On 10/15/05, jiho <jo.irisson@...400...> wrote:
I am assuming that you meant to post to the list.
On 15 oct. 05, at 18:34, Ben Fowler wrote:
On 10/15/05, bulia byak <buliabyak@...400...> wrote:
On 10/15/05, Ben Fowler <ben.the.mole@...400...> wrote:
Assuming that in general we cannot expect Inkscape to determine whether or not a bounding box is insane, I was thinking that we might exclude some items from the bbox estimation to make the behaviour less surprising.
I think some could be determined at least. For example, if only one object is insane this could be found: if all transform look like 1,0,1,0,0,1 and one is 10e15,0, 10e15... it is very probably wrong. This could be detected and corrected at openning time and if the user wants to see the unmodified file anyway he could just cancel the correction. This would allow users with specific needs to edit their files anyway.
Could I make sure that we are distinguishing at leaast two cases here? The first is when a file is in error, and the fix is forced. If possible, we should always do this. (I suspect that where this is not possible, we open in the XML editor, if even this is not possible, we show a helpful diagnostic - but this is not the current topic). The second is when the file is not in error, but contains some suspicious values, and we want to warn.
This happens in Freehand when a bitmap cannot be found or a requested font is missing.
Now I think that it is often a mistake for an application to put up a modal dialog and demand that the user pay attention. In some cases. the time to warn is just before saving, or to require that the file is saved under a new name, to ensure that the user does not lose data.
If the application feels that a file has 'warnings' (non fatal errors or failure of sanity checking) there should be an annunciator in a margin that one can click on to see details. Additionally or alternatively there should be a menu item: Verify File that would check the file with great rigour. Think of it as Norton's Disk Doctor for SVG. (We have a menu item: Vacuum Defs that is cognate to 'Speed Disk').
The problem with performing rigorous sanity checking at every start-up (file read), particularly by default is that we cannot as developers really know how long this will take, but we can be pretty sure that 9999 times out of 10 000 it is not necessary: It is a little user hostile.
O.K. We can do some statistical analysis of a) The diagonals, b) The x position and c) the y position of every bounding box, and by looking at twice the standard deviation determine if the out-liers were lying out too far.
The trouble with this approach is that it is the 'fool proof' approach, just making as a system proof against a fool only works until a better one comes along, this appraoch will be defeated in the field by the great variety of insane files.
Whether we like it or not, people are going to have to be opening SVG files with text editor (or the built-in XML editor) to fix problems with insane files for some time to come. It is madness to pretend otherwise.
Having said that, perhaps Inkscape compiled in debug mode should have some of these artifical limits, (just as we have assertion statements). It will help identify to developers just where the shoe pinches, but users do not need to handle this.
Ben