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Problem This is in response to Andrea's post titled "How to resize images?"
You have displayed a list of thumbnail images for selection using the technique as outlined in How to display a list of thumbnail images using GtkIconView?
Howver, as the images are of different width, you would like to auto scale each image to a maximum width.
In this example, the original images are all of width=49. You will see that all of them have been scaled to a width of 24 as shown below:
Solution
Sample Code Note: The following image files are required by the sample code below. Please save a copy of the image files and put them in the same directory where you store the sample code.
 | square_red.jpg |
 | square_yellow.jpg |
 | square_green.jpg |
 | square_blue.jpg |
 | square_blue2.jpg |
 | square_blue3.jpg |
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define('MAX_IMG_WIDTH', 24); // note 1
$window = new GtkWindow();
$window->set_size_request(400, 240);
$window->connect_simple('destroy', array('Gtk','main_quit'));
$window->add($vbox = new GtkVBox());
// display title
$title = new GtkLabel(" Display thumbnail images using GtkIconView\n".
"Part 4 - with auto-scaling to a max width of 24");
$title->modify_font(new PangoFontDescription("Times New Roman Italic 10"));
$title->modify_fg(Gtk::STATE_NORMAL, GdkColor::parse("#0000ff"));
$title->set_size_request(-1, 40);
$vbox->pack_start($title, 0, 0);
$vbox->pack_start(new GtkLabel(), 0, 0); // add a small gap
// Set up a scroll window
$scrolled_win = new GtkScrolledWindow();
$scrolled_win->set_policy( Gtk::POLICY_AUTOMATIC, Gtk::POLICY_AUTOMATIC);
if (defined("GObject::TYPE_STRING")) {
$model = new GtkListStore(GdkPixbuf::gtype, GObject::TYPE_STRING);
} else {
$model = new GtkListStore(GdkPixbuf::gtype, Gtk::TYPE_STRING);
}
foreach(array('square_red.jpg', 'square_yellow.jpg', 'square_green.jpg',
'square_blue.jpg', 'square_blue2.jpg', 'square_blue3.jpg') as $img) {
$pixbuf = GdkPixbuf::new_from_file($img);
$width = $pixbuf->get_width(); // note 2
$height = $pixbuf->get_height(); // note 2
if ($width>MAX_IMG_WIDTH) { // note 3
$new_width = MAX_IMG_WIDTH;
$new_height = MAX_IMG_WIDTH * $height / $width; // note 4
$pixbuf = $pixbuf->scale_simple($new_width, $new_height, Gdk::INTERP_HYPER); // note 5
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- Note that this is only 70% of the sample code. You have to be a registered member to see the entire sample code. Please login or register.
- Registration is free and immediate.
- Have some doubt about the registration? Please read this forum article.
Explanation
- Specify the maximum width.
- Get the width and height of the original image.
- Check if the width is greater than the maximum width.
- Calculate the new height.
- Scale it!
- Set the image.
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July 02, 2008 10:26pm