text underlining is not sufficient, for aesthetic
> reasons).
>
> But I'm seeing strange metrics reported for some strings.
>
> BEGIN TEST CASE
>
> Button.qml:
>
> import QtQuick 2.5
>
> // Attempt at a button with a size determined by the metrics
> // of its text.
>
> Rectangle {
>     property alias text: text.text
>     property alias pointSize: text.font.pointSize
>
>     width: textMetrics.width
>     height: textMetrics.height
>
>     TextMetrics {
>         id: textMetrics
>         font: text.font
>         text: text.text
>     }
>
>     Text {
>         id: text
>         text: "Button"
>     }
> }
>
>
> Test.qml:
>
> import QtQuick 2.5
>
> Rectangle {
>     width: 800
>     height: 600
>
>     // Something wrong with the metrics on this one :/
>
>     Button {
>         text: "Hej"
>         pointSize: 42
>         border.color: "red"
>
>         anchors.top: parent.top
>     }
>
>     // These two seem OK.
>
>     Button {
>         text: "Something longer"
>         pointSize: 42
>         border.color: "red"
>
>         anchors.verticalCenter: parent.verticalCenter
>     }
>
>     Button {
>         text: "Test"
>         pointSize: 42
>         border.color: "red"
>
>         anchors.bottom: parent.bottom
>     }
> }
>
> END TEST CASE
>
> See the attached screenshot (metrics_are_off.png) which shows the
> result. Notice how the size of the buttons (Rectangle) are correct for
> the last two buttons, but for the first, the text is sticking out a
> little :/
>
> Any idea why this is, and how I can solve it?
>
> I'm also attaching a sketch (sketch.png) of the look I'm after for my
> buttons. If you know of a simpler way to achieve this, I'm idle ears.

Nevermind. I realize now that the metrics are actually correct, it's
just that the 'H' in "Hej" has some leading space, which seems to not
be included in the reported metrics.

I'll have to rethink a little, but should get it to work now I think.
Still would appreciate if someone who's done something similar to what
I'm trying could chime in.

Elvis

>
> Cheers,
> Elvis