wxruby users - Jul 2009 - Re: form to save and load image to/from database

hendra kusuma wrote:
> I''m trying to save a bitmap into Postgresql
> using wxruby as front end (you see, wxFilePickerCtrl, and wxStaticBitmap)
> and bitmap is displayed on wxStaticBitmap after selecting file with 
> wxFilePickerCtrl
> and saved into db with pressing save button
> I''m using Ruby DBI to connect to database
Use Wx::Image.read and Wx::Image#write plus ruby''s in-built StringIO 
class to have image data in a recognised format (eg PNG, JPG) in a ruby 
string variable:

img_str = StringIO.new('''')
wx_img.write(img_str, Wx::BITMAP_TYPE_PNG)
# img_str now contains image data and can be saved to the database, 
probably in a BLOB column

# row has been retrieved from the database, and column [2] contains the 
image data
img_str = StringIO.new(column[2])
wx_img = Wx::Image.read(img_str, Wx::BITMAP_TYPE_PNG)

Note that unlike normal file-based constructors for Wx::Image, the type 
declarations are mandatory for write and read, because the image file 
format can''t be inferred from the file suffix.

I don''t know the exact DBI syntax, and the column type declaration 
needed for PostgreSQL but I expect you can figure this out.

hth
a

hendra kusuma wrote:
> Problem is, I don''t find any widget to display the picture
> (the doc says that wxStaticBitmap should only be used for displaying 
> small image such as icon)
For more general drawing of images (and other things) draw the image as 
a Wx::Bitmap upon a Wx::Window. This is pretty easy, see the 
samples/drawing/image.rb for the model of this.

PS - might you be able to alter your quoting settings when replying to 
messages, please, so it uses a recognised quoting character like
''>''?
Your emails show up with all the original, reply and new text looking 
identical, so it''s hard to find your reply.

alex