You can't manually remove that padding from the field. It's built
into the field as the ascent of the font + 4 pixels for the natural
field border (which also cannot be 'removed').
There are only two ways to shift up a field in Flash:
Method 1:
a. Bitmap snapshot of the text field
b. getColorRectBounds on the bitmap in question to retrieve a
bounding rectangle of the non-alpha pixels.
c. Capture the top position from the Rectangle returned from that
call and subtract that value from the y-position of the field.
Pros:
Will work every time
Cons:
Additional memory overhead. Tricky to do with the Flex component
architecture - especially TextArea
Method 2:
a. Capture font metrics from the text field
b. Subtract (metrics.ascent + 4) from the text field y position. It
is the ascent measurement, not descent.
Pros:
Less memory and less code to deal with.
Cons:
Will not work every time. Ascent and descent measurements from the
font metrics within Flash are not accurate measurements and are only
correct at very, very specific font sizes (8, 12, 17, 28, 36, 44 ...
etc.).
Almost all point sizes of text return incorrect ascent and descent
values in Flash. They usually return values less than they really are
(7,8,9 point type will return the same ascent value for most fonts,
for example).
Additionally, you'll still need to extend TextArea to handle the
functionality.
Does not function well at all with advanced antialiasing ... also a
known bug in the Flash text rendering. Saffron antialiasing causes a
jump in the leading and position values of lines in a field, so don't
use it.
------
This has been a long standing bug that I've been complaining to Adobe
about. I've worked on applications for some big greeting card
companies (take a couple guesses) creating a rendering system in
Flash that will match Photoshop and Illustrator text rendering.
Illustrator, btw, is the only Adobe application that let's you set
the first baseline position of a text field using a variety of measures.
Good luck.
- jon
On Dec 16, 2008, at 8:53 AM, bjorn wrote:
Any ideas on where I might find more info about this? .. or people
who might know more ...
2008/12/2 bjorn <[email protected]>
There is some padding before the first line in a TextArea. Have a
look at this image to see what I mean:
http://i34.tinypic.com/4uz8s0.jpg
I need to remove this, and the first solution that comes to mind is
to find that value and position the TextArea.y = TextArea.y - [that
value]. The padding before the first line seems to be equal (in
most cases) to the font's descent, which I can get from
getTextLineMetrics().descent.
However, this is not true in all cases. In some cases, the padding
is more.
Anyone have suggestions?
