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Image.setVisibleRect does not work for ImageBundle images #2820

Closed dankurka closed 9 years ago

dankurka commented 9 years ago

Originally reported on Google Code with ID 2814

Found in GWT Release: 1.5 rc2 

Detailed description: The Image function setVisibleRect does not work if 
the image is derived from a ImageBundle. When the function is called, the 
image simply dissapears.

Workaround if you have one: don't use ImageBundle

Links to the relevant GWT Developer Forum posts:

Reported by jacobtopper on 2008-08-26 21:57:37

dankurka commented 9 years ago

Reported by scottb+legacy@google.com on 2008-08-26 23:13:32

dankurka commented 9 years ago 
Please specify the browser(s) where you're seeing this problem, and a reproducing use
case. This is clearly not true in all circumstances, as the following code works fine:

  TreeImages imgs = GWT.create(TreeImages.class);
  Image img = imgs.treeClosed().createImage();
  img.setVisibleRect(0, 0, 8, 8);
  RootPanel.get().add(img);

Reported by jgw+personal@google.com on 2008-08-27 13:20:38

dankurka commented 9 years ago 
In have not tried testing it in any real browsers yet given that I can't even get it
to work in the testing browser that came with GWT.

In my specific case, I have code like this for getting an image from an ImageBundle:

ControlImageBundle panelimages = (ControlImageBundle)
GWT.create(ControlImageBundle.class);
Image img = panelimages.images_toolbar().createImage();

Above, ControlImageBundle is a interface that extends ImageBunle. I then add the
image to the RootPanel, and then try to crop the image like so:

img.setVisibleRect(0, 0, 20, 20);

Unfortunately, instead of a cropped image, I get nothing. On the other hand, if  I
don't use image bundle, and load the image individually with a new image and setURL,
and then attempt the same method for cropping, it works.

Image img = new Image();
img.setUrl("images/images_toolbar_icon.png");
RootPanel.get().add(img);
img.setVisibleRect(0, 0, 20, 20);

Reported by jacobtopper on 2008-08-27 18:32:41

dankurka commented 9 years ago 
I might have found the source of the problem. The ControlImageBundle interface I was
using had five images in the bundle. The image I was trying to crop was the second
one. If I comment out the other 4, then I get a properly cropped image.

Reported by jacobtopper on 2008-08-27 18:39:11

dankurka commented 9 years ago 
With some more tinkering, I realized that the first image in the bundle is taller
than the remaining four. Also, if I eliminate the first image, making all of the
images the same height, then when I use the setVisibleRect function, the cropped
portion of the image I see is always from the last image in the bundle, whereas if
I
don't crop, it displays the correct one.

Reported by jacobtopper on 2008-08-27 18:49:03

dankurka commented 9 years ago 
I have included an Eclipse project which displays the behavior I am referring to. I

included the project itself is in a folder titled gwtdemo, as well as the library it

requries, gwt-majic.jar, and the documentation for the library just in case. I also

compiled the java to javascript before packaging the zip to test in a real browser.

In order to cause the error, once the project is running, click "Toggle Slide Left"

or "Toggle Blind Right".

Reported by jacobtopper on 2008-10-28 02:59:48

dankurka commented 9 years ago 
I have a similar bug with my ImageBundle. I found that the problem is that 
setVisibleRect is applied to the big image, which is created by the ImageBundle and

not to the image instance created with the method .createImage(). 

For example look at the attached image "imageBundle.png", which is created by 
GWT.create(MyImageBundle.class). Now the original images text.png and scan.png (see

attachment),  are 50x50 pixels big. Now when i call:

Image text = MyImageBundle.textImage().createImage(); 
text.setVisibleRect(0, 0, 50, 25);

Everything works fine, since the original text.png image is also the fist image in

the imageBundle.png. However, when I call: 

Image scan = MyImageBundle.scanImage().createImage(); 
scan.setVisibleRect(0, 0, 50, 25); 

I don't get the rect form the original scan.png image, but rather again the rect from

the text.png image, because its start coordinates in the imageBundle.png are 0,0. 

Now when I call: 

Image scan = MyImageBundle.scanImage().createImage(); 
scan.setVisibleRect(50, 0, 50, 25); 

the rect from the original scan.png is displayed correctly, since its coordinates in

the imageBundle.png start at point 50,0. If I don't call scan.setVisibleRect(50, 0,

50, 25); at all, the whole original scan.png is displayed correctly. 

To my oppinion this is defenitelly a major bug, which should be fixed soon. 

Regards, Nikolay Georgiev 
University of Wuerzburg, Germany

Reported by n.g.georgiev on 2008-12-13 12:29:08

dankurka commented 9 years ago 
I don't know how bad the clip:rect css property is, but might I suggest that if this

bug gets fixed, that in the process setVisibleRect is changed to use clip:rect as it

has the ability to clip anything instead of just images. That way setVisibleRect can

be applied to widgets instead of just images. For my project at least,that would be

very very useful, notably because on older browsers the property is broken and only

works with no commas in between the rect arguments whereas newer browsers can do it

the correct way, with commas.

Reported by jacobtopper on 2008-12-14 18:24:33