Re[2]: Embedded images

[Yegor Kozlov <ye...@dinom.ru>]

SJ> Did you use "a" as the default character for any reason? Is that a standard
SJ> assumption to make?

It's not documented. Just a guess :) Another variant is '0' but I
can't tell for sure. It requires experiments.


SJ> There seems to be a bug with HSSFSheet.getColumnWidth(). According to the
SJ> javadocs, it should return the width of a column in units of 1/256 of a char
SJ> width. This is ok if the column width has already been explicitly set with
SJ> setColumnWidth(), but if not, it returns the same value as
SJ> HSSFSheet.getDefaultColumnWidth(), which is measured in characters. So I'm
SJ> getting the value 8 returned from getColumnWidth() for columns that haven't
SJ> had their width changed. Is this a known issue?

Looks so. Bug 25496 reports on it too. The fix is trivial but it can
affect existing code. Any programs that assume getDefaultColumnWidth()
returns 8 will be broken. I will look into it on the weekend.

Yegor

SJ> On 07/02/07, Yegor Kozlov <ye...@dinom.ru> wrote:
>>
>>
>> >>The problem is that the cell width and height don't seem to be measured
>> in the same units.
>> Exactly.
>> Excel anchores objects against top-left and buttom-right cells. In
>> addition it uses dx and dy for "fine positioning" relative to these
>> cells. So to get the correct aspect ratio you need to know the number
>> of cells and rows your image will occupy. Here it gets complicated :).
>>
>> The problem is that column width in Excel is expressed in units of 1/256th
>> of a character width of the default font.
>> Conversion from these weird 1/256th units to pixels is not trivial.
>>
>> The minimal steps to calculate width of a cell in pixels are as follows:
>>
>> - get default workbook font. HSSFWorkbook.getFontAt(0) should always
>> return
>> the default one.
>> - get default cell width expressed in 1/256th units. See
>> HSSFSheet.getColumnWidth
>> - Assuming that the default character is "a" compute the width of a
>> surrogate string using Java2D classes.
>>
>> image.width/cell.width is the number of columns to be used in the
>>   anchor.
>>
>> I think this logic needs to be buried into POI API somehow. Probably
>> it will be included in future.
>>
>> Regards,
>> Yegor
>>
>>
>> ---------------------------------------------------------------------
>> To unsubscribe, e-mail: poi-user-unsubscribe@jakarta.apache.org
>> Mailing List:     http://jakarta.apache.org/site/mail2.html#poi
>> The Apache Jakarta Poi Project:  http://jakarta.apache.org/poi/
>>
>>


---------------------------------------------------------------------
To unsubscribe, e-mail: poi-user-unsubscribe@jakarta.apache.org
Mailing List:     http://jakarta.apache.org/site/mail2.html#poi
The Apache Jakarta Poi Project:  http://jakarta.apache.org/poi/