Possibly fix multiline labels on windows

[mohad12211]

unix and darwin appear to have no problems with multiline labels (would like confirm that).
this is an attempt to solve that on windows and address #106.
the first commit from andlabs/libui#465 to calculate the correct width and solve #106

Screenshot and code example

#include <stdlib.h>
#include <string.h>
#include "../../ui.h"

int onClosing(uiWindow *w, void *data)
{
	uiQuit();
	return 1;
}

int main(int argc, char *argv[])
{
	uiInitOptions o;
	memset(&o, 0, sizeof (uiInitOptions));
	if (uiInit(&o) != NULL)
		abort();
	uiWindow *w = uiNewWindow("Hello", 100, 500, 1);
	uiBox *hbox = uiNewHorizontalBox();
	uiWindowSetChild(w, uiControl(hbox));
	uiButton *b = uiNewButton("TEST");
	uiLabel *l = uiNewLabel("1\n\n\n\n\n1\n\n\n\n\n1\n\n\n\n\n1\n\n\n\n\n1\n\n\n\n\n1\n\n\n\n\n1");
	uiBoxAppend(hbox, uiControl(b), 1);
	uiBoxAppend(hbox, uiControl(l), 1);
	uiWindowOnClosing(w, onClosing, NULL);
	uiControlShow(uiControl(w));
	uiMain();
	return 0;
}

before (smallest window width):

after:

second commit is to calculate the correct height based on how many lines will be in the label.

Screenshot and code example

if we change the label in controlgallery to:

uiControl(uiNewLabel("This is a label.\nRight now,\nlabels can\nonly span\none line.")),

before change:

after change:

This only addresses uiLabel, what about uiForm? does it make sense to have a form with multiline label?

[cody271]

This is comparing an ASCII literal against UTF-16 strings to parse the newlines. Otherwise looks good.

[cody271]

unix and darwin appear to have no problems with multiline labels (would like confirm that).

Confirmed to be a Windows only issue, correct.

Screenshot and code example

This always makes reviewing much easier, thanks! 👍

Maybe now also update that label text in the controlgallery example to reflect the fact that we do support multiline labels on all platforms? ;)

This only addresses uiLabel, what about uiForm? does it make sense to have a form with multiline label?

I wouldn't worry about supporting multiline labels in forms, no.

[szanni]

Nice work, definitely seems to work according to my tests.

Apart from removing out the old, now unneeded cruft, please remove the curly braces around the single if statements. The general guideline is to add them only when nesting gets too crazy or to match if/else blocks.

And please add the missing spaces around if () and while () statements. You did it in some places but not others.

Edit: and all the things @cody271 suggested of course.

[szanni]

Missed the memory leak in my first review.

[szanni]

Very nice. Code looks good to me.

I tested things as well under Window 7 with assistive technologies, as I was a little concerned about the hard coded line height. Results:

100% font/icon size:

150% font/icon size:

It seems like Windows actually takes care of things via some type of smart scaling. So all good it seems.